High-Grade Osteosarcoma of the Foot: Presentation, Treatment, Prognostic Factors, and Outcome of 23 Cooperative Osteosarcoma Study Group COSS Patients

Abstract EN

Osteosarcoma of the foot is a very rare presentation of a rare tumor entity.

In a retrospective analysis, we investigated tumor- and treatment-related variables and outcome of patients registered in the Cooperative Osteosarcoma Study Group (COSS) database between January 1980 and April 2016 who suffered from primary high-grade osteosarcoma of the foot.

Among the 23 eligible patients, median age was 32 years (range: 6–58 years), 10 were female, and 13 were male.

The tarsus was the most commonly affected site (n=16).

Three patients had primary metastases.

All patients were operated: 5 underwent primary surgery and 18 received surgery following preoperative chemotherapy.

In 21 of the 23 patients, complete surgical remission was achieved.

In 4 of 17 patients, a poor response to neoadjuvant chemotherapy was observed in the resected primary tumors.

Median follow-up was 4.2 years (range: 0.4–18.5).

At the last follow-up, 15 of the 23 patients were alive and 8 had died.

Five-year overall and event-free survival estimates were 64% (standard error (SE) 12%) and 54% (SE 13%), which is similar to that observed for osteosarcoma in general.

Event-free and overall survival correlated with primary metastatic status and completeness of surgery.

Our findings show that high-grade osteosarcoma in the foot has a similar outcome as osteosarcoma of other sites.