1028 A prospective trial of conservative surgery (CS) without radiation therapy (RT) for early-stage breast cancer

Abstract

We performed a one-arm prospective trial, 1986–92, to test the hypothesis that RT can be safely omitted after CS in selected pts with early-stage breast cancer. Pts were selected to include unicentric, clinical T1 carcinomas with neither an extensive intraductal component nor lymphatic vessel invasion. We required histologically negative margins of ≥ 1 cm and pathologically negative axillary nodes. The trial was closed after the accrual of 87 pts when early stopping rules were met. Median pt age was 67 yrs (27–84). The cancer was detected by mammography alone in 76%. Median pathologic tumor size was 0.9 cm. All pts underwent re-excision with only 2 having evidence of residual cancer. The median total volume of resected breast tissue was 114 cm3. Median f/u is 56 mos for the 84 surviving pts. 14 pts (16%) developed a LR as their first site of failure. The average annual LR rate is 3.6% and the crude 3-yr LR rate is 8%. 4 pts developed distant failures for a crude 3-yr rate of 1%. In comparison, 45 pts fulfilling the trial's strict eligibility criteria but treated with CS + RT between 1983–86 had a crude 3-yr LR rate of 0% and a crude 3-yr DF rate of 4%. This data suggests that even with careful selection and surgical treatment, this group of pts is at substantial risk of LR following treatment with CS alone. More accurate predictors of LR following CS alone are needed.