Patients with higher muscle quality during treatment with PD-1/PD-L1 inhibitor monotherapy for non-small cell lung cancer (NSCLC) had higher overall response rates and longer progression-free survival than patients with lower-quality skeletal muscle, researchers reported in study findings published in Cancer Medicine.

Researchers looked at data from 156 patients with NSCLC and compared high and low muscle quality (i.e., density) and high and low muscle quantity (i.e., size measurement) with response to treatment with PD-1/PD-L1 inhibitors. A total of 80 (51.3%) and 47 (30.1%) patients had low muscle quality and quantity, respectively.

They discovered a difference related to muscle quality only: Those with high muscle quality had higher overall response rates (35.0% versus 15.8%) and longer progression-free survival (a median of 4.5 months versus 2.0 months) than those with low muscle quality. Muscle quantity did not correlate with a difference in response, and overall survival did not differ among any of the study variables.

The researchers hypothesized that lower muscle quality suggested the presence of inflammatory markers such as TNF-alpha, IL-6, and CRP, all of which increase certain immune cells in the body that limit the effects of cancer immunotherapies.

“This study suggests that lumbar muscle quality can serve as a sensitive predictor of the therapeutic effects of PD‐1/PD‐L1 inhibitor monotherapy in patients with NSCLC,” the researchers said. Further studies are needed to confirm the results.