A pilot phase II study of neoadjuvant triplet chemotherapy regimen in patients with locally advanced resectable colon cancer

This study aims to investigate the feasibility, safety and efficacy of triplet regimen of neoadjuvant chemotherapy in patients with locally advanced resectable colon cancer.

Patients with clinical stage IIIb colon cancer received a perioperative triple chemotherapy regimen (oxaliplatin 85 mg/m² and irinotecan 150 mg/m², combined with folinic acid 200 mg, 5-fluorouracil 500 mg bolus and then 2,400 mg/m² by 44 h infusion or capecitabine 1 g/m² or S-1 40-60 mg b.i.d orally d 1-10, repeated at 2-week intervals) for 4 cycles. Complete mesocolic excision was scheduled 2-6 weeks after completion of neoadjuvant treatment and followed by a further 6 cycles of FOLFOXIRI or XELOX. Primary outcome measures of this stage II trial were feasibility, safety, tolerance and efficacy of neoadjuvant treatment.

All 23 patients received neoadjuvant chemotherapy and underwent surgery. Twenty-one patients (91.3%) had reductions in tumor volume after neoadjuvant treatment, and 13 patients (56.5%) had grade 3-4 toxicity. No patients had severe complications from surgery. Preoperative therapy resulted in significant down-staging of T-stage and N-stage compared with the baseline clinical stage including one pathological complete response.

Neoadjuvant triple chemotherapy has high activity and acceptable toxicity and perioperative morbidity, and is feasible, tolerable and effective for locally advanced resectable colon cancer.