I have posted here many times over the years, most of the money raised by THON goes into endowment and other funds building Penn State institutionally. It is a Penn State-only fund raising initiative intentionally wrapped in the guise of directly supporting pediatric cancer patients and their families, but it is completely unlike the Children's Miracle Network or national cancer charities that it tries to emulated in its branding.
According to this latest article, only 19 cents for every dollar donated go to actually immediately and directly supporting cancer patients and their families, and then only at Penn State Hershey. Unlike St. Jude's, Penn State Hershey does not cover all expenses for all patients, although it likely could if it was spending more than 19% of money raised on it instead of plowing into Penn State University endowments, operational reserves, and faculty start up packages.
When you want to help kids with cancer, give to your local children's cancer hospital. If you want to fund pediatric cancer research, there are many universities, including Pitt and CHOP, that are doing more highly regarded research, or give to more reputable national cancer research organizations that fund competitively evaluated research proposals from across the country.