RESUMEN
OBJECTIVE: To assess leukemia risks among children with Down syndrome in a large, contemporary cohort. STUDY DESIGN: Retrospective cohort study including 3 905 399 children born 1996-2016 in 7 US healthcare systems or Ontario, Canada, and followed from birth to cancer diagnosis, death, age 15 years, disenrollment, or December 30, 2016. Down syndrome was identified using International Classification of Diseases, Ninth and Tenth Revisions, diagnosis codes. Cancer diagnoses were identified through linkages to tumor registries. Incidence and hazard ratios (HRs) of leukemia were estimated for children with Down syndrome and other children adjusting for health system, child's age at diagnosis, birth year, and sex. RESULTS: Leukemia was diagnosed in 124 of 4401 children with Down syndrome and 1941 of 3 900 998 other children. In children with Down syndrome, the cumulative incidence of acute myeloid leukemia (AML) was 1405/100 000 (95% CI 1076-1806) at age 4 years and unchanged at age 14 years. The cumulative incidence of acute lymphoid leukemia in children with Down syndrome was 1059/100 000 (95% CI 755-1451) at age 4 and 1714/100 000 (95% CI 1264-2276) at age 14 years. Children with Down syndrome had a greater risk of AML before age 5 years than other children (HR 399, 95% CI 281-566). Largest HRs were for megakaryoblastic leukemia before age 5 years (HR 1500, 95% CI 555-4070). Children with Down syndrome had a greater risk of acute lymphoid leukemia than other children regardless of age (<5 years: HR 28, 95% CI 20-40, ≥5 years HR 21, 95% CI 12-38). CONCLUSIONS: Down syndrome remains a strong risk factor for childhood leukemia, and associations with AML are stronger than previously reported.
Asunto(s)
Síndrome de Down/epidemiología , Leucemia Megacarioblástica Aguda/epidemiología , Adolescente , Estudios de Casos y Controles , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Masculino , Ontario/epidemiología , Sistema de Registros , Medición de Riesgo , Estados Unidos/epidemiologíaRESUMEN
OBJECTIVE: This retrospective cohort study examined whether bariatric surgery is associated with reduced risk of breast cancer among pre- and postmenopausal women. BACKGROUND: Obesity is associated with increased risk of breast cancer, but the impact of weight loss on breast cancer risk has been difficult to quantify. METHODS: The cohort included obese (body mass index ≥35âkg/m) patients enrolled in an integrated health care delivery system between 2005 and 2012 (with follow-up through 2014). Female bariatric surgery patients (N = 17,998) were matched on body mass index, age, study site, and comorbidity index to 53,889 women with no bariatric surgery. Kaplan-Meier curves and Cox proportional hazards models were used to examine incident breast cancer up to 10 years after bariatric surgery. Pre- and postmenopausal women were examined separately, and further classified by estrogen receptor (ER) status. RESULTS: The analysis included 301 premenopausal and 399 postmenopausal breast cancer cases. In multivariable adjusted models, bariatric surgery was associated with a reduced risk of both premenopausal (HR = 0.72, 95% CI, 0.54-0.94) and postmenopausal (HR = 0.55, 95% CI, 0.42-0.72) breast cancer. Among premenopausal women, the effect of bariatric surgery was more pronounced among ER-negative cases (HR = 0.36, 95% CI, 0.16-0.79). Among postmenopausal women, the effect was more pronounced in ER-positive cases (HR = 0.52, 95% CI, 0.39-0.70). CONCLUSIONS: Bariatric surgery was associated with a reduced risk of breast cancer among severely obese women. These findings have significant public health relevance because the prevalence of obesity continues to rise, and few modifiable breast cancer risk factors have been identified, especially for premenopausal women.