So what I think we need is public education. We have to educate patients that most Gleason score 6 cancers can be followed with active surveillance, that they could have a good form of cancer that generally does not cause harm, but that they have to emphasize that there is a risk of having a more aggressive type of cancer that might have been missed, that the cancer could potentially change over time, and that the patient must be followed closely.
I think more and more patients are asking for active surveillance, compared with prior years, and I think urologists need to buy into the concept of “good cancer” to educate the appropriate patients for active surveillance because urologists are the first clinicians that patients typically see following their diagnosis.
One of the problems is that we don’t see Gleason patterns 1 and 2 anymore, so we don’t diagnose Gleason scores 2-5 anymore, for the most part. This makes Gleason score 6 pretty much the lowest cancer we see. The problem is that patients hear they have a Gleason score 6 tumor, they go on the Internet and find out the scale goes from 2-10, and they think their tumor is somewhere in the middle of the range.
Therefore, we are proposing a new grading system. We recently had a meeting in Chicago, which was attended by 85 prostate cancer experts, and this new grading system was accepted to be used, initially, in conjunction with the current Gleason scale. Basically, in the new scale, Gleason scores 2-6 are graded 1 out of 5; Gleason score 3+4=7 would be 2 out of 5; 4+3=7 would be 3 out of 5; Gleason score 8 would be a 4 out of 5; and Gleason scores 9-10 would be a 5 out of 5.
In summary, I don’t think we need to change calling Gleason score 6 cancer. We need to change what patients think when they hear that they have Gleason score 6 cancer. Urologists have to reassure and educate patients, and if you modify the grading system to tell someone that they have a grade 1 tumor out of 5 instead of a 6 out of 10, it will help reassure patients and realign the grading system in prostate cancer so Gleason score 6 tumors are more appropriately considered as indolent, but something that still needs following.
Dr. Jonathan I. Epstein is a professor of pathology, urology and oncology at Johns Hopkins University Hospital, Baltimore. He reported no relevant financial disclosures.
COUNTERPOINT: Dr. Rubin
If we were to name Gleason pattern 3 and Gleason score 6 today, we might go with something different. For me, the term “adenoma” comes to mind because adenomas are neoplastic, but we don’t call them cancer.
It’s very important to remind ourselves that if we look at a spectrum of cancer, ranging from indolent to aggressive, many of the [pertinent] studies that we’ve read or heard about are taken from a very discrete, carefully culled set of cancers in patients who were undergoing radical prostatectomies. One should consider that population-based studies are important for this type of evaluation. We should also remind ourselves that nothing in life is zero risk; even going to the gym and running has some risk associated with it, so the fact that we choose to classify something as cancer or an adenoma will always have some risk associated with it.
Dr. Mark A. Rubin
In a multi-institutional study that Dr. Epstein published recently, he described the risk of Gleason score 6 cancer progressing as approximately 3%. So what does 3% mean? Well, those 3% [of patients] led to prognostic categorizations similar to the ones we just heard about, and one of the important things to remember is that the endpoint here is biochemical recurrence.
A recently published study employed a modeling exercise to look at the meaning of biochemical failure. In that analysis, going from radical prostatectomy to developing biochemical failure, what is the likelihood that you’re going to have metastatic disease? This analysis found no significant association, at least in Gleason score 6 disease, for developing metastatic disease. So that 3% becomes a much smaller risk.
Continuing with Dr. Epstein’s work, he and his associates reviewed around 14,000 cases and identified 22 cases that had Gleason score 6 on the radical prostatectomy but showed metastatic disease. Every one of those cases were rereviewed and upgraded using the new classification system that Dr. Epstein outlined. The conclusion of this analysis was that “in contrast to prevailing assumptions, Gleason score 6 tumors do not appear to metastasize to lymph nodes.”