Patients with previously untreated extensive-disease small-cell lung cancer were treated with irinotecan 60 mg m À2 on days 1 and 8 and cisplatin 60 mg m À2 on day 1 with (n ¼ 55) or without (n ¼ 54) etoposide 50 mg m À2 on days 1 -3 with granulocyte colonystimulating factor support repeated every 3 weeks for four cycles. The triplet regimen was too toxic to be considered for further studies. Small-cell lung cancer (SCLC), which accounts for approximately 14% of all malignant pulmonary tumours, is an aggressive malignancy with a propensity for rapid growth and early widespread metastases (Jackman and Johnson, 2005). A combination of cisplatin and etoposide (PE) has been the standard treatment, with response rates ranging from 60 to 90% and median survival times (MSTs) from 8 to 11 months in patients with extensive disease (ED)-SCLC (Fukuoka et al, 1991;Roth et al, 1992). A combination of irinotecan and cisplatin (IP) showed a significant survival benefit over the PE regimen (MST: 12.8 vs 9.4 months, P ¼ 0.002) in a Japanese phase III trial for ED-SCLC (Noda et al, 2002), although another phase III trial comparing these regimens failed to show such a benefit (Hanna et al, 2006). Thus, irinotecan, cisplatin and etoposide are the current key agents in the treatment of SCLC. A phase II trial of the three agents, IPE combination, in patients with ED-SCLC showed a promising antitumour activity with a response rate of 77%, complete response (CR) rate of 17% and MST of 12.9 months (Sekine et al, 2003).We have developed these IP and IPE regimens in a 4-week schedule where irinotecan was given on days 1, 8 and 15. The dose of irinotecan on day 15, however, was frequently omitted because of toxicity in both regimens (Noda et al, 2002;Sekine et al, 2003).The objectives of this study were to evaluate the toxicities and antitumour effects of IP and IPE regimens in the 3-week schedule in patients with ED-SCLC and to select the right arm for subsequent phase III trials.
PATIENTS AND METHODS
Patient selectionPatients were enrolled in this study if they met the following criteria: (1) a histological or cytological diagnosis of SCLC; (2) no prior treatment; (3) measurable disease; (4) ED, defined as having distant metastasis or contralateral hilar lymph node metastasis; (5) performance status of 0 -2 on the Eastern Cooperative Oncology Group (ECOG) scale; (6) predicted life expectancy of 3 months or longer; (7) age between 20 and 70 years; (8) adequate organ function as documented by a white blood cell (WBC) count X4.0 Â 10 3 ml À1 , neutrophil count X2.0 Â 10 3 ml À1 , haemoglobin X9.5 g dl À1 , platelet count X100 Â 10 3 ml À1 , total serum bilirubinp1.5 mg dl À1 , hepatic transaminasesp100 IU l À1 , serum creatinine p1.2 mg dl À1 , creatinine clearance X60 ml min À1 , and PaO 2 X60 torr; and (9) providing written informed consent.Patients were not eligible for the study if they had any of the following: (1) uncontrollable pleural, pericardial effusion or ascites; (2) symptomatic brain metastasis; (3) active infection; (4) contr...