Differences in breast carcinoma immunohistochemical subtypes between immigrant Arab and European women

BACKGROUND There is a dearth of information on the clinicopathological differences, including the molecular subtypes, of breast carcinomas from immigrant Arab women in Europe. Therefore, the aim of our study was to examine and compare these features in immigrant Arab/Moroccan patients with those of European women. METHODS Included in this study were 441 cases of breast cancer: 91 Arab/Moroccan women and 350 European women. Age, size, grade, node involvement, and immunohistochemical profile (classification into the following subtypes: luminal A, luminal B, HER2 +/ER -, and triple negative) were analyzed. RESULTS The average age of breast cancer presentation in Arab women is almost a decade earlier than in European women (49 versus 60 years old; p = 0.00001). Arab patients also had a higher average tumor size (25 mm versus 19 mm; p =0,008) and more grade 3 and less grade 1 tumors (p = 0.02). It should be noted, however, that this variability in the size and grade do not appear statistically significant when compared in Arab and European patients under 50 years old. In contrast, independent of age, the immunohistochemical subtypes were different between the two populations, with a greater number of luminal B subtype and fewer luminal A subtype (p <0.02) in Arab patients. CONCLUSIONS Arab patients with breast carcinoma have different clinicopathological features from European patients, mainly the age of cancer presentation. Their immunohistochemical profile is also different, with more luminal B and less luminal A subtypes, suggesting that there are not only clinicopathological differences but also disparities in the expression profiling in these women. VIRTUAL SLIDE The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2104813621113288.