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

Tuesday, April 22, 2014

Imaging is Superior to Random Biopsy


Recently, our attention has been directed at the overtreatment of low-grade prostate cancer.  While PSA screening has been fingered as the problem, overuse of random needle biopsies is the real culprit. Over a million men undergo biopsies every year to address concerns about the possibility of underlying cancer.  Few people realize, however, that random biopsy reveals low-grade prostate cancer in one out of five men in the general population—even if PSA is normal.

Most of these “cancers” are harmless. Even so, it’s hardly surprising that patients with “cancer” want immediate treatment.  The words “low grade” or “microscopic” can’t offset the instinctual fears generated by this venomous word.   Despite dire warnings about the risks of treatment-induced impotence and incontinence—and reassurance from experts that low-grade prostate cancer can be safely monitored—studies show that 85% of men still throw caution to the wind and get treatment anyway.
Imaging is “Blind” to Small Low-Grade Cancers
While latent prostate cancers are more common, aggressive prostate cancer is also a reality. After all, 30,000 men die every year of prostate cancer. Back when doctors believed that all types of prostate cancer were universally dangerous, prostate imaging, which often misses small, low-grade lesions, was deemed inadequate. However, now with a more modern perspective we know that color Doppler ultrasound or multiparametric, three-tesla MRI overlook low grade disease while still detecting high-grade disease accurately.  Imaging spares men the shock of an unnecessary cancer diagnosis and unwarranted treatment.
Targeted Rather than Random Biopsies
When an overtly suspicious lesion is detected by imaging, a targeted biopsy (a limited number of cores aimed directly at the lesion) is typically recommended. Lesions that are biopsy-negative or show low-grade cancer can be monitored without treatment.  If high-grade disease is diagnosed, further staging followed by counseling about treatment is needed.
The doctor who reads the scan summarizes his 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
When to Biopsy Ambiguous Lesions
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, bulge the prostate capsule or are associated with increased blood flow or diffusion. An ambiguous lesion may require biopsy if a subsequent scans show an enlarging lesion. Expert judgment that takes individual patient characteristics into account comes into play during a discussion between the patient and doctor about whether or not a targeted biopsy is indicated.

“Cross Checking” Ambiguous Lesions
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.

New Technology Brings Growing Pains
You might think that new technological advances would immediately revolutionize prostate cancer management. Not necessarily. Many doctors simply don’t know what’s now available. Those that are aware are often unacquainted with the full capabilities modern imaging can achieve. And finally, even the well informed doctors may be reluctant to venture outside their comfort zone to embrace imaging as a substitute for doing a random biopsy.

Final Thoughts
Lack of awareness about how random biopsy leads to the over diagnosis of harmless, low grade cancers is resulting in a 100,000 men undergoing unnecessary surgery and radiation every year. Forgoing PSA screening altogether is both foolish and dangerous. State-of-the-art prostate imaging, not random biopsy, should be the first step in evaluating men with elevated PSA levels.

Join us in Long Beach, CA at Barnes & Noble Marina June 26, 2014 @ 7pm- Ask the Author: Mark Scholz, MD will be discussing his book, Invasion of the Prostate Snatchers and Men's Health. More June events and details here:!topic/prostateoncology/H1AE5oeW2jc 

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