Novel Strategy Makes Colorectal Cancers Sensitive to Immunotherapy

A team of researchers from Ifom (Institute Foundation of Molecular Oncology), the University of Turin and the University of Milan, in collaboration with the Memorial Sloan Kettering Cancer Center in New York, the San Raffaele Hospital and the Candiolo Irccs Institute, has identified an innovative strategy to make colorectal tumors sensitive to immunotherapy. The discovery, made possible thanks to the support of the European Research Council and the Airc Foundation, was published in the scientific journal Cancer Cell.

By combining two chemotherapeutics, researchers have managed to overcome the problem that afflicts patients with metastatic colorectal cancer, who in over 95% of cases do not respond to immunotherapy, a true revolution in the last fifteen years in the field of treatment of many tumors. The reason lies in the characteristics of this type of cancer, which make it practically invisible to the immune system. The turning point came by studying the combination of two drugs: temozolomide and cisplatin. Cells treated with this combination in an attempt to protect themselves from chemotherapy produce behaviors that make them recognizable and attackable by the immune system.

The combination of cisplatin and temozolomide is also able to modify the environment surrounding the tumor, the so-called tumor microenvironment, making it more favorable to the activation of the immune response against cancer. The first eighteen patients have already been treated experimentally with encouraging results at the Memorial Sloan Kettering Cancer Center in New York. The discovery, the researchers emphasize, "represents a significant paradigm shift: 'instead of directly fighting the tumor's resistance mechanisms, therapies have learned to exploit them'".