Matched-Pair Analysis of High Dose Versus Standard Dose Definitive Chemoradiation for Locally Advanced Non-Small-Cell Lung Cancer

Abstract

Background: Recent data have called into question the use of dose-escalated radiotherapy for locally advanced non-small-cell lung cancer and the effect of cardiac radiotherapy doses. We compared the outcomes after chemoradiation using standard-dose (SD; ≤ 64 Gy) or high-dose (HD; > 64 Gy) radiotherapy.

Patients and methods: A matched-pair analysis was performed of 178 patients with stage IIB-IIIB non-small-cell lung cancer for SD versus HD groups using age ± 5 years, gender, stage, tumor size ± 2 cm, yielding 86 patients. The clinical endpoints were estimated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox regression method.

Results: The median follow-up was 16.8 months for the entire cohort (HD, 21.6 months; SD, 12.1 months; P = .06). No significant differences were found in disease stage, histologic type, age, performance status, gender, or tumor size between the 2 groups. The median overall survival was 23.1 months for the HD group (95% confidence interval, 20.6-25.5) versus 13.6 months for the SD group (95% confidence interval, 9.6-17.5; P = .03). The 2-year freedom from locoregional recurrence was 48.7% for the SD and 65.3% for the HD groups (P = .07). The 2-year freedom from distant metastasis was 46.7% for the SD and 70.3% for the HD groups (P = .05). A higher cardiac V30 dose (P = .03) was the strongest predictor of survival besides clinical stage (P = .02).

Conclusion: Dose-escalated radiotherapy resulted in improved survival and recurrence rates. A higher cardiac dose was a significant predictor of decreased survival.

Keywords: Cardiac radiotherapy; Concurrent chemoradiotherapy; Dose-escalated radiation; Locally advanced NSCLC; Stage III.