Abstract IA20: Cancer subtypes and their immune microenvironments

In the vast majority of cancer types, as demonstrated and exemplified in colorectal cancer (CRC) and non-small cell lung cancer (NSCLC), a high density of CD8+ T cells associated with high densities of tertiary lymphoid structures (TLS) in the tumor microenvironment correlates with a good prognosis for the patient. However, an opposite association has been reported in primary clear cell renal cell carcinoma (RCC) and several other cancers. Our team studied the immune infiltrates of pulmonary metastases from CRC and RCC. As in the primary tumors, a high density of CD8+ T cells correlated with good prognosis for CRC metastases, while it correlated with a bad prognosis for RCC metastases. These results suggested that the identity of the tumor cells, rather than the organ where they grow, is critical for shaping the immune contexture of a given tumor.

Transcriptomic analyses of large cohorts of human CRC and RCC allow to define molecular subgroups associated with distinct risks of tumor progression. We therefore characterized the immune microenvironments of the molecular subgroups of CRC and RCC. In CRC, the MSI-enriched subgroup identified patients with high cytotoxic T cells infiltration and favorable prognosis. In CRC and RCC, we confirmed that patients with low tumoral T and B cell infiltrations presented with high risk of death; In addition, in both cancer types, we identified subgroups of poor-prognosis patients with high tumoral lymphocyte infiltration, in the context of high expression of genes related to inflammation, immunosuppression, and angiogenesis.

Integration of molecular and immune tumor phenotypes refines prognostic cancer groups. Moreover, these classifications allow to select immunotherapies appropriate to specific, potentially responding, groups of patients.

Citation Format: Etienne Becht, Nicolas A. Giraldo, Aurelien De Reynies, Pierre Laurent-Puig, Benoit Beuselinck, Jessica Zucman-Rossi, Marie Caroline Dieu-Nosjean, Catherine Sautes-Fridman, Wolf H. Fridman. Cancer subtypes and their immune microenvironments. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr IA20.