Retrospective study of impact of intratumoral Escherichia on outcomes with immune checkpoint inhibition in patients with advanced non-small cell lung cancer

The impact of the intratumoral microbiome on immune checkpoint inhibitor (ICI) efficacy in patients with advanced non-small cell lung cancer (aNSCLC) is unknown. A retrospective study at Memorial Sloan Kettering Cancer Center (New York, NY) evaluated the association of intratumoral Escherichia with outcomes of aNSCLC patients receiving ICI. In the discovery cohort, detection of intratumoral Escherichia was associated with significantly longer overall survival (median 16 versus 11 months; HR 0.73; p=0.0065) among patients treated with single-agent ICI, but not among patients receiving combination chemoimmunotherapy. The association with OS in the single-agent ICI cohort remained statistically significant in multivariable analysis adjusting for prognostic features including PD-L1 expression. Transcriptomic analysis correlated Escherichia-positive samples with expression signatures of immune cell infiltration. The association of Escherichia positivity with OS in patients receiving single-agent ICI was confirmed in an external validation cohort. The authors conclude that presence of intratumoral Escherichia was associated with longer OS among patients receiving single-agent ICI.