Immunohistochemistry subtypes (ER/PR/HER) of breast cancer: where do we stand in the West of Saudi Arabia?

In Saudi Arabia, cancer of breast is ranked the most frequent neoplasm and second source of cancer death in the female population. Breast cancer (BC) fast diagnosis, prognosis and medication management necessitate, these days, immunohistochemistry (IHC) assessment of hormone receptors and HER2 expression profile. The present report defines the IHC profile of ER, PR and HER2 in Saudi female breast neoplasms of ductal and lobular types and associations ER, PR and HER2 expression patterns with various clinicopathological factors (age, type of tumor, size, laterality, histological grade, and involvement of axillaries lymph nodes). Ninety nine cases of breast tumors were recruited from the pathology department archive of King Abdulaziz University Hospital, Kingdom of Saudi Arabia. ER, PR and HER2 expression was assessed using IHC staining. Ductal carcinomas with a variety of histological grades constituted 88 (88.8%) of total cases. Seventy four (77.8%), 59 (62.1%), and 35 (36.8%) of ductal carcinomas showed positive staining for ER, PR and HER2, in that order. Remaining breast cancer cases were four (4%) lobular carcinomas and two (2%) mixed form of ductal and lobular types, which were ER+, PR+, and HER2-. Breast cancer expression pattern of ER, PR and HER2 in Saudi female is different from that of Tunisian and Jordanian female populations and closer to the expression pattern of Egyptian, Lebanese, Iraqi and western country females. Furthermore, the present study found two IHC patterns of breast cancer ER+/PR-/HER2+ (5%) and ER+/PR-/HER2- (11.1%), which had not been reported in other Arabic studies. Thus the rates of IHC expression patterns in breast cancer show some variation among Arabic female populations.