This is one of those jobs that is absolutely necessary and requires tremendous passion and dedication. Unlike being a pediatrician or obstetrician, which are happy disciplines and usually have good outcomes, a pediatric oncologist knows from the outset that many patients will not survive. However, he or she still has to provide the best care, along with support for the family. But, the ones who do make it provide tremendous joy.
Some pediatric oncologists specialize in research, in order to eradicate childhood cancers. This is probably a somewhat easier discipline, since the doctor is not involved in direct patient care and can more easily leave the work in the lab, rather than bringing it home.