Phase 1/2 study of concurrent chemoradiotherapy with weekly irinotecan hydrochloride for advanced/recurrence uterine cancer: A multi-institutional study of Kansai Clinical Oncology Group

OBJECTIVE: Concurrent chemoradiotherapy using cisplatin was thought to be standard treatment for squamous cell carcinoma of cervix, but it had not been effective for adenocarcinoma. Concurrent chemoradiotherapy using irinotecan hydrochloride (CPT-11) had been effective for colorectal cancer, thus, we chose CPT-11 as a candidate for gynecologic adenocarcinoma. To evaluate the maximum tolerated dose (MTD) of weekly CPT-11 with external pelvic radiotherapy, a phase 1/2 study was conducted according to modified Fibonacci method. METHODS: Eligible patients were advanced uterine cancer with measurable diseases [performance score (PS): 0−2]. Study period was from August 1st, 2002 to December 31st, 2008. The starting dose level (DL) of CPT-11 was 30 mg/m(2) (DL1) given weekly for 4 weeks. Subsequently, dose escalation was scheduled in 10 mg/m(2) increments to 60 mg/m(2) (DL4). The fixed radiotherapy consisted of whole pelvic 1.8 Gy/d, once a day in weekday for five weeks and it amounted to 45 Gy (25 fractions) in total. RESULTS: Seventeen patients were enrolled. As for toxicities, one (1/17: 5.9%) grade (G) 4 neutropenia lasting 7 days had been seen in DL4. G2 diarrhea was identified in 35.3% (6/17) of the patients, and 11.8% (2/17) G3 diarrhea was observed in DL3 and DL4. Thus, the MTD of CPT-11 was defined as dose of 60 mg/m(2). The recommended dose was decided as 50 mg/m(2). The response rate was 88.2% [9 complete response (CR), 3 partial response (PR), 3 stable disease (SD), 2 not evaluable (NE)]. Disease control rate at 1 month after treatment completion was 100% but distant metastases were found in 24% (4/17) in longer outcome. CONCLUSIONS: MTD was 60 mg/m(2) and recommended dose was set as 50 mg/m(2). This concurrent chemoradiation using weekly CPT-11 was feasible at 50 mg/m(2), and it might be effective even in adenocarcinoma of the uterus.