Prevalence
A heterogeneous group representing ~15% of all skin and subcutaneous tumors in dogs. Includes fibrosarcoma, peripheral nerve sheath tumor, hemangiopericytoma, and several others.
Who gets it
Middle-aged to older medium-large breed dogs. Golden Retrievers, German Shepherds, Boxers commonly affected.
Symptoms to watch for
- A firm, slow-growing subcutaneous mass
- Often painless until large
- May ulcerate if size becomes significant
- Lameness if on a limb
How it's diagnosed
- FNA (often non-diagnostic for sarcomas — frequent false negatives)
- Incisional or core biopsy with histopathology + grading
- Mitotic count is the strongest prognostic factor
- Imaging of the local site (MRI for limb tumors) to plan surgery
- Three-view chest radiographs for staging
Prognosis ranges
Grade I/II with clean margins: often curative; >3 years median. Grade III: median ~9 months even with adjuvant therapy. Local recurrence is the bigger problem than metastasis for low-grade.
Treatment landscape
Recurrent mutations in this cancer
Frequencies from canine clinico-genomic cohorts. SciRouter Oncology auto-checks every mutation in your dog's report against the OncoKB-aligned database for matched targeted therapies.
Questions to ask your vet
- What's the grade and mitotic count?
- Were the margins clean?
- If not, what are our options — re-excision, radiation, or metronomic chemo?
- What's the metastatic risk for this grade?
- Could we have done a pre-surgical MRI to plan margins better?
Quality-of-life notes
Most STS dogs feel essentially normal. The QoL hit comes from the surgery itself, not the cancer. Limb-sparing techniques are worth asking about.