Neoadjuvant hyperfractionated accelerated radiotherapy plus concomitant 5-fluorouracil infusion in locally advanced rectal cancer: A phase Ⅱ study

AIM To evaluate the efficacy and tolerability of neoadjuvant hyperfractionated accelerated radiotherapy(HART)and concurrent chemotherapy in patients with locally advanced infraperitoneal rectal cancer. METHODS A total of 30 patients with histopathologically confirmed T2-3/N0+ infraperitoneal adenocarcinoma of rectum cancer patients received preoperative 42 Gy/1.5 Gy/18 days/bid radiotherapy and continuous infusion of 5-fluorouracil(325 mg/m2). All patients were operated 4-8 wk after neoadjuvant concomitant therapy. RESULTS In the early phase of treatment, 6 patients had grade Ⅲ-Ⅳ gastrointestinal toxicity, 2 patients had grade Ⅲ-Ⅳ hematologic toxicity, and 1 patient had grade Ⅴ toxicity due to postoperative sepsis during chemotherapy. Only 1 patient had radiotherapy-related late side effects, i.e., grade Ⅳ tenesmus. Complete pathological response was achieved in 6 patients(21%), while near-complete pathological response was obtained in 9(31%). After a median follow-up period of 60 mo, the local tumor control rate was 96.6%. In 13 patients, distant metastasis occurred. Disease-free survival rates at 2 and 5 years were 63.3% and 53%, and corresponding overall survival rates were 70% and 53.1%, respectively.CONCLUSION Although it has excellent local control and complete pathological response rates, neoadjuvant HART concurrent chemotherapy appears to not be a feasible treatment regimen in locally advanced rectal cancer, having high perioperative complication and intolerable side effects. Effects of reduced 5-fluorouracil dose or omission of chemotherapy with the aim of reducing toxicity may be examined in further studies.