Treatment and toxic effects of prophylactic cranial irradiation in stage II-III non-small cell lung cancer: A meta-analysis

Abstract

Objective: To determine the role of prophylactic cranial irradiation (PCI) in non-small cell lung cancer (NSCLC) patients using meta-analysis.

Methods: PubMed, Embase, the Cochrane Database of Systematic Review and the China National Knowledge Infrastructure databases were systematically searched for studies published between 1 January 1980 and 31 March 2019. Search terms included "non-small cell lung cancer," "prophylactic cranial irradiation" and "clinical trials." The research data extracted from above studies was analyzed by Review Manager 5.3 and Stata12.0 software. The outcomes included development of brain metastases (BMs), overall survival (OS), disease-free survival (DFS), BMs for different diagnoses, toxicity, quality of life (QoL).

Results: Fifteen trials (nine RCTs and six non-RCTs) involving 2418 NSCLC patients met the inclusion criteria. There was a significant reduction in the risk of developing BM in patients who received PCI compared with those who did not (95% CI, 0.20-0.37; P < 0.00001). PCI significantly reduced the BM of squamous cell carcinoma (P = 0.02), but not for adenocarcinoma (P = 0.07) and other pathological types (P = 0.29). There was a significant increase in DFS for the PCI compared to the non-PCI group (P = 0.006); however, OS did not significantly differ (P = 0.15). In addition, fatigue significantly increased in the PCI group (P = 0.0002). Cognitive disturbance showed no significant difference between PCI and non-PCI groups (P = 0.06).

Conclusion: This study showed that, compared with non-PCI, PCI significantly decreased the incidence of NSCLC BM and improved the DFS of patients, and reduced the BM rate from squamous cell carcinoma. However, it showed no effect on OS and the BM rate of adenocarcinoma and other pathological types of tumors. There were limited data concerning PCI-related toxicity and QoL.

Keywords: brain metastases; disease-free survival; non-small cell lung cancer; overall survival; prophylactic cranial irradiation; quality of life; toxicity.