A prospective randomized trial of desmopressin in canine mammary carcinoma

Prognostic Implications of Decorin, E-Cadherin and EGFR Expression in Inflammatory and Non-Inflammatory Canine Mammary Carcinomas

Inflammatory mammary carcinoma (IMC) is the most aggressive variant of invasive mammary tumours in dogs and in women. Decorin is an extracellular matrix molecule whose expression can be reduced or absent in various human cancers, which is associated with a poor prognosis. E-cadherin is a cell adhesion protein whose expression is reduced in several neoplasms. However, it is overexpressed in inflammatory breast cancers of women. EGFR is also associated with cancer development and is commonly overexpressed in aggressive neoplasms. This study aimed to characterise the expressions of Decorin, E-cadherin, and EGFR in canine inflammatory and non-inflammatory mammary carcinomas (IMC and non-IMC) and to evaluate their expression levels as prognostic indicators for survival and occurrence of metastases. Thirty-three IMC and 43 non-IMC cases were analysed retrospectively and submitted to immunohistochemical analysis. The reactions were quantified in five high-power field images from areas of the highest intensity and frequency of immunostaining (hot spots). We found significantly lower expression of Decorin and higher of E-cadherin and EGFR in canine IMCs. Patients with tumours that exhibited Decorin expression in less than 26.35% of epithelial cells had shorter survival (p = 0.0410) and a higher occurrence of distant metastases (p = 0.0115). E-cadherin is overexpressed in canine IMCs (p < 0.0001), similar to what occurs in women, reinforcing that dogs can be used as a study model for human IMC. EGFR overexpression in canine IMCs (p = 0.0322) provides evidence for potential targeted therapy with tyrosine kinase inhibitors.

Repurposing Drugs in Small Animal Oncology

Repurposing drugs in oncology consists of using off-label drugs that are licensed for various non-oncological medical conditions to treat cancer. Repurposing drugs has the advantage of using drugs that are already commercialized, with known mechanisms of action, proven safety profiles, and known toxicology, pharmacokinetics and pharmacodynamics, and posology. These drugs are usually cheaper than new anti-cancer drugs and thus more affordable, even in low-income countries. The interest in repurposed anti-cancer drugs has led to numerous in vivo and in vitro studies, with some promising results. Some randomized clinical trials have also been performed in humans, with certain drugs showing some degree of clinical efficacy, but the true clinical benefit for most of these drugs remains unknown. Repurposing drugs in veterinary oncology is a very new concept and only a few studies have been published so far. In this review, we summarize both the benefits and challenges of using repurposed anti-cancer drugs; we report and discuss the most relevant studies that have been previously published in small animal oncology, and we suggest potential drugs that could be clinically investigated for anti-cancer treatment in dogs and cats.

From Conventional to Precision Therapy in Canine Mammary Cancer: A Comprehensive Review

Canine mammary tumors (CMTs) are the most common neoplasm in intact female dogs. Canine mammary cancer (CMC) represents 50% of CMTs, and besides surgery, which is the elective treatment, additional targeted and non-targeted therapies could offer benefits in terms of survival to these patients. Also, CMC is considered a good spontaneous intermediate animal model for the research of human breast cancer (HBC), and therefore, the study of new treatments for CMC is a promising field in comparative oncology. Dogs with CMC have a comparable disease, an intact immune system, and a much shorter life span, which allows the achievement of results in a relatively short time. Besides conventional chemotherapy, innovative therapies have a large niche of opportunities. In this article, a comprehensive review of the current research in adjuvant therapies for CMC is conducted to gather available information and evaluate the perspectives. Firstly, updates are provided on the clinical-pathological approach and the use of conventional therapies, to delve later into precision therapies against therapeutic targets such as hormone receptors, tyrosine kinase receptors, p53 tumor suppressor gene, cyclooxygenases, the signaling pathways involved in epithelial-mesenchymal transition, and immunotherapy in different approaches. A comparison of the different investigations on targeted therapies in HBC is also carried out. In the last years, the increasing number of basic research studies of new promising therapeutic agents on CMC cell lines and CMC mouse xenografts is outstanding. As the main conclusion of this review, the lack of effort to bring the in vitro studies into the field of applied clinical research emerges. There is a great need for well-planned large prospective randomized clinical trials in dogs with CMC to obtain valid results for both species, humans and dogs, on the use of new therapies. Following the One Health concept, human and veterinary oncology will have to join forces to take advantage of both the economic and technological resources that are invested in HBC research, together with the innumerable advantages of dogs with CMC as a spontaneous animal model.