Intensive training technique utilizing the dog’s olfactory abilities to diagnose prostate cancer in men

Abstract

Carcinoma of the prostate is a commonly occurring malignant tumour in men and is a common cause of death. Early diagnosis and therapy is crucial for the successful treatment of this serious disease. It is therefore desirable to develop a sufficiently reliable, minimally invasive, and inexpensive method of diagnosing prostate cancer, which would usefully supplement the diagnostic techniques currently in common use (digital rectal examination, measuring the prostate-specific antigen level in serum, transrectal ultrasonography). This article describes in detail the methodology of a new technique for intensive training aimed at developing the dog's olfactory abilities to diagnose carcinoma of the prostate in men while the animal is still young. At the same time, the rate of success in establishing the diagnosis of prostate cancer in men using this method was evaluated based on the identification of urine samples from patients in whom the disease was histologically confirmed. The results of our study demonstrate that the diagnosis of prostate cancer in men using the olfactory abilities of a specially trained dog can be considered a reliable, non-invasive, and relatively inexpensive method of diagnosing carcinoma of the prostate. Urology, tumour, prostate gland, auxiliary methods of examinationCarcinoma of the prostate is the most common non-cutaneous malignant tumour among men in a number of the world's developed countries and, after carcinoma of the lung, it is the most common solid tumour in the male population of the United States (Jemal et al. 2009). Despite the progressive development of diagnostic methods (Vyhnánková 2015) in the area of diagnosing cancer, this disease is still one of the major causes of death in humans. Early detection and prompt commencement of therapy are crucial for the successful treatment of carcinomas and an appropriate way of reducing the economic burden of treatment and the mortality of the disease (Sonoda et al. 2011). The basic diagnostic methods used to diagnose prostate cancer include digital rectal examination (DRE), measuring the prostate-specific antigen (PSA) level in serum, and transrectal ultrasonography (TRUS) (Gerber and Chodak 1991). When patients are making decisions about undergoing preventative or early examination, the degree to which the procedure carried out is invasive and painful is quite important. It is therefore desirable to develop a method of diagnosing prostate cancer which is sufficiently reliable, but at the same time minimally invasive and not too expensive.In our study we focused on the development of diagnostics for prostate cancer in men from urine samples using the olfactory abilities of the dog. The aim of the study was to introduce a new technique for the intensive development of the dog's olfactory abilities to diagnose carcinoma of the prostate in men while the animal is young; to evaluate the success rate in establishing the diagnosis of prostate cancer in men on the basis of indicating urine

Identification of Sarcosine as a Target Molecule for the Canine Olfactory Detection of Prostate Carcinoma

“…The study demonstrated that a specially trained dog can detect PCa from urinary specimens with a sensitivity and specificity of 91%. Similar results have been achieved in our pilot study (sensitivity of 93.5% and specificity of 91.6%) 3 and in a study by Taverna et al . who used two dogs and reached a sensitivity of 98.6–100% and a specificity of 97.6–98.7%.…”

“…Our study was performed in regard to the excellent results of our sniffer dog in detecting PCa from the 2015 study 3 and the fact that urinary sarcosine appears to be a potential PCa biomarker, whose concentrations are increased in the urine of PCa-diagnosed patients 10 , 16 . Because we are using an animal as a “sensory device”, several issues should be mentioned.…”

“…In our previous study, we demonstrated that a specially trained sniffer dog can reach high sensitivity (93.5%) and specificity (91.6%) in diagnosing histologically confirmed PCa using its olfactory abilities by sniffing urinary specimens from patients with PCa 3 . The hypothesis that dogs may be able to detect malignant tumours on the basis of odour is not new and was first put forward by Williams and Pembroke in 1989 4 .…”

“…The hypothesis that dogs may be able to detect malignant tumours on the basis of odour is not new and was first put forward by Williams and Pembroke in 1989 4 . From that time, several reports have been published describing the olfactory identification of cancers of the bladder 5 , breast and lung 6 , skin 7 or prostate 3 .…”

“…If the olfactory detection of PCa depends on the amount of sarcosine in a complex mixture of urinary compounds, then a trained dog should be able to recognize the artificial urine with the addition of sarcosine. Hence, the aim of the present study is to perform olfactory analyses of artificially prepared urinary specimens containing distinct, physiologically relevant concentrations of sarcosine with the same dog that has an excellent accuracy for PCa diagnostics, per our previously published study 3 .…”