How should palliative thoracic radiotherapy be fractionated for octogenarians with lung cancer?

Abstract

Background/aim: Geriatric oncology practice should be based on dedicated studies and real-world experience. Therefore, we evaluated survival outcomes after palliative thoracic radiotherapy in octogenarian patients with lung cancer and analyzed prognostic factors. Patients and Methods: We carried out a retrospective analysis of 51 patients with a median age of 83 years. Three different fractionation regimens were compared: two fractions of 8.5 Gy, 10 fractions of 3 Gy, and higher doses than 30 Gy (maximum biologically equivalent dose in 2-Gy fractions (EQD2) was always lower than 50 Gy). No concomitant chemotherapy was prescribed. Patients with incomplete radiotherapy (16%) were included, in line with the intention-to-treat principle, i.e. based on prescribed rather than accumulated dose. Results: Median survival was 3.4 months. We observed a relatively high proportion of patients who received radiotherapy in the last 30 days of life (24%). Nevertheless, approximately 10% of patients were alive 3-5 years after treatment. Prognosis was similar for those with stage III and IV disease. Multivariate analysis identified four significant prognostic factors for shorter survival: reduced performance status, serum C-reactive protein (CRP) ≥30 mg/l, leukocytosis, and prescribed radiation dose ≤30 Gy (EQD2=33 Gy). The three different radiotherapy regimens resulted in median survival of 2.4, 2.6 and 11.8 months, respectively. Conclusion: Survival outcomes were highly variable. Given that survival after 10 fractions of 3 Gy was indistinguishable from that after two fractions of 8.5 Gy, we suggest that the latter regimen should be considered for patients with poor prognosis. Patients with favorable prognostic factors should be treated with higher radiation doses, e.g. 15 fractions of 3 Gy.