Reporting quality of outcomes after first-line RP for localized prostate cancer
Posted Mar 08 2011 12:00am
A new article has stimulated an important and public discussion about how to report the quality of outcomes of patients who receive a radical prostatectomy (RP) and therefore how to communicate the probabilities of specific outcomes of a certain quality to new patients considering radical prostatectomy as a first-line treatment option.All of the relevant information is available on line in one full-text article and two full-text editorial commentaries in European Urology (although all of the authors are based in the USA).
It is important to appreciate that outcomes after RP have, since about 2003, been reported in terms of the so-called “trifecta” of post-surgical cancer control, continence, and sexual function. In the patient’s ideal world (and presumably the surgeon’s too) any patient deciding to have a RP should within a period of 12 months after his surgery have every sign of complete cancer control (i.e., a PSA level < 0.1 ng/ml), complete continence (meaning the need for and use of no pads at all), and at least the same level of sexual functionality as he had when he was placed on the operating table to undergo the RP.
In their initial article , Patel et al. introduce a new concept which they call the “pentafecta” as a tool to report outcomes after RP. Their pentafecta is made up of the three outcomes traditionally reported in the trifecta together with two additional ideal outcomes the complete absence of complications from the surgery itself and the complete absence of positive surgical margins. In theory, this is an excellent concept. If one is going to carry out surgery as a first-line treatment for prostate cancer (particularly for younger patients with low-risk disease), then the addition of these two outcomes to the “trifecta” should certainly allow us to better assess and compare the skills of individual surgeons.
Patel et al. use data from their own series of 1,111 patients treated between January 2008 and September 2009 by robot-assisted laparoscopic prostatectomy (RALP) to make an initial assessment of their own “pentafecta” outcomes. And this is where controversy begins.
In assessing their outcomes, they eliminate from their assessment two groups of patients:
485/1,111 men who were not fully continent and fully potent pre-surgery (leaving them with 626 potential candidates prior to surgery)
294/626 men who either did not receive a bilateral, nerve-sparing operation or who did not have 12 months of follow-up post-surgery
As a consequence, their evaluation of their “pentafecta” was based on the 332 patients who are pre-defined as having a “best case” scenario and for whom 12 months of follow-up data were available. Unfortunately, Patel et al. do not tell us how many of the 626 fully continent and fully potent candidates for evaluation were not evaluable because 12 months of follow-up data were not available.
Furthermore, they define a successful sexual function/potency outcome as “the ability to achieve and maintain satisfactory erections firm enough for sexual intercourse in > 50% of attempts, with or without the use of [drugs like Viagra or Cialis or Levitra].” Although they do clearly state that patients who need vacuum devices, penile injections, or transurethral alprostadil to achieve functional erections are “not considered to be potent.” Now The “New” Prostate Cancer InfoLink while recognizing that this may well be the case for a lot of men post-surgery does not believe that a man who went to the operating table with full erectile capability (with or without Viagra, etc.) and who has only a minimum of > 50 percent ability to maintain some sort of erection “firm enough f0r sexual intercourse” at a year post-surgery has received the outcome he is looking for. The only acceptable way to use potency data as an outcome quality is to compare Sexual Health Inventory for Men (SHIM) scores before and after surgery. If the man goes into surgery with a SHIM score of > 21 (which indicates full potency) but comes out a year later with full continence but a SHIM score of (say) 15, he has very clearly lost sexual functionality. It doesn’t matter to that patient why it happened. It may have happened because nerve-sparing turned out not to be possible. It may have happened because of other surgical problems. And it may have happened because the operation was just complicated and there was a great deal of manipulation of the nerves and the other surrounding tissues which led to irreparable damage to the nerves, even though they were spared.
Based on their highly selected group of 332 patients and their definition of potency, Patel et al. claim that, at 12 months of follow-up:
Continence, potency, biochemical recurrence-free survival, and overall trifecta rates were 96.4, 89.8, 96.4, and 83.3 percent, respectively.
93.4 percent of the patients had no post-operative complication.
90.7 percent of the patient had negative surgical margins.
The overall pentafecta rate was 70.3 percent.
In an editorial commentary (appropriately entitled “The Devil is in the details”) on this article in the same issue of European Urology, Eastham and Scardino make several of the same points made above by The “New” Prostate Cancer InfoLink and suggest that the overall pentafecta rate for the 1,111 patients treated by Patel et al. in this series may actually be as low as 21 percent (if one includes all the patients in the series). They note that it is important for surgeons to be completely truthful in reporting their personal outcomes data, and not to use misleading data reported from other centers. From that point of view, they are implying that while it would be OK for Patel and his colleagues to tell new patients that if and only if the patient is fully continent and fully potent at the time of surgery, and it is possible to carry out a full bilateral nerve-sparing procedure, then they have a pentafecta outcome of 70.3 percent at their institution, so long as they also explain that post-surgical potency may be only half as good as it was pre-surgery. They are also carefully implying that it would not be appropriate for anyone else to start claiming that, in general, RALP is associated with an overall 70.3 pentafecta outcome.
The “New” Prostate Cancer InfoLink thinks that careful reporting of pentafecta data is an excellent idea. However, we think it needs to be reported by category: for all patients, for all patients with a pre-surgical SHIM score of > 21, and for all patient with a SHIM score of 21 who also were able to undergo full, bilateral, nerve-sparing procedure. Only then can a patient really appreciate what the reasonable probability of a specific outcome might be in his case at the hands of a specific surgeon. We also believe that post-surgical potency should be reported as a change from the pre-surgical potency status. In that way a man would be able to know what his risk was of loss of potency relative to his starting potency as opposed to some form of theoretical maximum.
In their response to the editorial commentary by Eastham and Scardino, Patel and Sivaraman take a sadly defensive position, complaining that Eastham and Scardino had “misinterpreted” their data. They state that large numbers of patients were excluded from their analysis not because they hadn’t had a nerve-sparing procedure but because they hadn’t had 12 months of follow-up data available. There would have been a simple answer to that which was to make that clear in the original paper, which they did not. They seem to entirely miss the point being made by Scardino and Eastham that failure to give a complete explanation of how one used available data to reach specific conclusions is what underlies many of the problems in how the surgical community (and others treating early stage prostate cancer) tend to over-represent the quality of the outcomes they actually achieve.
The chances that a fully potent and fully continent male with localized prostate cancer who elects to have an RP (of any type) will have no complications post-surgery, will have no positive surgical margins, will be completely cancer-free, will be fully potent, and will be fully continent at 12 months post surgery are small. Exactly what are they? Well, interestingly, if Patel and his colleagues were to reanalyze their data from a slightly different perspective in another 12 months’ time, when they had 12 months or more of follow-up data on a larger patient set, we might actually know for their patients at least. Scardion and Eastham may also have sufficient data from the Memorial Sloan-Kettering series to offer a comparable analysis. What is tiresome for the patient community, however, is the lack of some clear, “real world” consensus around standards for reporting outcomes after first line treatment of localized prostate cancer. It is time for us all to get on the same page. We suggest the following:
No significant peri-operative complications
No significant post-operative complications (e.g., strictures, significant penile shortening, etc.)
No positive surgical margins
A stable PSA level of < 0.1 ng/ml
Continence that is no worse that the level of continence pre-surgery
Potency that is no worse than the level of potency pre-surgery
The data needed to establish such outcomes can all be measured with a high level of accuracy at baseline and at any period post-surgery. It may well be that such “perfect” outcomes can only be achieved a the minority of young, low-risk prostate cancer patients, but at least we would then all be talking out of the same side of our mouths.