In a recent paper on development of (yet another) nomogram designed to predict the probability of prostate cancer, the authors begin by stating the following:
Overtreatment of prostate cancer … is a concern, especially in patients who might qualify for the diagnosis of insignificant prostate cancer ….
This raises what may be a very interesting question: Can the prostate cancer community define and start to use “clinically insignificant prostate cancer” with accuracy as a diagnosis? If this is possible, could such a diagnosis be defined and regularly used with such compelling accuracy that men would believe it and decide they did not need to get treated?
It would appear likely that we may already have opportunities to start to use such a diagnosis — for example when low risk prostate cancer gets diagnosed in men who are at significant risk for death from other causes. (Specific example: A 70-year-old male with a PSA of 2.7 ng/mL, no family history of prostate cancer, but a history of Type II diabetes starting in his late 50s, and a series of increasingly problematic cardiovascular conditions, including chronic heart failure. He somehow gets a 12-core biopsy that shows one small focus of Gleason grade 5 prostate cancer! Many would argue he should never have received the biopsy, but it happens frequently.)
At this time there are no diagnostic or statistical methods that are sufficiently accurate to predict with even 90 percent certainty that a man is not at risk from prostate cancer, given certain signs and symptoms. But there are all sorts of scenarios that can define men who are have a 90 percent probability of “clinically insignificant” prostate cancer.
Language is important. As a patient, there has to be a huge difference between being told
- “You have prostate cancer, but it’s probably not going to affect you in your lifetime. I think we can just monitor this and make sure it never becomes a problem.”
as compared to being told
- “You have clinically insignificant prostate cancer. The risks of treating this for a patient like you are high and include impotence, incontinence, and other serious problems. There is only a tiny chance that the disease might progress. We will monitor this risk and take action if we absolutely have to, but you don’t need to spend any time worrying about it. Come back again in 6 months and I’ll give you another DRE and PSA test.”
The authors of the abovementioned paper conclude by stating that, “Despite a high accuracy, currently available models for prediction of [clinically insignificant prostate cancer] are incorrect in 10% to 20% of predictions. … As a consequence, extreme caution is advised when statistical tools are used to assign the diagnosis of [clincially insignificant disease].” This is certainly the case. We are not at a point where we could accurately diagnose “clinically insignificant” prostate cancer in 95 percent of the men who actually have clinically insignificant disease. However, the question to be considered is, “Are we at a point where we could accurately diagnose clinically insignificant prostate cancer (and therefore use the term) in 95 percent of some groups of men who definitively have clinically insignificant disease?”
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Overdiagnosis and overtreatment are greatly exaggerated by those that oppose testing with PSA and DRE.
The current diagnosis of prostate cancer as related to biopsy results remains uncertain to define insignificant cancer with 95% accuracy. The keywords of this German study are:
“However, in cutoff-based analyses of patients who were qualified by our and the older nomograms as high probability for IPCa, respectively 63% and 45% harbored aggressive PCa variants at radical prostatectomy (Gleason score 7-10, ECE, SVI, and/or LNI).”
Furthermore, Carter et al in AS studies at JHU has shown that close monitoring of disease progression is required in the management of “insignificant” disease. Monitoring PSA doubling time and yearly biopsies are far from practical in a system that is opposed to testing with PSA.
The real question is what is the real dimension of overdiagnosis and overtreatment as compared to the limited use of PSA in our population of men at risk. It is my believe that the rate of underdiagnosis and undertreatment is still higher than the rate of overtreatment at this point in time.
Ralph: I wouldn’t disagree with you about most of this. But even if only 10 percent of the men diagnosed today really do have clinically insignificant prostate cancer (of types suggested by my example), isn’t it about time we made that clear for them, as opposed to terrifying them into pointless treatment?
Mike,
Yes, it would be great if that 10% could be identified with some degree of certainty and followed properly to avoid immediate treatment. I see that AS is a good option for such men, but it needs close monitoring and in many cases results in delayed treatment after all. The solution is in awareness and education. Slow in coming with all the contrary medical opinions that we are exposed to these days…
Granted … but we’ve still made great progress since (say) 1998. For starters, at least AS is now accepted as a reasonable option for appropriate men. I can remember a time when any man who went onto AS was almost harrassed into treatment (as much by other advocates as by the urology community).
I view Ralph’s reply to Mike “Yes, it would be great if that 10% could be identified with some degree of certainty and followed properly to avoid immediate treatment. I see that AS is a good option for such men, but it needs close monitoring and in many cases results in delayed treatment after all. The solution is in awareness and education. Slow in coming with all the contrary medical opinions that we are exposed to these days…” as the most appropriate consideration. However, it is the physician community that has to be educated to follow this recommendation since it is the physician who is placed in a position of trust by the patient to recommend subsequent care. We really do not have “over-diagnosis”….we have “over-treatment” by physicians when AS with close monitoring would be more appropriate.
Chuck: It’s all a matter of perspective. I have seen both ends of this spectrum. It is very common to come across appropriate patients who refused AS because they “just want you to take the damn thing out, doc.” At the other end of the scale are the physicians who will tell a patient, “I recommend treatment because who knows what will happen if you don’t have treatment early.” The education needs to be applied to both groups, but these things always take time. And naturally any patient who is on AS needs to be carefully (but not obsessively) monitored. If the monitoring becomes obsessive, then the patient loses his belief that there is minimal risk and starts to think that all anyone is really doing is waiting for a clear sign of progression, in which case, “Let’s take the thing out and have done with it.”
I always marvel how those that claim up to 84% overtreatment KNOW that these men would have never required treatment. Certainly all these men if the 84% is close to reality, do not impact the lower mortality rate. Damn statistics!
[...] for a diagnosis of “clinically insignificant adenocarcinoma of the prostate” in another blog item earlier this [...]
So Ralph … I certainly don’t think there is 84 percent overtreatment. I do believe there is a good deal, but I suspect it’s more like 24 percent than 84 percent. And you know as well as I do that statistics can be used to demonstrate (not prove, demonstrate) almost anything.
I agree that there is overtreatment and like Chuck mentioned some is fear induced by physicians on patients that have little education about PCa. It will take years before this situation will change.
One interesting data point in the UCSF study is that almost 40% of these patients had an increase in Gleason during the 3.6 years of follow up. The notion that prostate cancer is an indolent disease needs review. Again, given enough time indolent cancers progress, induce symptoms and can kill. It is always a patient’s choice and the key is awareness and education. Not an easy task…