Adjuvante chemoradiatie versus radiotherapie bij hoogrisico endometriumcarcinoom: PORTEC-3 vijfjaars definitief

BACKGROUND: The PORTEC-3 trial investigated the benefit of combined adjuvant chemotherapy and radiotherapy versus pelvic radiotherapy alone for women with high-risk endometrial cancer. We updated the analysis to investigate patterns of recurrence and did a post-hoc survival analysis. METHODS: In the multicentre randomised phase 3 PORTEC-3 trial, women with high-risk endometrial cancer were eligible if they had International Federation of Gynaecology and Obstetrics (FIGO) 2009 stage I, endometrioid grade 3 cancer with deep myometrial invasion or lymphovascular space invasion, or both; stage II or III disease; or stage I-III disease with serous or clear cell histology; were aged 18 years and older; and had a WHO performance status of 0-2. Participants were randomly assigned (1:1) to receive radiotherapy alone (48·6 Gy in 1·8 Gy fractions given on 5 days per week) or chemoradiotherapy (two cycles of cisplatin 50 mg/m2 given intravenously during radiotherapy, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m2 given intravenously), by use of a biased coin minimisation procedure with stratification for participating centre, lymphadenectomy, stage, and histological type. The co-primary endpoints were overall survival and failure-free survival. Secondary endpoints of vaginal, pelvic, and distant recurrence were analysed according to the first site of recurrence. Survival endpoints were analysed by intention-to-treat, and adjusted for stratification factors. Competing risk methods were used for failure-free survival and recurrence. We did a post-hoc analysis to analyse patterns of recurrence with 1 additional year of follow-up. The study was closed on Dec 20, 2013; follow-up is ongoing. This study is registered with ISRCTN, number ISRCTN14387080, and ClinicalTrials.gov, number NCT00411138. FINDINGS: Between Nov 23, 2006, and Dec 20, 2013, 686 women were enrolled, of whom 660 were eligible and evaluable (330 in the chemoradiotherapy group, and 330 in the radiotherapy-alone group). At a median follow-up of 72·6 months (IQR 59·9-85·6), 5-year overall survival was 81·4% (95% CI 77·2-85·8) with chemoradiotherapy versus 76·1% (71·6-80·9) with radiotherapy alone (adjusted hazard ratio [HR] 0·70 [95% CI 0·51-0·97], p=0·034), and 5-year failure-free survival was 76·5% (95% CI 71·5-80·7) versus 69·1% (63·8-73·8; HR 0·70 [0·52-0·94], p=0·016). Distant metastases were the first site of recurrence in most patients with a relapse, occurring in 78 of 330 women (5-year probability 21·4%; 95% CI 17·3-26·3) in the chemoradiotherapy group versus 98 of 330 (5-year probability 29·1%; 24·4-34·3) in the radiotherapy-alone group (HR 0·74 [95% CI 0·55-0·99]; p=0·047). Isolated vaginal recurrence was the first site of recurrence in one patient (0·3%; 95% CI 0·0-2·1) in both groups (HR 0·99 [95% CI 0·06-15·90]; p=0·99), and isolated pelvic recurrence was the first site of recurrence in three women (0·9% [95% CI 0·3-2·8]) in the chemoradiotherapy group versus four (0·9% [95% CI 0·3-2·8]) in the radiotherapy-alone group (HR 0·75 [95% CI 0·17-3·33]; p=0·71). At 5 years, only one grade 4 adverse event (ileus or obstruction) was reported (in the chemoradiotherapy group). At 5 years, reported grade 3 adverse events did not differ significantly between the two groups, occurring in 16 (8%) of 201 women in the chemoradiotherapy group versus ten (5%) of 187 in the radiotherapy-alone group (p=0·24). The most common grade 3 adverse event was hypertension (in four [2%] women in both groups). At 5 years, grade 2 or worse adverse events were reported in 76 (38%) of 201 women in the chemoradiotherapy group versus 43 (23%) of 187 in the radiotherapy-alone group (p=0·002). Sensory neuropathy persisted more often after chemoradiotherapy than after radiotherapy alone, with 5-year rates of grade 2 or worse neuropathy of 6% (13 of 201 women) versus 0% (0 of 187). No treatment-related deaths were reported. INTERPRETATION: This updated analysis shows significantly imp