Canine scent detection of sinonasal-inverted papilloma in blood plasma and nasal secretions

Abstract

Sinonasal-inverted papilloma (SNIP) is a rare, benign tumor of the sinonasal tract. Although these tumors are inherently benign, they are prone to malignant transformation and are associated with an unusually high rate of recurrence, even after complete surgical resection. As such, these patients must be followed long-term to monitor for recurrence or the presence of cancer. Unfortunately, there are currently no standards for long-term surveillance, and protocols usually require routine radiography and/or nasal endoscopy, which are not highly sensitive or specific, are time consuming, expensive, and confer morbidity to the patient. There is evidence that suggests that SNIP is associated with a uniquely detectable volatile metabolite signature. This study investigates the ability of four privately owned dogs to learn to identify the presence of SNIP in patients based on blood plasma samples. This type of medical detection is currently being used to create early diagnostic tools for other disease processes, which suggests promising results for the outcome of this study. Blood/plasma and nasal secretions were collected from both patients with SNIP, and healthy age-, sex-, and smoking-status-matched controls. Training was conducted twice weekly using errorless learning techniques that allowed the dogs to utilize odor concentration to guide their understanding of the target odor. After further training, a subsequent double-blind testing phase was conducted, in which the dogs' ability to expand recognition of the target odor from blood plasma samples to nasal secretion samples was assessed. Analysis of recorded training sessions revealed that the dogs exhibited successful odor discrimination between SNIP-positive plasma samples and SNIP-negative controls. Their pattern of behavior change also suggested similarity between SNIP odor in plasma and nasal secretions.