Epidemiology of transitional cell carcinoma among Israeli Arabs

Introduction and Objective: Environmental, nutritional and hereditary factors are known to influence the epidemiology and the course of transitional cell carcinoma of the bladder (TCCB) and hence attribute to major ethnic and national differences. The focus of this study was on the characteristics of TCCB among Israeli Arabs who form a particular ethnic group in the Israeli population and were treated in our medical centers. Methods: All the Arab patients who presented with TCCB between 1993-2003 to 3 medical centers (Meir, Kfar Saba Soroka, Beer Sheba and Hillel Yaffe, Hadera) were included in this study. Data was collected retrospectively, with special attention given to epidemiological parameters, risk factors, and treated history of TCCB among these patients. Results: Of 1638 patients who presented with TCCB between 1993 and 2004 at those 3 medical centers, 100 (6.1%) were Israeli Arabs. Male to female ratio among Arabs was 13.4:1 (93 males, 7 females). The prevalence of smoking was 91% and 14% among Arab men and women respectively. The mean age at presentation was 64 (22-93). Arab women were older than men at the time of presentation (mean age 75.7 and 63.1 respectively). Eighty-three percent of patients presented with superficial TCCB and 17% were diagnosed with invasive disease: 80% of patients who presented with superficial TCCB did not progress during the follow-up. In 15% of the patients with stage Ta TCCB progressed to stage T1, while 20% of the patients with superficial TCCB progressed to an invasive stage. The distribution of tumor grades at presentation was 21%, 47% and 32% for grades 1, 2 and 3 respectively. Conclusions: This study demonstrates some major differences in the epidemiology of TCCB among Israeli Arabs in comparison to the general Jewish population. The male to female ratio is significantly skewed towards male predominance. The mean age of the Arab men at presentation with TCCB is younger in comparison to Jewish men as well as to Arab women. The prevalence of smoking among Arab men who present with TCCB is especially high. On the other hand, the treated history and course of TCCB among Arabs seems to follow the known figures of TCCB. Environmental, life style, nutritional and hereditary factors characteristic to the Israeli Arab population may be associated with these ethnic epidemiological differences.