Rare Sarcoma - Hemangiopericytoma - Questions Please!!

Hi all,
I am new here. My 50 year old sister-in-law has a rare sarcoma, Hemangiopericytoma. About 7 years ago, she had a tumor on the front/side of her abdomen. She is very thin, so she found it. It was removed, and the path report was not clear about what it was. The doctors told her that they didn't think it was malignant, although it had some malignant characteristics. She was told that if it were malignant, it appeared to be the kind of tumor that later shows up in the lungs. She was told to get a CAT scan in a year, which she did, and then was never told to follow up further. (She just discovered, when she picked up her records at her GP's office, that the paperwork in her file said that she was to follow up every year. No one ever told her that. Everyone is screaming lawsuit at her but I advised her to save her strength and energy on staying serene and not pursuing that right now.)

Fast forward seven years. She was running and felt pain in her chest. She thought heart attack, there were some kind of tumors in her lungs. Her surgeon who took out the abdomenal tumor sent her to a thoracic surgeon. He removed and biopsied two of the tumors, again, they were unable to tell her what they were specifically. Just some vague type of sarcoma. He couldn't understand it, she had a 35 mm tumor in her lung, plus about 8 others, and was able to run, and was in great shape. A friend of her's and I convinced my SIL to go to Sloan, so she sent her paperwork, and they made her an appt with a sarcoma doctor.

The news was better than we expected at Sloan. The doctor told her that her type of sarcome, HPC, is very slow growing, and that he was just going to watch it for now. He wanted another CAT scan for baseline - when it came back, it showed tumor growth in at least two of the tumors in the two months since the last CAT, so he put her on Sutent.

Questions: can Sutent cure, or is it a way to buy time and hope for better meds? Can you shrink the tumors and then remove them? Is this chronic, can she live with this a long time??? Should she be looking at the Germany surgeon? She lives far from me, and I don't have the most recent info, as I wasn't at her appt with her, and I don't want to keep badgering her, but I am very, very concerned. Thanks for any help and knowledge you may have,
Adigal