ESTRO 2024 - Abstract Book

S1533

Clinical - Lower GI

ESTRO 2024

1929

Proffered Paper

Organ preservation in rectal cancer: the GRECCAR12 randomized phase 3 trial (NCT02514278)

Véronique Vendrely 1 , Benjamin Fernandez 2 , Nicolas Giraud 1 , Philippe Rouanet 3 , Jean-Jacques Tuech 4 , Eddy Cotte 5 , Jeremie Lefevre 6 , Anne Dubois 7 , Adeline Germain 8 , Antoine Camerlo 6 , Bernard Lelong 9 , Alain Valverde 10 , Zaher Lakkis 11 , Michel Rivoire 12 , Véronique Desfourneaux 13 , Thierry Conroy 14 , Julien Asselineau 15 , Quentin Denost 16 , Eric Frison 15 , Eric Rullier 2 1 CHU Bordeaux, Radiotherapy, Bordeaux, France. 2 CHU Bordeaux, Surgery, Bordeaux, France. 3 Institut du cancer de Montpellier, Surgery, Montpellier, France. 4 CHU Rouen, Surgery, Rouen, France. 5 CHU Lyon, Surgery, Lyon, France. 6 APHP, Surgery, Paris, France. 7 CHU Clermont Ferrand, Surgery, lermont-Ferrand, France. 8 CHU Nancy, Surgery, Nancy, France. 9 IPC, Surgery, Marseille, France. 10 La Croix Saint Simon, Surgery, Paris, France. 11 CHU Besançon, Surgery, esançon, France. 12 Centre Léon Bérard, Surgery, Lyon, France. 13 CHU Rennes, Surgery, Rennes, France. 14 Institut de cancérologie de Loraine, Oncology, Nancy, France. 15 CHU Bordeaux, USMR, Bordeaux, France. 16 Bordeaux Colorectal institute, Surgery, Bordeaux, France

Purpose/Objective:

Total neoadjuvant treatment comprising induction or consolidation chemotherapy and chemoradiotherapy (CRT) is recommended for locally-advanced rectal cancers. However, induction chemotherapy (ICT) has never been evaluated in an organ preservation (OP) strategy. GRECCAR12 trial aimed to increase the rate of organ preservation in a selective approach, by adding ICT (FOLFIRINOX) to CRT.

Material/Methods:

In this randomized phase 3 trial, 218 patients with cT2T3 N0-1 M0 rectal cancer (tumor size ≤4cm and ≤10cm from the anal verge) received induction chemotherapy with FOLFIRINOX (oxaliplatin 85 mg/m2, irinotecan 180 mg/m2, leucovorin 400 mg/m2, fluorouracil 2400 mg/m2 every 2 weeks for 4 cycles), and chemoradiotherapy (50 Gy and concomitant capecitabine), or chemoradiotherapy. Good responders evaluated by MRI were offered a tumorectomy, with complementary TME in case of histopathological stage ypT3 ou ypT2cN1. The primary outcome was the rate of organ preservation at 1 year after surgery. Secondary endpoints included compliance to treatment, rate of good clinical response (MRI) and complete pathologic response (ypT0), local recurrence, overall and disease-free survival at 2 years.

Results:

Among 214 patients (median age 64; 55% male) included between January 2016 and November 2020, 104 received ICT followed by CRT and 110 CRT. Compliance to ICT was 96.1% with grade≥3 adverse events (mainly diarrhea or neutropenia) in 29% of patients. Pathological complete response was 45% with ICT compared to 28% with CRT alone (OR: 2.13; 95%CI :1.16-3.91). One-year OP rates were 71,7% with ICT and 62.7% with CRT alone (OR:1.88; 95%CI : 0.99;3.57; p=0.056). At 3 years, overall survival and recurrence-free survival were 95% and 86% respectively without significant difference between arms.