RESUMEN
Importance: The benefits from colorectal cancer (CRC) screening may take 10 to 15 years to accrue. Therefore, screening is recommended for older adults who are in good health. Objective: To determine the number of screening colonoscopies done in patients older than 75 years with a life expectancy of fewer than 10 years, diagnostic yield, and associated adverse events within 10 days and 30 days of the procedure. Design: This cross-sectional study with a nested cohort between January 2009 and January 2022 in an integrated health system assessed asymptomatic patients older than 75 years who underwent screening colonoscopy in the outpatient setting. Reports with incomplete data, any indication other than screening, patients who had a colonoscopy within the previous 5 years, and patients with a personal history of inflammatory bowel disease or CRC were excluded. Exposures: Life expectancy based on a prediction model from previous literature. Main Outcomes and Measures: The primary outcome was the percentage of screened patients who had limited (<10 years) life expectancy. Other outcomes included colonoscopy findings and adverse events that developed within 10 days and 30 days of the procedure. Results: A total of 7067 patients older than 75 years were included. The median (IQR) age was 78 (77-79) years, 3967 (56%) were women, and 5431 (77%) were White with an average of 2 comorbidities (taken from a select group of comorbidities). The proportion of colonoscopies performed on patients with a life expectancy of fewer than 10 years aged 76 to 80 years was 30% in both sexes and increased with age-82% of men and 61% of women aged 81 to 85 years (71% total), and 100% of patients beyond the age of 85 years. Adverse events requiring hospitalizations were common at 10 days (13.58 per 1000) and increased with age, particularly among patients older than 85 years. The detection of advanced neoplasia varied from 5.4% among patients aged 76 to 80 years to 6.2% in those aged 81 to 85 years and 9.5% among patients older than 85 years (P = .02). Of the total population, 15 patients (0.2%) had invasive adenocarcinoma; among patients with a life expectancy of fewer than 10 years, 1 of 9 was treated, whereas 4 of 6 patients with a life expectancy of greater than or equal to 10 years were treated. Conclusions and Relevance: In this cross-sectional study with a nested cohort, most screening colonoscopies performed in patients older than 75 years were in patients with limited life expectancy and associated with increased risk of complications. Colorectal cancer was exceedingly rare.
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Colonoscopía , Neoplasias Colorrectales , Masculino , Humanos , Femenino , Anciano , Anciano de 80 o más Años , Estudios Transversales , Colonoscopía/efectos adversos , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/prevención & control , Esperanza de Vida , Tamizaje Masivo , Detección Precoz del Cáncer/métodosRESUMEN
Strong evidence demonstrates the protective benefit of frequent colonoscopy surveillance for colorectal cancer prevention in Lynch Syndrome (LS) and is endorsed by many guidelines. Until recently, the evidence supporting the utility of upper endoscopy [esophagogastroduodenoscopy (EGD)] for upper gastrointestinal (UGI) cancer surveillance was limited. Over the last 3 years, multiple studies have demonstrated that EGD surveillance in LS is associated with the detection of both precancerous lesions and early-stage UGI cancers. On the basis of the emerging favorable evidence derived from EGD surveillance programs, the 2022 National Comprehensive Cancer Network (NCCN) Guidelines for LS recommend UGI surveillance with EGD starting between age 30 and 40 years with repeat EGDs every 2 to 4 years, preferably in conjunction with colonoscopy, in all patients with a germline pathogenic variant (PV) in MLH1, MSH2, EPCAM, and MSH6 and, because of the lack of data, consideration in PMS2. Standardization of the approach to performing EGD surveillance in LS and reporting clinically actionable findings is requisite for both improving quality and understanding the cost efficiency and outcomes of patients undergoing EGD as a surveillance tool. Accordingly, the primary objective of this Quality of Upper Endoscopy in Lynch Syndrome (QUELS) statement is to articulate a framework for standardizing the approach to performing and reporting EGD findings in patients with LS by introducing emerging quality metrics. The recommendations presented herein were developed from available evidence and consensus-based expert opinion and provide a practical approach for clinicians applying EGD surveillance in accordance with the most recent and existing LS guidelines.
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Neoplasias Colorrectales Hereditarias sin Poliposis , Lesiones Precancerosas , Humanos , Adulto , Neoplasias Colorrectales Hereditarias sin Poliposis/diagnóstico , Endoscopía Gastrointestinal , Colonoscopía , ConsensoRESUMEN
OBJECTIVE: Serrated lesions such as sessile serrated adenomas or polyps (SSA/Ps) are important colorectal cancer precursors, but aetiological factors for these lesions are largely unknown. We aimed to determine the effects of calcium and vitamin D supplementation on the incidence of serrated polyps (SPs) in general and hyperplastic polyps and SSA/Ps specifically. DESIGN: Participants with one or more adenoma at baseline were randomised to receive 1200 mg/day of elemental calcium, 1000 IU/day of vitamin D3, both or neither agent. Treatment continued for 3 or 5 years, when risk of polyps was determined from surveillance colonoscopy (treatment phase). Outcomes after treatment ceased were also assessed (observational phase). Adjusted risk ratios (aRRs) of SPs were determined via multivariable generalised linear models. RESULTS: SPs were diagnosed in 565 of 2058 (27.5%) participants during the treatment phase and 329/1108 (29.7%) during the observational phase. In total, 211 SSA/Ps were identified during follow-up. In the treatment phase, there was no effect of either calcium or vitamin D on incidence of SSA/Ps. However, during the later observational phase, we observed elevated risks of SSA/Ps associated with calcium alone and calcium+vitamin D treatment (aRR (95% CI): 2.65 (1.43 to 4.91) and 3.81 (1.25 to 11.64), respectively). CONCLUSION: In a large multicentre chemoprevention study, we found evidence that calcium and vitamin D supplementation increased the risk of SSA/Ps. This appeared to be a late effect: 6-10 years after supplementation began. These possible risks must be weighed against the benefits of calcium and vitamin D supplementation. : Trial registration NUMBER: NCT00153816; Results.
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Calcio/efectos adversos , Pólipos del Colon/inducido químicamente , Suplementos Dietéticos/efectos adversos , Vitamina D/efectos adversos , Adenoma/inducido químicamente , Adenoma/diagnóstico , Anciano , Calcio/administración & dosificación , Pólipos del Colon/diagnóstico , Colonoscopía , Neoplasias Colorrectales/inducido químicamente , Neoplasias Colorrectales/diagnóstico , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Lesiones Precancerosas/inducido químicamente , Lesiones Precancerosas/diagnóstico , Vitamina D/administración & dosificación , Vitamina D/sangreRESUMEN
Calcium supplementation (1,200 mg/day) did not significantly reduce colorectal adenomas in our recent randomized, controlled trial (Vitamin D/Calcium Polyp Prevention Study, VCPPS, 2004-2013) in contrast to our previous trial (Calcium Polyp Prevention Study, CPPS, 1988-1996). To reconcile these findings, we identified participant characteristics that differed between the study populations and modified the effect of calcium supplementation on adenomas or high-risk findings (advanced or multiple adenomas). Compared to the CPPS, more participants in the VCPPS were obese (body mass index (BMI) ≥30 kg/m2 ; 37.5% vs. 24.4%) and fewer had normal BMI (BMI <25 kg/m2 ; 18.5% vs. 31%). BMI appeared to modify the effect of calcium supplementation on adenomas and especially on high risk-findings: in the VCPPS, there was a 44% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.56, 95% CI = 0.26-1.23), but not among overweight (RR = 1.09, 95% CI = 0.62-1.91) or obese (RR = 1.54, 95% CI = 0.92-2.57) individuals (pinteraction = 0.03). Similarly, in the CPPS, there was a 56% reduction in high-risk findings among individuals whose BMI was normal (RR = 0.44, 95% CI = 0.26-0.74), but not among overweight (RR = 0.87, 95% CI = 0.55-1.39) or obese (RR = 1.02, 95% CI = 0.57-1.82) individuals (pinteraction = 0.02). Standardization of each trial's findings to the BMI distribution in the other attenuated calcium's protective effect on adenomas in the CPPS but enhanced it in the VCPPS. In conclusion, 1,200 mg/day calcium supplementation may reduce risk of colorectal adenomas among those with normal BMI but not in overweight or obese individuals; and differences in BMI distribution partially account for the apparent difference in calcium efficacy between the two trials.
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Adenoma/epidemiología , Índice de Masa Corporal , Carbonato de Calcio/administración & dosificación , Neoplasias Colorrectales/epidemiología , Adenoma/prevención & control , Neoplasias Colorrectales/prevención & control , Suplementos Dietéticos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Riesgo , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND & AIMS: Endoscopists do not routinely follow guidelines to survey individuals with low-risk adenomas (LRAs; 1-2 small tubular adenomas, < 1 cm) every 5-10 years for colorectal cancer; many recommend shorter surveillance intervals for these individuals. We aimed to identify the reasons that endoscopists recommend shorter surveillance intervals for some individuals with LRAs and determine whether timing affects outcomes at follow-up examinations. METHODS: We collected data from 1560 individuals (45-75 years old) who participated in a prospective chemoprevention trial (of vitamin D and calcium) from 2004 through 2008. Participants in the trial had at least 1 adenoma, detected at their index colonoscopy, and were recommended to receive follow-up colonoscopy examinations at 3 or 5 years after adenoma identification, as recommended by the endoscopist. For this analysis we collected data from only participants with LRAs. These data included characteristics of participants and endoscopists and findings from index and follow-up colonoscopies. Primary endpoints were frequency of recommending shorter (3-year) vs longer (5-year) surveillance intervals, factors associated with these recommendations, and effect on outcome, determined at the follow-up colonoscopy. RESULTS: A 3-year surveillance interval was recommended for 594 of the subjects (38.1%). Factors most significantly associated with recommendation of 3-year vs a 5-year surveillance interval included African American race (relative risk [RR] to white, 1.41; 95% confidence interval [CI], 1.14-1.75), Asian/Pacific Islander ethnicity (RR to white, 1.7; 95% CI, 1.22-2.43), detection of 2 adenomas at the index examination (RR vs 1 adenoma, 1.47; 95% CI, 1.27-1.71), more than 3 serrated polyps at the index examination (RR=2.16, 95% CI, 1.59-2.93), or index examination with fair or poor quality bowel preparation (RR vs excellent quality, 2.16; 95% CI, 1.66-2.83). Other factors that had a significant association with recommendation for a 3-year surveillance interval included family history of colorectal cancer and detection of 1-2 serrated polyps at the index examination. In comparisons of outcomes, we found no significant differences between the 3-year vs 5-year recommendation groups in proportions of subjects found to have 1 or more adenomas (38.8% vs 41.7% respectively; P = .27), advanced adenomas (7.7% vs 8.2%; P = .73) or clinically significant serrated polyps (10.0% vs 10.3%; P = .82) at the follow-up colonoscopy. CONCLUSIONS: Possibly influenced by patients' family history, race, quality of bowel preparation, or number or size of polyps, endoscopists frequently recommend 3-year surveillance intervals instead of guideline-recommended intervals of 5 years or longer for individuals with LRAs. However, at the follow-up colonoscopy, similar proportions of participants have 1 or more adenomas, advanced adenomas, or serrated polyps. These findings support the current guideline recommendations of performing follow-up examinations of individuals with LRAs at least 5 years after the index colonoscopy.
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Adenoma/diagnóstico , Carcinoma/diagnóstico , Colon/patología , Neoplasias del Colon/diagnóstico , Colonoscopía , Detección Precoz del Cáncer/métodos , Gastroenterólogos , Pautas de la Práctica en Medicina , Adenoma/patología , Adenoma/prevención & control , Anciano , Anticarcinógenos/uso terapéutico , Calcio/uso terapéutico , Carcinoma/patología , Carcinoma/prevención & control , Neoplasias del Colon/patología , Neoplasias del Colon/prevención & control , Colonoscopía/normas , Colonoscopía/tendencias , Suplementos Dietéticos , Progresión de la Enfermedad , Detección Precoz del Cáncer/normas , Detección Precoz del Cáncer/tendencias , Femenino , Gastroenterólogos/normas , Gastroenterólogos/tendencias , Adhesión a Directriz , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , América del Norte , Oportunidad Relativa , Selección de Paciente , Guías de Práctica Clínica como Asunto , Pautas de la Práctica en Medicina/normas , Pautas de la Práctica en Medicina/tendencias , Valor Predictivo de las Pruebas , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Carga Tumoral , Vitamina D/uso terapéuticoRESUMEN
BACKGROUND: Epidemiologic and preclinical data suggest that higher intake and serum levels of vitamin D and higher intake of calcium reduce the risk of colorectal neoplasia. To further study the chemopreventive potential of these nutrients, we conducted a randomized, double-blind, placebo-controlled trial of supplementation with vitamin D, calcium, or both for the prevention of colorectal adenomas. METHODS: We recruited patients with recently diagnosed adenomas and no known colorectal polyps remaining after complete colonoscopy. We randomly assigned 2259 participants to receive daily vitamin D3 (1000 IU), calcium as carbonate (1200 mg), both, or neither in a partial 2×2 factorial design. Women could elect to receive calcium plus random assignment to vitamin D or placebo. Follow-up colonoscopy was anticipated to be performed 3 or 5 years after the baseline examinations, according to the endoscopist's recommendation. The primary end point was adenomas diagnosed in the interval from randomization through the anticipated surveillance colonoscopy. RESULTS: Participants who were randomly assigned to receive vitamin D had a mean net increase in serum 25-hydroxyvitamin D levels of 7.83 ng per milliliter, relative to participants given placebo. Overall, 43% of participants had one or more adenomas diagnosed during follow-up. The adjusted risk ratios for recurrent adenomas were 0.99 (95% confidence interval [CI], 0.89 to 1.09) with vitamin D versus no vitamin D, 0.95 (95% CI, 0.85 to 1.06) with calcium versus no calcium, and 0.93 (95% CI, 0.80 to 1.08) with both agents versus neither agent. The findings for advanced adenomas were similar. There were few serious adverse events. CONCLUSIONS: Daily supplementation with vitamin D3 (1000 IU), calcium (1200 mg), or both after removal of colorectal adenomas did not significantly reduce the risk of recurrent colorectal adenomas over a period of 3 to 5 years. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00153816.).
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Adenoma/prevención & control , Calcio/uso terapéutico , Neoplasias Colorrectales/prevención & control , Suplementos Dietéticos , Vitamina D/uso terapéutico , Vitaminas/uso terapéutico , Adenoma/epidemiología , Anciano , Calcio/efectos adversos , Neoplasias Colorrectales/epidemiología , Suplementos Dietéticos/efectos adversos , Método Doble Ciego , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Riesgo , Insuficiencia del Tratamiento , Vitamina D/análogos & derivados , Vitamina D/sangreRESUMEN
Serum C-reactive protein (CRP) is a sensitive marker of systemic inflammation. Because there is a well-recognized relationship between local inflammation and colorectal cancer, we aimed to evaluate whether serum CRP levels were associated with the occurrence of colorectal adenomas and serrated polyps using data from a large adenoma prevention trial. A total of 930 participants with a history of colorectal adenomas were enrolled in a randomized trial of calcium supplementation (1,200 mg/day) for the prevention of colorectal adenomas. Outcomes in this analysis are metachronous adenomas (and advanced neoplasms specifically), and serrated polyps at follow-up colonoscopy. High-sensitivity CRP levels were measured 1 year following baseline colonoscopy. Multivariate analysis was performed to estimate risk ratios (RR) using Poisson regression, controlling for potential confounders. We measured serum CRP levels in 689 participants (mean CRP, 3.62 ± 5.72 mg/L). There was no difference in CRP levels with respect to calcium versus placebo treatment assignment (P = 0.99). After adjustment for potential confounders, we found no association between CRP level and risk of recurrent adenoma or advanced lesion [quartile 4 vs. quartile 1: RR, 95% confidence interval (CI) = 0.99 (0.73-1.34) and 0.92 (0.49-1.75), respectively]. Similarly, no association was seen between CRP levels and risk of serrated polyps or proximal serrated polyps [quartile 4 vs. quartile 1: RR (95% CI) = 1.32 (0.85-2.03) and 1.19 (0.54-2.58), respectively]. In conclusion, this large prospective colorectal adenoma chemoprevention study found no significant relationship between CRP levels and occurrence of adenomas, advanced neoplasms, or serrated polyps.
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Adenoma/sangre , Proteína C-Reactiva/metabolismo , Pólipos del Colon/sangre , Neoplasias Colorrectales/sangre , Adenoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Colonoscopía , Femenino , Humanos , Inflamación , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Distribución de Poisson , Estudios Prospectivos , Resultado del Tratamiento , Adulto JovenRESUMEN
CONTEXT: Adequate serum 25-hydroxyvitamin D concentrations, [25(OH)D], are required for optimal bone health, and low levels are associated with chronic diseases. OBJECTIVE: We investigated whether 41 candidate single nucleotide polymorphisms (SNPs) in vitamin D and calcium pathway genes (GC, DHCR7, CYP2R1, CYP27B1, CYP24A1, VDR, and CASR) are associated with [25(OH)D] or modify the increase in [25(OH)D] from vitamin D3 supplementation. DESIGN AND SETTING: Baseline and year 1 [25(OH)D] measurements from a randomized controlled trial conducted at 11 clinical centers in the United States. PARTICIPANTS: A total of 1787 healthy non-Hispanic white participants aged 45-75 years. INTERVENTIONS: Vitamin D3 (1000 IU/d), calcium carbonate (1200 mg/d elemental), both, or placebo. MAIN OUTCOME MEASURES: Genotype main effects and interactions with vitamin D3 treatment estimated using multiple linear regression. RESULTS: The baseline serum [25(OH)D] was 25.4 ± 8.7 ng/mL (mean ± SD). Associations with baseline levels were discovered for SNPs in CYP24A1 (rs2209314, rs2762939) and confirmed for SNPs in GC and CYP2R1. After 1 year, [25(OH)D] increased on average by 6.1 ± 8.9 ng/mL on vitamin D3 treatment and decreased by 1.1 ± 8.4 ng/mL on placebo. The increase in [25(OH)D] due to vitamin D3 supplementation was modified by genotypes at rs10766197 near CYP2R1, rs6013897 near CYP24A1, and rs7968585 near VDR. CONCLUSIONS: The increase in [25(OH)D] attributable to vitamin D3 supplementation may vary according to common genetic differences in vitamin D 25-hydroxylase (CYP2R1), 24-hydroxylase (CYP24A1), and the vitamin D receptor (VDR) genes. These findings have implications for achieving optimal vitamin D status and potentially for vitamin D-related health outcomes.
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Colecalciferol/uso terapéutico , Colestanotriol 26-Monooxigenasa/genética , Receptores de Calcitriol/genética , Deficiencia de Vitamina D/genética , Vitamina D3 24-Hidroxilasa/genética , Vitamina D/análogos & derivados , Anciano , Carbonato de Calcio/uso terapéutico , Familia 2 del Citocromo P450 , Resistencia a Medicamentos/genética , Femenino , Variación Genética , Genotipo , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Resultado del Tratamiento , Vitamina D/sangre , Deficiencia de Vitamina D/tratamiento farmacológicoRESUMEN
Data regarding the association between folate status and risk of prostate cancer are sparse and conflicting. We studied prostate cancer occurrence in the Aspirin/Folate Polyp Prevention Study, a placebo-controlled randomized trial of aspirin and folic acid supplementation for the chemoprevention of colorectal adenomas conducted between July 6, 1994, and December 31, 2006. Participants were followed for up to 10.8 (median = 7.0, interquartile range = 6.0-7.8) years and asked periodically to report all illnesses and hospitalizations. Aspirin alone had no statistically significant effect on prostate cancer incidence, but there were marked differences according to folic acid treatment. Among the 643 men who were randomly assigned to placebo or supplementation with folic acid, the estimated probability of being diagnosed with prostate cancer over a 10-year period was 9.7% (95% confidence interval [CI] = 6.5% to 14.5%) in the folic acid group and 3.3% (95% CI = 1.7% to 6.4%) in the placebo group (age-adjusted hazard ratio = 2.63, 95% CI = 1.23 to 5.65, Wald test P = .01). In contrast, baseline dietary folate intake and plasma folate in nonmultivitamin users were inversely associated with risk of prostate cancer, although these associations did not attain statistical significance in adjusted analyses. These findings highlight the potential complex role of folate in prostate cancer and the possibly different effects of folic acid-containing supplements vs natural sources of folate.
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Antiinflamatorios no Esteroideos/uso terapéutico , Aspirina/uso terapéutico , Neoplasias Colorrectales/prevención & control , Suplementos Dietéticos , Ácido Fólico/uso terapéutico , Neoplasias de la Próstata/epidemiología , Complejo Vitamínico B/uso terapéutico , Adenoma/prevención & control , Anciano , Anciano de 80 o más Años , Inhibidores de la Ciclooxigenasa/uso terapéutico , Método Doble Ciego , Ácido Fólico/sangre , Estudios de Seguimiento , Humanos , Incidencia , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Neoplasias de la Próstata/inducido químicamente , Neoplasias de la Próstata/mortalidad , Neoplasias de la Próstata/prevención & control , Proyectos de Investigación , Encuestas y Cuestionarios , Estados Unidos/epidemiología , Complejo Vitamínico B/sangreRESUMEN
CONTEXT: Laboratory and epidemiological data suggest that folic acid may have an antineoplastic effect in the large intestine. OBJECTIVE: To assess the safety and efficacy of folic acid supplementation for preventing colorectal adenomas. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, placebo-controlled, 2-factor, phase 3, randomized clinical trial conducted at 9 clinical centers between July 6, 1994, and October 1, 2004. Participants included 1021 men and women with a recent history of colorectal adenomas and no previous invasive large intestine carcinoma. INTERVENTION: Participants were randomly assigned in a 1:1 ratio to receive 1 mg/d of folic acid (n = 516) or placebo (n = 505), and were separately randomized to receive aspirin (81 or 325 mg/d) or placebo. Follow-up consisted of 2 colonoscopic surveillance cycles (the first interval was at 3 years and the second at 3 or 5 years later). MAIN OUTCOME MEASURES: The primary outcome measure was occurrence of at least 1 colorectal adenoma. Secondary outcomes were the occurrence of advanced lesions (> or =25% villous features, high-grade dysplasia, size > or =1 cm, or invasive cancer) and adenoma multiplicity (0, 1-2, or > or =3 adenomas). RESULTS: During the first 3 years, 987 participants (96.7%) underwent colonoscopic follow-up, and the incidence of at least 1 colorectal adenoma was 44.1% for folic acid (n = 221) and 42.4% for placebo (n = 206) (unadjusted risk ratio [RR], 1.04; 95% confidence interval [CI], 0.90-1.20; P = .58). Incidence of at least 1 advanced lesion was 11.4% for folic acid (n = 57) and 8.6% for placebo (n = 42) (unadjusted RR, 1.32; 95% CI, 0.90-1.92; P = .15). A total of 607 participants (59.5%) underwent a second follow-up, and the incidence of at least 1 colorectal adenoma was 41.9% for folic acid (n = 127) and 37.2% for placebo (n = 113) (unadjusted RR, 1.13; 95% CI, 0.93-1.37; P = .23); and incidence of at least 1 advanced lesion was 11.6% for folic acid (n = 35) and 6.9% for placebo (n = 21) (unadjusted RR, 1.67; 95% CI, 1.00-2.80; P = .05). Folic acid was associated with higher risks of having 3 or more adenomas and of noncolorectal cancers. There was no significant effect modification by sex, age, smoking, alcohol use, body mass index, baseline plasma folate, or aspirin allocation. CONCLUSIONS: Folic acid at 1 mg/d does not reduce colorectal adenoma risk. Further research is needed to investigate the possibility that folic acid supplementation might increase the risk of colorectal neoplasia. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00272324.
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Adenoma/prevención & control , Neoplasias Colorrectales/prevención & control , Ácido Fólico/uso terapéutico , Adenoma/epidemiología , Adenoma/etiología , Adulto , Anciano , Antiinflamatorios no Esteroideos/uso terapéutico , Aspirina/uso terapéutico , Distribución de Chi-Cuadrado , Neoplasias Colorrectales/epidemiología , Método Doble Ciego , Femenino , Ácido Fólico/administración & dosificación , Ácido Fólico/efectos adversos , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Neoplasias/etiología , Riesgo , Insuficiencia del TratamientoRESUMEN
BACKGROUND: Clinical trials have shown that calcium supplementation modestly decreases the risk of colorectal adenomas. However, few studies have examined the effect of calcium on the risk of different types of colorectal lesions or dietary determinants of this effect. METHODS: Our analysis used patients from the Calcium Polyp Prevention Study, a randomized, double-blind, placebo-controlled chemoprevention trial among patients with a recent colorectal adenoma. Nine hundred thirty patients were randomly assigned to calcium carbonate (1200 mg/day) or placebo. Follow-up colonoscopies were conducted approximately 1 and 4 years after the qualifying examination. We used general estimating equation (GEE) and generalized linear regression analyses to compute risk ratios and 95% confidence intervals (CIs) to assess the effect of calcium treatment versus placebo on the risk of hyperplastic polyps, tubular adenomas, and more advanced lesions. Additionally, we used GEE analyses to compare the calcium treatment effects for various types of polyps with that for tubular adenomas. We also examined the interaction between calcium treatment and baseline intake of dietary calcium, fat, and fiber. All P values were obtained using Wald tests based on the corresponding models. All tests of statistical significance were two-sided. RESULTS: The calcium risk ratio for hyperplastic polyps was 0.82 (95% CI = 0.67 to 1.00), that for tubular adenomas was 0.89 (95% CI = 0.77 to 1.03), and that for histologically advanced neoplasms was 0.65 (95% CI = 0.46 to 0.93) compared with patients assigned to placebo. There were no statistically significant differences between the risk ratio for tubular adenomas and that for other types of polyps. The effect of calcium supplementation on adenoma risk was most pronounced among individuals with high dietary intakes of calcium and fiber and with low intake of fat, but the interactions were not statistically significant. CONCLUSION: Our results suggest that calcium supplementation may have a more pronounced antineoplastic effect on advanced colorectal lesions than on other types of polyps.