Update on the management of BCOR::CCNB3 sarcoma.

Area of Science:

• Oncology
• Genetics
• Pathology

Background:

• BCOR::CCNB3 sarcoma is a rare entity characterized by the BCOR::CCNB3 fusion gene.
• It primarily affects males under 20, often originating in bone, and was previously grouped with Ewing-like sarcomas.
• This distinct sarcoma is a significant component of 'sarcoma with BCOR genetic alterations'.

Purpose of the Study:

• To delineate the characteristics, diagnosis, and treatment of BCOR::CCNB3 sarcoma.
• To highlight its distinction from other bone sarcomas.
• To emphasize the need for collaborative research due to its rarity.

Main Methods:

• Review of radiological, pathological, and molecular diagnostic criteria.
• Analysis of treatment protocols, including surgical resection and chemotherapy (often Ewing sarcoma protocol).
• Evaluation of incidence, metastatic rates, recurrence, and survival data.

Main Results:

• Radiological findings are variable, mimicking other high-grade sarcomas or appearing benign.
• Pathological diagnosis relies on BCOR::CCNB3 fusion detection, with characteristic immunohistochemistry (CD99, BCOR, Cyclin D1, SATB2).
• Approximately 20% present with metastasis, and local recurrence rates are around 20%; 5-year survival is ~75%.

Conclusions:

• BCOR::CCNB3 sarcoma is a distinct entity requiring molecular confirmation.
• While less aggressive than Ewing sarcoma at diagnosis, it has a notable local recurrence rate.
• Collaborative multi-institutional studies and long-term follow-up are essential for advancing treatment and understanding outcomes.