NCRT with S-1 plus irinotecan for LALRC
Sato, Takeo Kitasato University
Hayakawa, Kazushige Kitasato University
Tomita, Naohiro Hyogo College of Medicine
Noda, Masafumi Hyogo College of Medicine
Kamikonya, Norihiko Hyogo College of Medicine
Watanabe, Toshiaki The University of Tokyo
Kato, Daiki Kawasaki Saiwai Hospital
Sakai, Yoshiharu Kyoto University
Hiraoka, Masahiro Kyoto University
Baba, Hideo Kumamoto University
Oya, Natsuo Kumamoto University
Oya, Masatoshi Dokkyo Medical University
Nemoto-Murofushi, Keiko The Cancer Institute Hospital Japanese Foundation for Cancer Research
Takeuchi, Masahiro Kitasato University
Watanabe, Masahiko Kitasato University
Background and purpose: Preoperative 5-fluorouracil-based chemoradiotherapy is a standard treatment for locally advanced lower rectal cancer (LALRC). We performed a phase I study to develop a new regimen combining irinotecan and S-1.
Materials and methods: Patients with LALRC (T3-4, N0-2) were studied. The radiation dose was 45 Gy in 25 fractions. S-1 (80 mg/m2/day) was administered on days 1–5, 8–12, 22–26, and 29–33. Irinotecan was administered on days 1, 8, 22, and 29. The dose of irinotecan was initially 60 mg/m2 (level 1). Surgery was performed 6–10 weeks after the chemoradiotherapy.
Results: Twenty patients were enrolled, of whom 18 patients were analyzed. Dose-limiting toxicity (DLT) did not occur in the first 3 patients treated with irinotecan at 80 mg/m2 (level 2), but developed in 3 of the 6 patients who received irinotecan at 90 mg/m2 (level 3). Then DLT occurred in 3 other patients at level 2. At level 2 or 3, DLT comprised neutropenia, thrombocytopenia, and diarrhea. Level 2 was designated as the maximum tolerated dose, and level 1 as a recommended dose (RD). The pathological complete response rate was 28%, and the down-staging rate was 56%.
Conclusions: Our results suggested that the RD of irinotecan when combined with preoperative S-1 and pelvic radiation was 60 mg/m2.
Radiotherapy and Oncology
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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