Nodal Ratio as a Prognostic Factor in Patients with Four or More Positive Axillary Nodes Treated with Breast-conserving Therapy and Regional Nodal Irradiation

Aim: This study aimed to investigate the prognostic value of the axillary lymph node ratio (i.e. positive axillary nodes to nodes removed) in patients with breast cancer treated with conservative surgery and regional radiotherapy. Patients and Methods: We retrieved the records of 195 patients with breast cancer with pathological stage pT1-2 pN2-3, treated from January 2005 to December 2013 at our Radiation Oncology Centers; their clinical data were retrospectively evaluated. All patients underwent lumpectomy or quadrantectomy with axillary lymph node dissection, adjuvant chemo-with/without hormonal therapy and irradiation to the whole breast and ipsilateral axillary apex, infraclavicular and supraclvicular nodes, excluding internal mammary nodes. The primary end-point was to evaluate the nodal ratio as a prognostic factor; moreover, the following prognostic factors were evaluated: age, biological status and molecular profile. Results: The median follow-up was 58 months (range=32-117.6 months). Two-and 5-year overall and recurrence-free survival rates were 96% and 88%, and 92% and 85%, respectively. On univariate analysis, factors influencing overall survival were nodal ratio >0.65 (p=0.033) and age (p=0.023); time to recurrence was detrimentally impacted only by Ki67 positivity >= 50% (p=0.049). At multivariate analysis, no significant associations were found. Conclusion: Adding irradiation to regional nodes after conservative surgery in patients with breast cancer with more than three positive axillary nodes does not alter the prognostic value of the nodal ratio, and we confirm this to be an important factor for predicting overall survival.