Clinical Presentation And Patterns Of Care In Scare Soft Tissue Sarcoma

Soft tissue sarcomas (STS) represent 1% of all adult malignancies and are rarely associated with lymph node involvement. Five sarcoma histologies, identified by the mnemonic SCARE (Synovial, Clear cell, Angiosarcoma, Rhabdomyosarcoma and Epithelioid), are commonly associated with lymph node (LN) involvement. Our aims were to analyze the incidence of lymph node involvement of SCARE histologies and identify the patterns of care. Adults individuals (>18 - 90+) diagnosed with SCARE-STS between 2004-2014 were identified from the NCDB. We included the 5 histologies of interest and excluded all patients who received adjuvant therapy more than 180 days from diagnosis. Chi-square tests were used to compare demographic factors, tumor characteristics and therapy received. 10,256 patients with SCARE-STS were identified. SCARE histologies comprised 34, 4, 35, 17 and 10% respectively. Of the total, 6% were located in the head and neck region, 17% in the upper extremities, 46% in the lower extremities and 30% in the trunk. Incidence of LN involvement in SCARE was 4.1, 23.5, 10.5, 21.4 and 19.4% respectively. Incidence of distant metastases was highest in rhabdomyosarcoma (27%) and lowest in synovial sarcoma (13%). Despite the lowest incidence of LN involvement (4.1%), synovial sarcoma demonstrated the highest correlation between nodal disease and distant metastases (33.3%), the highest of all SCARE histologies. Of all subtypes, chemotherapy was used in 47, 19, 32, 62 and 31% respectively. In patients with positive LN, use of chemotherapy was highest in rhabdomyosarcoma (77.4%) and lowest in clear cell sarcoma (28%). Radiation was given most often in synovial sarcoma (52%) and least often in clear cell sarcoma (26%). Multivariate analysis and survival data will be presented. An analysis of lymph node involvement in SCARE-STS revealed surprisingly less lymph node involvement (4.1%) in synovial sarcoma than previously believed, while confirming the high likelihood of lymph node involvement in the remaining four subtypes, thus supporting the mnemonic CARE. Notably, the use of chemotherapy in these 5 histologies is higher than that historically reported for other STS subtypes.