Clinical-pathologic study of early breast cancer treated by primary radiation therapy.

We performed a clinical-pathologic review of 231 patients with early breast cancer treated by primary radiation therapy. There were 27 patients with infiltrating ductal carcinoma treated with excisional biopsy whose tumors showed a constellation of histologic features: moderate or marked intraductal carcinoma in the tumor, intraductal carcinoma in the adjacent tissue, and high nuclear grade. These patients had a 5-yr local tumor control rate of 61% compared to 96% for similar patients whose tumors did not show all three features. Radiation dose to the primary tumor area influenced the likelihood of local recurrence in these 27 patients: 15 of these patients received 6000 rads or more to the primary tumor area and had a 5-yr local tumor control rate of 84%, compared to 48% for the 12 patients who received less than 6000 rads. These results indicate that a subgroup of breast cancer patients can be identified that has a high risk of local recurrence when an insufficient radiation dose (i.e., less than 6000 rads) is delivered to the primary tumor area.