How would you approach therapy for an elderly patient with NF1-associated metastatic MPNST who remains asymptomatic?  

The decision should be based on the extent/bulk of disease, rapidity with which it may be growing (or not), PS/organ function/co-morbidities and of course, in this incurable situation, the COVID-19 crisis. Since patient is asymptomatic and assuming you are not worried about impending symptoms, short...