Purpose: To provide a 10-year update of the experience of the Cancer and Leukemia Group B (CALGB) in the addition of thoracic radiation therapy to chemotherapy in limited-stage small-cell lung cancer.
Patients and methods: Three hundred ninety-nine patients with limited-stage small-cell lung cancer were randomized to receive thoracic radiation therapy that started on day 1 (arm I) or day 64 of chemotherapy treatment (arm II), or chemotherapy alone with cyclophosphamide, vincristine, and etoposide (later, doxorubicin). Thoracic radiation therapy consisted of 4,000 rad to the tumor and mediastinum with a 1,000-rad boost. All patients received prophylactic cranial radiation to a dose of 3,000 rad.
Results: Arm I patients had a median survival of 13.04 months, arm II patients 14.54 months, and arm III patients 13.58 months (log-rank test, P = .0072). Median time to clinical failure was 11 months in arm I, 11.21 months in arm II, and 8.7 months in arm III (log-rank test, P = .0004).
Conclusion: With 10 years of follow-up, the two arms that included thoracic radiation therapy remain superior to chemotherapy alone. The addition of thoracic radiation therapy to combination chemotherapy improved both complete response rates and survival, with increased but acceptable toxicity.