Randomized study of initial versus late chest irradiation combined with chemotherapy in limited-stage small-cell lung cancer. Aarhus Lung Cancer Group.

Purpose: To evaluate if the timing of chest irradiation with respect to chemotherapy would influence survival and local and distant control in patients with limited-stage small-cell lung cancer (LSCLC).

Patients And Methods: From 1981 to 1989, 199 consecutive patients with LSCLC were randomly allocated to receive initial chest irradiation (ICI; n = 99) or late chest irradiation (LCI; n = 100) given 18 weeks delayed. Both groups received the same nine cycles of combination chemotherapy: three cycles of cisplatin and etoposide and six cycles of cyclophosphamide, doxorubicin, and vincristine. In the first part of the study, prophylactic cranial irradiation (PCI) was only given to patients randomized to ICI, but after inclusion of 42 patients in the LCI arm, the protocol was changed, so that all patients received PCI independent of the timing of the chest irradiation (CI). A total of 157 patients received PCI with a radiation dose of 25 Gy in 11 fractions.

Results: The timing of radiotherapy had no significant effect on the 2-year overall survival rate (20% after ICI v 19% after LCI, P = .4) or the 2-year in-field recurrence rate (72% after ICI v 68% after LCI, P = .2). Median survival durations were 10.5 (ICI) and 12.0 (LCI) months. Similarly, no difference in the 2-year incidence of CNS recurrences was found between the 2 arms in patients who received PCI (19% after ICI v 13% after LCI, P = .24). Bone marrow toxicity was acceptable, as 15% developed World Health Organization (WHO) grade 4 leukocytopenia and 4% grade 4 thrombocytopenia. Grade 4 leukocytopenia was more pronounced in the ICI group. There was no difference in the frequency and severity of other toxicities between the 2 groups.

Conclusion: Timing of CI did not significantly influence the incidence of in-field recurrences, CNS recurrences, or overall survival.