Breast Cancer in Arab and Jewish Women in Northern Israel: A Retrospective Database Study

Background: In Israel, breast cancer prevalence is lower among Arab than Jewish women, but incidence is increasing among Arab women at a younger age. Objectives: To explore differences between Arab and Jewish women with breast cancer with respect to age at diagnosis, associated risk factors, and use of hormonal medications. Methods: We conducted a retrospective database study comparing Arab and Jewish women with breast cancer focusing on age at diagnosis, smoking history, obesity, and previous hormonal medication usage, including oral combined contraceptive pills (OCCP), progestogens, hormonal medications for treatment of infertility, and hormone replacement therapy (HRT). Results: The study included 2494 women who were diagnosed with breast cancer during 2004-2015. Age at diagnosis was lower among Arab women (50.7 +/- 13.1 years vs. 55.4 +/- 12.6 years, P < 0.0001). The rate of smoking was higher among Jewish women (16.0% vs. 4.3%, P< 0.0001). The rate of obesity was higher in Arab women older than 50 years at diagnosis (59.0% vs. 42.4%, P < 0.0001). Arab women demonstrated a lower overall chance of previous use of all types of hormonal medications (odds ratio [OR] 0.6, 95% confidence interval [95%CI] 0.6-0.8) compared to Jewish women. Arab women were more likely to have used progestogens (OR 1.7, 95%CI 1.4-2.2) and medications for treatment of infertility (OR 2.3, 95%CI 1.5-3.4) and less likely OCCP (OR 0.4, 95%CI 0.3-0.6) and HRT (OR 0.4, 95%CI 0.3-0.5). Conclusions: Previous use of hormonal medications may contribute to incidence of breast cancer in Arab women.