Cancer-sniffing dogs - Essay Example

Nikolay Denkov Liz Whiteacre English 1102 Dogs have been man's best friends ever since the beginning of the association: for centuries dogshave been man's hunting partners, loyal servants, and eventually cherished companions. They have been our saviors and our succor in countless instances of distress - from being rescuers during natural disasters to guides for the visually challenged. Can man's best friend now turn out to be his best hope in the fight against the horrifyingly painful and usually fatal disease of cancer According to the research conducted in the last 15 years and more, it seems that dogs could indeed be able to save us from yet another peril - cancer undetected until it is too late. Having lost my 5 year-old nephew, grandfather and girlfriend's father to cancer, I have immediate experience of the tragic loss cancer can bring, and find the issue of its early detection extremely relevant and important. Each year more and more people are being diagnosed with some or the other variety of cancer without a reliable cure in sight. I recall reading in my Anatomy & Physiology textbook that cancer is the second leading cause of death in the United States. Half of all men and one third of women in the United States could develop cancer during their lifetimes. But what exactly is cancer and what can be done against it Cancer develops when the DNA of normal cells gets damaged from certain factors in the patient's ambient environment or it could be genetically inherited, and lie dormant for years before becoming active. Unlike normal cells which grow, divide and die, active cancer cells continue to grow, divide and form new cancer cells, thus outliving and replacing the body's healthy cells. In a later stage of the disease, the cancer cells usually start spreading to other parts of the body, where they grow and replace even more normal cells. This spreading of cancer cells is called metastasis and usually happens through the bloodstream or the lymphatic system or both. The presence of metastasis usually indicates bad prognosis, as the treatment options currently available are rarely able to cure the patient once the cancer has gone to a later stage of development and begun to spread. In other words, the key to successful treatment of cancer is the early detection of the disease. Here is where a dog's sensitive nose unexpectedly shows a possibility of rescue. What drew my interest to this specific but experimental area of cancer detection was the promising statistic from the April's issue of Harper's Index about five cancer-sniffing dogs at a California clinic. The dogs were reportedly highly accurate in detecting lung and breast cancers with 99% and 88% accurate diagnosis respectively. Statistically, this made the canines even more effective than a standard mammogram in diagnosing breast cancer, with its accuracy rate of 85%. Reports of dogs being able to sniff out cancer have been doing the rounds since the past five years, though this method has only recently emerged as a possibly better alternative to the traditional cancer diagnostic tools. But is it really possible to sniff out cancer or could it be just another absurd idea as some people claim It is now an established fact in the scientific community that cancer patients emit traces of biochemical substances such as alkanes and benzene derivatives in their breath, especially those with lung and breast cancer (Kleiner).These are metabolic waste products of the cancer cells and are different from those given off by the normal cells in the body. Previous studies have pointed out that dogs, on their part, can detect chemicals in concentrations as small as a few parts per trillion (Kleiner). According to James Walker, director of the Sensory Research Institute at Florida State University in Tallahassee (Lovgren), the area devoted to the sense of smell in a dog brain is proportionally much larger than that of humans, though it is not known what exactly makes their sense of smell 10, 000 to 100, 000 times superior to that of humans. The emission of those by-products coupled with the canines' extraordinary sense of smell present a foundation for a scientific explanation of why and how it is possible to sniff out cancer. As a matter of fact, dogs have been shown to be more accurate than the latest mammograms, CAT and MRI scanners (Margolis). The results of the scientific trial at the Pine Street Clinic in San Francisco mentioned by Harper's involved 5 dogs, 55 lung cancer patients, 31 breast cancer patients and a control of 83 healthy individuals. The dogs achieved an accuracy rate in detecting cancer between 88% and 97% even in the first symptom-free stage, better than the accuracy of the most expensive and modern scanners (Margolis). According to Britain's biggest cancer investigator, Cancer Research UK, the most modern scanners, costing around $2 million and requiring another half a million per year for maintenance, have an accuracy of 85% to 90%. In my opinion these findings clearly and effectively dismiss the proposal of some skeptics that cancer-sniffing is simply another absurd idea. But the question that now arises is whether all dogs can be trained to detect cancer or only a few talented dogs are able to do so. It is a question Michael Broffman, the co- founder and director of the Pine Street Clinic had to ask himself when Shing Ling-hua, their star cancer-detecting dog, died. Shing Ling was the pioneer of the cancer detection pack at the clinic and had detected many cases of cancer with an extraordinary accuracy. The researchers at the clinic were determined to prove that Shing Ling was not a one-off phenomenon but that given proper training, other dogs too could diagnose cancer. According to the Pine Street Foundation, which owns the San Francisco clinic, most dogs given only several weeks of training will be able to sniff out cancer at an accuracy as good as or better than the traditional diagnostic instruments. The five dogs that showed remarkable accuracy in the test mentioned previously had no earlier training and were trained for only three weeks using breath samples exhaled into tubes by cancer patients. The dogs were trained to key off a scent, which is the methodology used with drug dogs and bomb-sniffing dogs (Guthrie). Many dogs that end up as career sniffers are rescued from shelters or pounds, as trainers look for dogs that are eager and enjoy games. Personality and not pedigree is the most important trait for them (Guthrie). So, logically, any eager dog with a learning personality can be trained to sniff out cancer in the same way as it can be trained to detect explosives. Not being machines, dogs do have certain limitations such as becoming tired, or being inconsistent. But these can be overcome with proper motivation, and by using a team of dogs rather than an individual. The advantage the pooches have in terms of accuracy and cost far outweighs their limitations. Apart from being much more affordable and somewhat more accurate than a $2 million machine, another important advantage of the cancer-sniffing canines is their access to people. While the traditional diagnostic tools won't be found anywhere else other than in a hospital, dogs have diagnosed cancer in people in different places such as homes, streets and at dog shows. Those are people that most likely wouldn't have been visiting the hospital for at least another few months and would have had longer and less successful treatment. Thus it can be concluded that using dogs to detect cancer is not as far-fetched as it sounds, because there is a definite scientific explanation as to why and how it is possible. The dogs' accuracy as well as easy availability as compared to traditional diagnostic devices argues in the favor of their widespread use in cancer detection, not merely in hospitals but at special workshops held specifically to enable early diagnosis and life-saving treatment. Kleiner, Kurt. "Dogs as good as screening for cancer detection". NewScientist.com news service. January 9, 2006. < http://www.newscientist.com/article.nsid=dn8549&feedId=online-news_rss20> Lee, Jennifer. "There's sense in wider use of dog-sniffing". New York Times News Service. June 13, 2006. < http://www.signonsandiego.com/uniontrib/20060613/news_7n13dogs.html> Goldston, Linda. "'Doctor Dogs' diagnose cancer by sniffing it out". The Mercury News. January 26, 2006. Guthrie, Julian. "Sensing sickness: Cancer-sniffing dogs have shown promise at detecting the disease in its early stages." San Francisco Chronicle. 1 June 2003. Hilton, Lisette. "Cancer-sniffing dogs: Researchers say pooches can identify urine from patients with bladder cancer." Nurse Week. 9 May 2005. < http://www.nurseweek.com/news/Features/05-05/CancerSniffingDogs.asp> Willis, Carolyn. "Olfactory detection of human bladder cancer by dogs: proof of principle study." BMJ.com. 25 September 2004. < http://bmj.bmjjournals.com/cgi/content/abridged/329/7468/712> Margolis, Jonathan. "Dr Dog, the cancer specialist." The Sunday Times. 6 November 2005. < http://www.timesonline.co.uk/article/0,,8123-1859073_1,00.html> Lovgren, Stefan. "Dogs Smell Cancer in Patients' Breath, Study Shows." National Geographic News. 12 January 2006. < http://news.nationalgeographic.com/news/2006/01/0112_060112_dog_cancer.html> SAGE Publications. "Can Dogs Smell Cancer" ScienceDaily.com. 6 January 2006 < http://www.sciencedaily.com/releases/2006/01/060106002944.htm> Read More