title: Physiological, reproductive factors and breast cancer risk in Jiangsu province of China.
abstract: 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.
authors.affiliation: Division of Epidemiology, Jiangsu Province Institute of Cancer Research, Nanjing, China.
authors.forename: Yan-Ting
authors.initials: YT
authors.lastname: Liu
authors.forename: Chang-Ming
authors.initials: CM
authors.lastname: Gao
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Ding
authors.forename: Su-Ping
authors.initials: SP
authors.lastname: Li
authors.forename: Hai-Xia
authors.initials: HX
authors.lastname: Cao
authors.forename: Jian-Zhong
authors.initials: JZ
authors.lastname: Wu
authors.forename: Jin-Hai
authors.initials: JH
authors.lastname: Tang
authors.forename: Yun
authors.initials: Y
authors.lastname: Qian
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima
mesh_terms: D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D001942:Breast Feeding; D001943:Breast Neoplasms / Q000209:etiology*; D016022:Case-Control Studies; D002681:China; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D010298:Parity; D011247:Pregnancy; D017584:Reproductive History; D012307:Risk Factors; D011795:Surveys and Questionnaires