Inpatient - I agree with APPs. Most of the solid tumor issues are social support/dispo management. PGY1 resident can do that, APPs are very capable of doing that. For any complex patients TTP etc, consultants should see the patients and should be directly supervising. Even seasoned APPs won't be able to reliably help on those patients. Utilizing APPs for inpatient services to free outpatient work is the way to go in community.
Outpatient - is a whole another issue. APPs should not and could not do a consult. Oncology is complex as it is and hematology except for some stuff (sent by APPs) which can be easily handled by PCPs (but choose not to) can be done? except for rare cases in which they will clearly miss non-secretory myeloma, HES etc. Grip of foundational sciences is a must. For chemo follow ups, some practices use APPs. IMO if you are productivity based, there is no reason to have APP in oncology. They would take easy cases and leave hard cases to you. For salaried academic positions, they usually like to deflect a lot to APPs (which I hold grudge against).
In short, oncology is proliferating so rapidly, that APPs won't be able to handle outpatient (cerebral things). As someone else mentioned, IRA and 340B may create a larger problem but pharma lobby and hospital lobby (for better or worse) is strong with deep pockets. In that case, there will be eventual pendulum swing to private practices.