Basal-Like Breast Cancer; Clinicopathological, Molecular, and Prognostic Features

Background: Molecular classification of breast tumors has identified the basallikesubtype, with high heterogeneity and very poor prognosis. These tumors aremainly triple negative, characterized by the expression of basal markers CK۵/۶and EGFR. In this study, we sought to investigate the features, outcome, andtherapeutic modalities of basal-like breast cancers (BLBC). Methods: We retrospectively identified ۹۰ BLBC patients diagnosed at theDepartment of Surgical Oncology of Salah Azaiez Institute between January ۲۰۰۹and December ۲۰۱۳. Results: The mean age of our patients was ۵۰ years, and ۱۵.۵% had a familyhistory of breast cancer. The mean tumor size was ۴۳.۸ mm. Histologicalexamination revealed invasive ductal carcinoma in ۸۸.۹% of the cases, metaplasticcarcinoma in ۵.۶%, and medullary carcinoma and adenoid cystic carcinoma in۲.۲%. BLBC was most often associated with a high tumor grade (۵۵.۳% had agrade ۳ tumor) and a high Ki-۶۷ proliferative index. Vascular invasion was foundin ۳۱.۱% of the cases. Regarding lymph node involvement, ۴۲.۹% had positivelymph nodes and ۷.۹% featured distant metastases. Surgical treatment wasprovided for ۸۵ patients. It consisted of conservative surgery in ۴۰ cases andradical surgery in ۴۵ cases. Neoadjuvant chemotherapy was administrated to ۲۳patients, with a ۱۳% complete pathologic response. The rates of overall survivaland disease-free survival at ۳ years for localized BLBC were ۷۴.۴% and ۷۵.۹%,respectively.Conclusion: BLBCs are aggressive tumors associated with poor prognosis.Thus, to identify novel prognostic factors and therapeutic targets, prospectivestudies should investigate the epidemiological and evolutive profile of thesetumors.

Keywords:

Basal-like carcinoma , immunohistochemistry , prognosis