LRP vs. RRP: the Memorial Sloan-Kettering data

Data published by Touijer et al. in the Journal of Urology represent the first prospective results of a trial comparing laparoscopic radical prostatectomy (LRP) to radical retropubic prostatectomy (RRP). In other words, this is the first study designed up front to compare the use of these two techniques (a “prospective” study) as opposed to the later analysis of accumulated data (a “retrospective” study).

Although this study is a single-institution study, and the patients themselves decided which form of surgery they wished to have, there are several reasons to take this study seriously, and it does allow us to draw some preliminary conclusions concerning the relative merits of the two forms of treatment:

  • First, three of the four participating surgeons were (and are) recognized experts in the surgical technique they were using at the time of the study. The fourth surgeon, who completed 110/612 LRPs, must certainly have had less experience.
  • Second, the institution at which the study was carried out (Memorial Sloan-Kettering Cancer Center in New York) is widely respected as a center of excellence for the management of prostate cancer. It is highly likely that the standard of care was both high and consistent.
  • Third, the data collection processes used at this institution are detailed and again suggest a high degree of quality control.

The study enrolled 1,430 consecutive men electing radical prostatectomy for treatment of clinically localized prostate cancer over a 3-year period, from January 2003 to December 2005. As indicated above, these men  were able to choose the type of surgery and their surgeon: 612 selected LRP carried out by one of two surgeons; 818 selected RRP, also carried out by one of two different surgeons. The men were followed for an average of 18 months post-surgery. Of the 1,430 patients enrolled, 415 (29.0 percent) also completed health-related quality of life questionnaires to assess their urinary function and their erectile function post-surgery.

The results of the trial can be summarized as follows:

  • Positive surgical margins were evident in 11 percent of patients in each arm of the trial.
  • Freedom from biochemical progression was close to identical in each arm of the trial at a median follow-up of 18 months.
  • The average time for the surgery was 199 min for LRP and 188 min for RRP.
  • LRP was associated with significantly lower blood loss (mean 315 mL) than RRP (1,267 mL) and thus a significantly lower need for blood transfusions (3 vs. 49 percent).
  • There were no significant differences between the two types of surgery with respect to cardiovascular, thromboembolic, or urinary complications (although one RRP patient did die as a consequence of a heart attack post-surgery).
  • Visits to the emergency department and hospital readmisions were slightly higher for LRP patients compared to RRP patients (15 vs. 11 percent and 4.6 vs. 1.2 percent, respectively).
  • Patients treated with LRP left the hospital after an average of 2.0 days as compared to 3.3 days for RRP patients.
  • The appeared to be no significant association between the type of operation and the time to postoperative potency (which was defined as the ability to complete penetration on at least 50 percent of attempts).
  • Patients treated with LRP were “much less likely to become continent” than those treated with RRP, and the authors further state that “this was an unexpected finding of our analysis.”

The authors stated the following conclusion in the abstract to their paper:

At our institution and during the study period [LRP] and [RRP] provided comparable oncologic efficacy. [LRP] was associated with less blood loss and a lower tranfusion rate, and higher postoperative hospital visits and readmission rate. While the recovery of potency was equivalent, that of continence was superior after [RRP].

However, in the main text of the paper their conclusion appears to be considerably less definitive:

At our institution and during the 2003 to 2005 study period [LRP] and [RRP] provided equivalent perioperative morbidity results, the laparoscopic approach being associated with lesser blood loss and transfusion rate but higher postoperative hospital visits and readmission rate. While the recovery of continence was higher after [RRP], potency was comparable in both groups. The 2 approaches seem to provide similar short-term oncological results regardless of the preoperative risk of the cancer.

In their discussion, the authors also make a number of important observations:

  • The fact that the patients were able to select their therapy may have introduced some bias. The RRP group had very slightly higher tumor grades, clinical stages, and pathological stages than the LRP group.
  • The positive surgical margin rate over the course of the study remained stable in the RRP patient group but decreased significantly in the LRP group, which can only be attributed to improving technique of at least one (if not both) of the two LRP surgeons.
  • The difference in the rates of recovery of urinary continence should be generalized with prudence because the study itself is at least as much (and maybe more) a comparison of the surgeons and their technique than it is a comparison of the surgical technique itself.

In his editorial comment about this paper, Rassweiler also notes an additional issue: LRP is a so-called “antegrade” surgical technique whereas RRP is a “retrograde” technique. What this means is that in this series of LRPs the surgeons started the excision of the prostate at the apex of the prostate and moved toward the base, whereas in these RRPs the surgeons started at the base of the prostate and moved toward the apex. Whether use of a retrograde LRP would solve some of the issues related to the long-term recovery of continence is not yet known. Other data have suggested that the antegrade technique may be superior.

What can we really conclude from this study? The following would appear to be certain:

  • LRP was (as would be expected) associated with less blood loss, fewer transfusions, and earlier discharge than RRP.
  • There were no differences in oncologic outcome: the incidence of positive surgical margins and of biochemical progression were near to identical.
  • There were no differences in time to recovery of potency.
  • There were minor differences in short-term, post-operative complications (visits to the emergency department and hospital readmissions) that favored RRP
  • In this study, there was a significant difference in rates of recovery of continence favoring RRP, but there is no clear explanation for this at the present time.

It is the view of The “New” Prostate Cancer InfoLink that in general this study confirms the potential for LRP as a “standard form of surgical treatment” for early stage prostate cancer, subject to all the usual provisos regarding the skill, experience, and volume of the surgeon.

Based on this study, however, the cautious patient considering LRP might want to ask his surgeon specifically about his or her data related to recovery of continence and post-surgical bladder neck strictures.

Content on this page last reviewed and updated May 13, 2008.

One Response

  1. […] with a recent article published by Toujier et al., which (as far as we are aware) is the only large, prospective study comparing LRP to RRP, and (also as far as we are aware) there is no large, published, prospective comparison of LRP or […]

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