GRECCAR 14 - a multicentric, randomized, phase II-III study evaluating the tailored management of locally advanced rectal carcinoma after a favourable response to induction chemotherapy: Study protocol.

AIM: Total neoadjuvant treatment (TNT) is becoming standard in patients with locally advanced rectal carcinoma (LARC). Preoperative chemoradiotherapy (CRT) has proven side effects on bowel and genitourinary function. An early tumoral response to induction chemotherapy demonstrates its high prognostic value. Tailored management could be used as an alternative to systematic CRT. The GRECCAR 14 trial will attempt to personalize treatment strategy according to the patient's early tumour response to intensive chemotherapy with the aim of achieving the best toxicity-efficiency ratio.

METHOD: GRECCAR 14 is a multicentric, randomized, two-arm, phase II-III noninferiority trial. Patients with mid or low LARC with a predictive circumferential resection margin ≤2 mm or T3c-d stage with extramural venous invasion will be included. Evaluation of the tumoral response will be performed after six courses of high-dose FOLFIRINOX chemotherapy. Good responders (GRs) will be defined by a 60% decrease in tumoral volume on magnetic resonance imaging. Patients will be randomized to CRT before surgery. The primary endpoints will be R0 resection for phase II and the 3-year disease-free survival (DFS) for phase III.

RESULTS

Tailored management of LARC is becoming an exciting challenge for the modality of neoadjuvant treatment and for the type of surgery or its omission. Neoadjuvant FOLFIRINOX has established efficacy, with a significant increase in the 3-year DFS. Better control of systemic disease must be accompanied by the same locoregional control, with the lowest morbidity. Our previous GRECCAR 4 trial demonstrated the high value of the early tumoral response after induction chemotherapy and the long-term safety of tailored management for GRs.

CONCLUSION

If GRECCAR 14 demonstrates the ability to tailor TNT for LARC, this could lead to changes in clinical practice.