[Predisposing factors for local recurrence after conservative treatment of breast cancer]

The factors predisposing to local relapse after conservative treatment of early stage breast cancer are controversial. To determine these factors, we analysed the results obtained in a series of 512 patients consecutively treated for invasive breast carcinomas by conservative surgery and radiotherapy. All patients were treated by tumorectomy and axillary dissection, radiation therapy of 45 Gy to the whole breast with a boost of 15 Gy to the tumor area, and adjuvant medical treatment for 168 out of 187 patients. The overall 5-year and 10-year survival rates were respectively 92.5% and 79.9%. The actuarial 5-year and 10-year local control rates were respectively 91.2% and 83.6%. Local relapses occurred in 35 patients. Local relapse occurred more frequently in premenopausal patients, in patients less than 50 years-old as compared to older patients, in patients with low body-mass index (BMI), and in patients with small breast size. Local control was not significantly affected by tumor size or node involvement. With multivariate analysis, the only factor influencing local control was the body-mass index: the actuarial risk of local relapse was increased by 5.7 in patients with a BMI less than or equal to 22 as compared to patients with a BMI greater than 22 (p less than 0.02). We concluded that although certain clinical factors such as age, menopausal status, breast size and body-mass index have an influence on local control, these factors are not sufficiently discriminant to question the indication of conservative treatment. There is a need to individualize factors that could allow a better discrimination of patients with a high probability of local relapse.