Purpose: The purpose of this retrospective study was to investigate whether Stage IIIC (TanyN3M0) breast cancer can be classified further into subgroups with different prognosis.
Materials and methods: One hundred and thirty-two patients with Stage IIIC breast cancer at Tianjin Medical University Cancer Institute and Hospital were analyzed. The disease-free survival (DFS) and overall survival (OS) were calculated by Kaplan-Meier method for lymph node ratio (LNR) and the number of positive lymph node (PLN). The receiver operating characteristic curve analysis was performed to determine the optimal cut-off value of the LNR and PLN. The univariate and multivariate analysis were applied to identify the prognostic factors.
Results: The results showed that the optimal cut-off value of LNR value was 0.65, and the optimal cut-off value of PLN was 15. The Kaplan-Meier survival analysis showed the higher value of LNR or PLN was correlated with shortened DFS (P = 0.002, P = 0.008, respectively) and OS (P < 0.001, P = 0.001, respectively). In multivariate survival analysis, the value of LNR and PLN were still remained as independent prognostic factors for DFS (P = 0.014, P = 0.013, respectively) and OS (P = 0.004, P = 0.002, respectively).
Conclusion: These results suggest that the value of LNR or PLN could be used as a new significant prognostic biomarker for Stage IIIC breast cancer patients. Stage IIIC breast cancer patients with lower value of LNR or PLN may be down staged.