Small cell osteosarcoma. A clinicopathologic study of 27 cases.

Area of Science:

• Oncology
• Orthopedic Oncology
• Pediatric Oncology

Background:

• Small cell osteosarcoma (SCO) is a rare, high-grade variant of conventional osteosarcoma.
• SCO accounts for up to 4% of all osteosarcoma cases.
• It affects a similar age group and anatomical locations as conventional osteosarcoma.

Purpose of the Study:

• To analyze the clinical characteristics, treatment, and outcomes of patients with small cell osteosarcoma.
• To compare the prognosis of SCO with conventional osteosarcoma.
• To evaluate the effectiveness of different treatment modalities for SCO.

Main Methods:

• Retrospective analysis of 27 patients with SCO from two institutions (M. D. Anderson Cancer Center and Pediatric Oncology Group).
• Histological subtyping into Ewing's-like, lymphoma-like, and spindle cell patterns.
• Review of initial treatment protocols, including intra-arterial cisplatin, amputation, radiotherapy, and chemotherapy.

Main Results:

• The study included 27 patients (12 male, 15 female) aged 6-28 years (median 14).
• Fourteen patients died from metastases (lung, spine, brain) within 1-23 months.
• Twelve patients are alive, with nine having follow-up data ranging from 25-90 months.

Conclusions:

• Small cell osteosarcoma is an aggressive subtype of osteosarcoma with a prognosis comparable to or worse than conventional osteosarcoma.
• While intra-arterial cisplatin shows efficacy for primary bone tumors, controlling distant metastases remains a significant challenge.
• Further research is needed to improve treatment strategies and outcomes for SCO patients.