Purpose: To determine the long-term outcome of a consistent treatment approach with electron beam postmastectomy radiation therapy (PMRT) in breast cancer patients with > or =10 positive nodes treated with combined-modality therapy.
Methods and materials: TSixty-three breast cancer patients with > or =10 positive lymph nodes were treated with combined-modality therapy using an electron beam en face technique for PMRT at the University of Florida. Patterns of recurrence were studied for correlation with radiation fields. Potential clinical and treatment variables were tested for possible association with local-regional control (LRC), disease-free survival (DFS), and overall survival (OS).
Results: TAt 5, 10, and 15 years, OS rates were 57%, 36%, and 27%, respectively; DFS rates were 46%, 37%, and 34%; and LRC rates were 87%, 87%, and 87%. No clinical or treatment variables were associated with OS or DFS. The use of supplemental axillary radiation (SART) (p = 0.012) and pathologic N stage (p = 0.053) were associated with improved LRC. Patients who received SART had a higher rate of LRC than those who did not. Moderate to severe arm edema developed in 17% of patients receiving SART compared with 7% in patients not treated with SART (p = 0.28).
Conclusions: TA substantial percentage of patients with > or =10 positive lymph nodes survive breast cancer. The 10-year overall survival in these patients was 36%. The addition of SART was associated with better LRC.