Man’s Best Friend
I’ve had some pretty remarkable dogs in my life. One that even understood “right” and “left”–even though I never trained him on it. But I think even he’d be impressed with this Belgian Malinois (it’s a breed of German shepherd widely used in law enforcement to sniff out bombs and drugs).
Two French researchers trained the Belgian Malinois to detect the difference between urine samples from men with prostate cancer and samples from healthy men.
This plan isn’t as far-fetched as it sounds. Scientists know that some types of tumors discharge compounds with distinct aromas. And dogs have previously been successful in identifying bladder, skin, and lung cancers.
After a year of training, researchers put the dog through 11 tests. In each test, the dog was presented with six urine samples–five from healthy men and one from a man with confirmed prostate cancer.
The dog found the cancer sample in eight tests. And in one of the three tests that he chose a “healthy” sample, the man who submitted that sample was soon diagnosed with prostate cancer.
So if I’m doing my math right, the dog has about an 82% accuracy rate.
Avoid at all costs
As I’ve mentioned before, elevated PSA indicates the possibility of prostate cancer.
But PSA levels can rise and fall based on factors other than cancer. Nearly two-thirds of all single PSA tests that indicate cancer end up being false positives (and, again, compare that to less than a 20% fail rate for the pooch!). That’s a lot of unnecessary biopsies, unnecessary risk, and unnecessary heartache for patients.
Having the dog sit on the side for a minute, researchers are finally figuring out how to harness PSA.
In a new study from Austria, researchers found that a series of PSA tests taken over four years can predict prostate cancer much more accurately, and may also reveal the severity of the cancer.
This couldn’t be more important for men–especially older men who have no need for overly aggressive treatment of slow-growing prostate cancer.
Hopefully, future research with dogs will follow the same track. Knowing dogs can identify prostate cancer is an important first step. But I’m not sure Fido is up to the big test: detecting the difference between slow-growing cancer and more aggressive, life-threatening cancer.
Men, please don’t assume your doctor is aware of all of this. If you take a blood test and it shows a high PSA, talk to him about the next step, but know that the next step should NEVER be a biopsy.
You can read more about biopsy dangers–with a revealing look at the blockbuster drug that’s been shown to skew PSA levels–in “Breaking Bad.”
To Your Good Health,
“Dogs Sniff Out Prostate Cancer” Charlene Laino, WebMD Health News, 6/2/10, webmd.com
“Tracking PSA Test Results Over Time Gives Clues to Cancer” Randy Dotinga, HealthDay News, 6/1/10, healthday.com