The Unending PSA Controversy

BY MARK SCHOLZ, MD

The controversy about PSA has been reignited by new data from Lancet and recently reported in the NY Times.  Even though PSA screening reduces mortality from the aggressive type of prostate cancer, the Lancet article again confirms that far too many men routinely receive unnecessary radical treatment for a low grade type of prostate cancer that is essentially harmless, an entity that should never have been called cancer in the first place.

Grade 6 “cancers” are harmless. However, it’s hardly surprising that men (and doctors) push for immediate treatment anyway.  No amount of reasoning seems to ease the instinctual fears generated by this venomous word.  Despite warnings about impotence and incontinence—and reassurance that low-grade prostate cancer can be safely monitored— 85% of these low-risk men undergo radical treatment anyway.

Unfortunately, outrage against the genuine harms of overtreatment is routinely directed at PSA when the real culprit is the 12-core random prostate biopsy. I have previously weighed in on this matter in various blogs and videos, but the prostate cancer intelligentsia continues to be totally clueless, routinely blaming PSA rather than the ridiculous policy of randomly jabbing needles into the rectums of a million men annually.

Random biopsy could perhaps be justified if prostate scans were unreliable. In fact prostate imaging does often miss small, low-grade cancers; the very ones we now know are harmless. But for high-grade disease, color Doppler ultrasound and multiparametric, three-tesla MRI, are very accurate. Evaluating an abnormal PSA with an imaging study rather than a biopsy greatly reduces the chance of diagnosing grade 6 disease, the type that so commonly leads to unwarranted treatment.

Low grade cancers are incredibly common. However, higher-grade cancers also occur.  When imaging detects a high grade lesion, a targeted biopsy (a limited number of cores aimed directly at the lesion) should be performed. Lesions that are biopsy-negative or show low-grade cancer, can be monitored without treatment.  If high-grade cancer is confirmed, further staging followed by treatment counseling is needed.

Trained doctors using state-of-the-art technology read the scans and summarize their overall impression which falls into one of three categories:

1.        No evidence for high grade disease, no need for biopsy

2.        A suspicious lesion is detected, a targeted biopsy is necessary

3.        An ambiguous area is detected. Either a targeted biopsy can be considered or alternatively, ongoing monitoring with another scan in 6-12 months can be considered

Imaging “sees” all sorts of things besides cancer, including scar tissue, areas of active prostatitis, and nodular areas from BPH. Lesions of greater concern are located in the peripheral zone, over a centimeter in size, show bulging of the prostate capsule or are associated with increased blood flow or diffusion. An ambiguous lesion should be targeted for biopsy if it enlarges over time during observation on subsequent scanning. Expert judgment that takes each individual’s characteristics into account comes into play during a discussion between the patient and doctor about whether or not a targeted biopsy is indicated.

Color Doppler ultrasound and multiparametric MRI are complementary. In our experience, the imaging findings between these two modalities match 80% of the time. However, in a minority of cases, one imaging modality illuminates a specific lesion more clearly. Therefore, with ambiguous lesions using one modality, we usually consider additional imaging with the other modality before recommending targeted biopsy.

One would think that new advances in imaging would lead to an immediate revolution in prostate cancer management. Unfortunately many doctors are either unaware of what’s available or unacquainted with the full capabilities of the latest technology.  Finally, even well informed doctors may be reluctant to embrace imaging when they are well paid to do random biopsies.

Random biopsy continues to fly unscathed under the radar while people mistakenly blame PSA for the great misfortune of having thousands of men undergo unnecessary surgery or radiation every year. Forgoing PSA screening altogether is both foolish and dangerous. State-of-the-art prostate imaging, rather than random biopsy, should be the first step in evaluating men with elevated PSA levels.