Neoadjuvant chemotherapy with FOLFOXIRI for high-risk relapsed locally advanced colon cancer: a single-arm phase II...

To evaluate the safety and deliverability of neoadjuvant chemotherapy (NAC) with three-drug-intensity chemotherapy [oxaliplatin, irinotecan, and fluorouracil (FOLFOXIRI)] in patients with high-risk factors for recurrence and metastasis of locally advanced colon cancer (hr-LACC).

A single-arm, open-label, phase II trial was conducted at West China Hospital of Sichuan University from July 2020 to October 2023. Patients with T4a/b and/or N2/fused lymph nodes and no distant metastases were considered as the hr-LACC patients. Eligible enrolled patients received four cycles of NAC with FOLFOXIRI followed by surgery and adjuvant chemotherapy with capecitabine and oxaliplatin (CAPOX) for two to five cycles or single-agent capecitabine for five cycles or observation. The primary endpoint was safety, deliverability, and the rate of tumor regression grade (TRG) 0-2 according to the criteria of the National Comprehensive Cancer Network (NCCN) guideline.

Of 72 patients enrolled [median age 53 (18-74) years, 65 were T4a/b (90.2%), 66 were N2 (91.6%)], 58 patients (80.6%) completed four cycles of FOLFOXIRI. One patient (4.2%) achieved clinical complete response. Twenty-seven patients (39.1%) obtained clinical partial response. The most common adverse event (AE) was nausea (86.1%, 62/72), and grade 3-4 AEs occurred in 37 of 72 patients (51.4%). R0 resection was achieved in 61 of 61 patients, and the TRG (0-2) rate was 86.9% (53/61). The pathological complete response rate was 3.3% (2/61). The proportions of pT0-2 and pN0 were 18.0% and 67.2%, respectively. Three (4.9%) patients had prolonged hospital stay due to perioperative complications. No patient died within 30 days and 90 days after surgery. The 2-year tumor recurrence rate was 17.2%.

For patients with hr-LACC, NAC with FOLFOXIRI regimen has preferable safety and deliverability. Longer follow-up and larger clinical studies are needed to validate its efficacy superiority.