A multicenter phase I study of preoperative chemoradiotherapy with S-1 and irinotecan for locally advanced lower rectal cancer (SAMRAI-1)

作者：Sato Takeo; Hayakawa Kazushige; Tomita Naohiro; Noda Masafumi; Kamikonya Norihiko; Watanabe Toshiaki; Kato Daiki; Sakai Yoshiharu; Hiraoka Masahiro; Shimada Mitsuo; Ikushima Hitoshi; Baba Hideo; Oya Natsuo; Oya Masatoshi; Nemoto Murofushi Keiko; Takeuchi Masahiro; Watanabe Masahiko^*

来源：Radiotherapy and Oncology, 2016, 120(2): 222-227.

DOI：10.1016/j.radonc.2016.06.002

• Neoadjuvant chemoradiotherapy
• S-1
• Irinotecan
• Rectal cancer

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/m(2)/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/m(2) (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/m(2) (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/m(2).

• 出版日期2016-8
• 单位中国医学科学院肿瘤医院