Two major forces have altered patterns of care for prostate cancer surgery over the past decade. Since high surgical volumes have been associated with improved cancer control and lower rates of morbidity and mortality following radical prostatectomy, many have advocated centralization of prostatectomies at higher volume centers.15–22, 24, 29
During the same time period, there has been rapid diffusion of RALP. First described about a decade ago, RALP has quickly emerged as the most common technique for radical prostatectomy.33
Between 2003 and 2006–7, the use of RALP increased almost fivefold in the Medicare population (9.2% vs. 43% of all prostatectomies).34
This study highlights how these changes are impacting prostate cancer care on the patient, hospital, and population level.
The number of radical prostatectomies performed annually has increased over the past decade and in particular over the past five years. Meanwhile, prostatectomies have been progressively centralized at high volume centers. Unlike other cancers for which centralization of extirpative procedures has occurred steadily over time, there was little centralization of prostatectomy evident until the publication of the first major studies advocating RALP. 25, 35–37
Beginning in 2004–2005, a rapid shift to higher volume centers ensued. Within 3 years, few prostatectomies were performed at centers without robotic surgery capabilities. The overall result has been sudden, population-wide, technology-driven centralization of procedures that is without precedent.
The interplay of these trends is supported by the fact that acquisition of a robot led to a rapid increase in the number of prostatectomies performed at a given hospital and that hospitals that did not acquire a robot performed fewer prostatectomies over time. Still, a few hospitals remain in the low volume categories for prostatectomy despite robot acquisition, suggesting that volume is a dynamic influenced by the complex interplay between hospitals and professional staff, where uptake of robotic techniques requires both hospital investment in technology and the presence of surgeons able to perform the procedures.
On a population-level, rapid centralization has been an unintended, but potentially beneficial, consequence of the introduction of robotics. Still, the full impact of the introduction and uptake of RALP on the triad of quality, cost, and access needs to be explored. Since publication of initial studies, RALP has been heavily marketed to patients, surgeons, and hospitals as an attractive alternative to traditional open prostatectomy with the promise of shorter hospitalization, faster recovery and minimal blood loss. However, observational studies have also suggested that patients may have higher rates of complications, such as incontinence and erectile dysfunction, following minimally invasive prostatectomies.34, 38
One study found patients undergoing RALP had greater dissatisfaction and regret with their treatment decision compared to patients who underwent open prostatectomy, likely due to heightened expectations and subsequent disappointment with this “innovative” technology.39
In addition, there is a steep learning curve for surgeons who had been trained to perform traditional open procedures.40–41
The impact of the early end of this learning curve on population-level cancer control and functional outcomes is not known. It is possible that the improvements in quality resultant from centralization could be offset, at least in part, by the higher complication rate associated with RALP, particularly early in the learning curve. The reported experience of surgeons at large referral centers supports the theory that outcomes improve with increased surgical experience.15, 40–43
Ultimately, however, no studies to date demonstrate that RALP, even in experienced hands, leads to improved
overall cancer control or functional outcomes compared to open prostatectomy.
The economic impact of the rapid diffusion of RALP also deserves consideration. The high upfront capital investment associated with robot acquisition ($1.2–1.7+ million), annual maintenance contracts ($150,000+/robot), and disposable instruments results in much greater direct costs compared to open prostatectomy.44–46
Given diagnosis-based reimbursement in the U.S., most hospitals receive little or no additional payment to offset these added costs. Many hospitals have marketed robotic surgery heavily to patients, likely in an effort to recoup the fixed capital investment costs of robot acquisition and maintenance, which may be amortized over a given volume of cases. This revenue shift places an additional burden on the health care system in exchange for potential yet incalculable societal benefits of more rapid convalescence and centralized care.
Many investigators have attempted to quantify the additional costs of this technology. In an early study, Lotan et al. optimistically assumed a utilization rate of 300 cases/year (far in excess of our upper quintile) and estimated the cost of RALP to be ≈$2500 more per case than open prostatectomy ($857/case for the robot + $1705/case for disposable instruments).46
Another analysis found the “break even” point for RALP versus open prostatectomy was between 10 and 15 cases/week, again well above hospital volumes in this study where only 2.9% of hospitals (7/244) performed >300 prostatectomies in 2009.45
Another group of investigators estimated an increase of $2315 in median direct costs for RALP compared to open prostatectomy due to additional surgical supply and OR costs. After adding the additional fixed costs of the robot, the total additional cost burden of RALP increased to $4713/case assuming an average of 126 cases/year.46
There is additional cost associated with the learning curve but this is difficult to quantify since the number of RALP each surgeon must complete to be competent varies widely.41
Based on eight published series, one group estimated the average learning curve was 77 cases, resulting in $217,034 additional operating room and anesthesia costs.47
Given that published studies have not demonstrated superior oncologic and functional outcomes for RALP over an open approach, many hospitals, insurers and federal agencies question both the comparative effectiveness and the cost effectiveness of this new technology.38, 46, 48
Understanding the extent to which individual and societal benefits may offset the indisputable direct cost disadvantages of RALP requires additional study. With >1000 robotic surgical systems installed in the past decade in the U.S., the scale of these economic considerations is considerable.
The impact of RALP and centralization on geographic access to care for prostate cancer has not been previously examined. In this study, the distance patients traveled to reach the treating hospital increased > 50% over the study period. This is consistent with previous work demonstrating that informal centralization results in increased patient travel.25
With market-driven centralization in the U.S., universal patient access is only a minor determinant of the geographic location of high volume centers. Consequently, the geographic distribution of high volume centers and robots is not necessarily optimized for patient travel and access to care. . While the absolute increase in median straight-line travel distance was only 3.7 miles, it is important to remember that straight-line distance underestimates actual road mileage by 20–40%.25, 28, 49
This increase in travel is particularly remarkable considering the study area is a densely populated region with extensive healthcare resources and relatively few rural counties. As a result, findings from this region likely underestimate the impact of centralization on patient travel burden nationwide.
In previous studies, we have demonstrated that patterns of centralization occurring in this region are similar to those seen nationwide.12, 25
Similarly, the uptake of robotics is not unique to this region, but is occurring nationally. . Still, trends in this region may not completely represent practice patterns across the country. For example, <10% of our study population lived in rural counties, so this study may underestimate the impact of centralization on travel distance and overestimate the availability of prostate cancer care for patients from more rural areas of the country.
Another major limitation of hospital discharge data is the lack of detailed case information. For example, while we examine the influence of robot acquisition, we do not know the proportion of prostatectomies at a hospital with a robot that are actually performed robotically. Additional information about the hospitals (i.e. teaching status, ownership, etc.) and the patients (i.e. comorbidity, cancer staging, etc.) would greatly enhance our analysis but were not available. In particular, without information on tumor stage, Gleason score, PSA, and other factors used to risk stratify cancer patients, we were not able to determine if the disease severity of patients treated with prostatectomy changed over time.
Similarly, we were not able to examine how centralization, the introduction of robotics, and travel influenced the relative frequency with which surgery, active surveillance, and radiation therapy were used to treat localized disease. Prostate cancer differs from other cancers to the extent that surgical therapy is not the clear “gold standard,” but rather one among several equivalently appropriate treatment options. The vast majority of men diagnosed with prostate cancer in the U.S. during the study period had clinically localized disease.50
For these men, surgery, radiation therapy and, in some cases, active surveillance are all considered acceptable treatment options.51
The perception that RALP was associated with quicker recovery or fewer side effects may have led patients with indolent disease, who previously would have chosen active surveillance, to proceed with surgery. These behavioral economics issues are important and deserve attention in future studies.
Over the past decade, there has been widespread adoption of RALP and increasing centralization of prostate cancer surgery at high volume centers. These changes have had a major impact on patterns of care for prostate cancer. On a population-level, the number of radical prostatectomies performed has risen substantially, but the true impact on patient level outcomes is unknown. Future studies should focus on the impact of these trends on access to care and cost, in addition to cancer control and functional outcomes.