Abstract
Significant morphological, clinical and biological prognostic factors vary according to molecular subtypes of breast tumors, yet comprehensive analysis of such factors linked to survival in each group is lacking. Clinicopathological and micro-environmental criteria, estrogen (ER), progesterone (PR) receptors, HER2, Ki67, basal markers, CD24, CD44, ALDH1, BCL2, E-Cadherin and Trio were assessed in 1070 primary operable breast cancers from a single center according to five main molecular subtypes and associations with distant metastasis-free survival (DMFS) were examined. There were 682 (64 %) luminal A (LA), 166 (16 %) Luminal B HER2 negative (LBH-), 47 (4 %) Luminal B HER2 positive (LBH+), 108 (10 %) triple negative (TN) and 67 (6 %) HER2-enriched tumors (H2+). Median follow-up was 13.7 years. At 5 years, DMFS in LA (90 %) was better than in LBH- (80.9 %), hazard ratio (HR) = 2.22 [1.44-3.43] P < 0.001; LBH+ (74.5 %), HR = 3.14 [1.69-5.84] P < 0.001, TN (71.5 %) HR = 3.63 [2.34-5.63], P < 0.001; and H2+ (65.2 %), HR = 4.69 [2.90-7.59], P < 0.001. In multivariable analysis, factors associated with shorter DMFS varied according to molecular subtype, with tumor size being associated with shorter DMFS in the LBH-, LBH+ and TN groups and the Rho GEF Trio and BCL2 phenotypes in TN tumors only. These findings help to define new clinicophenotypic models and to identify new therapeutic strategies in the specific molecular subgroups.