Does prostate cancer screening do more harm than good?
While the prostate cancer death rate continues to decline, a group of Canadian researchers argues it’s not because of PSA screening.
PSA screening measures the amount of prostate specific antigen (PSA) in a man’s blood.
The research, led by the University of Calgary’s Dr. James Dickinson, found that PSA screening increases the number of prostate cancer diagnoses, but doesn’t decrease the number of deaths caused by the disease.
“The good news is that the treatment of prostate treatment is better and so that’s maybe reducing the death rate,” Dickinson said.
Dickinson says prostate cancer death rates started going down before PSA screening could have possibly made an impact. He also believes the screening can lead to over-diagnosis and over-treatment.
“The screening test itself is no big deal; it’s what happens after that,” Dickinson said. “When you get a biopsy of the prostate then particularly when you get a false positive, you get over-diagnosed and over-treated.
“So, for every man who actually has a real cancer… maybe 20 or more men are being treated.”
Dickinson says many men who are diagnosed have an operation to remove the prostate.
“Often they have trouble with urine function and with impotence after that… Alternatively, if they don’t get that, they may get radiotherapy. Radiotherapy burns the prostate and after that you get scarring and problems arising from that. None of these treatments are wonderful.”
He says a better course of action might be to wait until there are symptoms before being screened.
However, one expert says that would be much too late.
“Generally, if you have symptoms from prostate cancer, you’re going to have metastatic disease and you’ve missed the chance of a cure at that point,” Dr. Eric Hyndman, a urologist with Calgary’s Prostate Cancer Centre, said. “Even men with high-grade metastatic disease aren’t symptomatic up front.
“If you’ve got symptoms then it’s too late.”
Hyndman explains that yes, there are a number of reasons elevated levels would show up in a PSA screening, including an infection or prostate cancer.
“The concern with the PSA test is that it doesn’t necessarily discriminate between low- and high-grade disease. We don’t need to identify these low-grade diseases. We do need to identify these high-grade diseases.”
He says men have about a one-in-six chance of being diagnosed with prostate cancer, but only a one in 30 chance of dying from it.
“It’s still the second-leading cause of cancer-related deaths in men,” Hyndman said.
He suggests something called “active surveillance” for men with elevated PSA levels. Doctors monitor patients regularly to see if low-grade cancer turns into high-grade.
“It’s becoming much more common as it should be… What we do is we follow them along with time, and if they stay with low-grade, low-volume disease then they don’t need surgery, they don’t need intervention.”
But Dickinson argues it’s difficult for a man to be told he has prostate cancer and not to do anything about it.
“When men have had the pants scared off them about prostate cancer – you’re getting screened to find cancer, we’ve got a positive test – it’s really hard for them to say, ‘Yeah, I have cancer, maybe, don’t know, but we’ll wait and see.'”
So, what does he suggest?
“They should keep on treating the true cancers that are causing trouble, but they should stop screening men who don’t have any problems,” Dickinson said.
He believes the road that PSA screening leads down can cause “a great deal of harm to men and their families” and says getting the blood test is a choice for men to seriously consider with their doctor.
“Men can have a choice. If it’s 20 to one, do you hope that you’re the one who benefits or do you say, 19 that are going to be harmed to get one that benefits, I don’t like those odds?”
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