Labrador beats lab in sniffing out cancer

BOSTON — Which is better at detecting cancer, a laboratory or a Labrador Retriever?

Consider the talents of Tsunami, a regal-looking dog with attentive eyes and an enthusiastic tail wag. University of Pennsylvania researchers say she is more than 90% successful in identifying the scent of ovarian cancer in tissue samples.

Picture: THINKSTOCK

The canine snout has 220-million olfactory cells, compared with 50-million for humans. The largest study ever done on cancer-sniffing dogs found they can detect prostate cancer by smelling urine samples with 98% accuracy.

At least one application is in the works seeking US approval of a kit using breath samples to find breast cancer.

“Our study demonstrates the use of dogs might represent … a real clinical opportunity if used together with common diagnostic tools,” said author of the prostate cancer research report Gian Luigi Taverna this week in Boston.

Mr Taverna, the head of urology pathology at Istituto Clinico Humanitas in Italy tested the ability of two explosives-detection dogs, Zoe and Liu, in 677 cases to assess their accuracy.

The next step will be to extend the research into prostate cancer subgroups and to other urological malignancies.

The results may one day be used to develop an electronic nose that follows nature’s lead in how a canine snout works, he said.

When dogs sniff for cancer, they are detecting the chemicals emitted by a tumour. These chemicals are referred to as volatile organic compounds (VOCs).

VOCs have been found in the breath of lung cancer patients, colon cancer patients and in the urine of prostate cancer patients.

The most recent findings have spurred increased interest in dog cancer-detection research, including efforts to develop devices that can mimic the animal’s exquisite olfactory system.

Dina Zaphiris, a trainer who works with dogs on federally funded studies to detect early cancer, is leading the charge for US Food and Drug Administration (FDA) clearance of a system that would use the unique olfactory talents of dogs in medical care. She plans to seek FDA approval for a canine medical scent detection kit. In her system, patients exhale through a tube onto a cloth, which captures molecules, or VOCs, of a malignancy. Dogs would then sniff the cloths for their presence.

In 2003 Ms Zaphiris worked with a research group on a study to detect breast and lung cancer, which is when her interest in the subject began.

A paper on that limited study, published in 2006, found dogs could detect lung tumours with 99% sensitivity and 99% specificity; for breast tumours, the results were 88% sensitivity and 98% specificity.

Bloomberg