Some biologists think that a target of 99% accuracy for any cancer screen is unattainable.

It seems that SignPost is not alone in this pursuit.

According to a company called BioScent Dx, dogs are able to smell minute changes in a human bio-markers including hormones, proteins and other organic compounds. This has lead to dogs being trained to aid in the monitoring of conditions such as diabetes, narcolepsy and cancer. BioScent Dx is working on developing a cancer screen for recurrent breast cancer.

Studies have shown that, when trained, dogs can detect cancer from human breath, fecal, and urine samples with up to 99% accuracy.

BreastDefense has determined through initial work that 99% accuracy of breast cancer is attainable.