Which classes to take to become a pediatric oncologist?

Peds heme/onc: A pediatric hematologist/oncologist has completed medical school then 3 years of pediatric residency followed by 3 years of fellowship.

Lots: The training is long and arduous. You need to go to medical school, then pediatric residency, then pediatric hematology/oncology fellowship and then become certified by passing your board exams.

None specifically: Pediatric oncologists have many different majors in college including non-science degrees in history, english, or art; although most are science majors in college. There are no specific classes in medical school for this career. A Pediatric residency program and a Pediatric hematology/oncology fellowship after completing medical school is what makes one a pediatric hematologist/oncologist.