The role of higher thoracic irradiation doses in patients with limited stage of small-cell lung cancer: Retrospective study

Background: Small-cell lung cancer is highly chemo- and radiosensitive tumor. We evaluated two different radiotherapy doses applied sequentially with chemotherapy in relation to time to progression, progression free survival, and overall survival in patients with limited disease of small cell lung cancer. Methods: From 1998 to 2003, 81 patients were treated for small-cell lung carcinoma. Median age was 57 years (range, 36-77 years) and female: male ratio was 1:4. Patients were initially treated with four cycles of chemotherapy during three weeks (cisplatin 80mg/m2 IV, day 1 and etoposide 100 mg/m2 IV, days 1 - 3). One month later, patients received up to 44 Gy, 2 Gy per day, 5 days per week (group I, 41 patients) or above 44 Gy, standard fractionation (group II, 40 patients), to mediastinum and tumor. Range of higher radiotherapy doses was 54 Gy to 64 Gy, standard fractionation. We evaluated if different radiotherapy doses had any influence on time to progression, progression free survival, and overall survival. Results: The median follow up time was 23 months (range, 12-72 months) for both groups of patients (81). The median time to progression in group I of patients (41) was 13 months (range, 11-29 months) while median time to progression in group II of patients (40) was 20 months (min=9, max=60). There was no statistically significant difference in relapse rate between two groups of patients (p>0.05, Fisher test). However, there was difference but not statistically significant in one-year progression free survival (p=0.05, chi square test) between groups, while there was statistically significant difference in two-year progression free survival favoring higher doses of radiotherapy (p0.05, chi-square test). However, there was statistically significant difference in overall survival favoring higher radiotherapy doses for two-year overall survival (p