There is a current phase 2 trial specifically for sarcomas that have metastasized to the lung. It uses Reolysin, which is a virus thought to be able to kill off the cancer cells. It's rare to find a trial specifically for sarcomas and is definitely worth looking into.
Two places are conducting it:
University of Michigan Medical School - 800-865-1125
and
Institute of Drug Development, Cancer Therapy Research Center San Antonio, TX. Contact is Monica Mita, MD, 210-450-1797.
Good luck!