Soft tissue sarcoma in dogs: treatment, prognosis and clinical trials

Dogs · USA & Canada

Understanding soft tissue sarcoma

Soft tissue sarcoma is a family of tumors that arise from connective tissues such as muscle, fibrous tissue, nerves and related structures. They often send microscopic extensions into nearby tissue even when the visible mass looks well defined. Grade, subtype, size and location determine how likely the tumor is to recur locally or spread.

What does the prognosis look like?

Many low- and intermediate-grade soft tissue sarcomas can be controlled for a long time when the first local treatment is well planned. Higher grade, large size, recurrence, difficult location and metastatic spread worsen the outlook. For an individual dog, grade and the ability to achieve durable local control are usually more useful than a single survival statistic.

What matters next

If the mass is still present, the first definitive surgery should be planned rather than treated as a simple lump removal because microscopic tumor can extend beyond what is visible. If it has already been removed, get the grade and measured margins from the pathology report before deciding whether more surgery, radiation or monitoring is appropriate.

Where are you now?

The mass is still present

The first definitive local treatment matters. Ask whether biopsy or imaging would change the surgical plan and whether wide margins are realistically achievable before the tumor is removed.

It was removed with clean margins

Grade still matters. Many low- or intermediate-grade soft tissue sarcomas need no automatic chemotherapy after complete excision; use grade and other pathology features to decide whether staging or additional treatment adds value.

It was removed with incomplete margins

Do not wait automatically for visible regrowth. Re-excision is often considered when feasible; radiation or another local-control method may be reasonable when wider surgery would be difficult.

It has recurred or cannot be widely removed

Re-image the local site and restage before simply repeating surgery. Radiation, systemic treatment, electrochemotherapy, or a trial may be considered according to grade, anatomy, and measurable disease.

If you are waiting for oncology

If the tumor is still present, avoid an unplanned narrow excision simply because an oncology appointment is delayed; the first surgery can determine whether durable local control is achievable. If it was already removed, obtain the grade and measured margins before deciding whether to watch, re-excise or use radiation or another local treatment.

Questions to ask your oncologist

What grade is the sarcoma and what are the measured surgical margins?
Is wider surgery still feasible, or is radiation or another local treatment more sensible?
Does this grade and site justify metastatic staging or systemic therapy?

How the diagnosis may appear in the record

Soft tissue sarcoma is a treatment group rather than one microscopic diagnosis. Reports may use names such as fibrosarcoma, peripheral nerve sheath tumor, myxosarcoma, or perivascular wall tumor. Grade, mitotic count, necrosis, and measured margins are usually more useful than the subtype name. Osteosarcoma, hemangiosarcoma, histiocytic sarcoma, and round-cell tumors should not automatically be treated as ordinary STS.

Changes to watch for at home

Measure a visible mass consistently and report rapid growth, skin breakdown, bleeding, pain, reduced limb use, or a new mass near the scar. A painless recurrence can still matter. New coughing, breathing difficulty, or unexplained decline warrants reassessment in higher-risk disease.

How it is usually treated

Wide surgery is the main treatment when the tumor can be removed with an appropriate margin. If margins are incomplete or another wide surgery is not practical, radiation can improve local control. Chemotherapy is usually reserved for higher-grade, metastatic or otherwise high-risk tumors rather than used automatically for every soft tissue sarcoma.

What can affect treatment choices

Grade, size, location, whether this is the first tumor or a recurrence, and whether wide local control is still possible matter most. High-grade or metastatic disease makes systemic treatment more relevant.

Tests that may matter

The most important information usually comes from pathology: exact diagnosis, grade and measured surgical margins. Imaging is selected according to tumor size, location and grade, especially when it will change surgery or staging. Keep pathology blocks and slides available if review, molecular testing or a trial may be considered.

Treatment options available now

12 options currently in our catalog.

Check eligibility

Local T-cell engager immunotherapy before surgery for canine soft tissue sarcoma

Multicenter local T-cell-engager STS immunotherapy · USA

Participating locations

WSU Veterinary Teaching Hospital, 205 Ott Rd, Pullman, WA 99164
VRCCO East, 62889 NE Oxford Ct, Bend, OR 97701

Study details

VRCCO is currently enrolling; confirm WSU intake separately

What is being offered: One local T-cell-engager protocol, AVMA study 534230, previously represented by two active catalog records. Current VRCCO primary evidence describes CD3/CD28 T-cell engagement targeting B7-H3/PD-L1, injected into the tumor, followed by standard surgical removal approximately one week later. There is no placebo. VRCCO eligibility includes cutaneous soft tissue sarcoma over 1.7 cm and body weight at least 5 kg. Previously published WSU criteria required easily accessible STS at least 2 cm; the WSU page could not be read in this audit, so its present intake and site-specific criteria require confirmation. Do not apply VRCCO-specific thresholds to the unverified WSU cohort.

Who may qualify: Confirmed cancer diagnosis required; Measurable; Planned surgery; Min weight kg: 5

Costs / coverage: VRCCO provides a $1,500 surgery credit and covers study-related ICU stays, bloodwork and medications. The previously published WSU offer was a $1,000 medical credit plus study-related ICU, medications and bloodwork; that WSU offer was not independently reverified today. Owners pay uncovered standard surgical/diagnostic care.

Contact: VRCCO / Dr. Kristen Couto — official clinical-trial page. WSU: Jennifer Heusser — jpmarcus3@wsu.edu; 509-592-3668; current WSU intake needs reconfirmation.

Official study / enrollment information →

Gold nanoparticle photothermal treatment for selected superficial tumors

Bridge Animal Referral Center · USA

Location

Bridge Animal Referral Center, 8401 Main St, Edmonds, WA 98026, Edmonds, WA

Study details

Active enrollment — eligible superficial gross tumors

What is being offered: Intravenous gold nanoparticles followed by near-infrared laser heating of the superficial tumor; BARC describes one heat session for smaller lesions and commonly two to three for larger sarcomas.

Who may qualify: Active tumor required; Measurable

Costs / coverage: Current BARC enrollment page does not specify costs or coverage. An older BARC page mentions support for different, narrower cohorts; those amounts cannot be assumed to apply to this enrollment.

Contact: Bridge Animal Referral Center, Edmonds — 425-697-2272

Official study / enrollment information →

Evaluation of TLR agonist Z-007 in dogs with cancer

Cummings School of Veterinary Medicine, Tufts University · USA

Location

Henry and Lois Foster Hospital for Small Animals, 200 Westboro Rd, North Grafton, MA 01536

Study details

Recruiting

What is being offered: Dog study of IV or intratumoral Z-007 for solid tumors including carcinomas, sarcomas and melanoma. Public criteria include a generally 2–7 cm repeat-biopsy-accessible tumor plus medical/laboratory requirements; no prior immunotherapy or autoimmune disease. Investigator prescreening required.

Who may qualify: Confirmed cancer diagnosis required; Min weight kg: 7; Measurable

May not qualify if: Prior immunotherapy

Costs / coverage: 🟡 Partially funded. Z-007 treatment through Day 63 and treatment of Z-007/biopsy-related side effects are covered; other owner costs should be confirmed with Tufts.

Contact: clinicaltrials@tufts.edu

Official study / enrollment information →

Radiation therapy plus XCSgel immunotherapy for canine soft tissue sarcoma

NC State College of Veterinary Medicine · USA

Location

NC State Veterinary Hospital, 1052 William Moore Dr, Raleigh, NC 27607

Study details

Actively recruiting — enrollment finish August 31, 2027

What is being offered: Blinded study of standard radiation therapy plus XCSgel immunotherapy; all enrolled dogs receive surgery and radiation, while XCSgel versus placebo is blinded. Pathologic confirmation of STS required and no prior radiation or chemotherapy.

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Measurable; Min tumor cm: 4; Max tumor cm: 10; Planned surgery; Planned radiation

May not qualify if: Prior chemo; Prior local radiation

Costs / coverage: 🟢 Fully funded — NC State states enrolled dogs receive free testing, treatment and follow-up, including bloodwork, CT, surgery and radiation therapy.

Contact: NC State Clinical Studies Core — see official trial page

Official study / enrollment information →

Engineered canine T cells with oral immunotherapy for soft tissue sarcoma

Colorado State University Flint Animal Cancer Center · USA

Location

Flint Animal Cancer Center, 300 W Drake Rd, Fort Collins, CO 80523

Study details

Actively recruiting — listed on CSU current clinical trials page

What is being offered: Autologous engineered CAR T-cell infusion with oral immunotherapy; tumor resection or repeat biopsy and follow-up

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Min weight kg: 11; chemotherapy washout: 14 days; Pretreatment biopsy; Planned chemo; radiation washout: 14 days

May not qualify if: Prior immunotherapy; Current chemo

Costs / coverage: Study support includes up to $3,200 in study-related treatment costs, $2,000 toward surgery or other treatment, oral immunotherapy medications excluding dispensing fees, and up to $500 for study-related side effects. Owners pay the initial exam/diagnostic testing and surgery costs beyond study support; screening-test assistance is available. Confirm the individual cost estimate with CSU.

Contact: CSU Flint Animal Cancer Center Clinical Trials — (970) 297-4001; online clinical-trial consult form

Official study / enrollment information →

FAP CAR-T cell therapy for canine soft tissue sarcoma

Tufts Cummings School of Veterinary Medicine · USA

Participating locations

Henry and Lois Foster Hospital for Small Animals, 200 Westboro Rd, North Grafton, MA 01536
UC Davis Veterinary Medical Teaching Hospital, 1 Garrod Dr, Davis, CA 95616

Study details

Actively recruiting — confirmed on the institution’s current clinical-trials page

What is being offered: Dogs need a 2-8 cm soft tissue sarcoma, resectable or non-resectable, adequate CBC/chemistry/urinalysis and no incompatible major heart, liver or kidney disease. Untreated tumors and recurrent tumors after chemotherapy and/or radiation may qualify; chemotherapy must have ended at least 14 days before enrollment. Excludes metastatic disease predicting survival under three months, concurrent experimental cancer therapy, pregnancy/lactation, autoimmune disease other than atopic dermatitis, prior monoclonal checkpoint inhibitor such as gilvetmab, or personalized T-cell vaccine/immunotherapy. At UC Davis the current protocol requires age at least one year and weight at least 11 kg, with eight visits over approximately 70 days; study-related side-effect coverage is capped at $2,500 for Davis care. Historical enrollment at CSU does not alone establish a third currently enrolling site.

Who may qualify: Active tumor required; Min tumor cm: 2; Min weight kg: 11; chemotherapy washout: 14 days; Max tumor cm exclusive: 8

May not qualify if: Pregnant or lactating; Autoimmune disease; Prior checkpoint inhibitor

Costs / coverage: 🟡 Partially funded. The study covers FAP CAR-T cancer treatment through Day 56, provides $2,000 toward tumor removal, and covers treatment of side effects related to biopsy, cyclophosphamide and FAP CAR-T administration; unrelated care is owner-paid.

Contact: clinicaltrials@tufts.edu

Official study / enrollment information →

Anti-MIC antibody plus adoptive NK-cell therapy for canine soft tissue sarcoma

The Ohio State University Veterinary Medical Center · USA

Location

The Ohio State University Veterinary Medical Center, 601 Vernon L Tharp St, Columbus, OH 43210

Study details

Actively recruiting — confirmed on the institution’s current clinical-trials page

What is being offered: Localized confirmed STS treated with anti-MIC antibody and expanded natural-killer-cell infusion.

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Localized

May not qualify if: Prior local radiation; Immunosuppressive

Costs / coverage: All trial-related procedures are covered and $700 compensation is provided upon trial completion.

Contact: Blue Buffalo Veterinary Clinical Trials Office — CVM-ClinicalTrials@osu.edu

Official study / enrollment information →

Surgical treatment study for resectable canine soft tissue sarcoma

University of Illinois Veterinary Teaching Hospital · USA

Location

University of Illinois Veterinary Teaching Hospital, 1008 W Hazelwood Dr, Urbana, IL 61802

Study details

Actively recruiting — confirmed on the institution’s current clinical-trials page

What is being offered: Tumor biopsy, one intratumoral JEN-101 injection seven days later, then required surgical excision at Illinois seven days after treatment

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Measurable; Planned surgery; chemotherapy washout: 21 days; Min tumor cm: 1; Max tumor cm: 5

May not qualify if: Prior local radiation; Immunosuppressive

Costs / coverage: Partially funded: cytokine treatment, treatment-day exam, biopsy charges and up to $2,500 toward surgical excision at Illinois are covered. Owner pays initial consultation/eligibility diagnostics and unrelated care.

Contact: Rebecca Kamerer, Clinical Trials Coordinator — rmoss81@illinois.edu · 217-300-6453; appointments 217-333-5300

Official study / enrollment information →

Intratumoral JEN-101 for recurrent canine soft tissue sarcoma

University of Illinois Veterinary Teaching Hospital · USA

Location

University of Illinois Veterinary Teaching Hospital, 1008 W Hazelwood Dr, Urbana, IL 61802

Study details

Actively recruiting — confirmed on the institution’s current clinical-trials page

What is being offered: Four intratumoral JEN-101 (IL-12) doses given every two weeks with CT, biopsy and blood monitoring

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Measurable; Recurrent; Prior surgery; chemotherapy washout: 42 days; radiation washout: 42 days; Min tumor cm exclusive: 2

May not qualify if: Prior immunotherapy; Prior steroids; Immunosuppressive

Costs / coverage: Fully funded after eligibility. Owner pays the initial consultation and eligibility diagnostics; unrelated-condition costs remain owner-paid.

Contact: Rebecca Kamerer, Clinical Trials Coordinator — rmoss81@illinois.edu · 217-300-6453; appointments 217-333-5300

Official study / enrollment information →

Proton FLASH radiation therapy for canine extremity soft tissue sarcoma

University of Pennsylvania School of Veterinary Medicine · USA

Location

Penn Vet Ryan Veterinary Hospital, 3900 Spruce St, Philadelphia, PA 19104

Study details

Current Penn Vet clinical trial

What is being offered: Three proton FLASH-RT treatments over 5–9 days for extremity STS where surgery is not feasible or has been declined. Prior surgery is acceptable.

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Extremity sts; Max tumor cm: 10; No metastasis; Planned radiation

May not qualify if: Pulmonary metastasis; Regional lymph node metastasis

Costs / coverage: 🟢 Fully funded after screening. Sponsor covers all study-related procedures including FLASH-RT treatments, examinations, chest radiographs, laboratory tests, sedation/anesthesia and CT; the screening visit is owner-paid.

Contact: Penn Vet VCIC — 215-573-0302; vcic@vet.upenn.edu

Official study / enrollment information →

Compassionate-Use Protocol for Advanced Non-Resectable Tumors

UT Southwestern Veterinary Research and Oncology Clinic · USA

Location

Veterinary Research and Oncology Clinic, 5801 Forest Park Rd, Dallas, TX 75235

Study details

Current

What is being offered: Investigational therapy, chemotherapy, immunotherapy and combination approaches under a prospective compassionate-use protocol

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Min weight kg exclusive: 2.5; min expected survival weeks: 3 weeks; Adequate organ function

May not qualify if: Severe systemic disease

Costs / coverage: ⚪ Owner-paid. The protocol brochure states that owners fully pay for the study, although possible subsidies may be available.

Contact: Paige Neumann, Research Study Coordinator — 214-645-6221; VROC@UTSouthwestern.edu

Official study / enrollment information →

Single-fraction SABR for progressive canine lung metastases

Tufts Cummings School of Veterinary Medicine · USA

Location

Henry and Lois Foster Hospital for Small Animals, 200 Westboro Rd, North Grafton, MA 01536

Study details

Recruiting

What is being offered: Single highly focused radiation dose for dogs with 2–10 progressive pulmonary metastatic nodules. The primary tumor, regional nodes and any non-pulmonary metastases must already be controlled; progression must be documented over 6–8 weeks, and all progressive lung lesions at least 5 mm must be safely treatable. Prior systemic therapy is allowed; cytotoxic chemotherapy pauses around SABR, while tolerated targeted therapy or immunotherapy may continue with radiation-oncologist approval. Tufts prescreening is required.

Who may qualify: Confirmed cancer diagnosis required; Active tumor required; Metastatic; Measurable lung metastases; Planned radiation

Costs / coverage: 🟡 Partially funded. The study covers SABR, the one-month follow-up, adverse-event rechecks related to lung toxicity, and up to $860 toward the 2–3-month CT visit. Owners pay pre-enrollment bloodwork, chest imaging, treatment-planning CT, and diagnostic confirmation.

Contact: Tufts Clinical Trials Office — clinicaltrials@tufts.edu; owner and referring-veterinarian prescreening questionnaires on the official page

Official study / enrollment information →