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Etiologic differences between subtypes of breast cancer defined by estrogen receptor (ER) and progesterone receptor (PR) status are not well understood. The authors evaluated associations of hormone-related factors with breast cancer subtypes in a population-based case-control study involving 1,409 ER-positive (ER+)/PR-positive (PR+) cases, 712 ER-negative (ER-)/PR-negative (PR-) cases, 301 ER+/PR- cases, 254 ER-/PR+ cases, and 3,474 controls aged 20-70 years in Shanghai, China (phase I, 1996-1998; phase II, 2002-2005). Polytomous logistic regression and Wald tests for heterogeneity across subtypes were conducted. Breast cancer risks associated with age at menarche, age at menopause, breastfeeding, age at first livebirth, waist-to-hip ratio, and oral contraceptive use did not differ by hormone receptor status. Among postmenopausal women, higher parity (≥2 children vs. 1) was associated with reduced risk (odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.52, 0.91) and higher body mass index (BMI; weight (kg)/height (m)(2)) with increased risk (highest quartile: OR = 2.40, 95% CI: 1.65, 3.47) of the ER+/PR+ subtype but was unrelated to the ER-/PR- subtype (for parity, P(heterogeneity) = 0.02; for BMI, P(heterogeneity) < 0.01). Hormone replacement therapy (OR = 2.25, 95% CI: 1.40, 3.62) and alcohol consumption (OR = 1.59, 95% CI: 1.01, 2.51) appeared to be preferentially associated with the ER+/PR- subtype. These findings indicate that BMI, parity, hormone replacement therapy, and alcohol consumption may play different roles in subtypes of breast cancer. More research is needed to better understand the etiology of 2 relatively rare subtypes, ER+/PR- tumors and ER-/PR+ tumors.

Certain polyphenols inhibit the activity of aromatase, a critical enzyme in estrogen synthesis that is coded by the CYP19A1 gene. Consumption of polyphenol-rich foods and beverages, thus, may interact with CYP19A1 genetic polymorphisms in the development of endometrial cancer. The authors tested this hypothesis in the Shanghai Endometrial Cancer Study (1997-2003), a population-based case-control study of 1,204 endometrial cancer cases and 1,212 controls. Dietary information was obtained by use of a validated food frequency questionnaire. Genotypes of CYP19A1 at rs28566535, rs1065779, rs752760, rs700519, and rs1870050 were available for 1,042 cases and 1,035 controls. Unconditional logistic regression models were used to calculate odds ratios and their 95% confidence intervals after adjustment for potential confounding factors. Higher intake of soy foods and tea consumption were both inversely associated with the risk of endometrial cancer, with odds ratios of 0.8 (95% confidence interval: 0.6, 1.0) for the highest versus the lowest tertiles of intake of soy and 0.8 (95% confidence interval: 06, 0.9) for ever tea consumption. The association of single nucleotide polymorphisms rs1065779, rs752760, and rs1870050 with endometrial cancer was modified by tea consumption (p(interaction) < 0.05) but not by soy isoflavone intake. The authors' findings suggest that tea polyphenols may modify the effect of CYP19A1 genetic polymorphisms on the development of endometrial cancer.

Background: Adult obesity is a well-established risk factor for endometrial cancer. However, little is known about the association of endometrial cancer risk with body size early in life and weight change during adulthood. We investigated whether women with greater early-age body size or with greater weight change during adulthood have an increased risk of endometrial cancer., Methods: We analysed data from a population-based case-control study of endometrial cancer conducted between 1997 and 2001 in Shanghai, China. Included in this analysis were 832 endometrial cancer cases aged 30-69 years and 846 population controls. Information on weight and height history from adolescence through adulthood was obtained via structured in-person interviews. A logistic regression model was used to derive odds ratios (ORs) and 95% confidence intervals (CIs) for endometrial cancer in association with adolescent and adult adiposity, as well as adult body weight change. All ORs were adjusted for age, education, menstrual status, duration of menstruation, number of pregnancies, oral contraceptive use, and family history of cancer., Results: Perceived weights and heights during puberty that were greater than average were associated with a modestly increased risk of cancer. The association for perceived weight was substantially weakened after adjustment for current body mass index (BMI). High BMI at all adult ages significantly predicted endometrial cancer risk, with recent BMI being the strongest predictor. Further analyses disclosed that weight gain during adulthood, particularly during the peri-menopausal period (age 40-50 years), was associated with a significantly elevated risk of endometrial cancer, even among currently non-obese women. Gaining >5 kg between age 40 and 50 was related to ORs of 2.3 (95% CI 1.4-3.9) for women with a BMI<25 kg/m2 and 2.0 (95% CI 1.3-3.0) for women with BMI>or=25 kg/m2., Conclusions: Adult weight gain, particularly during the peri-menopausal period, plays a significant role in the development of endometrial cancer risk.

The authors investigated the association between overweight at the time of or soon after cancer diagnosis and survival in a cohort of 1,455 breast cancer patients aged 25-64 years. The patients were recruited into the Shanghai Breast Cancer Study (Shanghai, China), a population-based case-control study, between August 1996 and March 1998. The median follow-up time for this cohort was 5.1 years (1996-2002) after breast cancer diagnosis, and 240 deaths were identified. Being overweight at cancer diagnosis or soon afterward, as measured by body mass index (BMI; weight (kg)/height (m)(2)), was associated with poorer overall survival and disease-free survival. Five-year survival rates were 86.5%, 83.8%, and 80.1% for subjects whose BMIs were <23.0, 23.0-24.9, and >or=25.0, respectively (p = 0.02); the corresponding 5-year disease-free survival rates were 81.9%, 78.1%, and 76.6% (p = 0.05). The inverse association between BMI and survival persisted after adjustment for age at diagnosis and other known prognostic factors for breast cancer, including disease stage. The authors found neither waist:hip ratio nor waist circumference to be independently associated with overall survival or disease-free survival. These results suggest that excess weight may be an independent predictor of breast cancer survival among Chinese women.

The authors conducted a population-based case-control study of 832 endometrial cancer cases and 846 frequency-matched controls in Shanghai, China (1997-2001), to examine the association of overall adiposity and body fat distribution with disease risk. Overall adiposity was estimated using weight and body mass index (BMI); upper body fat distribution was evaluated using waist circumference and waist:hip ratio. Overall and upper-body obesity were both associated with an elevated risk of endometrial cancer. Adjusted odds ratios and 95% confidence intervals for highest-versus-lowest quartile comparisons were 2.6 (95% confidence interval (CI): 2.0, 3.5) for weight, 2.9 (95% CI: 2.2, 3.9) for BMI, 4.7 (95% CI: 3.4, 6.4) for waist circumference, and 3.5 (95% CI: 2.6, 4.8) for waist:hip ratio. The positive associations with weight and BMI vanished after results were controlled for waist circumference, while associations with waist circumference and waist:hip ratio persisted after adjustment for BMI. The positive association with upper-body obesity was more pronounced among younger women, women who had never used oral contraceptives, and women with a history of diabetes mellitus (p for multiplicative interaction < 0.05). Upper-body obesity was related to increased risk among women with low BMI. These results suggest that obesity, particularly upper-body fat deposition, is associated with an increased risk of endometrial cancer.