(P 205) MULTI-MODAL TREATMENT IS ASSOCIATED WITH IMPROVED SURVIVAL IN AYA PATIENTS WITH METASTATIC NON-RHABDOMYOSARCOMA SOFT TISSUE SARCOMA

Objective: Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) account for over 8% of cancer diagnoses occurring in adolescent and young adult (AYA, ages 15-39 years) patients. Approximately 20% of patients are diagnosed with metastatic disease, which has a dismal prognosis, so optimal care is critical for these patients. Therefore, we sought to evaluate treatment patterns, receipt of multi-modal treatment and survival outcomes among AYA patients with metastatic NRSTS in a large population-based cohort.

Methods: We identified AYAs diagnosed during 2004-2018 with metastatic NRSTS in the California Cancer Registry. We defined multi-modal treatment as receipt of surgery, in addition to chemotherapy and radiation as first-line treatment, based on Children’s Oncology Group (COG) Trial ARST0332. We used multivariable logistic regression models to evaluate associations of clinical and sociodemographic factors with receipt of multi-modal treatment and Cox proportional hazards models to measure the impact of multi-modal treatment on survival.

Results: Of the 548 AYAs with metastatic NRSTS, 60% were male, 45% were ages 31-39 years, 47% were Hispanic, and 40% had public insurance. In this cohort, 18% received all their care at National Cancer Institute or COG (NCI-COG) facilities, and 16% received multi-modal treatment. Older age was associated with decreased odds of receiving multi-modal treatment (>21 years vs. 15-20). Five-year survival was higher for those receiving multi-modal treatment (20% vs 15%, p=0.013). In multivariable models, patients not receiving multi-modal treatment had a 41% increased risk of death; lower neighborhood socioeconomic status (vs. high), Asian/Pacific Islander race/ethnicity (vs. non-Hispanic White), and some or no care at NCI-COG facilities (vs. all) also were associated with an increased risk of death.

Conclusion: We found that few AYAs with metastatic NRSTS received multi-modal treatment despite the significant association with improved survival. While the management of NRSTS can vary greatly by institution and treating specialty, the role of multi-modal treatment, including combined surgery, chemotherapy and radiation, in this subset of patients should be considered. Furthermore, NRSTS are a heterogeneous group of soft tissue tumors whose management benefits from a multidisciplinary therapeutic approach available at NCI-COG facilities. However, only 18% of our study cohort received all their care at these facilities, highlighting the need to investigate barriers to care in this population.