Male breast cancer: immunohistochemical subtypes and clinical outcome characterization.
OBJECTIVE
The aim of this study was to assess the molecular subtype profiles of male breast cancer (MBC) and subsequent clinical outcome using a validated 6-marker immunohistochemical panel.


METHODS
A total of 43 cases of MBC were examined retrospectively using a semiquantitative immunohistochemical analysis of estrogen receptor (ER), progesterone receptor (PR), Ki-67, human epidermal growth factor receptor 2 (Her2), epidermal growth factor receptor and cytokeratin 5/6. Patients were classified into the following categories: luminal A, luminal B, Her2-positive or basal-like subtypes.


RESULTS
The median age of patients was 63 years (r: 32-89). The predominant histology was invasive ductal carcinoma (91%). Only 1 patient had advanced breast cancer at diagnosis. Ninety-three percent were ER-positive and 84% were PR-positive. Two patients had tumors that were ER- and PR-negative. The distribution of tumor molecular subtypes was 19 (44%) luminal A, 22 (51%) luminal B and 2 (5%) basal-like. The Her2-positive tumor subtype was not identified. The clinicopathological characteristics did not differ significantly between tumor subtypes A and B. There were no significant differences in 6-year disease-free survival (74 vs. 82%, p = 0.77) or overall survival (74 vs. 82%, p = 0.69) between luminal A and luminal B subtypes, respectively.


CONCLUSIONS
The most common subtypes in our cohort of MBC were luminal B followed by luminal A, and no differences were found between both tumor subtypes in terms of clinicopathologic characteristics and patient outcome.
Medical Oncology Service, Hospital Universitario Virgen de la Victoria, Málaga, Spain. asmoncomed@yahoo.es
Alfonso
A
Sánchez-Muñoz
Alicia
A
Román-Jobacho
Lidia
L
Pérez-Villa
Pedro
P
Sánchez-Rovira
José
J
Miramón
Diego
D
Pérez
Maria-Isabel
MI
Sáez
Vanesa
V
de Luque
Laura
L
Medina
César Luis
CL
Ramírez-Tortosa
Luis
L
Vicioso
José Antonio
JA
Medina
Nuria
N
Ribelles
Emilio
E
Alba
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D018567:Breast Neoplasms, Male / Q000145:classification* / Q000378:metabolism / Q000473:pathology; D002280:Basal Cell Carcinoma / Q000145:classification / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000145:classification / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000145:classification / Q000378:metabolism / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D012189:Retrospective Studies; D015996:Survival Rate
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone