Breast-conserving therapy with partial or whole breast irradiation: ten-year results of the Budapest randomized trial.

BACKGROUND AND PURPOSE To report the long-term results of a single-institution randomized study comparing the results of breast-conserving treatment with partial breast irradiation (PBI) or conventional whole breast irradiation (WBI). PATIENTS AND METHODS Between 1998 and 2004, 258 selected women with pT1 pN0-1mi M0, grade 1-2, non-lobular breast cancer without the presence of extensive intraductal component and resected with negative margins were randomized after BCS to receive 50 Gy WBI (n=130) or PBI (n=128). The latter consisted of either 7 × 5.2 Gy high-dose-rate (HDR) multi-catheter brachytherapy (BT; n=88) or 50 Gy electron beam (EB) irradiation (n=40). Primary endpoint was local recurrence (LR) as a first event. Secondary endpoints were overall survival (OS), cancer-specific survival (CSS), disease-free survival (DFS), and cosmetic results. RESULTS After a median follow up of 10.2 years, the ten-year actuarial rate of LR was 5.9% and 5.1% in PBI and WBI arms, respectively (p=0.77). There was no significant difference in the ten-year probability of OS (80% vs 82%), CSS (94% vs 92%), and DFS (85% vs 84%), either. The rate of excellent-good cosmetic result was 81% in the PBI, and 63% in the control group (p<0.01). CONCLUSIONS Partial breast irradiation delivered by interstitial HDR BT or EB for a selected group of early-stage breast cancer patients produces similar ten-year results to those achieved with conventional WBI. Significantly better cosmetic outcome can be achieved with HDR BT implants compared with the outcome after WBI.