Prognostic factors in patients undergoing curative irradiation for breast cancer.

We have evaluated 147 patients who received primary curative irradiation for breast cancer to determine if there were any common factors that predisposed to failure. There were 10 local recurrences, for an overall local control rate of 93.2%, with a 2 to 16 year follow-up. Disease-free survivals were 85% in Stage I, 69% in Stage II, and 50% in Stage III. Age seemed to be a determinant, with a 31.6% local recurrence rate in women under 50 vs. a 3.1% rate of local recurrence in women age 50 or older when treated. We have also noted a correlation between the radiation dose and local recurrence, with a recurrence rate of 9.1% following a dose of 6000 rad or less, vs. a rate of 4.7% with a dose of 6400 rad or more. The size of the primary carcinoma and the status of the axillary lymph nodes, each considered individually, were not significant prognostic factors. There was no relationship between recurrence and the performance of an axillary dissection. There was evidence suggesting that the recurrence rate was lower when a wide local excision was performed, compared to a lesser procedure. Multiple foci of carcinoma and a high nuclear grade appear to have a poor prognosis. Five of the recurrences occurred early (under 2 years) and three of these were accompanied by fatal distant metastases. None of the five patients with late recurrences (37 to 116 months) developed metastatic disease, suggesting that late recurrences may have a better prognosis.