The role of postoperative radiotherapy in node negative breast cancer patients with pT3–T4 disease

Aims To evaluate the role of postmastectomy radiotherapy (PMRT) in patients with pT3–T4N0M0 breast cancer. Methods 156 patients with T3–T4N0M0 breast cancer were retrospectively analyzed. Results Locoregional recurrences were seen in 17 of 156 patients with a median time for development of 27 months (5.7–248.7 months). Two of 9 patients who were not treated with post-operative radiation therapy had locoregional recurrence as compared with 16 of 147 patients receiving radiotherapy. In multivariate analysis, presence of locoregional recurrence was the only significant prognostic factor for overall survival (18% vs. 86%, p < 0.001, RR = 9.05). The patients with a median number of dissected lymph nodes ≥10 had a significantly better locoregional disease free survival rate as compared with patients with dissected lymph nodes <10 (90% vs. 78%, p = 0.04). Chest wall recurrences were clearly higher in patients without chest wall RT since 5 of 49 patients without RT had recurrences in the chest wall region while only 4 of 107 who received chest wall RT had recurrence. However receiving RT to peripherical lymphatic regions had no additional effect on reducing recurrences in these regions (5% vs. 4%). Conclusions Due to the lack of phase III randomized trials directly addressing the role of postmastectomy radiotherapy in these stages, our series suggest that postmastectomy radiotherapy to the ipsilateral chest wall is recommended for patients with PT3N0 and T4N0 breast cancer. The need for irradiating axillary or supraclavicular region shall be neglected in patients who undergo sufficient axillary sampling.