JC2011-09 CRC Screening with Odour Material by Canine Scent Detection

COLORECTAL CANCER SCREENING WITH ODOUR MATERIAL BY CANINE SCENT DETECTION : 

COLORECTAL CANCER SCREENING WITH ODOUR MATERIAL BY CANINE SCENT DETECTION SAMUEL KIM SUH

INTRODUCTION : 

INTRODUCTION Double blinded study FOBT (PPV 10%) Need for more effective CRC (colorectal cancer) screening Several other reports

METHODS : 

METHODS Enrollment from 6/20/08 to 5/20/09 Fukuoka Dental College Medical and Dental Hospital and Arita Kyoritsu Hospital Age >20 yo Patients and control completed questionnaire about factors that can affect volatile molecules CRC (colorectal cancer) diagnosed by colonoscopy and biopsy Exclusion criteria

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Breathing Sampling

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Watery stool sampling 50cc by suction during colonoscopy between rectum and descending colon

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Dog and Training A 8 yo female black Labrador retriever Trained since 2005 for cancer detection Training sessions completed when correctly distinguish between samples from patients vs controls Reward based on tennis ball

Sample stations : 

Sample stations

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Dog’s Response Correct: (true positive in sensitivity calculations) (true negative in specificity calculations)

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Incorrect: a) Indicating on a control sample (false positive) b) Sniffing but not indicating on a cancer sample (false negative) c) Hesitation (false positive or false negative)

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Testing From November to June For each test new samples, used only once Samples in new bag Identity of sample were blinded

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Standard sample Stations Response Fax Feedback Reward

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Occult blood test for watery stools Ordinary FOBT kit used Diagnostic accuracy was calculated as sensitivity or specificity of the dog’s response compared to the true diagnosis confirmed by colonoscopy

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Sensitivity or true positive rate: proportion of cancer samples correctly identified by the dog Specificity or true negative: proportion of control samples negatively indicated by the dog

RESULTS : 

RESULTS Samples: 48 from CRC 203 control 55 History of CRC Breath samples 33 CRC and 132 Control Watery Stool 37 CRC and 148 Control Background characteristics well matched between patients with CRC and control except age

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FOBT vs Dog Dog scent judgment based relied on blood? No correlation found FOBT sensitivity was 0.70 and specificity was 0.85

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Mixture test of watery stool samples Determine whether a specific cancer scent exists or if particular natural scent vanishes in patients with CRC One Mixture with one sample with CRC and four of control samples Four mixture samples consisting of five control samples

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FOBT-25 to 38% HEMOCULT-64 to 80% SENSA FIT-up to 90% Breath/Marine-91% Stool/Marine-97% Colonoscopy-91 to 97%

DISCUSSION : 

DISCUSSION Watery stools stronger because near colon Canine scent judgment high even in early stages Canine judgment not confounded by other factors Statistical age difference in age distribution Four discrepancies

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No correlation between FOBT and Canine scent judgment Volatile Organic compounds (VOC) Difficulties VOC reported as biomarkers in other GI disorders Next step cancer specific VOC by chemical analysis

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References: -McCulloch M, Jezierski T, Broffman M, et al. Diagnostic accuracy of canine scent detection in early and late stage lung and breast cancers. Integr Cancer Ther 2006; 5:30-9. -Willis C, Church S, Guest C, et al. Olfactory detection of human bladder cancer by dogs:proof of principle study. BMJ 2004;329:1-6 -O’Neill H, Gordon S, O’Neill M, et al. A computerized classification technique for screening of the presence of breath biomarkers in lung cancer. Clinical chemistry 1988; 43:8 - Uptodate: Robert H Fletcher, MD, J. Thomas Lamont. Tests for screening for colorectal cancer: Stool tests, radiologic imaging and endoscopy..

Cloned! : 

Cloned!

Questions to the audience : 

Questions to the audience What are the limitations of this study?