Breast Cancer in Bedouin-Arab Patients in Southern Israel: Epidemiologic and Biologic Features in Comparison with Jewish Patients

Background: Breast cancer (BC) is the most frequent cancer type, and the leading cause of death from cancer among women in Israel. The Bedouin-Arab (BA) population in southern Israel is characterized by a high rate of consanguinity, common hereditary disorders, and transition from a semi-nomadic, traditional society to a more sedentary and urbanized society. In this hospital-based study, the demographic and the clinicopathological characteristics of BC in BA were compared with Jewish patients. Materials and Methods: 85 BA patients treated at the Soroka Medical Center, Beer Sheba, during the years 2004-2012, were studied and compared with 180 consecutive Jewish patients treated during the year 2007. Clinicopathological features compared included age, menopausal state, number of births, a history of BC in first-degree relatives, tumor size (T), extent of lymph-node involvement (N), distant metastases (M), stage, grade, estrogen and progesterone receptor (ER/PR), and Her2 status. Types of treatment, relapse rate and site, as well as outcome were also studied. Cox's regression models were applied for studying disease-free, and overall survival. Results: Compared with Jewish patients, BA patients were younger (average age $49{\pm}12$ yrs vs $59{\pm}13$, p<0.001), had a lower rate of BC in first-degree relatives (p<0.001), and a larger number of births ($6{\pm}4.2$ vs $2.5{\pm}1.9$, p<0.001). BA patients had larger tumors (p=0.02), more extensive lymph-node involvement (p=0.002), and more advanced stage (p=0.003). Grade, ER, PR, and Her2 status were similar in the two ethnic groups. Relapse type was most commonly systemic in BA patients (p=0.05), and loco-regional in Jewish patients (p=0.02). Median survival was 63, and 35 months for Jewish and BA patients, respectively (log-rank test, p=0.02). In Cox multivariate analysis, stage and PR status (HR-0.14, p<0.0001; HR-3.11, p=0.046), but not ethnicity, influenced overall survival. Conclusions: BC presents a decade earlier, and with more advanced disease in BA compared with Jewish patients. Biologic parameters including grade, ER, PR, and Her2 status were similar in both groups. Although prognosis was worse in BA than in Jewish patients, it was affected only by stage and PR status, but not by ethnicity.