Toceranib phosphate in the management of canine insulinoma: A retrospective multicentre study of 30 cases (2009-2019)

Immunohistochemistry Screening of Different Tyrosine Kinase Receptors in Canine Solid Tumors-Part I: Proposal of a Receptor Panel to Predict Therapies

The use of tyrosine kinase inhibitors (TKI) has been growing in veterinary oncology and in the past few years several TKI have been tested in dogs. However, different from human medicine, we lack strategies to select patients to be treated with each TKI. Therefore, this study aimed to screen different tumor subtypes regarding TKI target immunoexpression as a predictor strategy to personalize the canine cancer treatment. It included 18 prostatic carcinomas, 36 soft tissue sarcomas, 20 mammary gland tumors, 6 urothelial bladder carcinomas, and 7 tumors from the endocrine system. A total of 87 patients with paraffin blocks were used to perform immunohistochemistry (IHC) of human epidermal growth factor receptor 2 (HER-2), epidermal growth factor receptors 1 (EGFR1), vascular endothelial growth factor receptor 2 (VEGFR-2), platelet derived growth factor receptor beta (PDGFR-β), c-KIT, and extracellular signal-regulated kinase 1/2 (ERK1/ERK2). The immunohistochemical screening revealed a heterogeneous protein expression among histological types with mesenchymal tumors showing the lowest expression level and carcinomas the highest expression. We have demonstrated by IHC screening that HER2, EGFR1, VEGFR-2, PDGFR-β and ERK1/ERK2 are commonly overexpressed in dogs with different carcinomas, and KIT expression is considered relatively low in the analyzed samples.

Establishment and characterization of six canine hepatocellular carcinoma cell lines

Background

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor in dogs. Although surgical resection is a major treatment option for canine HCC, there are no distinct strategies for unresectable tumor subtypes or adjuvant chemotherapy for tumors with positive margins. We aimed to establish and characterize novel HCC cell lines from canine patients.

Methods

The cellular morphology, general growth features and tumorigenicity of the established cell lines were evaluated. We also examined the sensitivity of the cell lines to multi-target tyrosine kinase inhibitors (TKIs).

Results

We established novel canine HCC cell lines from hepatic tumors and an additional kidney tumor of six canine patients. All cell lines showed colony forming and migratory ability. KU-cHCC-001 and KU-cHCC-001-Kidney, two cell lines exhibiting high epithelial-mesenchymal transition characteristics, showed tumorigenicity in xenografted mice. Toceranib, a veterinary TKI that targets vascular endothelial growth factor (VEGFR)/platelet-derived growth factor receptor (PDGFR)/c-kit, effectively inhibited the mitogen-activated protein kinase pathway and induced apoptosis. The established canine HCC cell lines showed greater sensitivity to toceranib than to sorafenib, a first-line treatment for human HCC targeting RAF/VEGFR/PDGFR. Sorafenib showed improved anti-tumor effects when co-treated with SCH772984, an extracellular signal-regulated kinase inhibitor.

Conclusion

Our study suggests new therapeutic strategies for canine HCC, and these cell lines are valuable research materials for understanding HCC tumor biology in both humans and dogs.

Laparoscopic partial pancreatectomy through an advanced lateral approach as treatment for insulinoma in dogs: a case series

A minimally invasive partial pancreatectomy was performed through a novel laparoscopic lateral flank approach in sternal-oblique recumbency in four clinical cases presented with an insulinoma. All four cases were female castrated dogs of older age (range 7-9 years) and different breeds (Wire haired dachshund, German shepherd, Jack Russel terrier, and Boxer), and all presented with episodic weakness, tremors, and/or seizures. The diagnosis was based on plasma glucose level below reference range with concomitant increased or normal insulin level. A laparoscopic approach was considered based on triple-phase contrast-enhanced computed tomography findings of the abdomen, revealing a pancreatic mass situated in the right pancreatic limb or left pancreatic limb without suspicion of metastasis. Laparoscopic procedures were performed without any major complications, and peri-operative glycemia increased to (supra-)normal levels in all cases. Histopathologic reports qualified the masses as neuroendocrine carcinomas, and in conjunction with the clinical picture, this neoplasia was further defined as insulinoma. Post-operative care in an intensive care unit was of short duration, and all animals were discharged being clinically normal and normoglycemic in between 1.5 and 2.5-day post-surgery. At short-term follow-up, no dogs showed clinical abnormalities, all recovered well from the surgical procedure, and blood glucose levels remained in the normal range. During long-term follow-up, 2 cases remained clinically normal at the time of writing, 564 and 1,211 days after surgery, 1 dog had recurrence of hypoglycemic episodes after 246 days and was euthanized after 673 days of surgery due to progressing disease, and 1 dog was euthanized after 1,028 days of surgery due to reasons unrelated to the insulinoma. Survival times ranged from 599 to 1,232 days after diagnosis. Considering the highly metastatic nature and difficulty of full laparoscopic staging of insulinoma patients, thorough pre-operative disease staging is warranted when considering a laparoscopic approach. This case series shows the feasibility of a novel laparoscopic flank approach for right and left partial pancreatectomy in dogs. Furthermore, proper case selection resulted in favorable outcome in these insulinoma patients.

Case report: Adjuvant therapy with toceranib for an incompletely resected renal cell carcinoma with suspected pulmonary metastasis in a dog

Primary renal neoplasia is rare in humans and dogs, with renal cell carcinoma (RCC) being the most common form of this cancer. As RCC is often diagnosed at an advanced stage, pulmonary metastasis is frequently observed. Tyrosine kinase inhibitors (TKIs) are the standard adjuvant treatments for metastatic RCC in humans. Similarly, in veterinary medicine, recent trials have employed TKIs for early-stage RCC patients who underwent complete surgical resection and showed no distant metastasis. However, the use of TKIs has not yet been reported commonly in cases of advanced RCC with metastasis. This case study presents the first clinical outcomes of TKI therapy in a dog with incompletely resected RCC and metastasis. A 5-year-old spayed female Chihuahua was referred to our hospital with a right renal mass and multiple pulmonary nodules suspected to be metastases. A portion of the renal mass was surgically removed, and histopathological examination revealed RCC with a high mitotic index. Adjuvant chemotherapy was administered, owing to incomplete resection with suspected pulmonary metastasis. An anticancer drug response prediction test was conducted using patient tissues. Since toceranib showed the most favorable responsiveness, it was selected as a therapeutic agent. Toceranib was orally administered at a dosage of 2.27 mg/kg every 48 h. Regular medical records for potential adverse effects were obtained, including systemic blood pressure, complete blood count, serum biochemical examination, and urinalysis. After 2 weeks of toceranib therapy, partial remission of pulmonary nodules continued for 2 months. The patient did not experience any adverse effects of the anticancer drug during the 4-month follow-up period. However, the patient died from an unidentified cause 6 months after the initial detection of the renal mass. This report describes the use of toceranib in dogs with RCC. In the present case, the patient showed an initial response to chemotherapy, and despite the presence of several poor prognostic factors, the dog survived beyond the expected 3-month lifespan to 6 months. Notably, no adverse events were observed during treatment.

Toceranib phosphate and firocoxib-mediated partial response in a dog with advanced intranasal sarcoma

A nine-year-old, castrated male mixed-breed dog presented with a three-month history of sneezing and stertorous breathing. Computed tomography revealed a soft tissue mass in the left nasal cavity with lysis of the cribriform plate. The mass was diagnosed as intranasal sarcoma based on histopathological analysis. The tumor cells were immunohistochemically positive for KIT and platelet-derived growth factor receptor α/β and negative for vascular endothelial growth factor receptor 2 and cyclooxygenase-2. Treatment with toceranib phosphate (TOC) and firocoxib reduced the tumor size, which was defined as partial response (PR). After PR induction, TOC alone mediated survival for 205 days. This case report suggests that the combination of TOC and possibly firocoxib may be a therapeutic option for canine intranasal sarcoma.