Risk of local recurrence of breast cancer and irradiation of the chest wall

Objective: Chest wall irradiation after mastectomy for breast cancer is now usually reserved for patients with extensive carcinomatous lymphangiosis o r positive surgical margins. However, recent studies suggest that the reduc ed risk for local recurrence following radiotherapy of the chest wall might improve the survival of these patients. We studied the influence of chest wall irradiation on local recurrence and overall survival rates in patients with breast cancer treated with mastectomy. Methods: We reviewed 1964 patients with pT(1-2) breast cancer treated with mastectomy since 1963. Patients treated before 1979 routinely received ches t wall irradiation while those treated after 1979 received irradiation only if there was histologic evidence of extensive carcinomatous lymphangiosis or positive surgical margins. The groups were compared with Kaplan-Meier an alysis and the log-rank test. Results: Patients, who received adjuvant radiotherapy had a significantly l ower rate of local recurrence regardless of the nodal status. Ten years aft er primary diagnosis, 98% of patients who received irradiation are free of local recurrence, compared with 86 % of those who did not (p < 0.001). In p atients with negative nodes, there was no difference in survival between pa tients who received irradiation and those who did not. In patients with pos itive nodes, patients who received irradiation had poorer overall survival than those who did not, probably due to more advanced disease. Conclusions: These data indicate that adjuvant radiotherapy after mastectom y for breast cancer decreases the rate of local recurrence but without impr oving overall survival.