Princess Kate and King Charles undergoing chemotherapy: How dangerous is a large audience for them?. Public appearances are associated with certain risks for cancer patients undergoing chemotherapy.

"When you undergo chemotherapy, you have higher rates of infection because of a weakened immune system,'" Dr. Julie Gralow, chief medical officer of the American Society of Clinical Oncology, tells people.com. King Charles is trying to take control of the situation in an unprecedented crisis. Is he endangering himself?