Canchola A.J.,Cancer Prevention Institute of California Formerly the Northern California Cancer Center |
Chang E.T.,Cancer Prevention Institute of California Formerly the Northern California Cancer Center |
Chang E.T.,Stanford University |
Bernstein L.,City of Hope National Medical Center |
And 8 more authors.
Cancer Causes and Control | Year: 2010
Objective: To investigate whether hormone therapy (HT) and obesity are associated with endometrial cancer risk among postmenopausal women in the California Teachers Study cohort. Methods: Of 28,418 postmenopausal women, 395 developed type 1 endometrial cancer between 1995 and 2006. Multivariate Cox regression was performed to estimate relative risks (RR), stratified by HT use (never used, ever estrogen alone (ET) or exclusively estrogen-plus-progestin (EPT)). Results: Among women who never used HT, overall and abdominal adiposity were associated with increased risk; when evaluated simultaneously, abdominal adiposity was more strongly associated (RR 2.2, 95% confidence interval (CI): 1.1-4.5 for waist ≥35 vs. <35 inches). Among women who ever used ET, risk was increased in women with BMI ≥ 25 kg/m2 (RR 1.6, 95% CI: 1.1-2.3 vs. <25 kg/m2). Neither overall nor abdominal obesity was associated with risk in women who exclusively used EPT (p-interaction <0.001 for BMI by HT use). Conclusions: Among women who never used HT, risk was strongly positively related to obesity and may have been influenced more by abdominal than by overall adiposity; however, due to small numbers, this latter finding requires replication. Among women who ever used ET, being overweight at baseline predicted higher risk, whereas use of EPT mitigated any effects of obesity. © 2010 Springer Science+Business Media B.V.
Wu H.-C.,Environmental Health science |
John E.M.,Cancer Prevention Institute of California formerly the Northern California Cancer Center |
John E.M.,Stanford University |
Keegan T.H.,Cancer Prevention Institute of California formerly the Northern California Cancer Center |
And 5 more authors.
Epigenetics | Year: 2011
Lower levels of global DNA methylation in white blood cell (WBC) DNA have been associated with adult cancers. It is unknown whether individuals with a family history of cancer also have lower levels of global DNA methylation early in life. We examined global DNA methylation in WBC (measured in three repetitive elements, LINE1, Sat2 and Alu, by MethyLight and in LINE1 by pyrosequencing) in 51 girls aged 6-17 years. Compared to girls without a family history of breast cancer, methylation levels were lower for all assays in girls with a family history of breast cancer and statistically significantly lower for Alu and LINE1 pyrosequencing. After adjusting for age, body mass index (BMI) and Tanner stage, only methylation in Alu was associated with family history of breast cancer. If these findings are replicated in larger studies, they suggest that lower levels of global WBC DNA methylation observed later in life in adults with cancer may also be present early in life in children with a family history of cancer.