Risk factors for breast carcinoma in Singaporean Chinese women

Abstract

METHODS.A forward stepwise logistic regression model adjusted for confounding variables of age, age at menarche, menopausal status, parity, age at first and last Breast Service, Singapore Cancer Center and delivery, use of oral contraceptives, hormone replacement therapy, family history Department of Surgery, Singapore General Hosof breast carcinoma, history of benign breast biopsy, smoking history, height, pital, Singapore, Republic of Singapore.weight, body mass index, and waist to hip ratio was used. RESULTS. Central obesity as indicated by women with a larger waist to hip ratiowas associated with highest risk for breast carcinoma (odds ratio [OR]: 9.18; 95% confidence interval [CI],4.8-17.5 comparing last and first quintile; P õ 0.0001, chisquare test for trend). Significant trends were also noted for increasing height and breast carcinoma risk (P Å 0.003, chi-square test). Women who were taller than 159 cm (OR: 2.3; 95% CI, 1.4-3.9) had approximately twice the risk of women shorter than 150 cm. Body mass index as a measure of generalized obesity did not significantly predict risk for breast carcinoma. Reproductive and menstrual factors significantly related to risk for breast carcinoma were number of deliveries (OR: 0.81; 95% CI, 0.7-0.9; P õ 0.001), age at last delivery (P Å 0.03), and use of hormone replacement therapy (OR: 0.54; 95% CI, 0.3-0.9; P Å 0.01). Previous breast biopsy for benign disease was also associated with a higher risk for breast carcinoma (OR:3.5; 95% CI, 2.1-5.7; P õ 0.001). CONCLUSIONS.The authors conclude that the risk of breast carcinoma is strongly associated with changes in lifestyle related to caloric intake (central obesity and height) and reproductive or menstrual factors (number of deliveries, age at last delivery, age at menopause, and breast feeding). Better and excess nutrition in early and later years of life and fewer births (related to rapid urbanization) may Supported by grants from the National Medical explain in part the increasing incidence of breast carcinoma occurring in SingaResearch Council, Singapore Totalisator Board, pore.

Anthropometric measures, plasma adiponectin, and breast cancer risk

“…Data from the present study confirm previous findings that the relationship between anthropometric measures of adiposity and breast cancer risk was modified by menopausal status, with higher BMI, waist circumference, and WHR associated with increased risk for postmenopausal women (Ng et al 1997, Huang et al 1999, Shu et al 2001, Morimoto et al 2002, Harvie et al 2003, Lahmann et al 2004, Modugno et al 2006, Rinaldi et al 2006. The possible biological mechanism underlying excess adiposity and postmenopausal breast cancer risk is that increased adiposity tends to be associated with higher circulating levels of estrogens through greater peripheral conversion of androgens to estrogens by aromatase in adipose tissue among postmenopausal obese women (Silteri 1987, Potischman et al 1996.…”

Anthropometric measures, endogenous sex steroids and breast cancer risk in postmenopausal women: A study within the EPIC cohort

“…This could be due to the fact that BMI does not allow for variations in the lean-to-fat mass proportion in the body, while especially waist circumference correlates with the amount of abdominal (visceral and subcutaneous) fat [26][27][28] --the adipose tissue component most strongly associated with insulin resistance, hyperinsulinemia and lower SHBG. On the other hand, in the current study, as in some, 29,30 but not all, 31 previous prospective studies, no association with breast cancer risk was found for WHR, an index of the relative accumulation of abdominal compared to gluteal fat. In our study, waist and hip circumferences were both highly related to risk, and also highly correlated to each other, so that calculating the ratio between the 2 measures could have attenuated the associations with cancer risk.…”

Risk factors for breast cancer for women in Punjab, Pakistan:Results from a case-control study

“…Late age at first FTP is an independent risk factor for 'postmenopausal women' and a moderate risk factor of breast cancer for premenopausal women that is consistent with the findings from other studies (Helmrich et al, 1983;Ng et al, 1997;Tung et al, 1999;Sasaki et al 1995). A history of early menarche (below age 13) was surprisingly observed to be protective for all women but the protection from early menarche was not observed to be statistically significant in the separate analysis of premenopausal and postmenopausal women in this study.…”