Chemoradiotherapy with or without granulocyte-macrophage colony-stimulating factor in the treatment of limited-stage small-cell lung cancer: a prospective phase III randomized study of the Southwest Oncology Group.

PURPOSE This phase III randomized trial was designed to determine if granulocyte-macrophage colony-stimulating factor (GM-CSF) reduces the hematologic toxicity and morbidity induced by chemoradiotherapy in limited-stage small-cell lung cancer (SCLC). METHODS This multicenter prospective trial randomized 230 patients to receive chemotherapy and radiotherapy (RT) with or without GM-CSF given on days 4 to 18 of each of six cycles. The primary end point was hematologic toxicity. Secondary end points included the following: nonhematologic toxicities; days of (1) fever, (2) antibiotics, (3) hospitalization, and (4) infection; number of transfusions; drug doses delivered; and response rates and survival. RESULTS There was a statistically significant increase in the frequency and duration of life-threatening thrombocytopenia (P < .001) in patients randomized to GM-CSF. GM-CSF patients had significantly more toxic deaths (P < .01), more nonhematologic toxicities, more days in hospital, a higher incidence of intravenous (IV) antibiotic usage, and more transfusions. Patients randomized to GM-CSF had higher WBC and neutrophil nadirs (P < .01), but no significant difference in the frequency of grade 4 leukopenia or neutropenia. Patients randomized to GM-CSF had a lower complete response rate (36% v 44%), but the differences were not significant (P = .29). There were no significant differences in survival (median, 14 months on GM-CSF and 17 months on no GM-CSF; P = .15). CONCLUSION GM-CSF, as delivered in this study, should not be included with concurrent chemoradiotherapy treatment programs for limited-stage SCLC. The simultaneous use of hematopoietic colony-stimulating factors (CSFs) and chemoradiotherapy should be performed only in experimental settings. Chemoradiotherapy programs with cisplatin and etoposide ([VP-16] PE) and simultaneous chest RT produce grade 4 neutropenia and thrombocytopenia in a small-enough proportion of patients that prophylactic hematopoietic growth factors are clinically unnecessary.