ROLE OF RADIOTHERAPY FOLLOWING TOTAL MASTECTOMY IN PATIENTS WITH EARLY BREAST-CANCER

Between June 1970 and April 1975 the CRC (King's/Cambridge) Trial for early breast cancer randomized 2800 patients following mastectomy to i mmediate prophylactic radiotherapy (DXT group, n = 1376) or control (W P group, n = 1424). Although no difference in overall survival has bee n demonstrated, there is an increase in mortality in the irradiated pa tients from nonbreast cancer causes beyond 5 years. It is because of a n increase in the number of deaths due to new nonbreast malignancies [ RR = 1.89 (1.18-3.05)] and to cardiac-related disease [RR = 1.52 (1.01 -2.29)]. This increased cardiac death rate may be related to the use o f orthovoltage, which has greater scatter. There was a significant inc rease in risk for those with left-sided rather than right-sided tumors in this subgroup [chi2 (int) = 5.08; p = 0.02]. Local relapse was sig nificantly reduced in those patients randomized to radiotherapy [RR = 0.44 (0.39-0.51)]. Median survival following local relapse was 1.35 ye ars in the DXT group and 2.66 years in the WP group (logrank p < 0.001 ). Patients with the first relapse in the supraclavicular nodes had a particularly poor prognosis (median survival: DXT 0.69 years; WP 1.37 years). Almost 50% of patients who have had a recurrence on the chest wall or in the axilla and subsequently died have had disease at the sa me site at death, regardless of whether they had radiotherapy immediat ely following surgery. However, the actual number of patients dying wi th persistent disease is halved by the use of prophylactic radiotherap y (DXT 66; WP 143). Classic pathologic features such as tumor size, tu mor grade, and nodal involvement help define those patients at high ri sk of local failure who should be recommended for immediate radiothera py.