Primary radiation therapy for early breast cancer: The experience at the joint center for radiation therapy

The results of primary radiation therapy in 176 consecutive patients with clinical Stage I and II carcinoma of the breast were reviewed. Median follow-up time was 47 months. The overall breast relapse rate was 7%. Patients undergoing interstitial implantation had a significantly lower breast relapse rate (1%) than patients not undergoing implantation (11 %). Breast relapse was more common in patients undergoing incisional or needle biopsy (17 %), compared to patients treated after excisional biopsy (5 %). In patients undergoing excisional biopsy, but not interstitial implantation, breast relapse was related to external beam dose. Twelve percent of the patients who received less than 1600 ret dose relapsed in the breast, compared to none of the 19 patients who received more than 1700 ret dose. These results imply that supplemental irradiation to the primary tumor area is required following excisional biopsy of a primary breast cancer when 4500–5000 rad is delivered to the entire breast.