Reproductive Factors and Risk of Breast Cancer: A Jordanian Case Control Study.

Aims: This study aims to identify reproductive factors associated with risk of breast cancer among Jordanian women. Study Design: A case-control study design was used. Place and Duration of Study: Data was collected between February and October 2016 from three large hospitals where cancer patients are treated in Jordan. Methodology: The sample comprised two groups: cases (418 women with breast cancer) and controls (405 women without any type of cancer). In the former, only breast cancer patients who met the following criteria were included: 18 years and older, with a confirmed breast cancer diagnosis as evident from the histopathology report, newly diagnosed, knowing their cancer diagnosis and agreeing to take part in the study. The control group was of women who had no cancer and lived in the same geographical area as the case group. After ethical approval, information about participants? demographic characteristics, parturition, breast feeding and its duration, the use of oral contraceptives and duration of use, the use of HRT, being menopausal or not, age at marriage and at first birth, age at menarche, and the number of children were collected. Results: The mean age of women in the case group was 49.2 years (SD 10.3), and in the control group 45.9 (SD 10.9). The majority of women were married in the groups (case: 90.1%; control: 93.5%). Increased age of marriage (OR 1.102, 95% CI 1.04-1.168), increased age at first birth (OR 1.062, 95% CI 1.013-1.113), the use of HRT (OR 0.396, 95% CI 0.184-0.853) and being menopausal (OR 0.622, 95% CI 0.432-0.896) were found to increase the risk of developing breast cancer among Jordanian women. Conclusion: The findings of the study demonstrate that several reproductive factors increase the likelihood of developing breast cancer among Jordanian women. Some discrepancies between the results of the current study and previous studies were highlighted, which might be the results of differences in culture, behaviour and habits.