Beyond Abscopal Effect: A Meta-Analysis of Immune Checkpoint Inhibitors and Radiotherapy in Advanced Non-Small Cell Lung Cancer.

BACKGROUND

Immune checkpoint inhibitors (ICI) plus radiotherapy (RT) have been suggested as an emerging combination in non-small cell lung cancer (NSCLC) patients. However, little is known about the magnitude of its benefits and potential clinical predictors.

OBJECTIVE

To assess the effects of this combination on the increase in overall and progression-free survival.

DATA SOURCES

The MEDLINE and CANCERLIT (1970-2020) electronic databases were searched, and the reference lists of included studies were manually searched.

STUDY SELECTION

Studies were included if they were comparative studies between combination ICI-RT and ICI or RT alone in advanced or metastatic NSCLC patients. Overall survival (OS) was analyzed according to the treatment strategy.

DATA EXTRACTION

Data on population, intervention, and outcomes were extracted from each study, in accordance with the intention-to-treat method, by two independent observers and combined using the DerSimonian method and Laird method.

RESULTS

Compared to ICI or RT alone, ICI-RT significantly increased the 1-year and 3-year OS RR by 0.75 (95% CI 0.64-0.88; = 0.0003) and 0.85 (95% CI 0.78-0.93; = 0.0006), respectively. Furthermore, there was a statistically significant benefit on 1- and 3-year progression-free survival (RR 0.73 (95% CI, 0.61-0.87; = 0.0005) and RR 0.82 (95% CI 0.67-0.99; = 0.04), respectively).

CONCLUSIONS

In patients with advanced or metastatic NSCLC, combination ICI-RT increases 1- and 3-year OS and progression-free survival compared to ICI or RT alone.