Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
Cancer ; 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-39369275

RESUMEN

BACKGROUND: Chemotherapy-induced peripheral neuropathy (CIPN) is a common and dose-limiting chemotoxicity caused by oxaliplatin. This study investigated the relationship between dietary quality and the development of moderate and/or severe CIPN in colon cancer survivors using data from the Focus on Reducing Dose-Limiting Toxicities in Colon Cancer with Resistance Exercise trial (ClinicalTrials.gov identifier NCT03291951). METHODS: Diet quality was collected using a 127-item food-frequency questionnaire and was scored using the Alternative Healthy Eating Index-2010 (AHEI-2010). CIPN was assessed with the Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events at each chemotherapy cycle. The association of dietary quality with time to the first moderate-to-severe (moderate-severe) or severe event of CIPN was estimated using Cox proportional hazards models. Only participants who received oxaliplatin were included in this analysis (n = 132). RESULTS: Seventy-four participants (56.1%) reported moderate-severe CIPN. Higher dietary quality was associated with a significantly decreased risk of moderate-severe CIPN (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.93-0.99) and severe CIPN (HR, 0.91; 95% CI, 0.85-0.98). Consumption of red and processed meat (HR, 1.78; 95% CI, 1.07-2.83) and sugar-sweetened beverages (HR, 1.33; 95% CI, 1.10-1.59) was associated with an increased risk of moderate-severe CIPN. Consumption of sugar-sweetened beverages also was associated with an increased risk of severe CIPN (HR, 1.57; 95% CI, 1.14-2.18), whereas vegetable consumption was associated with a reduced risk of severe CIPN (HR, 0.29; 95% CI, 0.09-0.73). CONCLUSIONS: Among patients with colon cancer who received oxaliplatin-based chemotherapy, higher baseline dietary quality was associated with a reduced risk of moderate-severe CIPN.

2.
Cancer Causes Control ; 30(2): 165-168, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30443695

RESUMEN

PURPOSE: Liver diseases including non-alcoholic fatty liver disease (NAFLD) and ensuing alterations to the micro-environment may affect development of liver metastasis. Mirroring the rise in obesity rates, prevalence of NAFLD is increasing globally. Our objective was to examine the association between NAFLD and mortality in colorectal cancer patients. METHODS: Colorectal Cancer-Sarcopenia and Near-term Survival (C-SCANS) is a retrospective cohort study which included 3,262 stage I-III patients, aged 18-80 years, and diagnosed between 2006 and 2011 at Kaiser Permanente Northern California. Cox proportional hazards regression was used to calculate multivariable adjusted hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: After up to 10 years of follow-up, 879 deaths, including 451 from CRC were identified. Cases diagnosed with NAFLD before and within 1 month after CRC diagnosis (pre-existing NAFLD; n = 83) had a HR of 1.64 (95% CI 1.06-2.54) for overall and a HR of 1.85 (95% CI 1.03-3.30) for CRC-specific mortality compared to those without NAFLD. Findings did not differ significantly by sex, stage, tumor location, and smoking status, and were also similar when restricted to obese patients only. CONCLUSIONS: Independent of body mass index and prognostic indicators, CRC patients with pre-existing NAFLD had a worse prognosis than those without NAFLD.


Asunto(s)
Neoplasias Colorrectales/epidemiología , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , California/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/epidemiología , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Adulto Joven
3.
Cancer ; 124(24): 4676-4684, 2018 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-30311638

RESUMEN

BACKGROUND: Although the proportion of triple-negative breast cancers (TNBCs) diagnosed among older women is low, the number of TNBC cases is substantial because of the high incidence of breast cancer after the age of 65 years. The molecular features of TNBC in this age group have not been well described. METHODS: This study examined a population-based cohort of women with stage I to III TNBC diagnosed between the ages of 25 and 91 years with the PAM50 gene expression subtyping assay. The concordance between the TNBC classification by immunohistochemistry and the gene expression classification by PAM50, the expression of individual genes, and 5-year recurrence and breast cancer mortality in older women (≥65 years old) and younger women (<50 years old) was assessed. RESULTS: The molecular subtype distribution in TNBC was significantly different according to the age at diagnosis. TNBC was more likely to be classified as basal-like in women younger than 50 years (sensitivity, 0.91; 95% confidence interval, 0.77-0.97) than women 65 years old or older (sensitivity, 0.72; 95% confidence interval, 0.48-0.87); 35% of clinical TNBC cases in the latter group were the human epidermal growth factor receptor 2 (HER2)-enriched subtype by molecular classification. Older women with TNBC also had significantly higher expression of ERBB2 and lower expression of all 10 proliferation-associated genes tested (P < .01). The risk of breast cancer death within 5 years was significantly higher in women with TNBC in comparison with women with hormone receptor-positive cancers in all age groups. CONCLUSIONS: This study revealed differences in molecular subtypes among clinical TNBC cases based on patient age. A potentially targetable HER2-enriched group raises the possible need for intrinsic subtyping in older women with TNBC.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Redes Reguladoras de Genes , Neoplasias de la Mama Triple Negativas/clasificación , Neoplasias de la Mama Triple Negativas/diagnóstico , Adulto , Factores de Edad , Edad de Inicio , Anciano , Anciano de 80 o más Años , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Receptor ErbB-2/genética , Análisis de Supervivencia , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología
4.
Cancer ; 124(14): 3008-3015, 2018 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-29797673

RESUMEN

BACKGROUND: Low skeletal muscle radiodensity (SMD) is related to higher mortality in several cancers, but the association with colorectal cancer (CRC) prognosis is unclear. METHODS: This observational study included 3262 men and women from the Kaiser Permanente Northern California population diagnosed between 2006 and 2011 with AJCC stages I to III CRC. The authors evaluated hazard ratios (HRs) of low SMD for all-cause and CRC-specific mortality, assessed by computed tomography using optimal stratification, compared with patients with normal SMD. They also evaluated the cross-classification of categories of low versus normal SMD and muscle mass (MM) with outcomes. RESULTS: The median follow-up was 6.9 years. Optimal stratification cutpoints for SMD were 32.5 in women and 35.5 in men. In multivariate-adjusted analyses, among patients with CRC, those with low SMD demonstrated higher overall (HR, 1.61; 95% confidence interval [95% CI], 1.36-1.90) and CRC-specific (HR, 1.74; 95% CI, 1.38-2.21) mortality when compared with those with normal SMD levels. Patients with low SMD and low MM (ie, sarcopenia) were found to have the highest overall (HR, 2.02; 95% CI, 1.65-2.47) and CRC-specific (HR, 2.54; 95% CI, 1.91-3.37) mortality rates. CONCLUSIONS: In patients with CRC, those with low SMD were found to have elevated risks of disease-specific and overall mortality, independent of MM or adiposity. Clinical practice should incorporate body composition measures into the evaluation of the health status of patients with CRC. Cancer 2018;124:3008-15. © 2018 American Cancer Society.


Asunto(s)
Neoplasias Colorrectales/mortalidad , Músculo Esquelético/diagnóstico por imagen , Sarcopenia/diagnóstico por imagen , Anciano , Composición Corporal/fisiología , Índice de Masa Corporal , Neoplasias Colorrectales/complicaciones , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Músculo Esquelético/fisiopatología , Estadificación de Neoplasias , North Carolina/epidemiología , Pronóstico , Factores de Riesgo , Sarcopenia/etiología , Sarcopenia/mortalidad , Sarcopenia/fisiopatología , Tasa de Supervivencia , Tomografía Computarizada por Rayos X
5.
JAMA Oncol ; 4(6): 798-804, 2018 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-29621380

RESUMEN

Importance: Sarcopenia (low muscle mass), poor muscle quality (low muscle radiodensity), and excess adiposity derived from computed tomography (CT) has been related to higher mortality in patients with metastatic breast cancer, but the association with prognosis in patients with nonmetastatic breast cancer is unknown. Objective: To evaluate associations of all 3 body composition measures, derived from clinically acquired CT at diagnosis, with overall mortality in nonmetastatic breast cancer. Design, Setting, and Participants: This observational study included 3241 women from Kaiser Permanente of Northern California and Dana Farber Cancer Institute diagnosed from January 2000 to December 2013 with stages II or III breast cancer. We calculated hazard ratios (HRs) to evaluate the associations of all-cause mortality with sarcopenia, low muscle radiodensity, and total adipose tissue (TAT). Models were adjusted for sociodemographics, tumor characteristics, treatment, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), and other body composition measures. We also evaluated the cross-classification of categories of sarcopenia (yes/no) and tertiles of TAT, with outcomes. Main Outcomes and Measures: Overall survival time and all-cause mortality. Results: Median (range) age of 3241 women included in this study was 54 (18-80) years, and median follow-up was 6.0 years; 1086 patients (34%) presented with sarcopenia, and 1199 patients (37%) had low muscle radiodensity. Among patients with nonmetastatic breast cancer, those with sarcopenia showed higher overall mortality (HR, 1.41; 95% CI, 1.18-1.69) compared with those without sarcopenia. Patients in the highest tertile of TAT also showed higher overall mortality (HR, 1.35; 95% CI, 1.08-1.69) compared with those in the lowest tertile. Low radiodensity was not associated with survival. In analyses of sarcopenia and TAT, highest mortality was seen in patients with sarcopenia and high TAT (HR, 1.89; 95% CI, 1.30-2.73); BMI alone was not significantly related to overall mortality and did not appropriately identify patients at risk of death owing to their body composition. Conclusions and Relevance: Sarcopenia is underrecognized in nonmetastatic breast cancer and occurs in over one-third of newly diagnosed patients. Measures of both sarcopenia and adiposity from clinically acquired CT scans in nonmetastatic patients provide significant prognostic information that outperform BMI and will help to guide interventions to optimize survival outcomes.


Asunto(s)
Adiposidad , Neoplasias de la Mama/patología , Músculo Esquelético/patología , Tomografía Computarizada por Rayos X , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Composición Corporal , Índice de Masa Corporal , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/diagnóstico por imagen , Causas de Muerte , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Persona de Mediana Edad , Músculo Esquelético/diagnóstico por imagen , Estadificación de Neoplasias , Obesidad/complicaciones , Tamaño de los Órganos , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Sarcopenia/etiología , Sarcopenia/patología , Adulto Joven
6.
Cancer ; 123(13): 2535-2542, 2017 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-28295245

RESUMEN

BACKGROUND: Studies of obesity and survival among patients with breast cancer produce conflicting results, possibly because of heterogeneity by molecular subtype. METHODS: This study examined whether the association of body mass index (BMI) at diagnosis with breast cancer recurrence and survival varied across subtypes defined by PAM50 (Prediction Analysis of Microarray 50) gene expression. Included were 1559 Kaiser Permanente Northern California members ages 18 to 79 years who had PAM50 assays and were diagnosed with American Joint Committee on Cancer stage I through III breast cancer from 1996 to 2013. Patients reported weight and height. Cox regression models were adjusted for age, menopause, race/ethnicity, stage, and chemotherapy. RESULTS: Over a median of 9 years (maximum, 19 years), 378 women developed recurrent disease, and 312 died from breast cancer. Overall, BMI was not associated with breast cancer recurrence or survival when controlling for subtype (eg, the hazard ratio per 5 kg/m2 of BMI was 1.05 [95% confidence interval, 0.95-1.15] for breast cancer-specific death). However, associations varied by subtype. Among women with luminal A cancers, those who had class II/III obesity, but not class I obesity or overweight, had worse outcomes. When women who had a BMI ≥35 kg/m2 were compared with those who had a BMI from 18.5 to <25 kg/m2 , the hazard ratio was 2.24 (95% confidence interval,1.22-4.11) for breast cancer-specific death and 1.24 (95% confidence interval, 1.00-1.54) for recurrence. There was no association within luminal B, basal-like or human epidermal growth factor over-expressing subtypes. CONCLUSIONS: Among patients who had accurately classified breast cancer subtypes based on gene expression, a BMI ≥35 kg/m2 was adversely associated with outcomes only among those who had luminal A cancers. Research is needed into whether tailoring recommendations for weight management to tumor characteristics will improve outcomes. Cancer 2017;123:2535-42. © 2017 American Cancer Society.


Asunto(s)
Neoplasias de la Mama/mortalidad , Recurrencia Local de Neoplasia/epidemiología , Obesidad/epidemiología , Adulto , Anciano , Índice de Masa Corporal , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , California/epidemiología , Comorbilidad , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Sobrepeso/epidemiología , Pronóstico , Modelos de Riesgos Proporcionales , Receptor ErbB-2/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Transcriptoma
7.
Breast Cancer Res Treat ; 162(3): 549-557, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28176174

RESUMEN

PURPOSE: Little research examines whether adiposity or post-diagnosis weight changes influence Cardiovascular disease (CVD) among breast cancer patients for whom effects may differ due to treatment and recovery. METHODS: We studied Stage I-III breast cancer survivors 18 to  <80 years, without pre-existing CVD, diagnosed from 1997 to 2013 at Kaiser Permanente. Women reported weight at diagnosis and weight and waist circumference (WC) around 24 months post diagnosis. Using Cox models for time to incident coronary artery disease, heart failure, valve abnormality, arrhythmia, stroke, or CVD death, we examined at-diagnosis body mass index (BMI, n = 3109) and post-diagnosis WC (n = 1898) and weight change (n = 1903, stable, ±5 to  <10-lbs or ±≥10-lbs). RESULTS: Mean (SD) age was 57 (11) years, and BMI was 28 (6) kg-m2. Post diagnosis, 25% of women gained and 14% lost ≥10-lbs; mean (SD) WC was 90 (15) cm. Over a median of 8.28 years, 915 women developed CVD. BMI 25-30-kg/m2 (vs. BMI < 25-kg/m2) was not associated with CVD, while BMI ≥ 35-kg/m2 increased risk by 33% (HR: 1.33; 95%CI 1.08-1.65), independent of lifestyle and tumor/treatment factors. The increased risk at BMI ≥ 35-kg/m2 attenuated with adjustment for pre-existing CVD risk factors to HR: 1.20; 95%CI 0.97-1.50. By contrast, even moderate elevations in WC increased risk of CVD, independent of pre-existing risk factors (HR: 1.93; 95%CI 1.31-2.84 comparing ≥100-cm vs. ≤80-cm). Post-diagnosis weight change had no association with CVD. CONCLUSION: Extreme adiposity and any elevation in WC increased risk of CVD among breast cancer survivors; however, changes in weight in the early post-diagnosis period were not associated with CVD. Survivors with high WC and existing CVD risk factors should be monitored.


Asunto(s)
Adiposidad , Peso Corporal , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/epidemiología , Supervivientes de Cáncer , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Adulto , Anciano , Anciano de 80 o más Años , Pesos y Medidas Corporales , Neoplasias de la Mama/patología , Neoplasias de la Mama/terapia , Enfermedades Cardiovasculares/mortalidad , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Modelos de Riesgos Proporcionales , Análisis de Supervivencia , Adulto Joven
8.
Cancer Epidemiol Biomarkers Prev ; 26(1): 44-50, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27566419

RESUMEN

BACKGROUND: Achieving a healthy weight is recommended for all breast cancer survivors. Previous research on postdiagnosis weight change and mortality had conflicting results. METHODS: We examined whether change in body weight in the 18 months following diagnosis is associated with overall and breast cancer-specific mortality in a cohort of n = 12,590 stage I-III breast cancer patients at Kaiser Permanente using multivariable-adjusted Cox regression models. Follow-up was from the date of the postdiagnosis weight at 18 months until death or June 2015 [median follow-up (range): 3 (0-9) years]. We divided follow-up into earlier (18-54 months) and later (>54 months) postdiagnosis periods. RESULTS: Mean (SD) age-at-diagnosis was 59 (11) years. A total of 980 women died, 503 from breast cancer. Most women maintained weight within 5% of diagnosis body weight; weight loss and gain were equally common at 19% each. Compared with weight maintenance, large losses (≥10%) were associated with worse survival, with HRs and 95% confidence intervals (CI) for all-cause death of 2.63 (2.12-3.26) earlier and 1.60 (1.14-2.25) later in follow-up. Modest losses (>5%-<10%) were associated with worse survival earlier [1.39 (1.11-1.74)] but not later in follow-up [0.77 (0.54-1.11)]. Weight gain was not related to survival. Results were similar for breast cancer-specific death. CONCLUSION: Large postdiagnosis weight loss is associated with worse survival in both earlier and later postdiagnosis periods, independent of treatment and prognostic factors. IMPACT: Weight loss and gain are equally common after breast cancer, and weight loss is a consistent marker of mortality risk. Cancer Epidemiol Biomarkers Prev; 26(1); 44-50. ©2016 AACR SEE ALL THE ARTICLES IN THIS CEBP FOCUS SECTION, "THE OBESITY PARADOX IN CANCER EVIDENCE AND NEW DIRECTIONS".


Asunto(s)
Índice de Masa Corporal , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/mortalidad , Causas de Muerte , Factores de Edad , Anciano , Peso Corporal , California , Estudios de Cohortes , Bases de Datos Factuales , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Análisis Multivariante , Invasividad Neoplásica/patología , Estadificación de Neoplasias , Modelos de Riesgos Proporcionales , Medición de Riesgo , Análisis de Supervivencia , Factores de Tiempo , Aumento de Peso , Pérdida de Peso
9.
J Clin Oncol ; 34(30): 3664-3671, 2016 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-27601537

RESUMEN

PURPOSE: The effects of obesity and metabolic dysregulation on cancer survival are inconsistent. To identify high-risk subgroups of obese patients and to examine the joint association of metabolic syndrome (MetSyn) in combination with obesity, we categorized patients with early-stage (I to III) colorectal cancer (CRC) into four metabolic categories defined by the presence of MetSyn and/or obesity and examined associations with survival. METHODS: We studied 2,446 patients diagnosed from 2006 to 2011 at Kaiser Permanente. We assumed MetSyn if patients had three or more of five components present at diagnosis: fasting glucose > 100 mg/dL or diabetes; elevated blood pressure (systolic ≥ 130 mm Hg, diastolic ≥ 85 mm Hg, or antihypertensives); HDL cholesterol < 40 mg/dL (men) or < 50 mg/dL (women); triglycerides ≥ 150 mg/dL or antilipids; and/or highest sex-specific quartile of visceral fat by computed tomography scan (in lieu of waist circumference). We then classified participants according to the presence (or absence) of MetSyn and obesity (BMI < 30 or ≥ 30 kg/m2) and assessed associations with overall and CRC-related survival using Cox proportional hazards models adjusted for demographic, tumor, and treatment factors and muscle mass at diagnosis. RESULTS: Over a median follow-up of 6 years, 601 patients died, 325 as a result of CRC. Mean (SD) age was 64 (11) years. Compared with the reference of nonobese patients without MetSyn (n = 1,225), for overall survival the hazard ratios (HR) and 95% CIs were 1.45 (1.12 to 1.82) for obese patients with MetSyn (n = 480); 1.09 (0.83 to 1.44) for the nonobese with MetSyn (n = 417), and 1.00 (0.80 to 1.26) for obese patients without MetSyn (n = 324). Obesity with MetSyn also predicted CRC-related survival: 1.49 (1.09 to 2.02). The hazard of death increased with the number of MetSyn components present, independent of obesity. CONCLUSION: Patients with early-stage CRC with obesity and MetSyn have worse survival, overall and CRC related.

10.
J Natl Cancer Inst ; 107(7)2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25921910

RESUMEN

BACKGROUND: Breastfeeding is associated with decreased breast cancer risk, yet associations with prognosis and survival by tumor subtype are largely unknown. METHODS: We conducted a cohort study of 1636 women from two prospective breast cancer cohorts. Intrinsic tumor subtype (luminal A, luminal B, human epidermal growth factor receptor 2 [HER2]-enriched, basal-like) was determined by the PAM50 gene expression assay. Breastfeeding history was obtained from participant questionnaires. Questionnaires and medical record reviews documented 383 recurrences and 290 breast cancer deaths during a median follow-up of nine years. Multinomial logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) between breastfeeding and tumor subtype. Cox regression was used to estimate hazard ratios (HRs) for breast cancer recurrence or death. Statistical significance tests were two-sided. RESULTS: Breast cancer patients with basal-like tumors were less likely to have previously breastfed than those with luminal A tumors (OR = 0.56, 95% CI = 0.39 to 0.80). Among all patients, ever breastfeeding was associated with decreased risk of recurrence (HR = 0.70, 95% CI = 0.53 to 0.93), especially breastfeeding for six months or more (HR = 0.63, 95% CI = 0.46 to 0.87, P trend = .01). Similar associations were observed for breast cancer death. Among women with luminal A subtype, ever breastfeeding was associated with decreased risks of recurrence (HR = 0.52, 95% CI = 0.31 to 0.89) and breast cancer death (HR = 0.52, 95% CI = 0.29 to 0.93), yet no statistically significant associations were observed among the other subtypes. Effects appeared to be limited to tumors with lower expression of proliferation genes. CONCLUSIONS: History of breastfeeding might affect prognosis and survival by establishing a luminal tumor environment with lower proliferative activity.


Asunto(s)
Lactancia Materna , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/mortalidad , Carcinoma Ductal de Mama/patología , Regulación Neoplásica de la Expresión Génica , Recurrencia Local de Neoplasia/mortalidad , Adulto , Anciano , Neoplasias de la Mama/terapia , Carcinoma Ductal de Mama/terapia , Femenino , Estudios de Seguimiento , Predisposición Genética a la Enfermedad , Humanos , Modelos Logísticos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/terapia , Oportunidad Relativa , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Encuestas y Cuestionarios
11.
BMC Cancer ; 15: 278, 2015 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-25884832

RESUMEN

BACKGROUND: Invasive breast cancers are now commonly classified using gene expression into biologically and clinically distinct tumor subtypes. However, the role of obesity in breast tumor gene expression and intrinsic subtype is unknown. METHODS: Early-stage breast cancer (BC) patients (n = 1,676) were sampled from two prospective cohorts. The PAM50 qRT-PCR assay was used to: a) assess tumor gene expression levels for ESR1, PGR, ERBB2, and 10 proliferation genes and b) classify tumors into intrinsic subtype (Luminal A, Luminal B, Basal-like, HER2-enriched, Normal-like). Body mass index (BMI) around BC diagnosis (kg/m(2)) was categorized as: underweight (<18.5), normal (18.5-24), overweight (25-29), mildly obese (30-34), and highly obese (≥35). In a cross-sectional analysis, we evaluated associations of BMI with gene expression using linear regression models, and associations of BMI with non-Luminal A intrinsic subtypes, compared with Luminal A subtype, using multinomial logistic regression. Statistical significance tests were two-sided. RESULTS: Highly obese women had tumors with higher expression of proliferation genes compared with normal weight women (adjusted mean difference = 0.44; 95% CI: 0.18, 0.71), yet mildly obese (adjusted mean difference = 0.16; 95% CI: -0.06, 0.38) and overweight (adjusted mean difference = 0.18; 95% CI: -0.01, 0.36) women did not. This association was stronger in postmenopausal women (p for interaction = 0.06). Being highly obese, however, was inversely associated with ESR1 expression (adjusted mean difference = -0.95; 95% CI: -1.47, -0.42) compared with being normal weight, whereas being mildly obese and overweight were not. In addition, women with Basal-like and Luminal B subtypes, relative to those with Luminal A subtype, were more likely to be highly obese, compared with normal-weight. CONCLUSIONS: ER expression may not increase correspondingly with increasing degree of obesity. Highly obese patients are more likely to have tumor subtypes associated with high proliferation and poorer prognosis.


Asunto(s)
Neoplasias de la Mama/genética , Receptor alfa de Estrógeno/biosíntesis , Obesidad/genética , Receptores de Progesterona/biosíntesis , Adolescente , Adulto , Anciano , Índice de Masa Corporal , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/patología , Proliferación Celular/genética , Receptor alfa de Estrógeno/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Obesidad/complicaciones , Obesidad/patología , Pronóstico , Receptor ErbB-2/biosíntesis , Receptor ErbB-2/genética , Receptores de Progesterona/genética
12.
Breast Cancer Res Treat ; 144(3): 689-99, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24604094

RESUMEN

To evaluate whether differences in PAM50 breast cancer (BC) intrinsic (Luminal A, Luminal B, Basal-like, and HER2-enriched) subtypes help explain the Black-White BC survival disparity. Utilizing a stratified case-cohort design, this study included 1,635 women from the Pathways and Life After Cancer Epidemiology cohorts, selecting women with tumors based upon IHC classification, recurrences, and deaths.One millimeter punches were obtained from tumor tissue, and expression of the PAM50 genes for molecular subtype was determined by RT-qPCR of extracted RNA. Cox proportional hazards models were used to analyze associations between race and BC outcomes, adjusted for PAM50 BC subtype. All tests of statistical significance were two-sided. Black women had a higher prevalence of the Basal-like BC subtype. Adjusted for potential confounding variables and disease characteristics at diagnosis, Black women had higher risks of recurrence (HR 1.65, 95 % CI 1.06-2.57) and breast cancer-specific mortality (HR 1.71, 95 % CI 1.02-2.86) than White women, but adjusting further for subtype did not attenuate survival disparities. By contrast, Hispanic women had a lower risk of recurrence (HR 0.54, 95 % CI 0.30-0.96) than Whites. Among those with the Basal-like subtype, Black women had a similar recurrence risk as women in other race groups but a higher recurrence risk for all other subtypes. Hispanic women had a lower recurrence risk within each subtype, though associations were not significant, given limited power. Although Black women had a higher risk of the Basal-like subtype, which has poor prognosis, this did not explain the Black-White BC survival disparity.


Asunto(s)
Neoplasias de la Mama/genética , Neoplasias de la Mama/mortalidad , Etnicidad/genética , Perfilación de la Expresión Génica , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Neoplasias de la Mama/diagnóstico , California , Estudios de Casos y Controles , Femenino , Humanos , Persona de Mediana Edad , Recurrencia , Sistema de Registros , Factores de Riesgo , Utah
13.
Cancer Epidemiol Biomarkers Prev ; 23(5): 714-24, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24521995

RESUMEN

BACKGROUND: Data are lacking to describe gene expression-based breast cancer intrinsic subtype patterns for population-based patient groups. METHODS: We studied a diverse cohort of women with breast cancer from the Life After Cancer Epidemiology and Pathways studies. RNA was extracted from 1 mm punches from fixed tumor tissue. Quantitative reverse-transcriptase PCR was conducted for the 50 genes that comprise the PAM50 intrinsic subtype classifier. RESULTS: In a subcohort of 1,319 women, the overall subtype distribution based on PAM50 was 53.1% luminal A, 20.5% luminal B, 13.0% HER2-enriched, 9.8% basal-like, and 3.6% normal-like. Among low-risk endocrine-positive tumors (i.e., estrogen and progesterone receptor positive by immunohistochemistry, HER2 negative, and low histologic grade), only 76.5% were categorized as luminal A by PAM50. Continuous-scale luminal A, luminal B, HER2-enriched, and normal-like scores from PAM50 were mutually positively correlated. Basal-like score was inversely correlated with other subtypes. The proportion with non-luminal A subtype decreased with older age at diagnosis, P Trend < 0.0001. Compared with non-Hispanic Whites, African American women were more likely to have basal-like tumors, age-adjusted OR = 4.4 [95% confidence intervals (CI), 2.3-8.4], whereas Asian and Pacific Islander women had reduced odds of basal-like subtype, OR = 0.5 (95% CI, 0.3-0.9). CONCLUSIONS: Our data indicate that over 50% of breast cancers treated in the community have luminal A subtype. Gene expression-based classification shifted some tumors categorized as low risk by surrogate clinicopathologic criteria to higher-risk subtypes. IMPACT: Subtyping in a population-based cohort revealed distinct profiles by age and race.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Carcinoma Basocelular/genética , Regulación Neoplásica de la Expresión Génica , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Carcinoma Basocelular/patología , Estudios de Cohortes , Receptor alfa de Estrógeno/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Técnicas para Inmunoenzimas , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , ARN Mensajero/genética , Grupos Raciales , Receptor ErbB-2/metabolismo , Receptores de Progesterona/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Adulto Joven
14.
Cancer Epidemiol Biomarkers Prev ; 23(5): 725-34, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24521998

RESUMEN

BACKGROUND: The PAM50, a gene expression assay to categorize breast tumors into intrinsic subtypes, has not been previously used to examine short- and long-term prognostication in a population-based cohort where treatment patterns and time of initial follow-up vary. METHODS: In a stratified case-cohort design of 1,691 women from the LACE and Pathways breast cancer survivor cohorts, we used PAM50 to categorize tumors into Luminal A (LumA), Luminal B (LumB), HER2-enriched (HER2-E), Basal-like and Normal-like, and to examine risk of early and late recurrence and mortality by Cox proportional hazards regression. RESULTS: Compared with LumA, cumulative risk of recurrence and breast cancer death was higher for LumB, HER2-E, and Basal-like tumors at 2, 5, and 10 years. However, HR of breast cancer death varied over time [<5 years (early) vs. > 5 years (late)] for both Basal-like (HR, 6.23 early vs. HR, 0.63 late) and HER2-E tumors (HR, 2.97 early vs. HR, 0.73 late) but not for LumB tumors where risk was elevated consistently (HR, 2.67 early vs. HR, 1.47 late). The contrast between LumB, HER2-E, and Basal-like compared with LumA on early recurrence was stronger when subtype was defined by PAM50 than by immunohistochemistry (IHC) markers. CONCLUSIONS: The PAM50 categorized intrinsic subtypes in a manner that more accurately predicts recurrence and survival, especially for luminal tumors, compared with commonly used methods that rely on traditional IHC clinical markers. IMPACT: The PAM50 is robust for use in epidemiologic studies and should be considered when archived tumor tissues are available.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Regulación Neoplásica de la Expresión Génica , Recurrencia Local de Neoplasia/diagnóstico , Adolescente , Adulto , Factores de Edad , Anciano , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Estudios de Cohortes , Receptor alfa de Estrógeno/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Técnicas para Inmunoenzimas , Persona de Mediana Edad , Clasificación del Tumor , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/metabolismo , Estadificación de Neoplasias , Pronóstico , ARN Mensajero/genética , Grupos Raciales , Receptor ErbB-2/metabolismo , Receptores de Progesterona/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Adulto Joven
15.
Cancer Epidemiol Biomarkers Prev ; 22(1): 32-41, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23150063

RESUMEN

BACKGROUND: Alcohol consumption is an established risk factor for incident breast cancer. However, its role in breast cancer prognosis remains unclear. METHODS: We conducted an investigation of postdiagnosis alcohol consumption with recurrence and mortality among 9,329 breast cancer patients in the After Breast Cancer Pooling Project. Women were diagnosed from 1990 to 2006 with AJCC Stage I-III breast tumors from three prospective US cohorts. Alcohol intake was assessed at cohort entry (mean 2.1 years postdiagnosis) using a food frequency questionnaire. HR and 95% confidence intervals (CI) were estimated using delayed entry Cox proportional hazards models with adjustment for known prognostic factors. RESULTS: After a mean follow-up of 10.3 years, 1,646 recurrences and 1,543 deaths were ascertained. 5,422 women (58%) were considered drinkers (≥0.36 g/day of alcohol, ≥0.25 drinks/week) with a median of 5.3 g/day. Overall, compared with nondrinking, regular alcohol intake (≥6.0 g/day) was not associated with risk of recurrence (HR for 6 to less than 12 g/day, 1.03; 95% CI, 0.86-1.24; HR for 12 to less than 24 g/day, 1.12; 95% CI, 0.93-1.34; HR for ≥24 g/day, 1.04; 95% CI, 0.84-1.31). However, risk varied significantly by menopausal status (P for interaction < 0.05). Postmenopausal women who regularly consumed alcohol (≥6.0 g/day) had increased risk of recurrence (HR, 1.19; 95% CI, 1.01-1.40). Alcohol intake was not associated with mortality. CONCLUSIONS: Regular alcohol consumption was not associated with breast cancer recurrence and total mortality overall, yet recurrence risk was only elevated in postmenopausal women. IMPACT: The association between alcohol intake and recurrence may depend on menopausal status at breast cancer diagnosis.


Asunto(s)
Consumo de Bebidas Alcohólicas/epidemiología , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/epidemiología , Recurrencia Local de Neoplasia/epidemiología , Sobrevivientes/estadística & datos numéricos , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Consumo de Bebidas Alcohólicas/efectos adversos , Neoplasias de la Mama/terapia , China/epidemiología , Estudios de Cohortes , Terapia Combinada , Intervalos de Confianza , Bases de Datos Factuales , Femenino , Humanos , Persona de Mediana Edad , Invasividad Neoplásica/patología , Recurrencia Local de Neoplasia/diagnóstico , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Medición de Riesgo , Análisis de Supervivencia , Estados Unidos/epidemiología
16.
Cancer Epidemiol Biomarkers Prev ; 21(8): 1260-71, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22695738

RESUMEN

BACKGROUND: Weight change after a breast cancer diagnosis has been linked to lower survival. To further understand effects of postdiagnostic weight variation on survival, we examined the relationship by comorbid status and initial body mass index (BMI). METHODS: The current analysis included 12,915 patients with breast cancer diagnosed between 1990 and 2006 with stage I-III tumors from four prospective cohorts in the United States and China. HRs and 95% confidence intervals (CI) representing the associations of five weight change categories [within <5% (reference); 5%-<10% and ≥10% loss and gain] with mortality were estimated using Cox proportional hazards models. RESULTS: Mean weight change was 1.6 kg. About 14.7% women lost and 34.7% gained weight. Weight stability in the early years postdiagnosis was associated with the lowest overall mortality risk. Weight loss ≥10% was related to a 40% increased risk of death (HR, 1.41; 95% CI, 1.14-1.75) in the United States and over three times the risk of death (HR, 3.25; 95% CI: 2.24, 4.73) in Shanghai. This association varied by prediagnosis BMI, and in the United States, lower survival was seen for women who lost weight and had comorbid conditions. Weight gain ≥10% was associated with a nonsignificant increased risk of death. CONCLUSIONS: Prevention of excessive weight gain is a valid public health goal for breast cancer survivors. Although intentionality of weight loss could not be determined, women with comorbid conditions may be particularly at risk of weight loss and mortality. IMPACT: Weight control strategies for breast cancer survivors should be personalized to the individual's medical history.


Asunto(s)
Neoplasias de la Mama/epidemiología , Obesidad/epidemiología , Aumento de Peso , Pérdida de Peso , Neoplasias de la Mama/mortalidad , China/epidemiología , Estudios de Cohortes , Femenino , Humanos , Persona de Mediana Edad , Obesidad/complicaciones , Obesidad/mortalidad , Factores de Riesgo , Análisis de Supervivencia , Resultado del Tratamiento , Estados Unidos/epidemiología
17.
Breast Cancer Res Treat ; 132(2): 729-39, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22187127

RESUMEN

Obese and underweight women who develop breast cancer may have poorer survival compared with normal-weight women. However, the optimal weight for best prognosis is still under study. We conducted a prospective investigation of pre-diagnosis body mass index (BMI) and mortality among 14,948 breast cancer patients in the After Breast Cancer Pooling Project. Breast cancer patients diagnosed from 1990 to 2006 with AJCC Stage I-III breast tumors were drawn from four prospective cohorts. Hazard ratios (HR) and 95% confidence intervals (CI) representing the associations of BMI categories (World Health Organization international classifications) with recurrence and mortality were estimated using delayed entry Cox proportional hazards models. Obese (30 to < 35 kg/m(2)), severely obese (35 to < 40 kg/m(2)), and morbidly obese (≥ 40 kg/m(2)) were examined. After a mean follow-up of 7.8 years, 2,140 deaths and 2,065 recurrences were documented. Both underweight (HR = 1.59; 95% CI: 1.18, 2.13) and morbidly obese women (HR = 1.81; 95% CI: 1.42, 2.32) had the greatest risk of overall mortality compared with normal weight (18.5-24.9 kg/m(2)) women. Severe obesity (HR = 1.09; 95% CI: 0.88, 1.36) and obesity (HR = 1.11; 95% CI: 0.97, 1.27) were related to small non-significant increased risks. Overweight (25.0-29.9 kg/m(2)) was not associated with any excess risk compared with normal weight. Similar associations were found for breast cancer death and non-breast cancer death but not recurrence. Women who were underweight and morbidly obese before breast cancer diagnosis were at the greatest risk of all-cause mortality. Morbidly obese women were also at increased risk of death from breast cancer. These results suggest that degree of obesity confers differential risk on survival.


Asunto(s)
Índice de Masa Corporal , Neoplasias de la Mama/mortalidad , Obesidad/mortalidad , Sobrevivientes/estadística & datos numéricos , Delgadez/mortalidad , Adulto , Anciano , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/secundario , China/epidemiología , Femenino , Humanos , Persona de Mediana Edad , Análisis Multivariante , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Obesidad/diagnóstico , Obesidad Mórbida/diagnóstico , Obesidad Mórbida/mortalidad , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Análisis de Regresión , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Delgadez/diagnóstico , Factores de Tiempo , Estados Unidos/epidemiología
18.
Breast Cancer Res Treat ; 131(2): 637-43, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21935600

RESUMEN

The 2008 Physical Activity (PA) Guidelines recommend engaging in at least 2.5 h (10 MET-hours/week) of moderate intensity PA per week (defined as 4 METs) to reduce risk of morbidity and mortality. This analysis was conducted to investigate whether this recommendation can be extended to breast cancer survivors. Data from four studies of breast cancer survivors measuring recreational PA from semi-quantitative questionnaires a median of 23 months post-diagnosis (interquartile range 18-32 months) were pooled in the After Breast Cancer Pooling Project (n = 13,302). Delayed entry Cox proportional hazards models were applied in data analysis with adjustment for age, post-diagnosis body mass index, race/ethnicity, menopausal status, TNM stage, cancer treatment, and smoking history. Engaging in at least 10 MET-hours/week of PA was associated with a 27% reduction in all-cause mortality (n = 1,468 events, Hazard Ratio (HR) = 0.73, 95% CI, 0.66-0.82) and a 25% reduction in breast cancer mortality (n = 971 events, HR = 0.75, 95% CI 0.65-0.85) compared with women who did not meet the PA Guidelines (<10 MET-hours/week). Risk of breast cancer recurrence (n = 1,421 events) was not associated with meeting the PA Guidelines (HR = 0.96, 95% CI, 0.86-1.06). These data suggest that adhering to the PA guidelines may be an important intervention target for reducing mortality among breast cancer survivors.


Asunto(s)
Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/rehabilitación , Ejercicio Físico , Cooperación del Paciente , Adulto , Anciano , Neoplasias de la Mama/epidemiología , Femenino , Adhesión a Directriz , Humanos , Persona de Mediana Edad , Actividad Motora , Recurrencia , Factores de Riesgo , Encuestas y Cuestionarios
19.
Breast Cancer Res Treat ; 129(2): 549-56, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21479924

RESUMEN

There is increasing interest in the relationship between host lifestyle factors and the outcomes of cancer treatment. Behavioral factors, comorbid conditions, and non-cancer-related pharmaceutical exposures may affect breast cancer (BC) outcomes. We used observational data from the LACE Study cohort (women with early stage BC from the Kaiser Permanente Northern California Cancer Registry) to examine the association between beta blockers (BBs) and/or angiotensin-converting enzyme inhibitors (ACEi) and BC recurrence, BC-specific mortality, and overall mortality. Among 1,779 women, there were 292 BC recurrences, 174 BC deaths, and 323 total deaths. 23% were exposed to either a BB and/or an ACEi. These drugs were associated with older age, postmenopausal status, tamoxifen therapy, greater pre-diagnosis BMI, hypertension, and diabetes. In Cox proportional hazards models, ACEi exposure was associated with BC recurrence (HR 1.56, 95% CI 1.02, 2.39, P = 0.04), but not cause-specific or overall mortality. Combined ACEi and BB were associated with overall mortality (HR 1.94, 95% CI 1.22, 3.10, P = 0.01). BB exposure was associated with lower hazard of recurrence and cause-specific mortality. However, there was no evidence of a dose response with either medication. For recurrence and cause-specific mortality, BB combined with ACEi was associated with a lower HR for the outcome than when ACEi alone was used. These hypothesis generating findings suggest that BC recurrence and survival were associated with exposure to two commonly used classes of anti-hypertensive medications. These observations need to be confirmed and suggest that greater attention should focus on the potential role of these commonly used medications in BC outcomes.


Asunto(s)
Antagonistas Adrenérgicos beta/efectos adversos , Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Antihipertensivos/efectos adversos , Neoplasias de la Mama/terapia , Recurrencia Local de Neoplasia , Adulto , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/secundario , California/epidemiología , Distribución de Chi-Cuadrado , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/mortalidad , Modelos de Riesgos Proporcionales , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
20.
J Natl Cancer Inst ; 102(19): 1468-77, 2010 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-20861456

RESUMEN

BACKGROUND: The long-term prognostic role of functional limitations among women with breast cancer is poorly understood. METHODS: We studied a cohort of 2202 women with breast cancer at two sites in the United States, who provided complete information on body functions involving endurance, strength, muscular range of motion, and small muscle dexterity following initial adjuvant treatment. Associations of baseline functional limitations with survival were evaluated in delayed entry Cox proportional hazards models, with adjustment for baseline sociodemographic factors, body mass index, smoking, physical activity, comorbidity, tumor characteristics, and treatment. Difference in covariates between women with and without limitations was assessed with Pearson χ(2) and Student t tests. All statistical tests were two-sided. RESULTS: During the median follow-up of 9 years, 112 deaths were attributable to competing causes (5% of the cohort) and 157 were attributable to breast cancer causes (7% of the cohort). At least one functional limitation was present in 39% of study participants. Proportionately, more breast cancer patients with functional limitations after initial adjuvant treatment were older, less educated, and obese (P < .001). In multivariable models, functional limitations were associated with a statistically significantly increased risk of death from all causes (hazard ratio [HR] = 1.40, 95% confidence interval [CI] = 1.03 to 1.92) and from competing causes (HR = 2.60, 95% CI = 1.69 to 3.98) but not from breast cancer (HR = 0.90, 95% CI = 0.64 to 1.26). The relationship between functional limitations and overall survival differed by tumor stage (among women with stage I and stage III breast cancer, HR = 2.02, 95% CI = 1.23 to 3.32 and HR = 0.74, 95% CI = 0.42 to 1.30, respectively). CONCLUSION: In this prospective cohort study, functional limitations following initial breast cancer treatment were associated with an important reduction in all-cause and competing-cause survival, irrespective of clinical, lifestyle, and sociodemographic factors.


Asunto(s)
Actividades Cotidianas , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/fisiopatología , Adulto , Factores de Edad , Anciano , Índice de Masa Corporal , Neoplasias de la Mama/patología , Comorbilidad , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Estilo de Vida , Persona de Mediana Edad , Análisis Multivariante , Estadificación de Neoplasias , Oportunidad Relativa , Valor Predictivo de las Pruebas , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Calidad de Vida , Factores de Riesgo , Muestreo , Factores de Tiempo , Estados Unidos/epidemiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA