There was a post, I think by Casey, a few months ago suggesting we change the name of low volume G6 cancers to something other than "cancer". I can't seem to find the thread, but was stunned by some of the reponses that it received, like that we would be lying to patients and that a "cancer is still a cancer" by any other name. The responses proved Casey's point that just the mention of the word "cancer" envokes a gut level response that may not conform to reality.
It is not patients or even Urologists that are asking this question, but some of our most noted oncologists and pathologists like Myers, Logothetis, Strum, Scholz and Oppenheimer and Epstien.
Dr Christopher Logothetis: " One of the problems with PC is the defination they label it as a cancer and force us to behave in a way that send us to a morbid therapy. Once that cancer label is put on there we are obligated to behave in a certain way and is driven by doctor's beliefs that frequently don't have anything to do with reality"
And Dr Oppenheimer: "It is time to reconcile the discrepancy of the term that pathologists assign to a micoscopic finding to the historical and significance of the term. The most common significant finding made by contempory pathologists on biopsies cannot be adequately described by "tumor", "cancer", or "maligant".
So what is prostate cancer? I cannot speak to the molecular structure of cells and when they cross the line and become cancer; only pathologists and oncologists have this ability. But in practical terms the defination is anything G6 or G 3+3 and above. But as we will see this is not very precise and is somewhat arbitrary and has changed in the past and will most likely change in the future.
In 1974 Dr Gleason observed the changes in prostate cell structures and created a scale of 1 to 5 to represent the changes from normal prostate cells to the most aggressive cancer. The Gleason Score represents the most predominant number of graded cells seen in a sample and the 2nd number indicates the 2nd most predominate grade. When added together we get the Gleason Score. The predominant grade must be 51% and the 2nd most predominant must be 5%, but less than 50%.
Currently a G6 is considered Prostate Cancer and a G5 is not reported by pathologists. What's the difference in a G5, 3+2 which is not considered cancer and a G6, 3+3? They both have a predominance of G3 cells, but a G5 can have 49% G2 cells and a G3+3 only 5% of the secondary grade G3 cells and only 44% of G2 cells. Is there a significant biological difference in where a G5 crosses over to a G6? Not likely.
The Gleason grade was developed so that 90% of pathologists would agree when viewing a sample. So we have a built in 10% error rate before we even start. What if Gleason made his scale 3 or 10 instead of 5? Our defination of cancer would be entirely different.
What if Gleason moved his dividing line between a G2 and G3 10% to the left or right? We would have 10s of thousands of patients given an entirely new diagonosis.
I find it helpful to view the Gleason score as a football field with each 10 yards indicating a Gleason score. The goal line would be normal cells and the 100 yard line a G5+5 or the most agressive cancer. I don't think that anyone would disagree that a patient on the 45 yard line does not have cancer or a patient above the 65 yardline does. But the 60 yard line is the dividing line between having cancer and not having it. If a patient is on the 59 1/2 yard line he is scott free, but when he takes that next little step his entire life has just changed. Does that one foot indicate a major biological event? Very unlikely.
So why is the line drawn at the 60 yard line instead of the 58 or 62 yard lines? The most likely answer is that it had to be drawn somewhere, but does it accurrately reflect the biological situation?
Many pathologists and onclogisists feel that it does not.
The Gleason scores have changed in the past. G5 used to be reported as a cancer and now it is not. There has also been a migration in Gleason grading; Jani et all in 2008 " the grade migration is likely due to pathological interpretation rather than to screening related changes in disease characteristics"
So the defination of "cancer" has changed over the years and will most likely change in the future as we have a greater understanding of the actual biological characteristics.
I would hope this thread generates some constructive critical thinking rather than the gut level responses to Casey's thread. We tend to think in black and white terms regarding what cancer is, but as you can see there is a grey area that affects 10s of thousands of patients who now fall between the 60 and 62 yard lines.
JohnT
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