Abstract: We identified 1549 records; 85 items from electronic databases, 45 from study registries, and 1419 from congress proceedings. The revised search strategy did not identify any additional RCTs. In the previous version of the review, we identified one RCT comparing HDCT followed by autologous HSCT versus standard-dose chemotherapy (SDCT). The trial randomized 87 participants who were considerably heterogeneous with respect to 19 different tumor entities. The data from 83 participants were available for analysis. In the single included trial, overall survival at three years was 32.7% in the HDCT arm versus 49.4% in the SDCT arm and there was no difference between the treatment groups (hazard ratio (HR) 1.26, 95% confidence interval (CI) 0.70 to 2.29, P = 0.44; 1 study, 83 participants; high quality evidence). In a subgroup of participants who had a complete response before HDCT, overall survival was higher in both treatment groups and overall survival at three years was 42.8% in the HDCT arm versus 83.9% in the SDCT arm and favored the SDCT group (HR 2.92, 95% CI 1.1 to 7.6, P = 0.028; 1 study, 39 participants). In the single included trial, the authors reported one treatment-related leukemia death two years after HDCT. They also evaluated severe adverse events WHO grade 3 to 4 in 22 participants in the HDCT arm and in 51 participants in the SDCT arm. The authors reported 11 events concerning digestive-, infection-, pain-, or asthenia-related toxicity in the HDCT arm and one event in the SDCT arm (moderate quality evidence). The development of secondary neoplasia was not addressed. We judged the study to have an overall unclear risk of bias as three of seven items had unclear and four items had low risk of bias. For GRADE, we judged three items as high quality and three items were not reported. The limited data of a single RCT with an unclear risk of bias and moderate to high quality evidence showed no survival advantage for HDCT. If this treatment is offered it should only be given after careful consideration on an individual person basis and possibly only as part of a well-designed RCT.

Plain-language summary: The evidence is current to 6 September 2016. We found one RCT that compared 38 people in the high-dose chemotherapy and transplantation group versus 45 people in the chemotherapy-only group and was judged to have mainly a low risk of bias (as it was well designed). The participants were 18 to 65 years old, had various types of nonrhabdomyosarcoma soft tissue sarcomas and were monitored for about 55 months. The treatment period ranged from 2000 to 2008. The single RCT was funded by a nonprofit organization (the funder did not benefit if the trial found good results). The results of the RCT did not favor either of the two treatment arms with respect to overall survival. There was one death related to treatment in the transplantation group and none in the chemotherapy-only group. There were eight cases of severe nonhematologic (not related to the blood) side effects in the transplantation group and one in the chemotherapy-only group. The overall quality of the data was unclear and based on only one RCT. Currently, research evidence is limited for the use of high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation for people with non-rhabdomyosarcoma soft tissue sarcomas. Further evidence is needed through well-designed clinical trials.