Dr. Schulte on the Prevalence of TSC1/TSC2 Mutations in Cancer

Brian Schulte, MD, sarcoma medical oncologist, the University of California San Francisco (UCSF) Health, discusses the prevalence of TSC1/TSC2 mutations in various cancers.

TSC1/2 mutations are pathogenic mutations that are seen in a variety of histologic subtypes and malignancies, but the prevalence of the mutation varies depending on the type of cancers, Schulte explains. For example, the mutation is as frequent as 8% in types of bladder cancer vs 3% in types of sarcomas, Schulte adds. Altogether, the TSC1/2 mutations can be seen in thousands of patients across the country, Schulte says.

TSC1/2 mutations are tumor suppressors by their nature, with the purpose of abrogating proteins that are downstream, such as mTOR, Schulte continues. The thought is that these mechanisms will lead to further tumor growth through an alternate pathway, Shulte adds. Whether those specific mutations alone can impact prognosis is not known, although previous studies revealed that inhibition of the mTOR pathway leads to high response rates and durable responses in patients, Schulte concludes.