Silvia C. Formenti

Silvia Chiara Formenti is an Italian-American oncologist who is Chair of the Department of Radiation Oncology at Weill Cornell. She is associate director of the Meyer Cancer Center. She investigates the role of ionizing radiation on the immune system. She was elected to the National Academy of Medicine in 2024.

Early life and education Formenti is from Milan. She completed her medical training at the University of Milan. She moved to the University of Southern California for specialty training, where she focused on cancer immunology.

Research and career Formenti works in radiation biology. She has studied the role of ionizing radiation on the immune system, and shown how tumors respond better to a combination of radiotherapy and immune therapy. She has designed clinical trials for metastatic breast cancer, lung cancer and melanoma. She showed that in the presence of an immune checkpoint blockade (e.g. CTLA-4) an irradiated metastatic tumor can become an immunogenic hub, and behave similar to a vaccine. When immunized against the metastatic tumor, the host develops an immune response that can reject other tumors. She has shown that localized radiation and immune checkpoint blockades can help patients enter remission. Her research has shown that it is possible to convert "immunogenically cold" (i.e. non-responsive) tumor into an "immunogenically hot" (i.e. responsive) tumor.

Formenti showed that radiotherapy modifies how breast cancer cells process biomolecules, activating signalling pathways that are activated in other viruses. She has developed new strategies to reduce the risk of cardiovascular toxicity during breast cancer radiotherapy. Her strategy prevents radiation fields damaging the lungs or heart.

Formenti joined Weill Cornell Medicine in 2015.

Selected publications