Long-term efficacy of radical treatment of patients with clear cell sarcoma

Clear cell sarcoma (CCS) is a rare subtype of soft tissue sarcoma (STS). The objective of this analysis was to evaluate the effectiveness of multidisciplinary treatment of CCS and to identify potential factors that influence the outcome.

A retrospective analysis of curative-intent treatment of CCS patients between 1998 and 2024 in the sarcoma reference centre.

The median Relapse-free Survival (RFS) and Overall Survival (OS) times were 33.1 (95% CI: 11.1-Not Reached, NR) and 55.5 (95% CI: 37.4-NR) months, respectively. One year after the surgery, the RFS was 63.5% (95% CI: 49.5-81.5), and at three and five years it was 41.8% (95% CI: 28-62.4) and 38.3% (95% CI: 24.8-59.2), respectively. Three years after the surgery 64.7% (95% CI: 50.3-83.2) of patients were alive, and at five years - 49.3% (95% CI: 34.1-71.2). Among 19 patients referred for sentinel lymph node biopsy (SLNB), it was positive in 8 (42.1%) patients, at the same time lymph node dissection (LND) was performed in 4 patients. Excluding patients undergoing electrochemotherapy and wide excision of scar, the R0 resection margins were achieved in 14 (48.3%) patients. Those patients had superior RFS compared to patients with R1/2 resection margins: 83 (95% CI: 14.8-NR) months and 11.1 (95% CI: 5.9-NR) months, respectively (p = 0.0095). We observed a similar trend for OS, where patients with R0 margins had NR (95% CI: 30-NR) compared to 37.4 (95% CI: 10.6-NR) in the case of R1/2 margins, p = 0.051.

Consequently, SLNB and LND procedures should be offered more often to patients with this diagnosis.