No, your oncologist will usually not oversee your diabetes management.
An oncologist is a doctor who specializes in treating cancer. They will work with you to decide which cancer treatment is right for you. Your oncologist will oversee the course of your cancer treatments, including managing side effects.
Cancer treatment is changing all the time. Oncologists have to keep up with the latest treatments. Because most oncologists are entirely focused on cancer, they are usually not comfortable managing your diabetes. It is important to keep visiting your regular diabetes doctor while being treated for cancer.
Oncologists are whizzes at cancer, but for diabetes they don’t have the answer!