Purpose: The aim of this study was to evaluate the efficacy and tolerance of preoperative chemoradiotherapy (CRT) with irinotecan (CPT-11) and 5-fluorouracil (5-FU) in patients with resectable rectal cancer.
Methods and materials: Patients with resectable T3-T4 rectal cancer and Eastern Cooperative Oncology Group performance status <2 were included. CPT-11 (50 mg/m(2) weekly) and 5-FU (225 mg/m(2)/day continuous infusion, 5 days/week) were concurrently administered with radiation therapy (RT) (45 Gy, 1.8 Gy/day, 5 days/week), during 5 weeks.
Results: A total of 74 patients were enrolled: mean age, 59 years (20-74 years; SD, 11.7). Planned treatment was delivered to most patients (median relative dose intensity for both drugs was 100%). Grade 3/4 lymphocytopenia occurred in 35 patients (47%), neutropenia in 5 (7%), and anemia in 2 (3%). Main Grade 3 nonhematologic toxicities were diarrhea (14%), asthenia (9%), rectal mucositis (8%), and abdominal pain (8%). Of the 73 resected specimens, 13.7% (95% confidence interval [CI], 6.8-23.7) had a pathologic complete response and 49.3% (95% CI, 37.4-61.3) were downstaged. Additionally, 66.7% (95% CI, 51.1-80.0) of patients with ultrasound staged N1/N2 disease had no pathologic evidence of nodal involvement after CRT.
Conclusions: This preoperative CRT schedule has been shown to be effective and feasible in a large population of patients with resectable rectal cancer.