Definitive irradiation for early stage breast cancer: The University of Pennsylvania experience.

From 1977 to 1984, 552 breast cancers in 548 women were treated with definitive irradiation following breast-conserving surgery at the Hospital of the University of Pennsylvania and the Fox Chase Cancer Center. All patients had invasive carcinoma and were AJC clinical Stage I or II. Pathologic axillary lymph node staging was known for all cases. The 5-year actuarial survival for the entire group was 93% with an NED survival of 81%. The 5-year survival for clinical Stage I and II patients was 97 and 87%, respectively, with a corresponding NED survival of 87 and 73%, respectively. For pathologic Stage I and II patients, the corresponding survival figures were 97 and 89%, respectively, with NED survival rates of 86 and 76%, respectively. The overall 5-year actuarial local failure rate was 6%, and the rate of local only as the first failure was 3%. The overall local-regional failure rate was 13% with a local-regional only first failure rate of 8%. These results compare favorably with other reported series and contribute a substantial number of patients to the increasing experience with definitive irradiation following breast-conserving procedures. The relatively low incidence of breast recurrence may be related to the emphasis on integrating the surgical, pathologic, and radiotherapeutic aspects of treatments, as well as the emergence of a re-excision policy for patients at high risk to have residual tumor.