Local control correlates with overall survival in radiotherapy for early-stage non-small cell lung cancer: A systematic review.

PURPOSE: Local control (LC) is an important outcome of local cancer therapy, besides overall survival (OS). We conducted a comprehensive literature search to investigate whether a high LC rate contributes to good OS in radiotherapy for early-stage non-small cell lung cancer (ES-NSCLC).

MATERIALS AND

METHODS

Studies in patients receiving radiotherapy for peripheral ES-NSCLC, mainly staged as T1-2N0M0 were included for a systematic review. Relevant information was collected including, dose fractionation, T stage, median age, 3-year LC, cancer-specific survival (CSS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and OS. Correlations between outcomes and clinical variables were evaluated.

RESULTS

After screening, 101 data points from 87 studies including 13,435 patients were selected for the quantitative synthesis. Univariate meta-regression analysis revealed that the coefficients between the 3-year LC and 3-year DFS, DMFS, CSS, and OS were 0.753 (95% confidence interval (CI): 0.307-1.199; p < 0.001), 0.360 (95% CI: 0.128-0.593; p = 0.002), 0.766 (95% CI: 0.489-1.044; p < 0.001), and 0.574 (95% CI: 0.275-0.822; p < 0.001), respectively. Multivariate analysis revealed that the 3-year LC (coefficient, 0.561; 95% CI: 0.254-0.830; p < 0.001) and T1 proportion (coefficient, 0.207; 95% CI: 0.030-0.385; p = 0.012) were significantly associated with the 3-year OS and CSS (coefficient for 3-year LC, 0.720; 95% CI: 0.468-0.972; p < 0.001 and T1 proportion, 0.002; 95% CI: 0.000-0.003; p = 0.012). Toxicities ≥ grade 3 were low (3.4%).

CONCLUSIONS

Three-year LC was correlated with three-year OS in patients receiving radiotherapy for ES-NSCLC. A 5% increase in 3-year LC is expected to improve the 3-year CSS and OS rates by 3.8% and 2.8%, respectively.