A systematic review and meta-analysis of stereotactic body radiation therapy versus surgery for patients with non-small cell lung cancer

Abstract

Objective: Stereotactic body radiation therapy is the preferred treatment modality for patients with inoperable early-stage non-small cell lung cancer. However, comparative outcomes between stereotactic body radiation therapy and surgery for high-risk patients remain controversial. The primary aim of the present meta-analysis was to assess overall survival in matched and unmatched patient cohorts undergoing stereotactic body radiation therapy or surgery. Secondary end points included cancer-specific survival, disease-free survival, disease recurrence, and perioperative outcomes.

Methods: A systematic review of relevant studies was performed through online databases using predefined criteria. The most updated studies were selected for meta-analysis according to unmatched and matched patient cohorts.

Results: Thirty-two studies were identified in the systematic review, and 23 were selected for quantitative analysis. Surgery was associated with superior overall survival in both unmatched (odds ratio, 2.49; 95% confidence interval, 2.10-2.94; P < .00001) and matched (odds ratio, 1.71; 95% confidence interval, 1.52-1.93; P < .00001) cohorts. Subgroup analysis demonstrated superior overall survival for lobectomy and sublobar resection compared with stereotactic body radiation therapy. In unmatched and matched cohorts, cancer-specific survival, disease-free survival, and freedom from locoregional recurrence were superior after surgery. However, stereotactic body radiation therapy was associated with fewer perioperative deaths.

Conclusions: The current evidence suggests surgery is superior to stereotactic body radiation therapy in terms of mid- and long-term clinical outcomes; stereotactic body radiation therapy is associated with lower perioperative mortality. However, the improved outcomes after surgery may be due at least in part to an imbalance of baseline characteristics. Future studies should aim to provide histopathologic confirmation of malignancy and compare stereotactic body radiation therapy with minimally invasive anatomical resections.

Keywords: meta-analysis; non–small cell lung cancer; stereotactic body radiation therapy; surgery; survival.

Figure 1

Forest plot of the odds ratio (OR) of overall survival in unmatched patients (A), overall survival in matched patients (B), and cancer-specific survival in matched patients (C) after stereotactic body radiation therapy (SBRT) versus surgery in patients with early-stage non-small cell lung cancer. The estimate of the OR of each study corresponds to the middle of the squares, and the horizontal line shows the 95% confidence interval (CI). On each line, the numbers of events as a fraction of the total number randomized are shown for both treatment groups. For each subgroup, the sum of the statistics, along with the summary OR, is represented by the middle of the solid diamonds. A test of heterogeneity between the trials within a subgroup is given below the summary statistics. SE, standard error.

Figure 2

Reconstructed Kaplan-Meier graph of overall survival using aggregated data from matched patients with early-stage non-small cell lung cancer who underwent stereotactic body radiation therapy (SBRT) versus surgery. Shading represents the 95% confidence limits around the central estimate.

Figure 3

Reconstructed Kaplan-Meier graph of cancer-specific survival using aggregated data from matched patients with early-stage non-small cell lung cancer who underwent stereotactic body radiation therapy (SBRT) versus surgery. Shading represents the 95% confidence limits around the central estimate.