Phase I/II study of induction chemotherapy using carboplatin plus irinotecan and sequential thoracic radiotherapy (TRT) for elderly patients with limited-disease small-cell lung cancer (LD-SCLC): TORG 0604.

Background: The role of irinotecan for elderly patients with LD-SCLC has been unclear, and the timing of TRT combined with chemotherapy has not been fully evaluated.

Methods: Patients aged > 70 years with untreated, measurable, LD-SCLC, performance status (PS) 0-2, and adequate organ function were eligible. Treatment consisted of induction with carboplatin on day 1 and irinotecan on days 1 and 8, every 21 days for 4 cycles, and sequential TRT (54Gy in 27 fractions). Carboplatin doses were based on AUC of 4 and 5 (levels 1 and 2, respectively), with a fixed irinotecan dose (50 mg/m). Primary objective of the phase II study was overall responce rate.

Results: Forty-three patients were enrolled and forty-one were finally analyzed (median age: 75 years [range 70-86 years); males 31; PS 0/1/2, n = 22/18/1]. Two patients were excluded because of protocol violation (ascertained to be extensive disease). Twelve patients were accrued at phase I and the number of patients with carboplatin dose-limiting toxicities at levels-1 (n = 6) and -2 (n = 6) were 1(grade 3 hypertension) and 2 (grade 4 thrombocytopenia), respectively. The phase II trial was expanded to 29 additional patients receiving the level 1 carboplatin dose, total of 35 patients. The median number of chemotherapy cycles was 4 (range 1-4), and the median radiation dose was 54Gy (range 36-60). Toxicities were generally mild. There were 4 complete and 27 partial responses (response rate 88.6%). With a median follow-up of 52 months, the median progression-free and overall survival times of phase II were 11.2 and 27.1 months, respectively.

Conclusions: Induction chemotherapy of carboplatin plus irinotecan and sequential TRT was well tolerated and effective for elderly patients with LD-SCLC. Additional confirmatory studies are warranted.

Trial Registration: Trial registration number: UMIN000007352 Name of registry: UMIN. Date of registration: 1/Dec/2006. Date of enrolment of the first participant to the trial: 6/Feb/2007. Clinical trial registration date: 1/Feb/2006 (prospective).