Pilot study of modified FOLFOX6 adjuvant chemotherapy for high-risk rectal cancer treated with neoadjuvant chemoradiotherapy

Purpose: Neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision is considered the standard of care for patients with locally advanced adenocarcinoma of the middle/low rectum. The present study evaluated the feasibility of using modified FOLFOX6 regimen as an adjuvant treatment for high-risk patients with locally advanced rectal cancer (LARC) treated with neoadjuvant CRT. Methods: Forty patients with LARC (ypT3-4 or N+) treated with neoadjuvant CRT were enrolled at Kyungpook National University Medical Center (Daegu, Korea) between December 2011 and December 2012. All the patients underwent rectal surgery with curative intent 8 weeks after the end of the neoadjuvant treatment. Adjuvant chemotherapy using modified FOLFOX6 regimen was delivered for 3 months. Results: The treatments were generally well tolerated. Dose reduction was recorded in 11 of the 40 patients (27.5 %). The incidence of febrile neutropenia was 5 %, the incidence of grade 3 or 4 asthenia was 10 %, and the incidence of grade 3 gastrointestinal adverse events was 5 % during treatment. Treatment discontinuation caused by toxic effects or any other reasons was observed in six patients (15 %). The reasons for discontinuation were asthenia (n = 2, 5 %), diarrhea (n = 2, 5 %), acute renal failure (n = 1, 2.5 %), and relapse during chemotherapy (n = 1, 2.5 %). With a median follow-up duration of 18 months, six patients (15 %) relapsed and one patient (2.5 %) died of disease progression. The estimated 3-year disease-free survival and overall survival rates were 84.2 and 97.3 %, respectively. Conclusions: Postoperative adjuvant modified FOLFOX6 regimen was found to be feasible for patients with LARC treated with neoadjuvant CRT.