Researchers examine procedure utilization trends in patients with clinically localized renal masses

ScienceDaily (May 15, 2011) — New techniques in science and technology allow the medical community to continually improve patient care and experience, but as these new procedures are introduced, physicians must closely consider the relative risks and benefits for each patient. Laparoscopic surgery offers the short-term benefits of smaller incisions, shorter hospital stays, and less pain during recovery, but are there negative consequences in the long run for some patients? Certain groups of patients, like those with localized renal masses, may be more appropriately treated through surgical techniques that focus on preserving as much functional kidney as possible--especially since emerging data suggests that a loss of kidney function can lead to higher long-term risks of morbidity and mortality.

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A new study to be presented by researchers from Fox Chase Cancer Center on Saturday, May 14, 2011, at the AUA 2011 Annual Meeting, examines whether the rapid adoption of minimally invasive techniques on the national level has had a negative impact on utilization rates of partial nephrectomy for patients with clinically localized renal masses.

"The AUA guidelines for localized renal masses recommend that kidney preservation is paramount when treating localized masses, but the rise of the number of partial nephrectomies--procedures that remove only part of a person's kidney--over time is lower than expected," says Marc Smaldone, M.D., urologic oncology fellow and lead author on the study. "As patient care evolves over time, we would expect to see the number of kidney preserving procedures increasing. Unfortunately, our results demonstrate that radical nephrectomy rates have remained consistent, which may be due to the preferential adoption of laparoscopic nephrectomy over partial nephrectomy in community practice."

When treating a patient with a localized renal mass, doctors have many surgical options. In radical procedures, surgeons remove the entire kidney, while partial nephrectomy techniques focus specifically on tumor removal while preserving as much functional kidney as possible. Either procedure may be performed via an open procedure through a large incision or a minimally invasive (or laparoscopic) approach.

In their study, researchers at Fox Chase demonstrated a dramatic 58 percent decrease in the percentage of open radical nephrectomy procedures performed from 1995 to 2005. However, they also observed more than a two-fold increase in laparoscopic nephrectomies in comparison to kidney sparing procedures over the same time period. These results suggest that more urologists are opting for laparoscopic nephrectomy, which may be due to increased familiarity and technical ease over more complex open or laparoscopic kidney preserving procedures. As a result, there is not the expected increase in the number of kidney preserving operations being performed, and more patients than necessary are being exposed to the adverse long-term consequences of chronic renal insufficiency.

"Knowing what we do about the long-term risks associated with removing a person's kidney, such as higher rates of long-term morbidity, it is crucial that, as physicians, we are doing all we can to spare as much of the organ as possible," says Robert G. Uzzo, M.D., F.A.C.S., chairman of the department of surgery at Fox Chase and member of the AUA Guidelines Council. "In this study, we're seeing a preference for laparoscopic procedures when we should be seeing a preference for nephron-sparing procedures."

To investigate this issue, Fox Chase identified 6,716 patients who underwent surgery for clinically localized renal masses between 1995 and 2005, drawn from linked SEER-Medicare data. They then compared utilization rates over time of four differing surgical procedures: open radical nephrectomy (ORN), laparoscopic radical nephrectomy (LRN), open partial nephrectomy (OPN), and laparoscopic partial nephrectomy (LPN). Their results demonstrate that over the ten-year period, utilization of nephron-sparing techniques--or partial nephrectomy--only increased by 15.5%, whereas 77% of patients with localized tumors were still managed with radical nephrectomy in 2005.

"Studies like these highlight that practice patterns evolve slowly over time, but more research is necessary," says Smaldone. "We now need to further investigate which types of institutions are performing specific procedure types and which patients have access to kidney preserving surgeries. These studies will ultimately help to ensure that we are providing all patients access to the best possible care."

"It is important that patients seek out care from physicians with expertise in kidney preservation techniques," adds Uzzo. "The benefits of laparoscopy don't offset the consequences of removing a patient's entire kidney if it's avoidable, and often, at most expert centers, a patient can receive the benefits of both through a laparoscopic partial nephrectomy."

Co-authors on the study include Fox Chase researchers Alexander Kutikov, Daniel J. Canter, Brian L. Egleston, Rosalia Viterbo, Ervin Teper, David Y.T. Chen, Richard E. Greenberg, and Robert G. Uzzo.

Statistical support for this project was supported by Fox Chase Cancer's Keystone Program in Personalized Kidney Cancer Therapy. Established in 2008, this collaborative program brings researchers and clinicians from multiple disciplines together to investigate the biological mechanisms that lead to kidney cancer metastasis and to uncover the molecular signals that predict how an individual patient's kidney tumor will respond to therapies. Ultimately, the research supported by this privately-funded program will allow clinicians to optimize therapies for a given patient based on the unique molecular characteristics of his or her tumor.

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Rapid growth may be appropriate trigger for treatment in patients with renal masses

ScienceDaily (May 15, 2011) — With an increase in abdominal imaging over the past decade, there has been an increase in the detection of incidental kidney cancer, which has led to concerns that we may be over-treating indolent disease. As part of this effort, clinicians have started to investigate the effectiveness of active surveillance (AS), or close observation as opposed to immediate surgery, for select patients with small renal masses (SRMs).

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Fox Chase Cancer Center researchers have announced the results of its systematic review and pooled analysis, which for the first time combined several institutions' experience with active surveillance of small renal masses. Their goal was to identify trends in radiographic tumor growth rates and progression to either treatment or metastasis, and found that in select patients, active surveillance may be a viable option when surgery is risky due to poor health or advanced age.

Marc Smaldone, M.D., urologic oncology fellow at Fox Chase and lead author on the study, will present the results at the AUA 2011 Annual Meeting on Tuesday, May 17, 2011.

"Kidney cancer is most often a surgically treated disease, so studies such as this one, which help to confirm that active surveillance with curative intent can be an effective strategy for certain patients, are crucial," says Smaldone. "Surgery has substantial consequences for many patients with competing risks such as heart or lung disease. The ability to offer a management strategy that avoids the risks of potentially unnecessary surgery is an attractive concept in contemporary cancer treatment."

To further investigate the risks of cancer progression in patients undergoing active surveillance, Fox Chase researchers combined all the available individual data published by institutions examining the observation of small renal masses. The team identified and pooled a total of 18 institutional series, of which Fox Chase's experience represented the largest published series. The researchers then examined the pooled experience for trends in radiographic growth rates, tumor size at presentation, and progression to treatment or metastasis.

They found that, of the observed 936 SRMs in 880 patients, only a very small proportion -- 2.1% (18 patients) -- progressed to metastasis. Pooled analysis of progressors and non-progressors revealed significant trends including increased age, increased tumor size at presentation, and increased growth rates in the progression group. These metrics can be used to help determine if a patient should stop surveillance and undergo surgical intervention for his or her SRM. However, Fox Chase researchers learned that growth kinetics alone cannot predict a tumor's natural growth history. Therefore, active surveillance should not be considered an equivalent alternative to definitive surgical therapy, but it can be used as an initial short-term option for select patients who are poor surgical candidates.

"There is a perception that all cancers, once detected, should be treated immediately because they are all equally lethal, but what we've seen in this study is that small, asymptomatic kidney cancers can be managed through active surveillance," says Robert G. Uzzo, M.D., F.A.C.S., chairman of the department of surgery at Fox Chase and member of the AUA Guidelines Council. "As a medical community, we need to recognize this shift and begin to risk stratify patients and counsel them based on criteria other than the presence of small renal masses on scans."

While more research is necessary, this study suggests that growth kinetics may be the best measurement currently available for determining which patients should undergo immediate intervention and which should not. As a supplement to radiographic data, future biomarker discovery in conjunction with percutaneous -- or renal biopsy -- might ultimately influence management decisions on an individual patient basis. Based on these findings patients should seek out urologic oncology experts to help them understand the implications of small kidney cancers and avoid overtreatment.

Co-authors on the study include Fox Chase researchers Alexander Kutikov, Daniel J. Canter, Brian L. Egleston, Rosalia Viterbo, David Y.T. Chen, Richard E. Greenberg and Robert G. Uzzo.

Statistical analysis for this research was supported by Fox Chase Cancer Center's Keystone Program in Personalized Kidney Cancer Therapy. Established in 2008, this collaborative program brings researchers and clinicians from multiple disciplines together to investigate the biological mechanisms that lead to kidney cancer metastasis and to uncover the molecular signals that predict how an individual patient's kidney tumor will respond to therapies. Ultimately, the research supported by this privately-funded program will allow clinicians to optimize therapies for a given patient based on the unique molecular characteristics of his or her tumor.

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