Dose-intensive chemotherapy in extensive-stage small-cell lung cancer

The importance of the dose intensity of chemotherapy in achieving maximal therapeutic effect has recently been reported for several chemosensitive malignant diseases, with Murray et al. reporting that intensive weekly chemotherapy using the cisplatin, vincristine, doxorubicin, and etoposide (CODE) regimen in small-cell lung cancer (SCLC) is very effective. However, leukopenia is the major obstacle to delivering the planned dose in intensive regimens. Therefore, we investigated whether recombinant human granulocyte colony-stimulating factor (rhG-CSF) could allow full drug doses to be given as scheduled, thereby improving the final outcome. Extensive-stage (ES) SCLC patients were randomized to receive either CODE alone or CODE with rhG-CSF, with the CODE regimen consisting of cisplatin given i.v. at 25 mg/m2 weekly for 9 weeks; vincristine given i.v. at 1 mg/m2 during weeks 1, 2, 4, 6, and 8; and doxorubicin given i.v. at 40 mg/m2 and etoposide given i.v. at 80 mg/m2 for 3 days during weeks 1, 3, 5, 7, and 9, rhG-CSF at 50 micrograms/m2 was given s.c. on the days on which cytotoxic drugs were not given. From May 1989 to September 1991; 64 patients were enrolled in the study, of whom 63 were analyzable (31 for CODE alone and 32 for CODE with rhG-CSF). No difference in any of the patients' characteristics except gender was found between the two groups. The complete response (CR) rate was 34% in the CODE with rhG-CSF group and 23% in the CODE alone group; the median survival was 59 and 32 weeks, respectively, in these groups (P = 0.004). Therefore CODE with rhG-CSF improved the survival of ES SCLC patients. On the basis of these results a phase III study to determine whether CODE with rhG-CSF would increase survival as compared to the standard regimen in ES SCLC was designed by the Japan Clinical Oncology Group.