Image analysis reveals molecularly distinct patterns of TILs in NSCLC associated with treatment outcome

Despite known histological, biological, and clinical differences between lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC), relatively little is known about the spatial differences in their corresponding immune contextures. Our study of over 1000 LUAD and LUSC tumors revealed that computationally derived patterns of tumor-infiltrating lymphocytes (TILs) on H&E images were different between LUAD (N = 421) and LUSC (N = 438), with TIL density being prognostic of overall survival in LUAD and spatial arrangement being more prognostically relevant in LUSC. In addition, the LUAD-specific TIL signature was associated with OS in an external validation set of 100 NSCLC treated with more than six different neoadjuvant chemotherapy regimens, and predictive of response to therapy in the clinical trial CA209-057 (n = 303). In LUAD, the prognostic TIL signature was primarily comprised of CD4(+) T and CD8(+) T cells, whereas in LUSC, the immune patterns were comprised of CD4(+) T, CD8(+) T, and CD20(+) B cells. In both subtypes, prognostic TIL features were associated with transcriptomics-derived immune scores and biological pathways implicated in immune recognition, response, and evasion. Our results suggest the need for histologic subtype-specific TIL-based models for stratifying survival risk and predicting response to therapy. Our findings suggest that predictive models for response to therapy will need to account for the unique morphologic and molecular immune patterns as a function of histologic subtype of NSCLC.

Automated summary

This study reveals the spatial differences in tumor-infiltrating lymphocytes (TILs) between lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC). TIL density is prognostic of overall survival in LUAD, while spatial arrangement is more prognostically relevant in LUSC. The TIL signature specific to LUAD is associated with overall survival and response to therapy. In both subtypes, TIL features are associated with immune scores and biological pathways related to immune recognition, response, and evasion.