Highly-Trained Dogs’ Olfactory System Detects Prostate Cancer in Urine Samples
The detection of volatile organic compounds ( VOCs ) in urines is a promising approach to cancer recognition . Here , we establish the level of accuracy in term of sensitivity and specificity at which a rigorously trained canine olfactory system can recognize prostate cancer ( PC ) – specific VOCs in urine .
A total of 902 participants were investigated . These were divided into two Groups : a ) Prostate Cancer Group ( n = 362 ) and b ) Control Group ( n = 540 ) . The Prostate Cancer Group included patients with PC ranging from very – low risk to metastatic .
Methods and results
The Prostate Cancer Group included patients with PC ranging from very – low risk to metastatic . The Control Group included a heterogeneous cohort of healthy participants , patients with non – neoplastic diseases or non – prostatic tumors . Two dogs and a full – time , highly specialized , multidisciplinary team was involved in the study .
During the evaluation phase , the dogs achieved the following performances : Dog 1 : sensitivity 100 % ( 95 % CI : 99.0 -100.0 % ) and specificity 98.7 % ( 95 % CI : 97.3 – 99.5 % ) . Dog 2 : sensitivity 98.6 % ( 95 % CI : 96.8 – 99.6 % ) and specificity 97.6 % ( 95 % CI : 95.9 – 98.7 % ) .
When the female participants were excluded, Dog 1 achieved a sensitivity of 100% and specificity of 98.3% (95%CI: 96.6-99.3%), while Dog 2 achieved a sensitivity of 98.6% (95%CI: 96.8-99.6%) and specificity of 96.9% (95%CI: 94.7-98.3%). When only the adult men in the Control Group were considered, Dog 1 achieved a sensitivity of 100% and specificity of 98% (95%CI: 96-99.2%), while Dog 2 a sensitivity of 98.6% (95%CI: 96.8-99.6%) and specificity of 96.4% (95%CI: 93.9-98.1%). Analysis of false positive cases did not reveal any consistent pattern in terms of participant demographics or tumor characteristics.
INTERPRETATION: A trained canine olfactory system detects PC specific-VOCs in urine samples. These findings are unattainable through current urological tools. What used to seem no more than a myth has definitely turned into a clinical opportunity no longer to be ignored.