With robot-assisted laparoscopic radical prostatectomy (LRP), the prostate gland can be removed via several 1- to 2-inch incisions in the patient's abdomen. The procedure involves use of a robotic system consisting of a device that holds surgical instruments and a laparoscopic camera (Fig. 1); the device is guided by the surgeon through computer interface near the operating table. Open retropubic radical prostatectomy (ORP) is the gold standard for definitive prostate resection. However, enthusiasm for and adoption of robot-assisted LRP has grown rapidly, and has done so despite a lack of high-quality evidence showing superiority to ORP. Few randomized trials have compared ORP and LRP, and relatively few observational studies have been conducted. Moreover, most of the available data involve a small number of surgeons and patients from a single institution.^1,2 Two large population-based analyses were limited by lack of data on tumor characteristics.^3,4 Most observational data indicate reduced blood loss and reduced duration of hospital stay with LRP.²

Featured Study

In a recently reported study using Surveillance, Epidemiology, and End Results (SEER) cancer registry data linked with Medicare claims, Lowrance and colleagues5 compared outcomes of ORP and LRP in men with clinically localized prostate cancer, while controlling for patient and tumor characteristics. They also assessed the impact of surgeon volume on outcome with LRP.

The analysis included 5,923 men aged 66 years or older with clinical stage T1 or T2 prostate cancer in the SEER-Medicare database who received LRP (n = 1,065, 18%) or ORP (n = 4,858, 82%) in 2003-2005. It could not be directly ascertained that all LRP procedures were robot-assisted. However, based on manufacturer information, it could be estimated that most LRPs were robot-assisted. LRP increased in use as a proportion of all procedures in each successive year of the study. LRP patients were more likely to live in a metropolitan area, the West or Northeast, and in census tracts with the highest quartile of median income. LRP patients generally had a lower clinical T stage and, when known, pathologic T stage, and were less likely to have any regional lymph nodes examined (57% vs 80%). LRP and ORP patients had similar distributions of categorical prostate-specific antigen and Gleason scores.

The primary study findings were as follows:

• Median length of hospital stay was 2.0 days with LRP and 3.0 days with ORP, with length of stay being 35% shorter with LRP after controlling for patient and tumor characteristics (P < .0001). Length of stay was longer in patients who were older, nonwhite, unmarried, lived in census tracts in the lowest median income quartile, had greater comorbidity, had surgery earlier in the study period, or were operated on by lower-volume surgeons.
• The 90-day mortality rate was < 0.5% in both groups.
• The 90-day rate of general medical or surgical complications was 21% with LRP and 24% with ORP, with no significant difference between groups after adjustment for covariates. Risk of complications was greater with older age, greater comorbidity, and lower-volume surgeons.
• Within 1 year after surgery, genitourinary or bowel complications occurred in 40% of LRP patients and 35% of ORP patients, with no significant difference in risk after adjustment for patient/tumor characteristics. Lower surgeon volume, unmarried status, and higher clinical stage were predictive of complications. Bladder neck/urethral obstruction occurred in 29% of both groups; after adjustment for patient/tumor characteristics, LRP was associated with a significant 26% reduction in risk. Bladder neck/urethral obstruction was more common in men who were unmarried, lived in the Northeast, had a clinical stage T2 tumor, or did not have pelvic lymphadenectomy, and in those treated by lower-volume surgeons.
• In the year following surgery, cancer therapy (radiation therapy, androgen deprivation therapy, or both) was received by 9% of LRP patients and 12% of ORP patients, with no significant difference between groups after adjustment for patient/tumor characteristics.
• More than half of all patients receiving LRP had a surgeon with an annual volume of fewer than 5 LRP procedures; less than one-fifth had a surgeon with an annual volume of at least 30 LRPs. After adjustment for patient/tumor characteristics, greater surgeon volume was significantly associated with shorter hospital length of stay among LRP patients (P < .001) and reduced risk for genitourinary/bowel complications (P < .01), but not with a difference in risk for general medical/surgical complications. The probability of bladder neck/urethral obstruction at 1 year after surgery was 31% among patients with surgeons performing fewer than 5 LRPs in the preceding year, compared with 16% for patients with surgeons performing 30 or more.

Thus, overall, this study showed no difference between LRP and ORP with regard to 90-day mortality or complication rates or subsequent additional cancer therapy, and advantages to LRP in reducing length of stay and reducing risk of bladder neck/urethral obstruction. Other studies have shown that blood loss, which was not examined in the current study, is reduced with LRP.

Pros and Cons

A potential problem with the widespread availability and marketing of robot-assisted LRP is overstatement of benefits. Thus, for example, the economic benefit resulting from reduced hospital stay may not be robust. Cost comparisons indicate that savings in hospital stay costs do not always offset the additional operative costs of robot-assisted LRP, particularly in low LRP volume settings.^6,7 Further, as noted by Lowrance and colleagues,⁵ standardization of care pathways may reduce differences between length of stay associated with the two procedures. With regard to the effect of marketing on patient expectations, a survey of 400 men undergoing radical prostatectomy showed that those undergoing ORP were four times more likely to express satisfaction with their procedure than were those undergoing robot-assisted LRP, whereas the latter were more than three times more likely to express dissatisfaction with their procedure.⁸

However, it should also be noted that overall (LRP and ORP combined) in the current study, higher surgeon volume was consistently associated with benefits, including shorter hospital stay, lower risk of general medical/surgical complications, and lower risk of genitourinary/bowel complications, including bladder neck/urethral obstruction. Most of these benefits were also seen with higher surgeon volume in the LRP group when considered alone. The increased adoption of robot-assisted LRP implies that the procedure is being used by a large number of less-experienced surgeons. As with ORP, increased surgeon experience with LRP can be expected to improve outcomes. Lowrance and colleagues⁵ suggest that regionalization of robot-assisted LRP might serve to increase surgeon volume and increase clinical and economic benefits of the procedure.

Conclusions

Lowrance and colleagues5 concluded that LRP and ORP are associated with similar rates of postoperative morbidity and use of subsequent cancer therapies. They urged that men who are considering prostate cancer surgery should understand the expected benefits and risks of both ORP and LRP and have realistic expectations regarding outcomes with each approach.

With regard to expectations regarding outcomes of treatment of prostate cancer, it is also important to note that the rapid adoption of robot-assisted LRP appears to have increased the proportions of patients opting for surgical treatment of localized prostate cancer vs nonsurgical treatment or watchful waiting. In a recent New England Journal of Medicine "Perspective" piece on robotic technology, Barbash and Glied9 report a recent striking increase in hospital discharges for prostatectomy despite an overall reduction in the background incidence of prostate cancer, with the increase being contemporaneous with a dramatic increase in performance of robot-assisted LRP procedures. The authors note that in this setting, robotic technology may have increased both the cost per surgical procedure and the volume of cases treated surgically, with there as yet being no evidence that robot-assisted LRP improves long-term patient outcomes or quality of life. It may thus be important to increase efforts to ensure that patients with localized prostate cancer understand the relative risks and benefits of surgical vs nonsurgical treatments, as well. ■

References

1. Guazzoni G, Cestari A, Naspro R, et al: Intra- and peri-operative outcomes comparing radical retropubic and laparoscopic radical prostatectomy: Results from a prospective, randomised, single-surgeon study. Eur Urol 50:98-104, 2006.

2. Ficarra V, Novara G, Artibani W, et al: Retropubic, laparoscopic, and robot-assisted radical prostatectomy: A systematic review and cumulative analysis of comparative studies. Eur Urol 55:1037-1063, 2009.

3. Hu JC, Hevelone ND, Ferreira MD, et al: Patterns of care for radical prostatectomy in the United States from 2003 to 2005. J Urol 180:1969-1974, 2008.

4. Hu JC, Wang Q, Pashos CL, et al: Utilization and outcomes of minimally invasive radical prostatectomy. J Clin Oncol 26:2278-2284, 2008.

5. Lowrance WT, Elkin EB, Jacks LM, et al: Comparative effectiveness of surgical treatments for prostate cancer: A population-based analysis of postoperative outcomes. J Urol 183:1366-1372, 2010.

6. Lotan Y, Cadeddu JA, Gettman MT: The new economics of radical prostatectomy: Cost comparison of open, laparoscopic and robot assisted techniques. J Urol 172:1431-1435, 2004.

7. Scales CD Jr, Jones PJ, Eisenstein EL, et al: Local cost structures and the economics of robot assisted radical prostatectomy. J Urol 174:2323-2329, 2005.

8. Schroeck FR, Krupski TL, Sun L, et al: Satisfaction and regret after open retropubic or robot assisted laparoscopic radical prostatectomy. Eur Urol 54:785-793, 2008.

9. Barbash GI, Glied SA: New technology and health care costs-the case of robot-assisted surgery. N Engl J Med 363:701-704, 2010.