Lower Urinary Tract Cancer: Adjuvant Therapies

Lower urinary tract (LUT) cancer is relatively uncommon in dogs and even less frequently reported in the cat. Bladder and urethral cancer, most typically transitional cell carcinoma (TCC) accounts for ±2% and prostate cancer (carcinoma) for less than 1% of all canine cancers. Although data in the cat are no limited, urinary bladder TCC appears to be the most common bladder tumor and reports on feline prostate cancer are anecdotal. Although TCC accounts for the majority of all bladder tumors in both the dog and cat, other tumor types, including lymphoma and rhabdomyosarcoma, have been reported and a histological biopsy is still recommended because treatment and prognosis varies between these tumor types. Tumors diagnosed in the prostate other than carcinoma include lymphoma, hemangiosarcoma and leiomyosarcoma. Canine prostatic carcinoma (PCA) appears to arise from the prostatic (collecting) ducts, rather than from the peripheral acini as in humans, but TCCs arising from the prostatic urethra have also been reported. The prognosis of prostatic carcinoma is poor due to locally advanced disease and/or the presence of metastatic disease and one study reports that 58 of 72 dogs were euthanized at the time of diagnosis and the median survival time for the remaining dogs (not clear if and what treatment was attempted) was 30 days.

Although surgery plays a major role in the management of this group of tumors, it is often either not feasible due to adverse functional consequences (urinary incontinence) or not indicated due to the presence of metastatic disease. In these cases, but also in an adjuvant setting following successful surgery, non-surgical therapies should be considered. Potential non-surgical treatment options include medical therapy, in particular NSAIDs and various cytotoxic drugs (chemotherapy), immunotherapy, photodynamic therapy, radiotherapy, interventional radiology and combinations thereof. Despite their different anatomical location and histological origin, the treatment of the most important LUT tumors (bladder, urethra, prostate) is similar and are discussed by treatment modality rather than tumor type or location.  [...]