The co-authors of Invasion of the Prostate Snatchers, blog alternate posts weekly. We invite you to post your comments.

Tuesday, November 3, 2015

Biopsy, Not PSA, Leads to Prostate Cancer


Prostate cancer is way over treated, and the problem starts with over diagnosis.  Once men are diagnosed, the fear of cancer naturally drives them toward radical treatment. In 2011 the US Preventive Services Task Force intervened, trying to stop overtreatment, argued that PSA testing causes more harm than good.

Some have questioned the expertise of the panel because of the lack of representation by urologists, radiation therapists or medical oncologists --the types of doctors usually responsible for treating prostate cancer.  Actually, the credentials of the panel constituents appear entirely appropriate to comment on screening, because this is an area of medicine usually handled by primary care doctors.  The panel members consisted of twelve MD’s and four PhD’s trained in primary care, public health and statistics.

The Task Force agrees that PSA screening may save lives. Their judgment, however, was that too few lives are saved to justify thousands of men getting unnecessary radical treatment. One statistic indicates that a thousand men must be screened to save one life within the next 12 years.

Personally, I agree with the panel in regards to over diagnosis is a root cause of over treatment. However, simply discarding PSA is an oversimplification. PSA can detect a variety of problems infection and benign prostate enlargement. Actually, the majority of men with elevated PSA, don’t have prostate cancer.

No, the real problem is after a PSA test rises. Every year, a million men are advised to have a dozen, large-bore needles jabbed into their rectums “Just to be sure there is no cancer.”  Such behavior sounds ridiculous, but really, it is just the survival instinct in action. People will do practically anything when they fear for their lives.

So if not a biopsy to evaluate an elevated PSA, what’s next?

First, the fear must be faced. Ralph Waldo Emerson says “Knowledge is the antidote to fear.” So let’s look at some basic facts:

  • One out of 38 men die of prostate cancer
  • One out of seven men are diagnosed with prostate cancer
  • In men who are “diagnosed”
    • Five-year survival is 100%
    • Ten-year survival is 99%
    • Fifteen-year survival is 94%
Considering it is cancer, survival rates are great! At least these numbers should overcome any urge to rush. Clearly there is plenty of time is to study and learn more. Confusion arises because a minority of prostate cancers can indeed be dangerous. Not as dangerous as lung or pancreas cancer which kill within months. However, demise from prostate cancer certainly qualifies as “dangerous,” even if it is rather infrequent and much postponed.

These statistics reveal something else that is quite useful. Prostate management issues are of long-range nature, like saving for college or for retirement. Just as expert financial planners are limited in the ability to make predictions about economic activity ten years in the future, doctors should be equally humble in their pronouncements about the future of prostate cancer. We don’t know for sure, but we strongly suspect there will be substantial breakthroughs in the diagnosis and treatment of prostate cancer in the next ten years.

For the short term, I think the best way to proceed is with imaging the prostate with a 3Tmulti-parametric MRI or color Doppler ultrasound. Scans are about as accurate as a random biopsy for detecting aggressive cancers and they usually fail to detect the harmless low grade types, which is a good thing. However, if there is a worrisome abnormality, a targeted biopsy with just a couple cores is needed.

Over-diagnosis and over-treatment is not due to PSA. It’s the misguided policy of rushing into an immediate random biopsy whenever there is a slight elevation.  .The random biopsy procedure should be abandoned.  PSA abnormalities should be evaluated with prostate imaging A targeted biopsy can be considered in men who have a distinct abnormality detected by imaging.    

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