First and foremost Medical Detection Dogs can advance research into the early diagnosis of cancer. It is well known that early diagnosis would save countless lives and so benefit the public hugely. Research is the only way of finding an answer.

When conducting research you can never be sure that a particular line of investigation will produce the results you are hoping for. However research is warranted when there is sufficient motivation to find an answer and a reasonable belief that a particular line of investigation may provide answers. Both of these premises are clear with this work. If the answer is a negative, that is that dogs cannot in practice help doctors with early diagnosis, the research completed will nevertheless be beneficial to overall research into cancer.

The scientific basis of the ability of dogs to detect the odour of cancer is believed to be linked to Volatile Organic Compounds produced by malignant cells. It has been established that during tumor growth protein changes in these cells which leads to peroxidation of the cell membrane components and this produces Volatiles that can be detected in the headspace of the cells.

Following our 2004 BMJ study, Medical Detection Dogs (aka Cancer and Bio-detection Dogs) has continued this work and recently published in the journal Cancer Biomark, Willis CM, Britton LE, Harris R, Wallace J, Guest CM. ‘Volatile organic compounds as biomarkers of bladder cancer: Sensitivity and specificity using trained sniffer dogs’.

The charity is now working in conjunction with Professor Karol Sikora, mass spectrometry scientists and a medical statistician in the detection of prostate cancer from human breath and urine. There are massively powerful reasons for such a study. Prostate cancer is a major killer and the current test, the prostate specific antigen test [PSA], is so unreliable that many GP’s are reluctant to use it. If dogs can sniff prostate cancer from a urine sample the chances are high that from the results of the dogs’ sniffing research, a test can be developed that is far superior to the PSA test. The results would indicate the existence of a potential odour signature of prostate cancer that may correspond to one or, more likely, multiple Volatiles. These molecules should then be assessed by specific gas chromatography/mass spectrometry analysis.

A recent study has just completed by Cornu et al, ‘Olfactory Detection of Prostate Cancer by Dogs Sniffing Urine: A Step Forward in Early Diagnosis’, indicated the possibilities of this. A second study in 2011 by Senoda on colorectal cancer using faecal samples (sensitivity 0.97 specificy 0.99) published in the journal Gut has shown equally promising results.

In 2011 the charity published in the journal ‘Cancer Biomark’ ‘Volatile organic compounds as biomarkers of bladder cancer: Sensitivity and specificity using trained sniffer dogs’. Specificity ranged from 92% for urine samples obtained from healthy, young volunteers down to 56% for those taken from older patients with non-cancerous urological disease.

There is strong indication from a number of studies that cancer Volatiles may appear on the breath at an early stage in the disease process.

Additional evidence published in the European Respiratory Journal carried out in Schillerhoehe Hospital Germany. This is the first to be published showing that sniffer dogs can reliably detect lung cancer from a breath sample.

We are now also focusing in conjunction with Professor Karol Sikora, mass spectrometry scientists and a medical statistician in the detection of breast cancer from human breath.

This work opens the door of Volatile Organic Compound detection for cancer diagnosis and suggests that the conditioned dog should be used in the near future to validate candidate molecules emerging from metabolomic screening. Evidence base building indicating that dogs could assist in improving current diagnosis of lung, bowel, prostate and breast cancer.