Do children, adolescents, and young adults with soft tissue sarcoma benefit from early detection of recurrences? Results of a population-based study.

9573 Background: Most patients with pediatric soft tissue sarcoma (PSTS) achieve a 1st remission with primary therapy, but recurrences are frequent and drive mortality. Relapse detection (RD) is the foundation of post-treatment surveillance. The rationale for frequent follow-up investigations is RD in an early stage with better salvage options. There is however little evidence regarding the value of early asymptomatic RD and it was not investigated by any larger or population-based study in PSTS. We determined whether early radiographic RD in asymptomatic patients improves post-relapse outcome. Methods: Patients aged < 18 years at first reference-reviewed PSTS-diagnosis registered with CWS were enrolled if a 1st relapse occurred between 1/2003 and 7/2010. The methods of RD and their impact on outcome were evaluated. The data were correlated with the German Childhood Cancer Registry (GCCR), which receives all information about cancer patients < 18 years. Results: 235 patients from Germany (n = 212) and Swe...