How would you treat a patient with concurrent diagnoses of symptomatic multiple myeloma and a newly diagnosed upper extremity undifferentiated pleomorphic sarcoma?

Partly would depend on the prognostic details of the UPS - ?size, ?resectable. Sounds like the "symptomatic MM" needs urgent treatment and should take precedence. Considering pre-op XRT followed by a planned surgical excision at an opportune time could address both active problems.

I would approach the upper extremity UPS with the same principle as an extremity sarcoma- pre-op RT followed by surgery. However, it seems that the myeloma treatment takes precedence here- hence, a 6-8 week delay in treating the UPS may have to be tolerated. I would not combine IO with RT in this patient.

In this particular patient, an argument can be made to treat with hypofractionated RT instead of regular fractionation of RT (albeit there is no RCT yet comparing the regular fractionation with...