Patients with early-stage breast cancer who received irradiation of the regional nodes showed a marginal effect on overall survival, but improved disease-free survival, distant disease-free survival, and decreased breast cancer mortality, according to an article published online ahead of print in The New England Journal of Medicine.
Researchers randomly assigned 4004 patients with a centrally or medially located primary tumor or an externally-based tumor with axillary involvement to either whole-breast or thoracic-wall irradiation in addition to regional nodal irradiation (nodal-irradiation group) or whole-breast or thoracic-wall irradiation alone (control group).
Most patients (76.1%) underwent breast-conserving surgery. After mastectomy, 73.4% of patients in both groups underwent chest-wall irradiation.
Almost all patients with node-positive disease (99%) and 66.3% of patients with node-negative disease received adjuvant treatment.
At a median follow-up of 10.9 years, 811 patients had died. At 10 years, overall survival was 82.3% in the nodal irradiation group, and 80.7% in the control group (P=0.06).
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Disease-free survival was 72.1% in the nodal irradiation group and 69.1% in the control group. Distant disease-free survival was 78.0% versus 75.0%, and breast cancer mortality was 12.5% versus 14.4%
In regard to safety, acute side effects of regional nodal irradiation were modest.
- Poortmans PM, Collette S, Kirkove C, et al. Internal mammary and medial supraclavicular irradiation in breast cancer. N Engl J Med. [epub ahead of print]. 2015. doi: 10.1056/NEJMoa1415369.