Dogs have long been used to find explosives and drugs.Now,a new study shows that man's best friend can also help to find lung and breast cancer,researchers report in integrative Cancer Therapies.The findings show that trained ordinary household dogs can detect early--stage lung and breast cancers by smelling the breath samples of patients. Researchers have found that cancer cells send out molecules different from those of healthy ones,and that might be sensed by smell by the highly sensitive dog's nose. For the study,five dogs were trained by a professional instructor to respond differently to breath samples of healthy and cancer patients."The dogs learned to sit or lie down in front of cancer patient samples and to ignore control samples through the method of food reward," McCulloch explained. After a period of training,researchers tested the animals'ability to distinguish cancer patients from controls.The animals were given breath samples from 55 patients with lung cancer,3 1 with breast cancer and 83 healthy controls who were not included in the original training period. McCulloch's group found that the dogs were able to correctly distinguish the breath samples of cancer patients from those of the control subjects in about 90 percent of the cases.The dogs were also able to detecting early-stage lung and breast cancers. "These results show that there is hope for early detection,"McCulloch said.The re-searches are planning to conduct further studies on the breath composition of cancer patients to possibly design an electronic device that can do the dogs'job."A dog's nose is so powerful it can detect odors 10 000 to 100 000 times better than a human nose can.I hope people will be interested in doing this research,"McCulloch added,"It shows that there is definitely something out there." McCulloch and his group used_in their research.
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