Cancer is the leading cause of death in dogs, in part because many cases are identified at an advanced stage when clinical signs have developed, and prognosis is poor. Increased understanding of cancer as a disease of the genome has led to the introduction of liquid biopsy testing, allowing for detection of genomic alterations in cell-free DNA fragments in blood to facilitate earlier detection, characterization, and management of cancer through non-invasive means. Recent discoveries in the areas of genomics and oncology have provided a deeper understanding of the molecular origins and evolution of cancer, and of the “one health” similarities between humans and dogs that underlie the field of comparative oncology. These discoveries, combined with technological advances in DNA profiling, are shifting the paradigm for cancer diagnosis toward earlier detection with the goal of improving outcomes. Liquid biopsy testing has already revolutionized the way cancer is managed in human medicine – and it is poised to make a similar impact in veterinary medicine. Multiple clinical use cases for liquid biopsy are emerging, including screening, aid in diagnosis, targeted treatment selection, treatment response monitoring, minimal residual disease detection, and recurrence monitoring. This review article highlights key scientific advances in genomics and their relevance for veterinary oncology, with the goal of providing a foundational introduction to this important topic for veterinarians. As these technologies migrate from human medicine into veterinary medicine, improved awareness and understanding will facilitate their rapid adoption, for the benefit of veterinary patients.

BackgroundIt has been an open question how similar human and canine lung cancers are. This has major implications in availability of human treatments for dogs and in establishing translational models to test new therapies in pet dogs. The prognosis for canine advanced lung cancer is poor and new treatments are needed. Heat shock protein 90 (HSP90) is an ATPase-dependent molecular chaperone ubiquitously expressed in eukaryotic cells. HSP90 is essential for posttranslational conformational maturation and stability of client proteins including protein kinases and transcription factors, many of which are important for the proliferation and survival of cancer cells. We investigated the activity of STA-1474, a HSP90 inhibitor, in two canine lung cancer cell lines, BACA and CLAC.ResultsComparative genomic hybridization analysis of both cell lines revealed genetic relevance to human non-small cell lung cancer. STA-1474 inhibited growth and induced apoptosis of both cell lines in a dose- and time-dependent manner. The ICs50 after 72 h treatment with STA-1474 were 0.08 and 0.11 μM for BACA and CLAC, respectively. When grown as spheroids, the IC50 of STA-1474 for BACA cells was approximately two-fold higher than when grown as a monolayer (0.348 μM vs. 0.168 μM), whereas CLAC spheroids were relatively drug resistant. Treatment of tumor-stromal fibroblasts with STA-1474 resulted in a dose-dependent decrease in their relative cell viability with a low IC50 of 0.28 μM.ConclusionsHere we first established that lung adenocarcinoma in people and dogs are genetically and biochemically similar. STA1474 demonstrated biological activity in both canine lung cancer cell lines and tumor-stromal fibroblasts. As significant decreases in relative cell viability can be achieved with nanomolar concentrations of STA-1474, investigation into the clinical efficacy of this drug in canine lung cancer patients is warranted.

Objective To determine the median survival time (MST) of dogs with nasal carcinoma treated with toceranib phosphate. Material and methods The databases of four Spanish referral hospitals were retrospectively searched for dogs with a diagnosis of nasal tumours presented between January 2015 and October 2020. Dogs treated with radiotherapy or other chemotherapies prior toceranib were excluded. Results Twenty‐three dogs with a confirmed nasal carcinoma treated with toceranib phosphate and with a CT scan for initial staging according to Adams Modified Staging System were included. Nine dogs had a stage III nasal carcinoma whereas 14 dogs had a stage IV nasal carcinoma. No dog had stages I and II nasal carcinoma. The median overall survival time was 139 days. The difference between the MST between dogs with stages III and IV was not statistically significant [P = 0.6, 140 days for stage III (range 46–401) vs 120 days for stage IV (range 23–600)]. Overall, dogs with epistaxis achieved a longer median survival (166 days) than dogs without epistaxis (83 days). Toceranib phosphate was generally well tolerated. Most dogs had an initial clinical benefit followed by progressive disease. Significance This is the first study to report the MST in dogs with stages III and IV nasal carcinoma treated with toceranib phosphate. This retrospective study showed that toceranib phosphate decreases the clinical signs associated with nasal carcinomas.

Dog owners are increasingly seeking treatment when their pets develop cancers. As in human cancer patients, dogs with cancer are commonly treated with complementary and alternative therapies, including herbal medicines and nutritional supplements. A novel antitumor agent was developed from six different herbs including Rhus verniciflua (Rv-PEM01). The components were established from traditional herbal medicine and designed to affect antitumor activity and maintain host immune function. Previous studies identified anti-proliferative activity in human, murine and canine cancer cell lines. In this clinical study the safety and tolerability of Rv-PEM01 were evaluated in pet dogs with spontaneously occurring cancers. Twelve dogs were treated orally daily for 30 days in escalating dose (4 -10 mg/kg orally once daily) cohorts. Rv-PEM01 was well tolerated; only transient mild elevations in BUN were observed in 2 dogs. Although tumor response was not a primary endpoint for this study, stable disease was maintained for 30 days in 5 (42%) of the dogs. In conclusion, Rv-PEM01 was found to be safe and well tolerated in the dosage range tested. Future studies should evaluate higher dosages of Rv-PEM01 in dogs with cancer, and specifically address other potential benefits of Rv-PEM01 in canine cancer patients, including correlative assessments of immune function, quality of life and owner satisfaction.

A 12 yr old intact female Siberian husky was referred with a 2 wk history of progressive weakness, paraparesis, anorexia, and panting. A 4 cm diameter grade 3 mammary solid carcinoma involving the fifth right mammary gland had been removed 2 days prior to the current visit. While hospitalized, the dog was diagnosed with Addison’s disease based on electrolyte disturbances and low serum cortisol levels following adrenocorticotropic hormone stimulation test. An abdominal ultrasound revealed adrenal glands at the upper limit of normal size. Despite treatment, the dog deteriorated and died 4 days after presentation. A postmortem examination revealed a neoplastic infiltrate of epithelial malignant cells in both adrenal glands, popliteal lymph nodes, vertebral bodies, and paralumbar musculature, compatible with metastasis from mammary carcinoma. To our knowledge, this is the first reported case of Addison’s disease secondary to metastatic mammary carcinoma in a dog.