Pan-cancer analysis in the real-world setting uncovers immunogenomic drivers of acquired resistance post-immunotherapy.

Immunotherapy, specifically a type called immune checkpoint blockade, helps the human immune system recognize and attack cancer. However, many tumors eventually figure out how to survive the treatment. To understand why, researchers analyzed a massive collection of real-world data from over 5,000 patients with various types of cancer. They wanted to compare cancers that never responded to immunotherapy, known as primary resistance, with cancers that initially responded but later outsmarted the drugs, known as acquired resistance.

The study revealed an interesting clinical pattern. Patients whose tumors developed acquired resistance experienced extended survival across all the cancer types studied compared to those whose tumors never responded at all. When scientists looked closely at the area immediately surrounding these acquired resistance tumors, known as the tumor microenvironment, they found it was highly inflamed but ultimately dysfunctional. The immune system was still active, but the tumors had adapted to survive by altering their metabolism and multiplying rapidly.

The researchers also pinpointed the specific genetic changes that allow tumors to pull off this escape act. They confirmed known genetic culprits, but they also discovered new genes that lose their normal function and drive this resistance. Specifically, they identified new genetic mediators, including a loss of function in the TGFBR2 gene for non-small cell lung cancer, the CYLD gene in head and neck cancer, and the RUNX1 gene in triple-negative breast cancer.