Cutaneous and subcutaneous metastasis of appendicular osteosarcoma in dogs: 20 cases

Abstract

Background Metastasis of appendicular osteosarcoma is most common to the lungs and is generally considered a terminal event in dogs. Behavior and prognosis associated with cutaneous or subcutaneous metastases (CSM) is poorly defined. Objective Describe the population and gather prognostic information regarding appendicular osteosarcoma with CSM in dogs. Animals Twenty dogs with appendicular osteosarcoma and CSM. Methods Retrospective case series. Medical records were searched to identify dogs diagnosed with appendicular osteosarcoma that developed CSM. Demographic data, order of metastatic events, and CSM clinical features were evaluated. Kaplan‐Meier survival curves were constructed and log‐rank tests were used to compare survival between groups of dogs. Results In 19 dogs (95%), CSM was an incidental finding. Seventeen dogs (85%) developed pulmonary metastasis, and 1 dog (5%) developed bone metastasis. No other metastatic sites were detected before euthanasia. The median CSM‐free interval and CSM survival time were 160 days (range: 0‐542 days) and 55 days (range: 5‐336 days), respectively. The median CSM survival time was significantly longer for dogs treated with surgery and chemotherapy (94 days) or chemotherapy only (64 days) than for dogs that did not receive these treatments (11 days) (P = .002 and P = .03, respectively). No other factors were associated with survival after diagnosis of CSM. Conclusion and Clinical Importance The skin or subcutaneous tissue can be the first osteosarcoma metastatic site detected. After CSM diagnosis, the prognosis is grave with median survival <2 months. Although this finding could have been biased by case selection, treatment with surgery and chemotherapy may improve outcome.

The role of toceranib phosphate in dogs with non‐mast cell neoplasia: A systematic review

“…One further significant finding of the review was the evidence which shows lack of efficacy for toceranib in canine OSA. Four studies regarding the use of toceranib in dogs with metastatic OSA were identified and based on the results it was one of the most well described tumours 28,40–42 . While a study showed that toceranib can slightly inhibit cell growth in vitro, 87 the results of three of the clinical studies did not show promising results 40–42 .…”

“…Four studies regarding the use of toceranib in dogs with metastatic OSA were identified and based on the results it was one of the most well described tumours. 28,[40][41][42] While a study showed that toceranib can slightly inhibit cell growth in vitro, 87 the results of three of the clinical studies did not show promising results. [40][41][42] Multiple tyrosine kinase inhibitors, including sorafenib, apatinib, pazopanib and regorafenib, have been used in people with OSA with some encouraging findings.…”

“…28 However, three subsequent studies (one prospective and two retrospective), including a total of 45 cases, have specifically evaluated the use of toceranib for dogs with metastatic OSA and found a much smaller proportion (0%-17.6%) achieved stable disease and the median progression free interval for these dogs was short (between 36 and 57 days). [40][41][42] In dogs with SD, the duration was approximately 112 days, 40 while in one dog the duration of SD was 288 days. 41 Based on the results of these studies, it is difficult to recommend toceranib for metastatic OSA.…”

What is your diagnosis? Dermal mass in a dog

“…Although few cases involving dogs, cats, and rabbits with extraskeletal OSA (primary or metastatic) have been reported, cutaneous and subcutaneous metastasis (CSM) of dogs with primary appendicular OSA is an uncommon finding. A retrospective study by Parachini‐Winter et al 2 concluded that CSM can be the first site of metastasis with a possible predilection for the trunk and ventrum, and suggested that subcutaneous tissues are more commonly affected than the dermis.…”

Canine and murine models of osteosarcoma

“…Most metastasize to the lung (50%-85%); other reported locations include distant bone, regional lymph nodes, liver, and skin (dermis/subcutis). 24,35,105,131 Many canine patients develop metastases to multiple tissue sites (Figs. [17][18][19].…”