HIGH TOTAL DOSE RADIATION IMPROVES SURVIVAL OF PATIENTS WITH LOCALLY ADVANCED SMALL CELL LUNG CANCER: RESULTS OF SINGLE-CENTRAL RETROSPECTIVE ANALYSIS

Abstract

The overall survival of patients with locally advanced small cell lung cancer who received at least 2 courses of chemotherapy and external beam radiation therapy at a total dose >50 Gy delivered to the primary tumor was retrospectively studied. Patients were dividedinto 2 groups. Patients in the standard treatment group (n=71) were treated to 50–58 Gy total dose. The dose escalation group (n=69) was treated to 60–74 Gy. Accelerated fractionation regimen in radiotherapy was more frequently given in dose escalation treatment group. The 1-, 3- and 5-year survival rates in the dose escalated and standard dose groups were respectively 54 % (95 % CI 42–65 %) and 32 % (95 % CI 23–44 %), р=0,11; 25 % (95 % CI 16–36 %) and 1 % (95% CI 0–8 %), р=0,0003; 17 % (95 % CI 10–28 %) and 0 % (95 % CI 0–5 %) (р=0.0007). The median survival was 14 months (95 % CI 10–17 months) in the dose escalated treatment group and 9 months (95 % CI 8–11months) in patients of the standard treatment group (χ2=16,8, р<0,0001). Multifactorial analysis showed that a total dose of ≥60 Gy resulted in reduction in risk of death (RR 0,57 (CI 0,37–0,88), р=0,012). Radiation dose escalation can result in improvement of local control for patients with locally advanced small cell lung cancer. Prospective randomized studies are required to finally confirm this hypothesis.

Keywords

• locally advanced small cell lung cancer
• radiation therapy