Prostate cancer screening game-changer

Prostate Cancer
Prostate Cancer

Dr. Jon LaPook is a medical correspondent for CBS News.

An important new study out yesterday should lead to far fewer prostate biopsies.

First, some background. A lot more men will get prostate cancer than will die from it. On autopsy studies of men who die from other causes at age 70, about 40 percent have microscopic evidence of prostate cancer. 

But only about 3 percent of men die from prostate cancer.

Right now there's a huge focus on figuring out which men with prostate cancer should be treated - and how aggressively.

In order to try to detect prostate cancer, doctors measure a protein in the blood called prostate-specific antigen or PSA. It tends to go up in prostate cancer (though not always) but can also be elevated in more innocent conditions such as inflammation of the prostate (prostatitis) or enlargement of the prostate with aging (benign prostatic hypertrophy.)

In recent years, doctors have been performing biopsies on men whose PSA level has been rising rapidly, even if it remains in the normal range - thinking this might identify men with aggressive cancers that should be treated.

But a large study out yesterday from Memorial Sloan-Kettering Cancer Center by Andrew Vickers, Ph.D. and colleagues found that rapidly rising PSA - by itself - is not a reason to do a biopsy.

However, men with increasing PSA levels should be still be followed with repeat PSA tests and with digital examinations - and biopsy considered if a prostate irregularity (such as a nodule) is felt on exam or if the total PSA goes over a certain level.

There's debate over what that level should be. A PSA of up to 4 is considered "normal" in most labs but some doctors consider doing a biopsy at a lower level; biopsying the prostate at a lower PSA level - say 2.5 - might pick up more cancers but would also lead to many more unnecessary biopsies (i.e., finding no cancer or finding a cancer that would never have caused any clinical problem).

The bottom line: screening for prostate cancer is a very tricky subject filled with nuance. What's clear is that men should carefully discuss the pros and cons with their doctor. But for men who do decide to have their PSA checked, the new data suggest they shouldn't worry about changes or spikes in their PSA, as long as their PSA is still in the normal range.

  • Jon Lapook
    Jonathan LaPook

    Dr. Jonathan LaPook is the chief medical correspondent for CBS News. Follow him on Twitter at @DrLaPook