Publication details
Late side-effects and cosmetic results of accelerated partial breast irradiation with interstitial brachytherapy versus whole-breast irradiation after breast-conserving surgery for low-risk invasive and in-situ carcinoma of the female breast: 5-year results of a randomised, controlled, phase 3 trial
| Authors | |
|---|---|
| Year of publication | 2017 |
| Type | Article in Periodical |
| Magazine / Source | Lancet Oncology |
| MU Faculty or unit | |
| Citation | |
| Web | http://dx.doi.org/10.1016/S1470-2045(17)30011-6 |
| Doi | http://dx.doi.org/10.1016/S1470-2045(17)30011-6 |
| Field | Oncology and hematology |
| Keywords | accelerated partial breast irradiation |
| Description | Background We previously confirmed the non-inferiority of accelerated partial breast irradiation (APBI) with interstitial brachytherapy in terms of local control and overall survival compared with whole-breast irradiation for patients with early-stage breast cancer who underwent breast-conserving surgery in a phase 3 randomised trial. Here, we present the 5-year late side-effects and cosmetic results of the trial. Methods We did this randomised, controlled, phase 3 trial at 16 centres in seven European countries. Women aged 40 years or older with stage 0-IIA breast cancer who underwent breast-conserving surgery with microscopically clear resection margins of at least 2 mm were randomly assigned 1: 1, via an online interface, to receive either whole-breast irradiation of 50 Gy with a tumour-bed boost of 10 Gy or APBI with interstitial brachytherapy. Randomisation was stratified by study centre, menopausal status, and tumour type (invasive carcinoma vs ductal carcinoma in situ), with a block size of ten, according to an automated dynamic algorithm. Patients and investigators were not masked to treatment allocation. The primary endpoint of our initial analysis was ipsilateral local recurrence; here, we report the secondary endpoints of late side-effects and cosmesis. We analysed physician-scored late toxicities and patient-scored and physician-scored cosmetic results from the date of breast-conserving surgery to the date of onset of event. Analysis was done according to treatment received (as-treated population). This trial is registered with ClinicalTrials.gov, number NCT00402519. Findings Between April 20, 2004, and July 30, 2009, we randomly assigned 1328 women to receive either whole-breast irradiation (n=673) or APBI with interstitial brachytherapy (n=655); 1184 patients comprised the as-treated population (551 in the whole-breast irradiation group and 633 in the APBI group). At a median follow-up of 6.6 years (IQR 5.8-7.6), no patients had any grade 4 toxities, and three (< 1%) of 484 patients in the APBI group and seven (2%) of 393 in the whole-breast irradiation group had grade 3 late skin toxicity (p= 0.16). No patients in the APBI group and two (< 1%) in the whole-breast irradiation group developed grade 3 late subcutaneous tissue toxicity (p= 0.10). The cumulative incidence of any late side-eff ect of grade 2 or worse at 5 years was 27.0% (95% CI 23.0-30.9) in the whole-breast irradiation group versus 23.3% (19.9-26.8) in the APBI group (p= 012). The cumulative incidence of grade 2-3 late skin toxicity at 5 years was 10.7% (95% CI 80-13.4) in the whole-breast irradiation group versus 69% (48-90) in the APBI group (diff erence -38%, 95% CI -72 to 0.4; p= 0020). |