Contribution of Canine Detection in the Diagnostic Strategy of High-risk Prostate Cancer

The sense of smell allows both humans and dogs to carry out a chemo-sensory analysis of their environment. Volatile organic compounds enter the nasal cavities and bind to receptors in the nasal mucosa. Neuroepithelium cells perform chemoelectric transduction of olfactory information. The latter is supported by one of the fibers of the olfactory nerve which crosses the cribriform plate of the ethmoid to arrive in the olfactory bulb of the brain. Incorporating this information can lead to behavioral responses. The dog has a sense of smell 100,000 times more sensitive than humans, it is able to detect one particle among 1 trillion. The use of detection dogs involves learning the behavioral response to an olfactory stimulus. Prostate cancer represents 25% of male cancers, it is the second deadliest cancer in France with 10,000 deaths per year. Diagnosis of prostate cancer requires a Prostate Specific Antigen (PSA) blood test and a digital rectal examination. In the event of an abnormality in one of these parameters, a prostate MRI is indicated, supplemented by prostate biopsies in the event of an abnormal MRI. However, one situation remains open to discussion: what should be done when faced with a normal MRI despite an abnormal PSA level or digital rectal examination? In this situation and according to current recommendations, the practitioner has the choice between performing prostate biopsies, i.e. an invasive procedure with a high risk of being negative, and simple monitoring, this time with the risk of missing the diagnosis of prostate cancer. Several studies have shown the effectiveness of dogs in detecting very specific volatile organic compounds. Can the investigators train them to detect the catabolites of prostate tumours?