Canine Transitional Cell Carcinoma

Abstract

Transitional cell carcinoma (TCC) of the urinary bladder, the most common malignancy of the urinary tract in dogs, is challenging to both diagnose and treat effectively. The prevalence of this disease may be increasing. The etiology of canine TCC is likely multifactorial. Epidemiological studies of TCC in the dog have revealed a number of risk factors, including breed and female gender, as well as environmental factors, such as insecticide exposure. This tumor is difficult to remove surgically and responds poorly to chemotherapy. The efficacy of radiotherapy and other treatment modalities needs further investigation. Cyclooxygenaseinhibiting drugs have some activity against TCC, and studies to further define these effects are ongoing. Use of the tumor/node/ metastasis (TNM) classification scheme for bladder cancer has allowed for the identification of prognostic factors. Urinary tract obstruction and metastatic disease remain challenges to treat. Work with canine TCC has demonstrated how closely this disease resembles human invasive urinary bladder cancer. Therefore, future research has the potential to benefit both dogs and humans with TCC.Key words: Animal models; Bladder cancer; Chemotherapy; Cyclooxygenase; Piroxicam; Risk factors.U rinary bladder cancer in dogs is a challenging disease to diagnose, stage, and treat. Fortunately, urinary bladder cancer is uncommon in the dog, comprising Ͻ2% of all reported canine malignancies. 1 Transitional cell carcinoma (TCC) is the most common neoplasm affecting the urinary bladder of dogs. In this article, we review current knowledge of canine TCC with regard to frequency, etiology, histopathological characteristics, cellular and molecular features, response to therapy, and prognostic factors. We also discuss why canine TCC is a good model of human invasive bladder cancer. FrequencyAlthough the true prevalence of canine TCC is not known, it is the most common form of urinary tract cancer in the dog and comprises 1.5-2% of all canine cancers. 2,3 The hospital prevalence, or proportionate morbidity, of bladder cancer at university-based veterinary hospitals appears to be increasing. 4 A search of the Veterinary Medical Data Base (VMDB) 5 from 1975 to 1995 showed a continuous increase in the prevalence of bladder cancer, with prevalence defined as the number of dogs with bladder cancer divided by the total number of individual dogs seen for any reason at the same participating university veterinary hospitals. 4 Etiology and Risk FactorsThe etiology of canine TCC is most likely multifactorial. Risk factors that have been identified include exposure to topical insecticides for flea and tick control, exposure to marshes that have been sprayed for mosquito control, obe- University, West Lafayette, IN. Reprint requests: Deborah W. Knapp, DVM, MS, DACVIM, Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN 47907-1248; e-mail: knappdw@purdue.edu. Submitted December 28, 2001; Revised April 23, 2002; Accepted June 17, 2002. Copyright ᭧ 2003 sity, ...

The in Vitro and in Vivo Anti-Cancer Potential of Mycobacterium Cell Wall Fraction (MCWF) Against Canine Transitional Cell Carcinoma of the Urinary Bladder

“…Canine TCC closely resembles high-grade, muscleinvasive TCC in humans, making it a relevant animal model for transitional research [1,7]. Although progress has been made in the treatment of TCC, a signifi cant number of affected dogs succumb to the disease each year.…”

“…Urinary bladder cancer accounts for approximately 2% of all reported malignancies in dogs affecting tens of thousands of dogs worldwide every year [1]. The prevalence of canine bladder cancer in North America, Europe and South America continues to increase despite ongoing research in the prevention and treatment of TCC [2].…”

“…Multiple risk factors contribute to the development of TCC in dogs including exposure to older types of fl ea control products, lawn chemicals, obesity, sex, and breed [1,[3][4][5]. Invasive TCC is the most common form of canine urinary bladder cancer and the majority of TCCs are categorized as intermediate to high grade papillary infi ltrative tumors [6,7].…”

“…Currently, the veterinary oncology standard for the treatment of TCC in dogs is systemic medical therapy comprised of chemotherapy, cyclooxygenase inhibitors or combination of these [1,10,12]. Although medical therapy is not usually curative, remission or stable disease can be accomplished with several different drugs [1,11].…”

“…Although medical therapy is not usually curative, remission or stable disease can be accomplished with several different drugs [1,11]. Surgery as a treatment option for TCC in the urinary bladder is used to obtain the tissue sample for histopathology, to attempt cancer removal from the bladder or to restore urine fl ow [12].…”