BACKGROUND: Neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC) does not achieve effective control of distant metastases. Induction chemotherapy is a promising strategy, and bevacizumab (BV) could improve the results of CRT. 5-Fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI) plus BV is a treatment option in metastatic colorectal cancer. We evaluate feasibility and efficacy of neoadjuvant treatment comprising induction FOLFOXIRI plus BV followed by CRT with fluoropyrimidines plus BV.
METHODS: In this phase II single-arm trial, patients node-positive or clinical T4 or high-risk T3 LARC underwent 6 cycles of induction FOLFOXIRI plus BV, followed by CRT (50.4 Gy plus concomitant capecitabine) and BV (5 mg/kg on days 1, 15 and 28). Surgery was planned 8 weeks after completion of CRT. Primary end-point was 2-year disease-free survival (DFS).
RESULTS: We enrolled 49 patients: All but one (withdrewing consent after enrolment) were included in the per-protocol analyses. The study met its primary end-point: 36 patients were free of recurrence at 2 years (2-y DFS: 80.45%, 95% confidence interval [CI]: 78.79-82.10). Forty-four patients underwent surgery; pathologic complete response rate was 36.4%. Forty-six patients completed induction: neutropenia (41.6%) and diarrhoea (12.5%) were main G3/4 toxicities. Forty-five patients received CRT, but the protocol was amended and the capecitabine schedule during CRT was slightly modified after 13 patients due to the incidence of G3 hand-foot syndrome and proctitis (23.1%). After amendment, no severe events during CRT were reported.
CONCLUSIONS: FOLFOXIRI plus BV followed by CRT plus BV is feasible and active. Results in terms of DFS suggest that this strategy may improve distant disease control in LARC.