RESUMEN
Background and Objectives: Multifocal/multicentric (MF/MC) breast carcinomas are not uncommon and its prognostic significance debated. We attempted to analyze the association of focality and prognostic factors in operated pT1 and pT2 breast carcinomas of no special type (NST). Materials and Methods: Retrospectively identified pathologically proven 124 unifocal (UF) and 49 MF/MC pT1 and pT2 breast carcinomas of NST over the past three years were compared in terms of clinical and pathological factors. Results: The patients with MF/MC NST tumors were more likely to undergo radical surgery (P = 0.028). The tumors showed higher incidence of lymphovascular invasion (P = 0.024), perineural invasion (P = 0.046), ductal carcinoma in situ component (P < 0.001), higher number of positive axillary lymph nodes (P < 0.001), and higher anatomical staging (P = 0.048) when compared to the UF counterparts. Morphological intertumoral heterogeneity was noted in MF/MC tumors in 16 of 49 cases (32.65%). Conclusion: Most published studies on MF breast cancers have included all histological types and varying definitions. We included only pathologically defined stages and a single histological type to ensure “purity” of the groups. Higher anatomic staging and morphological interlesional heterogeneity suggest that early MF/MC tumors represent multiple primaries with a different biology. Careful consideration of features of each focus needs to be considered when deciding appropriate adjuvant therapy and for accurately prognosticating these patients. Immunohistochemical and morphological (grade) heterogeneity between the different foci may pose problems with “prognostic stage grouping” these tumors according to the American Joint Committee on Cancer staging system (8th edition).