LOCAL RELAPSE AND CONTRALATERAL TUMOR RATES IN PATIENTS WITH BREAST-CANCER TREATED WITH CONSERVATIVE SURGERY AND RADIOTHERAPY (INSTITUT-GUSTAVE-ROUSSY 1970-1982)

Background. Breast conservation is now established treatment for patie nts with small breast cancers. The authors reviewed a large series of patients with long term follow-up who underwent conservative treatment . Clinical and pathologic factors were analyzed to identify patients a t an increased risk of relapse in the breast (local relapse) or develo pment of a contralateral tumor. Methods. Seven hundred fifty-seven pat ients with unilateral invasive breast cancer (TO-2, NO-1, MD) were tre ated conservatively (wide local excision and radiotherapy) at the Inst itut Gustave-Roussy between 1970 and 1982. The median follow-up was 9 years. The risk of local relapse or development of a contralateral tum or (as first event) was studied by univariate analysis for the main cl inical, pathologic, and treatment factors. Those found to be significa nt were entered into a Cox proportional regression analysis. Results. Fifty-one patients relapsed in the treated breast (actuarial local rel apse rates at 5 and 10 years were 5% and 8%, respectively) and 34 in t he contralateral breast (actuarial contralateral tumor rates at 5 and 10 years were 3% and 6%, respectively). Multivariate analysis of the r isk factors for local relapse showed that only age younger than 40 yea rs (P < 0.02) or inadequate surgical excision (P < 0.02) were signific ant. No particular risk factors for contralateral tumor development we re identified. Conclusions. Overall, for most patients, the risk of lo cal relapse or of developing a contralateral tumor was low. A small nu mber of young patients with inadequately excised tumors are at higher risk of local relapse, need more meticulous surgery, and may merit hig her dose radiotherapy.