The Body: A Guide for Occupants

by Bill Bryson

The problem is that the test for prostate cancer, called a PSA test, is not trustworthy. It measures levels in the blood of a chemical called prostate-specific antigen (PSA). A high PSA reading indicates a possibility of cancer, but only a possibility. The only way of confirming if cancer exists is with a biopsy, which involves sticking a long needle into the prostate via the rectum and withdrawing multiple tissue samples—not a procedure any man is likely to undertake eagerly. Because the needle can only be randomly inserted into the prostate, it is a matter of luck whether it strikes a tumor or not. If it does find a tumor, there is no telling with current technology if the cancer is aggressive or benign. On the basis of this uncertain information, a decision must be made on whether to surgically remove the prostate—a tricky operation with frequently dispiriting consequences—or treat it with radiation. Between 20 and 70 percent of men suffer impotence or incontinence after treatments. One in five experience complications from the biopsy alone. The PSA test is “hardly more effective than a coin toss,” Professor Richard J. Ablin of the University of Arizona has written, and he should know. He was the man who discovered the prostate-specific antigen in 1970. Noting that American men spend at least $3 billion a year on prostate tests, he added, “I never dreamed that my discovery four decades ago would lead to such a profit-driven disaster.” A meta-analysis of six randomized c...