Evaluation of the efficacy and toxicity of neo-adjuvant short course radiation therapy concurrently with continuous infusion 5-fluorouracil in the management of locally advanced rectal cancer patients.

Abstract

Purpose: To assess the safety and efficacy of neo-adjuvant short-course radiation therapy (SCRT) concurrently with continuous infusion of 5-fluorouracil (5-FU) in the treatment of locally advanced rectal cancer. Method and material: Patients with cT3-4 or any T with N+ rectal cancer diagnosed by magnetic resonance imaging (MRI) and proved pathologically as adenocarcinoma were eligible to be enrolled in our study. Patients received continuous infusion of 5-FU with dose escalation from 100mg/m2/day up to 200mg/m2/day through 5 days concurrently with a SCRT (5 Gy x 5 fractions), followed by 2 months of neo-adjuvant mFOLFOX, radical surgery with total mesorectal excision (TME) was done for patients with complete clinical (cCR), partial response (PR) or stationary disease (SD) and was follow by 4 months of adjuvant mFOLFOX. Results: Twenty patients were included in the study. All patients completed a SCRT concurrently with 5-FU and the 5-FU dose was safely escalated to 200 mg/m2/d with no dose-limiting toxicity (DLT). Four patients (20%) out of 20 patients showed cCR, 14 patients (7o%) had PR, and 2 patients (10%) had disease progression (PD). Four patients (26.7) out of 15 patients had complete pathological response (pCR), and 11 patients (73.3%) had PR. The most common grade III and Ⅳ toxicities according to common terminology criteria of adverse events version 5.0 (CTCAE) were diarrhea and abdominal pain. The most common grade Ⅰ and Ⅱ toxicities were non-hematological toxicity mainly gastrointestinal.