A new algorithm DEtectS critical Congenital Heart Disease at different altitudes: ANDES-CHD study.

BACKGROUND: Neonatal pulse oximetry screening (POS) algorithms for critical congenital heart disease (CCHD) have contributed towards decreasing neonatal mortality but cannot be applied at high altitudes. New POS algorithms at high altitudes are needed. METHODS: This observational, prospective study included newborns born at different altitudes from 0 to 4380 meters above the sea level in Peru. Healthy newborns underwent neonatal preductal and postductal oximetry, echocardiography and telephonic follow-up up to 12 months of age. Newborns with CCHD underwent preductal and postductal oximetry at the time of telemedicine evaluation while located at the high-altitude hospital where they were born, and their diagnoses were confirmed with echocardiography locally or after arriving to the referral center. Two new algorithms were designed using clinically accepted neonatal oximetry cutoffs or the 5th and 10th percentiles for preductal and postductal oximetry values. RESULTS: A total of 502 healthy newborns and 15 newborns with CCHD were enrolled. Echocardiography and telephonic follow-up were completed in 227 (45%) and 330 healthy newborns (65%), respectively. The algorithm based on clinically accepted cutoffs had a sensitivity of 92%, specificity of 73% and false positive rate of 27% The algorithm based on the 5th and 10th percentiles had a sensitivity of 80%, specificity of 88% and false positive rate of 12%. CONCLUSIONS: Two algorithms that detect CCHD at different altitudes had adequate performance but high false positive rates.

Effect of altitude on mortality of end-stage renal disease patients on hemodialysis in Peru.

BACKGROUND: In Latin America, the prevalence of end-stage kidney disease (ESKD) has risen tremendously during the last decade. Previous studies have suggested that receiving dialysis at high altitude confers mortality benefits; however, this effect has not been demonstrated at >2000 m above sea level (masl) or in developing countries. METHODS: This historical cohort study analyzed medical records from six Peruvian hemodialysis (HD) centers located at altitudes ranging from 44 to 3827 masl. Adult ESKD patients who started maintenance HD between 2000 and 2010 were included. Patients were classified into two strata based on the elevation above sea level of their city of residence: low altitude (<2000 masl) and high altitude (≥2000 masl). Death from any cause was collected from national registries and Cox proportional hazards models were built. RESULTS: A total of 720 patients were enrolled and 163 (22.6%) resided at high altitude. The low-altitude group was significantly younger, more likely to have diabetes or glomerulonephritis as the cause of ESKD and higher hemoglobin. The all-cause mortality rate was 84.3 per 1000 person-years. In the unadjusted Cox model, no mortality difference was found between the high- and low-altitude groups {hazard ratio [HR] 1.20 [95% confidence interval (CI) 0.89-1.62]}. After multivariable adjustment, receiving HD at high altitude was not significantly associated with higher mortality, but those with diabetes as the cause of ESKD had significantly higher mortality [HR 2.50 (95% CI 1.36-4.59)]. CONCLUSIONS: In Peru, patients receiving HD at high altitudes do not have mortality benefits.

Values of heart rate at rest in children and adults living at different altitudes in the Andes.

INTRODUCTION: The heart rate (HR) is useful for the monitoring of patients, but almost no studies have been found which describe their variations according to different geographic locales and altitudes using centiles in children and adults. METHODOLOGY: Descriptive, cross-sectional study of secondary data. Measurements were taken with a calibrated pulse oximeter; our participants resided in host cities for more than 2 months and underwent clinical evaluations by physicians. The results were categorized according to their age group and the altitude of residence using centile charts. RESULTS: Our sample size consisted of 6,289 subjects across different villages in Peru. Using Pearson correlation between HR and altitude, it was found in the group of patients aged 1-5 years, a coefficient of -0.118 (p value = 0.012), in the group of patients aged 6-17, 0.047 (p value = 0.025), in the group of patients aged 18-50, -0.044 (p value = 0.041) and for the group of patients aged 51-80, 0.042 (p value = 0.256). In the groups of 1-5, 6-17 and 18-50 years of age, the variations were negligible but statistically significant due to our large sample size. When all of the data was evaluated, HR values were also found to have negligible variations according to the residence altitude, with a Pearson coefficient of -0.033 (p value = 0.009). Centiles charts were used to describe the distribution of HR for different age groups by altitude of residence. CONCLUSION: There are minimal variations of the HR according to the altitude of residence in all age groups.

Reference values for oxygen saturation from sea level to the highest human habitation in the Andes in acclimatised persons.

Oxygen saturation, measured by pulse oximetry (SpO2), is a vital clinical measure. Our descriptive, cross-sectional study describes SpO2 measurements from 6289 healthy subjects from age 1 to 80 years at 15 locations from sea level up to the highest permanent human habitation. Oxygen saturation measurements are illustrated as percentiles. As altitude increased, SpO2 decreased, especially at altitudes above 2500 m. The increase in altitude had a significant impact on SpO2 measurements for all age groups. Our data provide a reference range for expected SpO2 measurements in people from 1 to 80 years from sea level to the highest city in the world.

[Geographic Altitude of Residence and Alcohol Dependence in a Peruvian Population]. / Altitud geográfica de residencia y dependencia alcohólica en pobladores peruanos.

The aim of this study was to determine the association between alcohol dependence and altitude of residence in 11 villages in two high altitude areas of Peru. An analytical cross-sectional study was performed using a survey conducted by physicians in primary health care in 11 villages until 2013, that were divided into low altitude (≤2500m asl (above sea level)), and high altitude (>2500m asl) areas. The CAGE test for alcoholism (cut point, ≥2) was applied to those who responded positively when asked if they consumed alcohol. Statistical associations were obtained with generalised linear models Of the 737 participants, 51% were women and the median age was 36 years [interquartile range, 25-50], 334 (45%) lived at low altitude, and 113 (15%) had alcohol dependence. The highest frequency of alcoholism was positively associated with being a village considered extremely poor (Likelihood Ratio (LP)=2.42; 95%CI, 1.40-4.19), while being female (LP=0.44; 95%CI, 0.23-0.89) and residing at high altitude (LP=0.15; 95%CI, 0.07-0.31) were negatively associated. These were adjusted for nine socio-occupational and pathological variables. According to these data, there is a higher frequency of alcohol dependence in being, male, extremely poor, and residing at low altitude. These results should be taken into account by professionals who work in primary care and those involved in mental health care, because of their implications in society.

Altitud geográfica de residencia y dependencia alcohólica en pobladores peruanos / Geographic Altitude of Residence and Alcohol Dependence in a Peruvian Population

El objetivo de este estudio es determinar la relación entre la dependencia alcohólica y la altitud de residencia en once poblados de dos zonas altitudinales del Perú. Se realizó un estudio transversal analítico aplicando una encuesta por médicos que hasta 2013 realizaron atención primaria de salud en once poblados, que se clasificaron en zonas de baja altitud (≤ 2.500 msnm) y gran altitud (> 2.500 msnm). A los que respondieron afirmativamente a la pregunta de si consumían bebidas alcohólicas, se les aplicó el test CAGE para alcoholismo (punto de corte, ≥ 2). Con los modelos lineales generalizados, se obtuvieron los estadísticos de asociación. De los 737 participantes, el 51% eran mujeres y la mediana de edad, 36 [intervalo intercuartílico, 25-50] años 334 (45%) vivían en baja altitud y 113 (15%) tenían dependencia alcohólica. La mayor frecuencia de alcoholismo se asoció positivamente con ser de un poblado considerado como extremadamente pobre (razón de prevalencia ajustada [RPa] = 2,42; intervalo de confianza del 95%, [IC95%], 1,40-4,19); mientras que, ser mujer (RPa = 0,44; IC95%, 0,23-0,89) y residir a gran altitud (RPa = 0,15; IC95%, 0,07-0,31) se asociaron negativamente, ajustando por nueve variables sociolaborales y patológicas. Según estos datos, hay mayor frecuencia de dependencia al alcohol entre los varones, los extremadamente pobres y residentes a baja altitud. Los profesionales que realizan atención primaria y los implicados en el cuidado de la salud mental deben tomarlo en cuenta por sus implicaciones para la sociedad.

The aim of this study was to determine the association between alcohol dependence and altitude of residence in 11 villages in two high altitude areas of Peru. An analytical cross-sectional study was performed using a survey conducted by physicians in primary health care in 11 villages until 2013, that were divided into low altitude (≤2500 m asl (above sea level)), and high altitude (>2500 m asl) areas. The CAGE test for alcoholism (cut point, ≥2) was applied to those who responded positively when asked if they consumed alcohol. Statistical associations were obtained with generalised linear models Of the 737 participants, 51% were women and the median age was 36 years [interquartile range, 25-50], 334 (45%) lived at low altitude, and 113 (15%) had alcohol dependence. The highest frequency of alcoholism was positively associated with being a village considered extremely poor (Likelihood Ratio (LP) = 2.42; 95%CI, 1.40-4.19), while being female (LP = 0.44; 95%CI, 0.23-0.89) and residing at high altitude (LP = 0.15; 95%CI, 0.07-0.31) were negatively associated. These were adjusted for nine socio-occupational and pathological variables. According to these data, there is a higher frequency of alcohol dependence in being, male, extremely poor, and residing at low altitude. These results should be taken into account by professionals who work in primary care and those involved in mental health care, because of their implications in society.

SENP1, but not fetal hemoglobin, differentiates Andean highlanders with chronic mountain sickness from healthy individuals among Andean highlanders.

Chronic mountain sickness (CMS) results from chronic hypoxia. It is unclear why certain highlanders develop CMS. We hypothesized that modest increases in fetal hemoglobin (HbF) are associated with lower CMS severity. In this cross-sectional study, we found that HbF levels were normal (median = 0.4%) in all 153 adult Andean natives in Cerro de Pasco, Peru. Compared with healthy adults, the borderline elevated hemoglobin group frequently had symptoms (headaches, tinnitus, cyanosis, dilatation of veins) of CMS. Although the mean hemoglobin level differed between the healthy (17.1 g/dL) and CMS (22.3 g/dL) groups, mean plasma erythropoietin (EPO) levels were similar (healthy, 17.7 mIU/mL; CMS, 12.02 mIU/mL). Sanger sequencing determined that single-nucleotide polymorphisms in endothelial PAS domain 1 (EPAS1) and egl nine homolog 1 (EGLN1), associated with lower hemoglobin in Tibetans, were not identified in Andeans. Sanger sequencing of sentrin-specific protease 1 (SENP1) and acidic nuclear phosphoprotein 32 family, member D (ANP32D), in healthy and CMS individuals revealed that non-G/G genotypes were associated with higher CMS scores. No JAK2 V617F mutation was detected in CMS individuals. Thus, HbF and other classic erythropoietic parameters did not differ between healthy and CMS individuals. However, the non-G/G genotypes of SENP1 appeared to differentiate individuals with CMS from healthy Andean highlanders.

Giant insulinoma: a report of 3 cases and review of the literature.

Insulinoma is a rare pancreatic neuroendocrine tumor that is usually described as benign, sporadic, and very small (<2 cm). However, there have been rare case reports of insulinoma presenting as a giant tumor. We describe 3 cases of giant insulinomas, all of which developed liver metastases. The patients were aged 38, 63, and 67 years. Clinically, all patients presented with Whipple's triad associated with a large mass located in the pancreatic tail. The tumors ranged in size from 10 to 15 cm. On microscopic examination, the tumors were well differentiated with amyloid deposition ranging between 20% and 30%. Immunohistochemically, all 3 tumors showed strong diffuse expression of chromogranin and synaptophysin, whereas they were only focally positive for insulin. One patient developed liver recurrence 3 years after resection of the primary tumor yet remained asymptomatic without treatment. Another patient with liver recurrence underwent right hepatectomy and has been free of disease for 2 years. The third patient died of metastatic disease 13 years after initial surgery. Giant insulinomas are characterized by focal expression of insulin and high rates of liver metastases. Long-term follow-up is mandatory in these patients, as recurrence is expected after primary surgery.

Historia de obesidad como factor asociado al cáncer de mama en pacientes de un hospital público del Perú / History of obesity as risk factor for breast cancer in patients at a public hospital in Peru

Realizamos un estudio de casos y controles, en 123 pacientes con diagnóstico de cáncer mamario (casos) y 208 pacientes sanas (controles). En la medición se consideró el índice de masa corporal (IMC) antiguo (peso promedio de la vida adulta de la persona) e IMC actual (peso cuantificado al momento de efectuar la investigación) y otros factores de riesgo conocidos. Los IMC antiguos mostraron un riesgo incrementado tanto en mujeres en la premenopausia: sobrepesoOR: 7,29 (IC95 por ciento: 1,75 - 30,38) y obesidad OR: 23,43 (IC95 por ciento: 2,4 - 229.7); como en mujeres posmenopáusicas: obesidad OR: 3,33 (IC95 por ciento: 1,54 - 7,19) y obesidad OR: 6,04 (IC95 por ciento: 1,78 - 20,50). Por otro lado, al evaluar el IMC actual, se encontró asociación en las premenopáusicas donde el sobrepeso es un factor protector OR: 0,23 (IC95 por ciento: 0,05 - 0,99) y la obesidad no muestra asociación OR: 0,37 (IC95 por ciento: 0,08 - 1,8), asimismo, en las posmenopáusicas no se evidenció asociación con el sobrepeso OR: 0,79 (IC95 por ciento:0,35 - 1,85) ni con la obesidad OR: 1,19 (IC95 por ciento: 0,42 - 3,38). Se concluye que la historia de obesidad está asociada con un incremento de riesgo de cáncer mamario tanto en mujerespremenopáusicas y posmenopáusicas.

A case control study was performed including 123 patients with breast cancer diagnosis as cases and 208 healthy women as controls. For analysing obesity we had two parameters: Past BMI (with weight during a long period of patientÆs lifetime) and current IMC (with quantified current weight). Also other known risk factors were included. PastBMI shown increased risk both in premenopausal women: in 25.0-29.99 kg/m2 OR:7.29(CI95 per cent:1.752-30.38); in major or equal 30.0 kg/m2 OR:23.43(CI95 per cent:2.401û229.7); as in postmenopausal women: in 25.0-29.99 kg/m2 OR:3.33(CI95 per cent:1.54-7.19); in major or equal 30.0 kg/m2 OR:6.04(CI95 per cent:1.78-20.50). On the other hand current BMI didnÆt show the same association both in premenopausal women: in 25.0-29.99 kg/m2 OR:0.229(CI95 per cent:0.053-0.99); in major or equal 30.0kg/m2 OR:0.369 (CI95 per cent:0.076û .802); as in postmenopausal women: in 25.0-29.99 kg/m2 OR:0.79(CI95 per cent:0.35-1.85); in major or equal 30.0 kg/m2 OR:1.19(CI95 per cent:0.42û3.38). In conclusion, the history of obesity is associated with increased risk of breast cancer both in premenopausaland postmenopausal women

Efecto citotóxico de las semillas de Annona cherimola en cultivos de cáncer de cérvix, mama y leucemia mieloide crónica / Cytotoxic activity of seeds of Annona cherimola in cell cultures of cervical and breast cancer and chronic myeloid leukemia

Introducción: Diversos productos naturales del género Annona han sido utilizados en el tratamiento del cáncer. Annona cherimola posee diversos compuestos puros de sus semillas y tallos que han demostrado actividad antitumoral frente a células de carcinoma nasofaríngeo. Objetivo: Determinar el efecto citotóxico del extracto etanólico de Annona cherimola en las líneas celulares MCF-7 (adenocarcinoma de mama humano), ME-180 (carcinoma epidermoide de cervix), K562 (leucemia mieloide crónica) y 3T3 (fibroblastos normales de ratón). Materiales y métodos: Las líneas MCF-7, ME-180, K562 y 3T3, fueron expuestas a cuatro concentraciones del extracto etanólico de Annona cherimola (0,125, 0,031, 0,008, 0,002 mg/mL). Asimismo, a diferentes concentraciones de 5-fluorouracilo (0,01563, 0,00391, 0,00098, 0,00024 mg/mL) y Cisplatino (0,00250, 0,00063, 0,00016, 0,00004 mg/mL) como controles positivos. Se hallaron los porcentajes de crecimiento en 48 horas. Luego se determinó la concentración inhibitoria de crecimiento 50 (CI50) mediante correlación lineal, Asimismo se obtuvieron los coeficientes de determinación r2 utilizando Microsoft Office Excel 2007. Finalmente, se precisó el Índice de Selectividad de cada muestra. Resultados: Los CI50 en μg/mL del extracto etanólico de semillas de Annona cherimola fueron 9,4(r2 = 0,96) para MCF-7; 6,6(r2 = 0,99)para ME-180; 2,2(r2 = 0,96) para K562 y 29,5(r2 = 0,98) para 3T3. Los CI50 de 5-fluorouracilo fueron 3,4 (r2 = 0,95) para MCF-7; 3,8 (r2 = 0,96) para K562 y 0,2 (r2 = 0,98) para 3T3 y los CI50 del Cisplatino fueron 12,1 (r2 =0,96) para MCF-7; 0,1 (r2 = 0,96) para K562 y 0,3 (r2 = 0,99) para 3T3. La relación dosis respuesta del extracto para la línea normal 3T3 fue de -0,98 (p menor que 0,05) y para una línea tumoral K562 fue de -0,98 (p menor que 0,05). Los índices de selectividad del extracto fueron de 2,17, 6,07 y 2,39 para las líneas MCF-7, K562 y ME-180 respectivamente. Contrariamente, el 5-FU y Cisplatino, solo alcanzaron...

Introduction: Diverse natural products of the Annona sort have been used in the treatment of the cancer. Annona Cherimola has diverse pure compounds of its seeds and stems that have demonstrated to antitumor like activity front to cells of nasofaríngeo carcinoma. Objective: To determine the cytotoxic effect of the extract of Annonacherimola in the cell lines MCF-7 (adenocarcinoma of human breast), ME-180(carcinoma epidermoide of cervix), K562 (chronic myeloidleukemia) and 3T3 (normal fibroblasts of mouse). Materials and methods: The lines MCF-7, ME-180, K 562 and 3T3, were exposed to four concentrations of the etanolic extract of Annona cherimola (0,125, 0,031, 0,008, 0,002 mg/mL), also to different concentrations of 5-fluorouracilo (0,01563, 0,00391, 0,00098, 0,00024mg/mL) and Cisplatino (0,00250, 0,00063, 0,00016, 0,00004 mg/mL) like positive controls. We found the growth percentages in 48 hours. Then, the inhibiting concentration of growth 50 (CI50) was determined through linear correlation, also we obtained the determination coefficients r2 using Microsoft Office Excel 2007. Finally the Selectivity Index of each samplewas determined. Results: The CI50 in μg/mL of the extract of Annona cherimola were 9,4(r2 = 0,96) for MCF-7; 6,6(r2 = 0,99) for ME-180; 2,2 (r2 = 0,96) for K562 and 29,5(r2 = 0,98) for 3T3. The CI50 of 5-fluorouracilowere 3,4 (r2 = 0,95) for MCF-7; 3,8(r2 = 0,96) for K562 and 0,2 (r2 = 0,98)for 3T3 and the CI50 of Cisplatino were 12,1(r2 = 0,96) for MCF-7; 0,1(r2 = 0,96) for K562 and 0,3(r2 = 0,99) for 3T3. The relation dose answer of the extract for the normal line 3T3 was -0,98 (p less than 0,05) and for the line K562 was -0,98 (p less than 0,05). The Selectivity Index of the extract was of 2,17, 6,07 and 2,39 for the lines MCF-7, K562 and ME-180 respectively; contrary, the 5-FU and Cisplatino, only reached values of 0,07 and 0,06; 0,02 and 2,25 for the lines MCF-7 and K562 respectively...

Propuesta de un nuevo puntaje para optimizar estimados ecográficos de peso fetal: estudio piloto / New score to optimize ultrasound fetal weight estimation: a pilot study

Introducción: La estimación del peso fetal es importante para las decisionesobstétricas; la precisión de los estimados ecográficos no ha sido estudiada. Objetivos: Determinar la precisión del estimado ecográfico del peso fetal mediante un puntaje basado en parámetros clínicos, ecográficos y maternos. Diseño: Estudio de tipo transversal. Lugar: Hospital Nacional Guillermo Almenara Irigoyen, Lima, Perú. Participantes: 130 gestantes y sus fetos. Intervenciones: Se consignó datos clínicos, ecográficos y maternos. Se procedió a dicotomizar los aciertosentre menor o igual a mas o menos10 por ciento (acertadas) y mayor a mas o menos 10 por ciento (erradas) del peso real. Se analizó las variables clínicas, ecográficas y maternas mediante el uso de las curvas ROC, para identificar aquellas que tuvieron más influencia en la precisión ecográfica. Con las variables identificadas, se procedió al desarrollo de un modelo de regresión logística, para establecer un puntaje que estimara la probabilidad devariación, teniendo como punto de corte mas o menos 10 por ciento del peso real. Principales medidas de resultados: Precisión de un puntaje que relaciona la edad gestacional con la circunferencia abdominal y el diámetro biparietal del feto, el ponderado clínico y el peso materno. Resultados: El nuevo puntaje tuvo un buena capacidad de discriminación de las ecografías, según su variación a mas o menos 10 por ciento del peso real (área bajo la curva ROC: 0,76 p menor que 0,001). Según los puntajes obtenidos, se obtuvo tres grupos: rendimiento alto 20 por ciento, rendimiento convencional 44,4 por ciento y rendimiento bajo 71,2 por ciento. Conclusiones: El nuevo puntaje propuesto tiene la capacidad de estimar la probabilidad de variación de los estimados ecográficos mayores al mas o menos 10 por ciento del pesoreal, conformando tres grupos de rendimiento: alto, convencional y bajo.

Introduction: Fetal weight estimation is important for obstetrical decisions;accuracy of ultrasound fetal weight estimations has not been studied. Objective: To determine ultrasound fetal weight estimations precision by developing a score based on clinical, ultrasound and maternal parameters. Design: Cross sectional study. Setting: Guillermo Almenara Irigoyen National Hospital, Lima, Peru. Participants: 130 pregnant women and their fetuses. Interventions: Clinical, ultrasound and maternal data were collected. We dichotomized predictions as actual birth weight less or equal to mor or less 10 per cent (correct) and more than more or less 10 per cent(erroneous). We analyzed clinical, ultrasonographic and maternal variables using ROC curves in order to identify those with more influence in ultrasound accuracy. With such identified variables we developed a logistic regression model to establish a score that would estimate the probability of variation, having a per cent 10 per cent of real fetal birth weight cut point. Main outcome measures: Precision ofa score that relates gestational age and both fetal abdominal circumference andbiparietal diameter, clinical fetal weight estimation and maternal weight. Results: The resulting score had a good capacity of discrimination of ultrasonographic fetal weight estimations according to their variation to more or less 10 per cent of real birth weight (area under the curve ROC: 0,76 p minor that 0,001). Three groups resulted: high performance 20 per cent, conventional performance 44,4 per cent, and low performance 71,2 per cent. Conclusions: The new score proposed estimates the probability of variation of fetal weight above mroe or less 10 per cent of real birth weight, with three groups of performance: high, conventional and low.

Lactancia materna y cáncer de mama: un estudio caso-control en pacientes del Hospital Nacional Arzobispo Loayza, Lima-Perú / Breastfeeding and breast cancer: a case-control study in patients at Arzobispo Loayza National Hospital. Lima - Peru

Introducción: El cáncer de mama es un problema de salud pública a nivel mundial con un permanente incremento en su incidencia. La lactancia materna ha mostrado ser un factor protector del cáncer de mama en diferentes estudios; sin embargo, ha sido poco evaluado en poblaciones latinoamericanas. Objetivo: Evaluar el efecto de la lactancia materna sobre el riesgo de desarrollar cáncer de mama en una población peruana. Diseño: Estudio de tipo caso-control. Lugar: Hospital Nacional Arzobispo Loayza, Lima - Perú, en los servicios de Oncología Médica y Radiología (sección de Mamografía). Participantes: Pacientes con cáncer de mama y mujeres con mamografías Birads 1 y 2. Intervenciones: Se recolectó información de forma prospectiva, desde julio del 2006 hasta octubre del 2007. Se entrevistó 103 pacientes con cáncer de mama como casos y a 208 pacientes con mamografías Birads 1 y 2 como controles. Se consignó datos de factores de riesgo y patrones de lactancia materna. Se utilizó la estadística descriptiva, así mismo análisis bivariado y de regresión logística. Principales medidas de resultados: Protección de la lactancia materna sobre el cáncer de mama. Resultados: La ausencia de lactancia materna estuvo asociada con un ligero incremento no significativo del riesgo, comparado con las pacientes que por lo menos alguna vez dieron de lactar (OR ajustado 1,99; IC 95 por ciento 0,23 a 6,99). Excluyendo las nulíparas, las que dieron de lactar de un mes a más por cada hijo comparadas con las que dieron de lactar menos de un mes por hijo tuvieron una reducción del riesgo, no significativo (OR ajustado 0,28: IC 95 por ciento 0,06 a 1,27). Sin embargo, si comparamos la duración de lactancia total de las mujeres que dieron de lactar de 3 meses a más comparadas con las que dieron menos de 3 meses o nunca, tuvieron una reducción significativa del riesgo de desarrollar cáncer de mama (OR ajustado 0,24; IC 95 por ciento 0,06 a 0,92)...

Introduction: Breast cancer is a global public health problem with incidence increasing in the world. Breastfeeding has been shown to be a protective factor, but evaluation in Latin American populations has scant. Objective: To evaluate the effect of breastfeeding on breast cancer developing risk in a Peruvian population. Design: A case-control study. Setting: Departments of Medical Oncology and Radiology, section of Mammography, at Arzobispo Loayza National Hospital, Lima - Peru. Participants: Patients with breast cancer and women with Birads 1 and 2 mammograms. Interventions: Information was collected from July 2006 through October 2007 from 103 patients with breast cancer as cases and 208 women with Birads 1 and 2 mammograms as controls. Interviews included information on risk factors and patterns of breastfeeding. We used descriptive statistics, and bivariate and logistic regression analysis. Main outcome measures: Breastfeeding protection on breast cancer. Results: Absence of breastfeeding was associated with a non- significant risk increase compared with patients that ever lactated (adjusted OR 1,99; 95 per cent CI 0,23-6,99). Excluding nulliparous, women that breastfed one month or more per child had a non-significant reduced risk compared with women that breastfed less than a month per child (adjusted OR 0,28, 95 per cent CI 0,06-1,27). However, women who breastfed 3 months or more had a significant reduction in breast cancer risk compared with those that never breastfed or breastfed less than 3 months (adjusted OR 0,24; 95 per cent CI 0,06-0,92). Conclusions: Breastfeeding by parous women showed protection on breast cancer risk especially if breastfeeding period was for three month or more.