diamond.
Good questions.
First, you need to understand that if you do peds Hem Onc, it's 3 full years after residency. Once finished you will enter either private practice, or most likely join the faculty at an academic institution.
In private practice, Peds Hem-Onc ( and there are not a lot of jobs by the way ), you will function more as a generalist. So your desire to treat children in their teens, is not really viable in this setting. There are simply not enough patients, in most cases, for you to exist. You would end up treating most childhood malignancies, and hematologic disorders.( 2 year olds with Wilms tumors or neuroblastomas, or 8 year olds with Thalassemia or Sickle cell. )Most peds hem onc docs, even in a private practice setting, continue to follow their patients into young adulthood, so your desire to do this is really not a problem. There's basically no difference between a 24 yr old and an 18 yr old in this setting . Eventually, you'll cut them loose to the mercy of some adult doctor.
In the Acadamic setting, which is where the majority of the jobs exist, you would typically find some niche that appealed to you, while doing department coverage, of the wide spectrum of illnesses. This means, you may choose to work in Bone marrow transplant, or treat exclusively solid tumors, or even further specialize, and treat osteosarcomas. In large academic settings, there is a large enough referral base for this. Plus, you spend a lot of time doing research. Again, you'll do blocks of time, away from your research and specialty interests " on service" which means you function as the attending on the inpatient service, treating a little bit of everything. Depending on your job description, you'll do 2 to 10 months a year on service
In terms of doing peds vs. med peds, I really see no advantage in doing the medicine part, just to do long term follow up. You will be doing the vast majority of your work in peds hem-onc, in the field of your choice. As I mentioned earlier, you will continue to do long term follow up of your patients into adulthood.
Normally, you do not select an age group you like treating, but rather a disease you treat. There are some illnesses that are more common in the teenage group, like lymphoma and some soft tissue sarcomas.
my advice would be to skip the med-peds route and do straight peds, with a peds hem-onc fellowship. Absolutely do at least a few electives in it before you make the decision, because I found the reality of the career a lot different than I imagined it would be.
Certainly try and do a med student rotation, adn at least one rotation as a peds resident.
MD Anderson and St Jude are IMO, 2 of the best programs to train, especially if you want a research focused academic career
