A panel of experts in preventive medicine released a draft proposal Tuesday on screening for prostate cancer. “Another one?” you may ask, remembering an earlier recommendation. Don’t worry; we’re here to help you avoid whiplash:
What’s new?
What was emphatic before is wishy-washy now. The last time the US Preventive Services Task Force weighed in on prostate cancer screening via blood tests, in 2012, it issued unambiguous advice to physicians: discourage men of all ages from getting tested for levels of prostate-specific antigen (PSA). That’s still the advice for men older than 70 or younger than 55.
But for those aged 55 to 69, the task force, a panel of independent experts who advise the federal government, is punting: It recommends “informed, individualized decision making based on a man’s values and preferences.”
Great. How do I do that?
The task force created a useful graphic to help you. We hope you like numbers:
If 1,000 men get PSA screening (cost: roughly $40), 240 will be told their PSA level suggests cancer might be present. Next step: a biopsy, in which a needle, usually inserted through the rectum, samples several spots in the prostate gland.
Of those 240 biopsies, 140 men will be told, oops, the PSA was misleading: You have no signs of cancer. These are called false positives.
Of the other 100 men, in whom biopsy shows definite cancer, up to 50 have malignant cells that will turn out to be so slow-growing — “indolent” — that the cancer would never spread or harm them. These are called overdiagnoses.
Unfortunately, it’s impossible to tell from looking at cancer cells if they’re wimps or killers, so 80 of the 100 men with prostate cancer choose surgery or radiation treatment, either right away or after first trying “active surveillance” (frequent PSA tests, exams, biopsies). At least 60 men suffer urinary incontinence and sexual impotence from the treatment.
Of the 80 treated men, only three benefit. In the other 77, the cancer either wouldn’t have caused harm if left untreated or is so aggressive that treatment doesn’t help.
Of the three men who benefited at all, 1.3 who would have been killed by prostate cancer without PSA screening will not be, over a period of 10 to 15 years.