Abstract

Objective: We aimed to explore different features of rarely seen breast cancer (BC) subtypes, including their stage, molecular subtypes, treatment choices, and prognosis. Material and Methods: We retrospectively screened patients who were diagnosed with BC in our hospital between July 2010 and June 2018. A total of 97 patients who had micropapillary, cribriform, mucinous, papillary, tubular, apocrine, metaplastic, medullary, and myoepithelial subtypes of BC were finally included in the current study.Results: Ninety-four (96.9%) patients were females. Patients with cribriform and mucinous subtypes were in the younger median age of 41 and 45 years, respectively, whereas papillary cases were reported in the oldest median age (64.5 years). Lymph node and TNM stages showed a statistical difference between the subtypes (p=0.029 and p=0.008, respectively). Most of the cribriform (60%), metaplastic (66.7%), and papillary (70%) cases were diagnosed without lymph node involvement. Apocrine (79%) and micropapillary (75%) tumors mostly presented with nodal involvement. While medullary (75%), tubular (66.7%), and cribriform (66.7%) carcinomas were more likely to be diagnosed at stage II, micropapillary (70.8%), and apocrine (62.5%) carcinomas were mostly diagnosed at stage III. Mucinous, tubular, and cribriform tumors were noticed in the luminal group. Medullary, metaplastic, apocrine, and papillary tumors included triple-negative subgroups. HER2-enriched tumors included apocrine (62.5%), medullary (50%), and micropapillary (25%) subtypes. Disease-free survival and overall survival of the patients showed marginal statistical significance according to tumor subtypes (p=0.086, p=0.085, respectively). Conclusion: In this study, we investigated important features, clinical behavior, management, and outcomes of several rare BC subtypes. We opine that the current study may prove instrumental and informative for both daily clinical practice and future studies.