Concomitant boost plus large-field preoperative chemoradiation in locally advanced uterine cervix carcinoma: Phase II clinical trial final results (LARA-CC-1)

Objective: To report the Phase II study final results in terms of pathological complete response (pCR) and complications in locally advanced cervical carcinoma (LACC) patients treated with chemoradiation (CT/RT) regimen based on accelerated fractionation, nodal extended fields and adjuvant radical surgery. Methods: The sample size was quantified according to published data which shows that CT/RT followed by radical surgery in LACC patients provides a pCR rate above 45%. The 2-stage design by Simon was used to test the null hypothesis that the true pCR would improve by above 20%. The chemoradiation regimen was considered active if > 24/43 pCRs were recorded. 40 Gy/2 Gy fraction in 4 weeks was delivered to nodal volume extending up to L3 vertebra, concurrently with chemotherapy. 45 Gy in 20 fractions with a concomitant boost strategy was delivered to the macroscopic disease only. Results: 47 patients were enrolled. Median follow-up was 26 months (3-52 months). Pathological response was assessed in 44/47 patients: 17/44 (38.6%) showed a pCR to treatment, and 9/44 cases (20.5%) showed microscopic disease. Pelvic nodal metastases were documented in 9/44 cases (20.5%). 87.5% of recurrences were extra pelvic. Five patients (11%) developed acute severe gastrointestinal toxicity. The actuarial cumulative 2-year incidence of G ≥ 2 late cutaneous, gastrointestinal, and genitourinary toxicity was 10.3%, 8.3% and 24.9%, respectively. The 3-year DFS was 77.1%, while the 3-year OS was 80.5%. Conclusions: Our results confirm the high tolerability and efficacy of this accelerated regimen. However, based on the study design, 45 Gy as a concomitant boost CT/RT delivered by a 3D technique does not seem sufficient to increase pCR rate