Predictors of survival in triple-negative breast cancer patients treated with neoadjuvant chemotherapy, surgery, and radiotherapy

Abstract

Background Triple-negative breast cancer (TNBC) is known for its heterogeneity. Due to the small sample sizes in prior studies, there is limited understanding of whether different molecular subtypes have distinct predictive values following comprehensive treatment. Methods Females with TNBC treated with neoadjuvant chemotherapy (NAC), surgery, and radiotherapy from 2019 to 2022 were retrospectively analyzed. Disease-free survival (DFS) and overall survival (OS) were evaluated using the Kaplan-Meier method to compare the basal-like immune-suppressed (BLIS) and non-BLIS subtypes. Univariate and multivariate Cox analyses were employed to identify prognostic factors for DFS. Results The median follow-up time was 34 months. The 4-year DFS rates for non-BLIS and BLIS subtypes were 74.8% and 56.1%, respectively (P = .035). Independent predictors of DFS included molecular subtype (HR = 2.071, P = .034) and ypN status (HR for ypN1-2 = 4.891, P = .018; ypN3 = 7.444, P = .008). Additionally, both nodal stage and lymph node ratio categories (LNRC) were negatively correlated with DFS in both subgroups (P <.001 for both). Moreover, in the BLIS group, there was a statistically significant difference between low and high LNR (P < 0.05), while in the non-BLIS group, DFS differed significantly across subgroups with low, intermediate, or high LNRC (P < 0.05). Conclusions Molecular subtyping plays a crucial role in prognosis, with the non-BLIS subtype showing more favorable outcomes. The presence of residual nodal disease post-NAC helps distinguish between favorable and unfavorable outcomes in different TNBC subtypes. These findings underscore the importance of developing more individualized radiotherapy strategies following NAC for each molecular subtype.