Ethnic disparities in colorectal cancer outcomes: a population study from Israel

Objectives: Colorectal cancer (CRC) is an important cause of morbidity and mortality worldwide. Clear ethnic disparities in the incidence of CRC and its outcomes have been observed globally, but only few research efforts have been invested so far in the unique ethnic scene of Israeli population. This study aims to compare the clinico-pathologic features, tumor's characteristics and prognosis between Arab and Jewish CRC patients as well as among Jewish subgroups living within the same central coastal region in Israel.Methods: In this retrospective, single center study, a total of 401 patients with pathologically confirmed CRCs diagnosed during the years 2008-2015 were included. These were divided into Jewish (n = 334) and Arab (n = 67) groups. Data collected included demographics, country of birth, clinical presentation and family history. Tumor stage, location, histologic grade and mortality rate were compared retrospectively between both groups and within Jewish sub-populations.Results: Arabs were significantly younger at diagnosis (62.7 ± 12.9 vs. 69.3 ± 13.01; P < 0.01), presented more frequently with rectal bleeding, and were less likely to be diagnosed due to positive fecal occult blood test (9% vs. 22.6%; P = 0.012). Tumor distribution through the colon was comparable between both groups and characterized by a distal predominance. Arabs had a significantly higher rate of advanced stage at diagnosis (58% vs. 50.5%, OR = 2.454, 95%CI = 1.201-5.013; P = 0.02) when compared to Jews. Mortality rates were comparable between both groups. In the Jewish subpopulation analysis, we found that immigrants, especially those born in the former USSR, presented with significantly advanced tumor stages when compared to native Israelis (55% vs. 37.5%; P = 0.02).Conclusion: CRC in two major ethnic populations in Israel, Arabs and Jews, varied in terms of age at diagnosis, clinical presentation and stage at diagnosis. Similar findings were documented within a non-native Jewish subpopulation, raising the possibility of a low utilization of screening programs in these groups.