Risk of Severe Pneumonitis After CCRT in Limited-Stage Small-Cell Lung Cancer

Patient undergoing radiotherapy.
Patient undergoing radiotherapy.
An estimated 3% to 6% of patients with limited-stage small-cell lung cancer develop grade 3-5 pneumonitis after concurrent chemoradiation.

An estimated 3% to 6% of patients with limited-stage small-cell lung cancer (LS-SCLC) exposed to concurrent chemoradiation (CCRT) develop grade 3 or higher pneumonitis, according to a meta-analysis published in Clinical Lung Cancer.

The meta-analysis included 7 studies with data on grade 3-5 pneumonitis in patients with LS-SCLC who were treated with CCRT. 

There were 3 randomized clinical trials (RCTs) encompassing 6 treatment arms with a total of 957 patients, and there were 4 non-RCT studies that included 5 treatment arms and a total of 306 patients.

The pooled incidence of grade 3-5 pneumonitis was 3.28% in the RCTs and 6.34% in non-RCTs. The pooled incidence of grade 5 pneumonitis alone was 0.29% in the RCTs and 0.88% in the non-RCTs.

“This increased incidence of pneumonitis observed in the non-RCT setting may be attributable, at least partially, to the differences in the study designs,” the researchers wrote. “Exclusion criteria in some RCTs, such as a prior history of pneumonitis, likely resulted in study populations with a lower risk of pneumonitis, compared to patients in non-RCT studies.”

The researchers suggested that the results of this meta-analysis will be useful as a reference for clinical trials currently investigating the combination of immunotherapies with CCRT in LS-SCLC. 

“[E]stablishing the baseline risk of severe pneumonitis associated with CCRT alone is beneficial in understanding the safety of novel immunotherapy or other therapeutic agents with regard to pneumonitis when concomitantly used with CCRT to treat LS-SCLC,” the researchers wrote. “With the current focus on the promising combination modality of CCRT with immunotherapy for the treatment of patients with recalcitrant LS-SCLC, these results should provide useful insights of the incidence rate of severe pneumonitis to understand the safety of this treatment combination for future trials.”

Disclosures: This research was supported by Merck Sharp & Dohme Corp. The study authors are employed by Merck or IQVIA, Inc. Please see the original reference for a full list of disclosures.


Kuang Y, Singh R, Nevo A, et al. Incidence of pneumonitis among limited stage small cell lung cancer patients exposed to concurrent chemoradiation: A systematic literature review and meta-analysis. Clin Lung Cancer. Published online September 26, 2022. doi:10.1016/j.cllc.2022.09.008

This article originally appeared on Cancer Therapy Advisor