Early-Stage Soft Tissue Sarcoma in Dogs

Sarcoma can rapidly progress, leading to severe consequences for a dog’s health. Since I started hospice care and euthanasia services for pets in 2007, I’ve seen how early detection can significantly improve a dog’s prognosis. I would like to discuss soft tissue sarcoma in more detail to help families understand this type of cancer and be more prepared for keeping thier dog or cat more comfortable for as long as possible.

Early Stage Soft Tissue Sarcoma in Dogs

Soft tissue sarcomas in dogs encompass various cancers originating from connective tissues, including muscle and nervous tissue, and can develop anywhere on the body. Despite arising from different cell types, these tumors typically exhibit similar behavior, with treatment protocols generally remaining consistent. Early clinical manifestations are contingent upon the tumor’s location, commonly presenting as lumps, swelling, bleeding, or pain. Additional symptoms may include decreased appetite and activity level. Manifestations specific to the tumor’s site include pain or lameness for muscle-affected tumors, impaired mobility or swelling for limb-located tumors, and lameness or “root signature” for nerve sheath tumors. Intestinal tumors may lead to vomiting or decreased appetite due to obstruction. Clinical presentations vary depending on the tumor’s location.

How are Soft Tissue Sarcomas Diagnosed?

A fine needle aspirate (FNA) or biopsy is typically performed to diagnose soft tissue sarcomas in dogs. FNA involves extracting a cell sample from the tumor for examination by a veterinary pathologist, offering a quick but potentially less definitive diagnosis. Biopsy, preferred for its larger and more representative sample, provides greater certainty but may require sedation or anesthesia. If cost or anesthesia risk is a concern, FNA may be recommended. However, it’s possible that FNA results may not conclusively confirm cancer. Staging, assessing the extent of tumor spread, involves procedures like blood tests, lung X-rays, abdominal ultrasounds, and lymph node FNAs to detect metastasis to other organs or nearby lymph nodes.

Tumor Grading: What Should I know?

Tumors often invade surrounding tissues especially if the tumors are higher grade. Tumors are typically graded I-III. The higher grade III have a higher potential to invade and spread throughout the body. 

What is the Treatment?

Recommended treatment options for soft tissue sarcomas in dogs include surgery, chemotherapy, and radiation. Surgery is typically the primary recommendation, aiming for wide margins around the tumor to ensure complete removal. If surgery doesn’t achieve complete excision (known as incomplete margins), radiation therapy may be suggested, or another surgery if feasible. If neither surgery nor radiation is viable, or if the tumor recurs, palliative measures to alleviate discomfort, reduced appetite, mobility issues, or lethargy may be initiated, potentially leading to hospice care. In cases where symptoms become unmanageable, euthanasia may be considered.

Early detection is crucial as these tumors are often locally invasive with a low tendency to metastasize. Surgery is usually recommended if feasible, which may offer a curative outcome. However, in cases where complete removal isn’t possible due to tumor size or location, radiation therapy or euthanasia may be advised, especially when the focus is on maintaining the dog’s quality of life.

 

Canine Sarcoma          Details
Types
  • Fibrosarcoma: malignant tumor of fibroblasts 
  • Mastocytoma: Mammary Gland tumors
  • Peripheral Nerve Sheath Tumors
  • Liposarcoma: rare type of cancer affecting adipose of fat tissue.  
  • Leiomyosarcoma: Cancer affecting smooth muscle usually in the intestines, stomach, uterus or bladder
Clinical signs
  • Lumps or masses
  • Swelling
  • Pain or lameness/limping
  • Bleeding
  • Weight loss, Lethargy, decreased appetite
  • Vomiting, regurgitation or diarrhea if the gastrointestinal tract is affected ie. leiomyosarcoma
Side effects
  • Pain
  • Infections
  • Appetite loss
  • Nausea
  • Fatigue
  • Diarrhea
  • Bruising
Prevention
  • Spay or neuter to prevent leiomyosarcoma
  • Limit sun exposure to prevent skin cancer: cutaneous Hemangiosarcoma
  • Monitor lumps or increased size, discomfort, bleeding or discharge
  • Regular veterinarian exams
Diagnostic procedures
  • Fine needle aspirate
  • Biopsy
  • CT scan or MRI not usually recommended but possible depending on suspected tumor location
  • Metastatic screening or staging including abdomen ultrasound and or X rays 
Treatments
  • Surgery
  • Radiation
  • Chemotherapy
  • Pallliative care to manage symptoms such as Pain medication, antibiotics, appetite stimulant, anti-nausea medication
Euthanasia
  • If cancer is too advanced or aggressive
  • Poor quality of life or sudden deterioration or when palliative care is no longer effective

Overview of Soft Tissue Sarcoma

Soft tissue sarcomas (STS) in dogs are a collection of malignant tumors originating from mesenchymal cells, which include connective and nervous tissue supporting the body. In veterinary practice, various forms of STS are encountered, each exhibiting unique behavior and prognosis. Prognosis often hinges on factors such as tumor grade and staging. Grade, determined through biopsy, indicates the aggressiveness of the tumor, while staging involves assessments like blood panels, X-rays, or radiographs, and abdominal ultrasounds to ascertain if the tumor has metastasized to other organs.

A man and a woman holding a clipboard and a pet card

Types of Soft Tissue Sarcomas

These are among the most common types I encounter, and each type can present diverse challenges in early-stage detection and treatment.

  • Hemangiosarcoma: Hemangiosarcoma in dogs originates from blood vessels. This type of cancer affecting the skin has a better prognosis with surgery potentially curing the cancer, unlike the other forms affecting the liver, spleen or heart. Hemangiosarcoma affecting these organs has a poor prognosis because these tumors are not responsive to surgery, chemotherapy or radiation.
  • Liposarcoma: Derived from fat cells, it tends to be slower-growing yet may recur after removal.
  • Leiomyosarcoma: This arises from smooth muscle tissues usually affecting the gastrointestinal tract or uterus.
  • Fibrosarcoma: Arises from fibrous tissue and can be locally invasive, with a moderate to high potential for recurrence.

Clinical Signs of Early Stage Sarcoma in a Dog

Soft tissue sarcomas comprise 7% of skin and subcutaneous tumors in cats, with 17 out of 100,000 cats at risk of the condition. Recognizing the early signs increases the chance of a positive outcome.

  • Lump or mass: Dogs may have lumps or swelling under the skin, which may increase in size over time, which may be the strongest initial clue.
  • Lethargy and pain: Dogs might exhibit discomfort or pain in the affected area.

A dog standing in the water at the beach, enjoying a sunny day by the sea

Treatment Options for Early Stage Soft Tissue Sarcomas in a Dog

I recommend multiple treatment options to ensure the best possible outcome. The main goals are to remove the tumor, prevent recurrence, and maintain a good quality of life.

  • Complete surgical excision: The first line of treatment is typically to remove the tumor surgically. It’s crucial to achieve wide and deep margins to minimize the risk of recurrence.
  • Post-surgical radiation: If surgery doesn’t achieve clear margins, radiation therapy may control any remaining cancer cells.
  • Palliative: In some cases, radiation can be used as palliative care to relieve symptoms if the tumor is not completely resectable.
  • Chemotherapy: Chemotherapy may be considered as an adjunct to surgery, especially if there’s a high risk of metastasis.

Post-Treatment Care

After the initial treatment phase, your goal is to assist your dog in regaining strength and preventing any disease recurrence.

  • Rehabilitation and recovery: Physical therapy, pain management, weight management, and nutritional support to maintain optimal body condition.
  • Regular check-ups: A consistent schedule of follow-up appointments for physical examinations and imaging when necessary.

Euthanasia Option for Canine Sarcoma (reword Lauren please)

When facing a diagnosis of soft tissue sarcoma in dogs, I consider the full range of care options, including the possibility of euthanasia. My priority is the quality of life for my patients.

If a dog is in significant pain or the prognosis is poor, euthanasia may be the most compassionate choice. I strongly advocate for a thorough evaluation of available treatment options before considering euthanasia.

It’s a deeply personal decision that should be made in the dog’s best interest, considering their current well-being and future quality of life after treatment. My role is to provide compassionate guidance, information on prognosis, and potential outcomes, ensuring that owners are fully informed in making this sensitive decision.

Related Questions

What is Stage 1 Sarcoma in Dogs?

Stage 1 sarcomas in dogs indicate small, low-grade tumors that have not spread to the local lymph nodes or other sites in the body. They are confined to the tissue of origin without invasion into surrounding structures.

What is the Prognosis of Soft Tissue Sarcoma in Dogs?

With aggressive treatment of early stage sarcomas, dogs have a good prognosis and may live one to three years or longer. However, without any treatment, the cancer typically progresses rapidly, and most dogs will succumb to the disease within a matter of months. 

What Are Preventive Measures for Early Stage Canine Soft Tissue Sarcoma?

Regular check-ups and prompt veterinary attention to unusual growths can lead to early detection, which is often key to successful treatment. A well-balanced diet tailored to your dog’s needs can support their immune system. Minimize your dog’s exposure to carcinogens, such as household chemicals or pesticides.

Conclusion

While early detection and treatment provide the best hope for beating soft tissue sarcomas, be prepared for the possibility of euthanasia if the cancer progresses despite therapy. Though extremely difficult, choosing euthanasia at the appropriate time can spare pets prolonged pain and bring a peaceful end to a devastating disease.

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I can't recommend them enough. I had to say goodbye to my 21 year old cat companion. I read the reviews here on Yelp and chose Paws Into Grace and they made an unbearable situation not worse - from the people on the phone to the amazing doctor who came out to the house. She was so understanding and supportive. They were all so helpful, understanding and nice. My girl got to stay at home and say goodbye in the backyard (a hummingbird flew over and it seemed like a good sign too). So glad I didn't have to take her to a cold vet office.

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