In a clinical trial in Scandinavia, a great number of aging men were divided into two groups. Those who were offered and opted for surgery for their elevated PSA gained very little for the experience compared to those who were not offered surgery. They gained too little for me to opt for the surgery if my PSA was elevated. Therefore, I won't let anyone check my PSA. You need to have this discussion with your doctor before you opt to have a screening PSA.
A few rare families and rare diseases aside, colon cancer is another disease of the sunset years.
Like prostate cancer, it is slow to grow and slow to spread but it is far less common than prostate cancer. The treatment, surgical removal, has far less likelihood of complications than prostate surgery.
The screening is not a blood test; it's hunting for the cancer directly. More and more, this is done by inserting a tube into the colon and looking inch-by-inch. It's not a perfect test, requiring patience as much as dexterity.
And it has complications, many of which relate to the removal of polyps which are grape-like growths on a stalk that have very little potential for harm (if they develop into cancer at all, it takes decades).
So we are back to our critical question. The issue is not whether one can find a cancer and remove it, but whether one can find and remove the cancer that is likely to cost me time on this earth.
I don't care if I develop colon cancer in my 80s; something else is likely to kill me long before it can. I don't care if I develop colon cancer in my 70s either, for the same reason. Furthermore, screening me in my 40s is largely an exercise in futility; colon cancer is so very, very rare in 40-year-olds that the chances of a complication of colonoscopy far outweighs the chances of finding the rare cancer. It's in the 50s and 60s that finding and removing the rare colon cancer is likely to be meaningful to that person and worth the risks to all those who don't have colon cancer.
Hence, I had my one colonoscopy. In fact, I settled for a partial look (flexible sigmoidoscopy) because that was good enough risk assessment for me and the procedure is gentler and safer.
I am not alone in realizing the limitations of these tests and others such as mammography or even the annual physical examination. Many a researcher has been recruited to the task of improving screening tests. However, until we have much better screening tests, no person should be screened unaware of the limitations of the test.
Dr. Nortin Hadler is professor of medicine and microbiology/immunology at the University of North Carolina at Chapel Hill, and an attending rheumatologist at University of North Carolina Hospitals. He is the author of Worried Sick: A Prescription for Health in an Overtreated America and The Last Well Person.