Physiological, reproductive factors and breast cancer risk in Jiangsu province of China
Liu, Y.-T.; Gao, C.-M.; Ding, J.-H.; Li, S.-P.; Cao, H.-X.; Wu, J.-Z.; Tang, J.-H.; Qian, Y.; Tajima, K.
Asian Pacific Journal of Cancer Prevention Apjcp 12(3): 787-790
2011
ISSN/ISBN: 2476-762X PMID: 21627384 Document Number: 551863
To evaluate the relationship between physiological, reproductive factors and risk of breast cancer, we conducted a case-control study with 669 cases and 682 population-based controls in Jiangsu Province of China. A structured questionnaire was used to elicit detailed information. All subjects completed an in-person interview. Unconditional logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs) as measures of risk for breast cancer. The results have revealed that there was an increasing risk of breast cancer, include early age at menarche(≤ 13 year), late age at menopause(< 50 year) and older age at first pregnancy (≤ 30 year). Breastfeeding was associated significantly with a reduced risk of breast cancer. Women who had history of breastfeeding were at significantly decreased OR (0.44, 95%CI: 0.27-0.73). The protective effects of breastfeeding for breast cancer seemed greater for women who had extended duration of breastfeeding during their lifetime (p for linear trend: 0.0095). These results suggested that physiological and reproductive factors may play important roles in the development of breast cancer among Jiangsu' women of China.