Introduction

• Uncommon.
• Spontaneous cancer.
• Average age: 10 years.
• More common in neutered dogs.
• Usually advanced before presented.
• Signs: pain on defecating/urinating; hindlimb locomotor/neurological signs.
• Diagnosis: clinical signs, biopsy.
• Treatment: poor efficacy, rarely indicated because of metastasis.
• Prognosis: extremely poor because of early dissemination and absence of response to treatment.

Pathogenesis

Etiology

• Unknown.
• Androgen dependent.
• High-grade prostatic intraepithelial neoplasia (PIN) - a precursor of human prostatic cancer - has been detected in dogs without prostatic disease and in dogs with prostatic cancer.
• Chromosomal abnormalities.
• Overexpression of COX-2.
• TGF - beta and PTHrP involved in bone metastasis.

Pathophysiology

• Insidious onset - usually advanced (often metastasized) before presented.
• Abscesses/cysts/hyperplasia may be concurrent.
• Early dissemination to lumbar vertebrae, pelvis and bones of hindlimbs.
• Local infiltration and regional node involvement common.

Diagnosis

Treatment

Outcomes