French physicians and researchers are using dogs to develop an effective test for early detection of prostate cancer
The dog would it be more reliable than humans in detecting cancer? The animal is well known, has exceptional olfactory abilities in screening. Recently, a team of doctors and biochemists led by Olivier Cussenot, Professor of Urologic Oncology at the Hospital Tenon in Paris, decided to capitalize on it. It uses as a dog to improve biochemical tests currently used in laboratories to detect the existence of prostate cancer patients.
For this, the dog, malinois, widely used to detect explosives, narcotics or people buried in an avalanche, is trained to recognize the urine of people globally living with prostate cancer. "In Orleans, the French Air Force has trained a dog that is able to sniff out cancer of the prostate. A second is being formed, "says Olivier Cussenot, behind the initiative.
Because of the specificity and sensitivity of olfactory sensors that canines possess in the epithelium of their noses, their performance is 91%, according to results recently published in European Urology in which he is co-signer.
Cancer cells produce molecules volatile "We were surprised by the performance of these animals. No test, including that of prostate specific antigen (PSA), does this performance, "added the doctor. This test, now widely prescribed, most often gives up to 80% false positives (the man has a prostate infection but not cancer) and 10% false-negative (cancer escapes detection) .
The ability to detect prostate cancer is that cancer cells produce volatile compounds such as alkanes and methyl-alkanes in the urine. However, present in tumor cells, the sarcosine is not found in the urine. "We try to reconstruct the combinations of molecules detected by the dog and which are signatures of cancer," says Olivier Cussenot.
Meanwhile, the laboratory study of drug metabolism in Saclay, Christophe Junot analysis using a sophisticated device - mass spectrometer - all the molecules present in the urine of patients and those of healthy people . Thus, by cutting the data acquired through the dogs and those obtained by chemical analysis laboratory, the researchers hope to precisely define the composition of the "fragrance" of prostate cancer.
Medicine has long been interested in animal instinct If the operation of the flair of some animals to detect the smell of various diseases may seem surprising, medicine is interested in is long. In 1989, the medical journal The Lancet reported cases of dogs scenting a cancerous lesion of skin melanoma.
Other observations of detector dogs of cancer, including lung, through the breath, or cancer of the bladder smelling the smell of urine, have been reported in medical literature.
Since 1997, Tanzania, the NGO Apopo uses Gambian giant rats to detect TB patients by smelling their saliva samples. With 71,500 new cases and 8790 deaths in 2010, according to estimates by the National Cancer Institute, the research on prostate cancer represents a major public health issue.