Should pure Gleason 6 disease still be called cancer — or not?


The annual meeting of the Society for Urological Oncology has been going to in Washington, DC, this week, and reports on the various sessions have been available on the UroToday web site.

In one particular pro/con debate, Dr. Jonathon Epstein of John Hopkins and Dr. Mark Rubin of Weill Cornell Medical College focused on the continuing controversy over whether Gleason pattern 3 disease (and therefore true Gleason 3 + 3 = 6 disease) should really be called cancer or not.

The continuing controversy revolves around both pathological and clinical terminology, and there is no simple answer to this question. Terms like “indolent lesions of epithelial origin” (IDLE) and “prostatic neoplasia of low malignant potential” (PNLMP) have been suggested as alternative clinical descriptors for low-risk, Gleason 3 + 3 = 6 prostate cancer, but these terms have yet to be formally accepted by either the uropathology or the urologic oncology communities (let alone the broader urology, medical oncology, and radiation oncology communities).

As Dr. Epstein basically argued, Gleason pattern 3 “looks like prostate cancer” under the microscope and in cytological testing. And he worries that using any term other than “prostate cancer” to describe Gleason pattern 3 disease could lead to improper nomenclature and misinformation about cancers that actually turn out to be (say) Gleason 3 + 4 = 7. As he points out, cancers diagnosed as Gleason 3 + 3 = 6 on biopsy do get upgraded in about 20 percent of cases when they are treated surgically.

In contrast, Dr. Rubin proposed that use of terms like IDLE and PNLMP to describe cancers found to be Gleason 3 + 3 = 6 on biopsy came with limited risk; that there was a real need to “unlink diagnosis of cancer from treatment”; and that if we used terms like IDLE or PNLMP to describe these cancers, it would be a lot easier for both doctors and patients to appreciate the value of just monitoring such cancers as opposed to rushing men into overly-early, aggressive, and potentially unnecessary forms of treatment.

Obviously this is not a new debate, and Dr. Epstein was very clear that even if we continue to call Gleason pattern 3 disease “cancer”, we also need to be very focused on public education about low-risk (Gleason 3 + 3 = 6) disease, buy-in from urologists and others that such cancers are “good cancers”, and counseling of patients that Gleason 6 disease is such a “good cancer” that can just be monitored closely to watch for any risk of progression over time.

Dr. Epstein also went so far to a propose an alternative grading system for prostate cancer, such that

  • All Gleason score cancers of 1 + 1 = 2 through 3 + 3 = 6 be reclassified as Grade 1/5
  • Gleason 3 + 4 = 7 be reclassified as Grade 2/5
  • Gleason 4 + 3 = 7 be reclassified as Grade 3/5
  • Gleason 4 + 4 = 8 be reclassified as Grade 4/5 and
  • All Gleason score cancers of 4 + 5 = 9 through 5 + 5 = 10 be reclassified as Grade 5/5

Whether this is something that his colleagues in the uropathology and urologic oncology would be willing to accept is hard to know. We can see merits to this approach, but we can also see the value of terminology like IDLE and  PNLMP from a clinical perspective.

At the end of the day, this debate is as much about purity of pathological language as it is about our social responses to the word “cancer”, which still tends to scare all too many patients into an urgent need to “do something” that may no longer be justified by the clinical characteristics of low- and very low-risk forms of prostate cancer (and low-risk forms of other cancers too).

We don’t expect an early resolution of this discussion.

3 Responses

  1. Love this post.You must have known it is my birthday today! ;-)

  2. As technology progresses, the ability to detect and classify new items grows exponentially with their unimportance.

    Much of the public is already aware of this, and have adjusted. Sixty years ago, the public took the term “microbe” to mean “small bad germ that we should always exterminate completely.” But now, most of us understand on some level that being inhabited by microorganisms is the usual condition, and only rarely an abnormality requiring action.

    This was not accomplished by redefining the words “microbe” or “germ”. It was accomplished by educating people that most microbes are harmless or unimportant.

    The terms “genetic defect” and “cancer” should come to occupy a somewhat similar position: We all harbor germs, we all harbor cancers, we all harbor genetic defects. In most cases, they do no harm; but sometimes some of them can cause a great deal of harm.

    To some extent, similar reasoning applies to mental illness. Many people, perhaps now most, recognize that minor mental illness is almost as common as a minor stomach bug. These minor bugs often need no treatment at all, or only common-sense care. However, this doesn’t or shouldn’t detract in any way from the fact the some kinds of mental illness can sometimes cause a great deal of harm.

    Because this type of public awareness transition has occurred in microbes, genetic defects, and mental illness — from “horrible scourge that must be fought, prevented, or contained by any means necessary” to “commonplace ailment that only merits treatment in rare nasty cases”, I disagree with the “don’t call it cancer” suggestion from the otherwise estimable Dr. Rubin; Dr. Epstein’s suggestion for a grading system strikes me as far superior.

    I wonder if the perceived problem exists only or mainly in data and statistics. Perhaps epidemiologists and healthcare researchers worry that we mustn’t start (for example) reporting Gleason 3 = 1 + 2 as “cancer” because it would skew the cancer statistics. To this argument, I would quote Richard Feynman: “Reality must take precedence over public relations, for nature cannot be fooled.”

    The more information we gather and share about all cancers — including the vast majority that do no harm but are cancer nonetheless — the more accurate and truthful will be our understanding of the communication.

  3. Great post Paul C.

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