Background
Breast cancer is the first cancer among females in the Kingdom of Saudi Arabia, accounting for 27.4% of all newly diagnosed female cancers in 2010. There are several risk factors affecting the incidence of breast cancer where some factors influence the risk more than the others.

Aim
We aimed to identify the different risk factors related to breast cancer among females participating in the breast-screening program in Riyadh, KSA.

Methods
Based on data from phase-I of the breast-screening program, a case–control study was conducted on women living in Riyadh, KSA. A sample of 349 women (58 cases and 290 controls) was recruited to examine the different breast cancer correlates. Multivariate regression model was built to investigate the most important risk factors.

Results
The mean age of cases was 48.5 ± 7.1 years. Age at marriage, number of pregnancy, age at menopause, oral contraceptive pills, breast feeding and family history of breast cancer in first-degree relative were identified as the most important correlates among the studied cohort.

Conclusions
The findings of the current work suggested that age at marriage, age at menopause ⩾50 years and 1st degree family history of breast cancer were risk factors for breast cancer, while, age at menopause <50 years, number of pregnancies and practicing breast feeding were protective factors against breast cancer. There was no effect of body mass index or physical inactivity. Further studies are needed to explore the hereditary, familial and genetic background risk factors in Saudi population.

Abbreviations
BC, breast cancer; ACS, American Cancer Society; ASR, age specific ratio; NCCN, national comprehensive cancer network; HRT, hormone replacement therapy; NCI, National Cancer Institute; BMI, body mass index