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Courtesy Sage Publications
and World Science staff
In a society where lung and breast cancers are leading causes of cancer death worldwide, early detection of the disease is highly desirable. A new study has found that dogs might be able to help detect these cancers early.
The study is to appear in the March 2006 issue of the research journal Integrative Cancer Therapies.
The scientists said dogs’ extraordinary scenting ability can distinguish people with both early and late stage lung and breast cancers from healthy people. The research, performed in California, was recently documented by the BBC in the United Kingdom, and is soon to be aired in the United States, researchers said.
Other studies have documented dogs’ abilities to identify chemicals that are diluted as low as parts per trillion. The clinical implications of canine sniffing first came to light in the case report of a dog alerting its owner to skin cancer by constantly sniffing the skin lesion. Subsequent studies published in medical journals reported trained dogs’ ability to detect both melanomas and bladder cancers.
The new study, led by Michael McCulloch of the Pine Street Foundation in San Anselmo, California, and Tadeusz Jezierski of the Polish Academy of Sciences, Institute of Genetics and Animal Breeding, is the first to test whether dogs can detect cancers only by sniffing the exhaled breath of cancer patients, the researchers said.
Five household dogs were trained within a three-week period to detect lung or breast cancer by sniffing the breath of cancer participants.
The trial was comprised of 55 lung cancer and 31 breast cancer patients who had not yet undergone chemotherapy, and 83 healthy patients.
The dogs were presented with breath samples from the human participants, captured in a special tube. Dogs were trained to identify a cancer patient by sitting or lying down directly in front of a test station containing a cancer patient sample, while ignoring samples from healthy people.
The results showed dogs can detect breast and lung cancer with sensitivity and specificity between 88 percent and 97 percent, the researchers reported. The accuracy persisted even after results were adjusted to take into account whether the lung cancer patients were currently smokers.
Moreover, the study also confirmed that the trained dogs could even detect the early stages of both diseases. The researchers concluded that with further work, breath analysis could substantially reduce the uncertainties of cancer diagnosis methods.
Further reading at the SAGE Journals Online
