Analysis of menstrual, reproductive, and life-style factors for breast cancer risk in Turkish women - A case-control study

ORAN B., Celik I., Erman M., BALTALI E., ZENGİN N., Demirkazik F., ...More

MEDICAL ONCOLOGY, vol.21, no.1, pp.31-39, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 21 Issue: 1
  • Publication Date: 2004
  • Doi Number: 10.1385/mo:21:1:31
  • Journal Name: MEDICAL ONCOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.31-39
  • Hacettepe University Affiliated: Yes


The aim of this study was to investigate the association between menstrual, reproductive, and life-style factors and breast cancer in Turkish women. In a hospital-based case-control study in Ankara, 622 patients with histologically confirmed breast cancer were compared with 622 age-matched controls, admitted to the same hospital for acute and non-neoplastic diseases. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) related to risk factors. Overall, menopausal status and age at menopause were found to be significantly associated with breast cancer. Having a full-term pregnancy and early age at first birth were associated with decreased breast cancer risk (OR = 0.45, 95% CI = 0.30-0.66; OR = 0.34, 95% CI = 0.22-0.53, respectively). Postmenopausal women with lactation longer than 48 mo had reduced risk of breast cancer (OR = 0.36, 95% CI = 0.14-0.93). In conclusion, decreased parity, late age at first birth, early menopause, and shorter duration of lactation were the most important determinants of breast cancer risk in Turkish women.