Session Item

To report the 20-year results of a randomized study comparing the survival and cosmetic results of breast-conserving treatment with partial breast irradiation (PBI) or conventional whole breast irradiation (WBI).

Between 1998 and 2004, 258 selected patients with pT1 pN0-1mi, Grade 1-2, non-lobular breast cancer without presence of extensive intraductal component and resected with negative margins were randomized after breast-conserving surgery to receive 50 Gy WBI (n=130) or PBI (n=128). The latter consisted of either 7 x 5.2 Gy high-dose-rate (HDR) multicatheter brachytherapy (BT; n=88) or 50 Gy electron beam (EB) irradiation (n=40).

At a median follow-up time of 17 years (range: 18 to 254 months) the 20-year actuarial rates of local and regional recurrences were 9.6% versus 7.9% (p=0.59), and 4.5% versus 5.7% (p=0.56) in PBI and WBI arms, respectively. There was no significant difference in the 20-year probability of overall survival (59.5% vs. 59.7%), cancer-specific survival (92.6% vs. 88.1%), and disease-free survival (79.7% vs. 78.3%), either. The rate of excellent/good cosmetic results was 79.2% in the PBI, and 59.5% in the control group (p=0.0007). 

PBI delivered by interstitial HDR BT or EB for a selected group of early-stage breast cancer patients produces similar 20-year results to those achieved with conventional WBI. Significantly better cosmetic outcome can be achieved with carefully designed HDR multicatheter implants compared with the outcome after WBI.

Financial support from the Hungarian Thematic Excellence Programme (TKP2020-NKA-26) is greatly acknowledged.