Efficacy of Gemcitabine-based Chemotherapy in Clear Cell Sarcoma of Soft Tissue

BACKGROUND/AIM

Clear cell sarcoma (CCS) is an aggressive sarcoma subtype, resistant to conventional anthracycline-based chemotherapy and radiation. The diagnosis is often challenging due to similarities with malignant melanoma.

PATIENTS AND METHODS

We aimed to analyse the activity of gemcitabine-based chemotherapy in a cohort of patients with CCS treated at the Royal Marsden Hospital.

RESULTS

Five patients with metastatic CCS received gemcitabine as first- or second-line systemic therapy. The median time-to-progression was 10 weeks. The median number of cycles of gemcitabine-based therapy was 3 (range=2-7 cycles). Median overall survival in our cohort was 66 months from the initial diagnosis but in the metastatic setting, the overall survival was reduced to 28 months.

CONCLUSION

Gemcitabine-based therapy has modest activity in CCS. There remains a significant unmet medical need for novel, effective therapies for this disease.

Sclerosing Epithelioid Fibrosarcoma of the Bone With Rare EWSR1-CREB3L3 Translocation Driving Upregulation of the PI3K/mTOR Signaling Pathway

Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon neoplasm that rarely presents in bone. It is characterized by epithelioid cells arranged in nests and single-file cords within a sclerotic stromal background which may mimic neoplastic bone. SEF harbors an EWSR1 translocation, which may complicate its distinction from Ewing sarcoma in cases with histomorphologic overlap. We present a diagnostically challenging case of SEF in the mandible of a 16-year-old girl. Our experience highlights the lack of specificity of traditional morphology and EWSR1 break-apart fluorescent in situ hybridization. Open-ended RNA-based fusion gene testing coupled with MUC4 immunohistochemistry aided the eventual diagnosis in this case. Herein, we report the third case of SEF with EWSR1-CREB3L3 translocation and show that this fusion leads to aberrant upregulation of the phosphoinositide 3-kinase/mammalian target of rapamycin signaling pathway in heterologous cell models.