Is sarcoma genetic?

ACTUALLY IT CAN BE. There are some genetic abnormalities that predispose people to have sarcoma- for instance: li- fraumeni syndrome- where there is 7% risk for sarcoma; gardner syndrome/fap- related to high frequency of intraabdominal desmoid tumor, retinoblastoma is associated with osteosarcoma, rothmund-thomson syndrome (poikiloderma congenitale) is associated with osteosarcoma- etc.
No. Not usually. There are no specific genetic syndromes that predispose pts to sarcoma unlike breast cancer, ovarian, colon cancer etc. Having said that, there may be some new mutations causing a saroma that may be ocassionally transmitted.