Soft-tissue sarcoma in adolescents and young adults compared with older adults: A report among 5000 patients from the Scandinavian Sarcoma Group Central Register.

Background: In recent years, there has been growing awareness of the distinct characteristics of adolescents and young adults (AYA) diagnosed with cancer. Soft-tissue sarcoma (STS) accounts for approximately 1% of all cancers diagnosed in adults and 8% of cancers diagnosed in AYA. To the best of our knowledge, only a few sarcoma registers include data regarding histological subtype, age at diagnosis, and detailed clinical information. Therefore, little is known regarding clinical presentation and outcomes in AYA diagnosed with STS.

Methods: Using the Scandinavian Sarcoma Group Central Register, data were obtained regarding 4977 patients who were diagnosed with STS for the period between 1986 and 2011. AYA (those aged 18-39 years) were compared with older adults (OA; those aged 40-80 years) with respect to clinical presentation, treatment, and outcome.

Results: There were 868 AYA and 4109 OA. Overall and by STS subtype, there were significant differences noted between AYA and OA with regard to presentation, treatment, and survival. The distribution of STS subtypes was different between OA and AYA (eg, OA were more likely to be diagnosed with malignant fibrous histiocytoma compared with AYA [34% vs 16%; P < .001]). OA also were more likely to have tumors measuring ≥5 cm (68% vs 56%; P < .001) and a higher malignancy grade (75% vs 67%; P < .001). In the majority of STS subtypes AYA had significantly better overall survival and less disease recurrence compared with OA, but this finding was not true for those with malignant peripheral nerve sheath tumors.

Conclusions: There are several differences between AYA and OA with STS with regard to presentation, treatment, and survival, and such differences must be taken into consideration when designing clinical trials. Additional work also is needed to characterize the potential biological mechanisms underlying these differences.