Prognostic Impact of Adjuvant Radiotherapy in Breast Cancer Patients with One to Three Positive Axillary Lymph Nodes

Radiotherapy, as an adjuvant treatment, plays a well-known role in prevention of locoregional recurrence in breast cancer patients. This study aims to investigate the impact of radiotherapy in patients with N1 disease.
In this retrospective study, we reviewed the characteristics and treatment outcomes of 316 patients with a biopsy proven diagnosis of breast carcinoma and 1-3 positive axillary lymph nodes. The patients received treatment between 1995 and 2014. The patients had a median follow-up of 60 (range: 6-182) months.
This study was conducted on 316 patients with a median age of 48 (range: 26-86) years. Among patients, 215 underwent modified radical mastectomy and 101 had breast-conserving surgery before adjuvant treatment. Indeed, 259 patients received radiotherapy (radiation group) and 57 did not (control group). There was locoregional recurrence in one control group patient and two patients in the radiation group. Multivariate analysis results indicated hormone receptor status as an independent prognostic factor for the 5-year disease-free survival rate. Estrogen and progesterone receptor negativity (HR = 1.80, 95% CI: 1.02-3.19, P=0.043) also had a negative influence on the 5-year disease-free survival rate. However, radiotherapy had no significant effect on disease-free survival (P=0.446) and overall survival (P=0.058) rates.
The results showed that adjuvant radiotherapy had no prognostic impacts on locoregional and distant disease control in breast cancer patients with N1 disease.