Prostate: Interest of biomarkers

Introduction

The prostate is the only accessory gland of the male reproductive tract in the dog. Prostatic diseases are relatively prevalent in intact middle-aged to old dogs. Prostatomegaly is commonly associated with most prostatic conditions. In the presence of suggestive clinical signs of prostatic disease, several tests can be used, such as radiography, ultrasonography, cytological and microbiological evaluation of the prostatic fluid, biomarker assays and, if necessary, biopsy of prostatic samples followed by histopathological exam. Among the imaging diagnostic methods to accurately assess the prostate, ultrasonography is one of the most used as it allows the precise evaluation of size, shape, position, echogenicity of parenchyma and detection of focal or diffuse lesions, and evaluation of prostatic limits. However, and despite the reliability of this diagnostic tool, additional methods should often be used in order to obtain a specific diagnosis.

Benign prostatic hyperplasia

The most common prostatic disease in the geriatric canine prostate is benign prostatic hyperplasia (BPH). Prostatitis (acute and chronic), squamous metaplasia and neoplasia are also important disorders that can occur in the canine prostate, although neoplasia is relatively uncommon. BPH occurs spontaneously with ageing; 50% of intact dogs develop histological evidence of the disease at 4 years old, which comprises both hyperplasic and hypertrophic changes of the prostate, specially affecting the epithelial cells. Factors involved in the pathogenesis of BPH are testosterone and mostly its major active metabolite, dihydrotestosterone (DHT), 17-ẞ-estradiol, and other mediators such as growth factors, which could act independent or synergistically. Besides glandular hyperplasia, also stromal and its fibromuscular components could evidence hyperplasia. BPH starts as glandular hyperplasia in young dogs but with aging pathological features change and often progresses to a cystic hyperplasia, which is commonly found at dogs older than 6 years, being the development of intraparenchymal cysts one of its main features (Smith, 2008). [...]