Metastatic axillary node ratio predicts recurrence and poor long-term prognosis in patients with advanced stage IIIC (pN3) breast cancer

PURPOSE Patients with stage IIIC breast cancer are classified as having pathologic nodal stage 3 (pN3) according to the 7th American Joint Committee on Cancer Tumor Node Metastasis (AJCC TNM) staging system. However, the prognosis of patients with this stage is still highly variable. This study was carried out to investigate the validity of metastatic axillary lymph node ratio (mALNR) as a predictor of long-term prognosis in stage IIIC breast cancer. METHODS Medical records of 297 patients who underwent surgery with more than level II axillary dissection for breast cancer and who were diagnosed with pN3 by pathology between 1990 and 2010, were reviewed. Clinicopathologic variables were evaluated as prognostic factors of disease-free and overall survival by univariate and multivariate analyses. RESULTS A preliminary analysis revealed the cutoff value of mALNR to be 0.65 (Low65 group vs. High65 group). The mean mALNR was 0.62 (0.16-1.0) and was the most significant independent predictor of disease-free and overall survival on multivariate analysis. The rates of recurrence were significantly different according to mALNR (Low65, 40.3%; High65, 63.0%; P < 0.001). The 10-year disease-free (Low65, 57.0%; High65, 35.0%) and overall (Low65, 64.2%; High65, 38.3%) survival rates decreased significantly with increased mALNR (P < 0.001). CONCLUSION Patients with stage IIIC breast cancer can be subdivided into subgroups with significantly different long-term prognoses. Our data suggest that the mALNR is an independent risk factor of recurrence and mortality. The mALNR is a valuable prognostic factor to predict the long-term prognosis of stage IIIC breast cancer patients.