Prognostic significance of a combined clinicopathologic score for response to primary systemic therapy in locally advanced breast cancer.

The response to chemotherapy is one of the best indicators of prognosis in locally advanced breast cancer (LABC). The pathologic response (pR) of 108 LABC patients was analysed and compared with their clinical response (cR). Our aim was to define a new combined clinicopathologic response score (cpR) and to explore its correlation with survival data. The 108 stage IIB to IIIB breast carcinomas were first treated with high-dose anthracycline-based chemotherapy. Standard criteria were used to assess cR. Pathologic analysis of surgical specimens allowed the definition of 5 types of pR. Three groups of combined clinicopathologic response were defined. Twenty-two patients (20%) had complete or almost complete pR. Most patients (88, 81%) had partial cR. This large group of partial cR was very heterogeneous, ranging from pR1 to pR5 and from cpR1 to cpR3. In univariate analysis, pR and cpR both strongly correlated with EFS. cR, pR and cpR all correlated with OS. Subgroups of incomplete pathologic responses were not prognostically different. In multivariate analysis, only cpR correlated strongly with both EFS and OS (p<0.002), identifying good (20%), intermediate (61%) and poor (19%) prognosis patients. In conclusion, in 108 stage IIB to IIIB breast cancer patients initially treated by high-dose chemotherapy, combined grading of clinical and pathologic responses in a single score allowed accurate prediction of outcome.