Should Radical Nephrectomy Be Standard Of Care For Renal Cortical Tumors 4cm Or Less? Raised Incidence Of Chronic Renal Disease After Radical Nephrect
UroToday.com - Since the studies of Robson, radical nephrectomy has remained the gold standard for treatment of renal cortical tumors. More recently, partial nephrectomy, even in the setting of a normal contralateral kidney, has demonstrated oncologic equipoise with radical nephrectomy for resection of renal tumors that in anatomically favorable sites and are 7 cm or less. The obvious benefit of partial nephrectomy over radical nephrectomy is the salvage of functional nephron mass. Recent studies have suggested that despite numerous studies that have demonstrated the efficacy of partial nephrectomy (both open and laparoscopic), nephron sparing surgical approaches remain a rarity in the practice patterns of urologists, even in the setting of small renal masses. Here Huang and colleagues demonstrate that there is a significantly higher incidence of renal insufficiency after radical nephrectomy when compared to partial nephrectomy, providing further compelling evidence that nephron sparing approaches, when feasible, should be pursued as a surgical plan.
In this study, 662 patients underwent radical or partial nephrectomy for renal cortical tumors ≤ 4 cm who had a normal serum creatinine and a normal contralateral renal unit based on imaging. The authors used the abbreviated Modification of Diet in Renal Disease (MDRD) study equation to estimate glomerular filtration rate (GFR) and defined chronic renal insufficiency as a GFR < 60 ml/min per 1.73m2. Of note, 171 patients (26%) had pre-existing chronic renal disease based on pre-operative GFR estimation. Following surgery, the 3 year probability of freedom from a GFR < 60 was 80% for partial nephrectomy versus 35% for radical nephrectomy (p< 0.0001). The 3 year probability of freedom from a GFR < 45 was 95% partial nephrectomy versus 64% for radical nephrectomy (p<0.0001). In their multivariate analysis, radical nephrectomy remained an independent risk factor that predicted chronic renal disease after surgery (p<0.0001).
This study demonstrates that clinically significant renal disease exists, even in the setting of a normal appearing contralateral kidney and a normal serum creatinine. When appropriate, nephron sparing approaches should be considered a new standard of care for small renal masses to avoid the sequelae of chronic renal insufficiency.
Lancet Oncology 2006; 7:735-740
Reviewed by UroToday.com Contributing Editor Christopher G. Wood, MD, FACS
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Laparoscopic Partial Nephrectomy For Renal Masses: Effect Of Tumor Location
Not all small renal masses are created equal. This study demonstrates that not only size, but location, depth, and relation to the hilar vessels and collecting system all impact on the histopathology of the small renal lesion amenable to a partial nephrectomy.
This retrospective review of 123 renal masses, managed by laparoscopic partial nephrectomy, demonstrated that the overall rate of benign histopathology was 30%, as has been previously reported by numerous investigators in the literature. However, those tumors that were exophytic, or 60% of the mass extending off the surface of the kidney, had a benign histopathology in 45% of cases.
Those tumors that were endophytic, less than 60% off the natural surface of the kidney, and within 5 mm of the renal hilum had only a 16% and 12%, respectively, chance of being benign. In addition, the complication rate was least for the exophytic tumors (10%) and progressively increased for the mesophytic (13%), endophytic (47%), and hilar (50%).
Upper pole tumors and those requiring closure of the collecting system resulted in the greatest blood loss and complication rates compared to interpolar and lower polar tumors. These clinical observations can assist the urologist in preoperative planning of the procedure and in accurately counseling patients.
By Elspeth McDougal
Urology Volume 67, Issue 6 , June 2006, Pages 1169-1174
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Overtreatment Of Localized Renal Cell Carcinoma: Are We Over Utilizing Developing Technologies?
UroToday.com - Recently published studies based on SEER database analyses have suggested that nephron sparing approaches are being vastly underutilized in the surgical treatment of small renal masses. The concern is that the application of the "newer" technology of laparoscopic nephrectomy may supercede concerns for the benefits of retaining normal nephron mass that are gained through partial nephrectomy (done either through open or laparoscopic techniques). In this report by Hollingsworth and colleagues, the experience at the University of Michigan, a large academic urology center, is reviewed.
Over a 5 year period, the center saw 381 patients and performed 391 procedures for renal cell carcinoma (RCC). Of these, 336 patients had organ confined tumors (T1-T2) and are the subject of this report. The authors broke down their experience into early (1998-2000) and late (2001-2003) for comparative purposes and to determine changes in trends over time. They found no difference in the use of laparoscopic nephrectomy for T1a tumors over time (21% early versus 20% late), although there was an increased utilization of laparoscopic nephrectomy over time for larger lesions, including T1b (36% early versus 56% late, p=0.017) and T2 (24% early versus 41% late, p=0.056). The authors also noted that there was increased utilization of nephron sparing approaches (open and laparoscopic) over time for both T1a and T1b tumors. In their multivariate analysis, the authors noted a significant increase in the utilization of both nephron sparing approaches (p=0.002) and laparoscopic nephrectomy (p=0.001) over time. Neither procedure was associated with an increase in perioperative complications relative to similar radical (p>0.05) or open (p>0.05) procedures. Also of note in the study, the incidence of cases of localized RCC increased by 87% over time, when comparing the early to late experience.
The authors conclude that biology, not technology, dictates the application of treatment modalities at their institution. Most small renal masses were treated with nephron sparing approaches, including both T1a and T1b lesions. They suggest that their results should be regarded as a model for the "responsible" incorporation of laparoscopy and nephron sparing into the management of small renal masses.
By Christopher G. Wood, M.D.
Reference:
Urology 67(6): 1175-1180, 2006.
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Radical Surgery For Kidney Cancer Is Risk Factor For Chronic Kidney Disease
For forty years, the gold standard for treating a single, small tumor in the kidney has been to remove the entire kidney. A retrospective study, which appears in the September issue of The Lancet Oncology, by urologists at Memorial Sloan-Kettering Cancer Center (MSKCC) and their colleagues, suggests that this practice needs to be re-evaluated. Researchers add that with advances in imaging, almost 70 percent of kidney cancer patients have their tumor detected at a very small size (less than 4 cm), allowing surgeons to perform less radical surgery with superior results.
The study revealed that patients with two otherwise healthy kidneys who underwent kidney-sparing surgery (partial nephrectomy) to remove a small cancer developed chronic kidney disease at a rate one-third lower than patients whose entire kidney was removed (radical nephrectomy). The three-year probability of staying free of chronic kidney disease was 80 percent for the partial nephrectomy patients compared with 35 percent for patients who underwent a radical nephrectomy. In fact, radical nephrectomy was shown to be a significant risk factor for developing chronic kidney disease.
"The results of our study demonstrate that prior to surgery, the baseline kidney function of patients with small kidney tumors was significantly lower than previously recognized," explained Dr. William C. Huang, the study's first author. "Patients who undergo a radical nephrectomy, the most common treatment for small kidney tumors, are at significantly greater risk for the development of chronic kidney disease after surgery compared with those who undergo a partial nephrectomy."
The retrospective study of 662 patients at MSKCC showed that up to 26 percent of the patients had pre-existing chronic kidney disease before undergoing surgery to remove a small tumor (less than 4 cm) from the kidney. In addition, those patients who had the entire kidney removed were more than twice as likely to develop chronic kidney disease.
Although partial nephrectomies account for 30 to 65 percent of all kidney surgeries performed in tertiary care centers in the United States like MSKCC, the latest analysis from the Nationwide Inpatient Sample reported in the journal Urology indicated that 92.5 percent of all kidney cancer surgeries in the United States from 1998 to 2002 were radical nephrectomies. Statistics from the Department of Health in England for the same period reflected a similar trend. In 2002, 96 percent (2,671) of kidney cancer surgeries performed in England were nephrectomies and 4 percent (108) were partial nephrectomies.
"Evidence has accumulated from our Center and elsewhere that partial nephrectomy provides effective local tumor control and equivalent survival rates to that of radical nephrectomy for small tumors," said Dr. Paul Russo, the study's senior author. "However, while approximately 70 percent of kidney tumor operations at MSKCC are partial nephrectomies, national databases from the United States and abroad suggest that greater than 80 percent of patients may be unnecessarily undergoing the more radical surgery to remove the entire kidney, even for small renal tumors. One explanation may be that partial nephrectomy is a more complex surgical procedure."
A number of risk factors for chronic kidney disease, such as diabetes, hypertension, and smoking, are commonly found in patients with kidney tumors, and may account for why the majority of these patients are at risk for developing chronic kidney disease following a radical nephrectomy. Chronic kidney disease can result in the loss of kidney function, sometimes leading to kidney failure. Complications associated with chronic kidney disease include anemia, hypertension, malnutrition, and neuropathy, as well as a reduced quality of life, and even heart disease and death.
"Our study clearly demonstrates, for the first time, the serious effects on kidney function and the high risk of chronic kidney disease when an entire kidney is removed for a small cancer. Chronic kidney disease leads to an increased risk of cardiovascular events, hospitalizations, and even death," said Dr. Peter T. Scardino, Chairman of the Department of Surgery and co-author of the study. "By removing only the cancerous part, we are much more likely to preserve a patient's normal kidney function and avoid the long-term consequences of chronic kidney disease."
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The study's co-authors are Ganesh V. Raj, MD; Angel M. Serio, MS; Mark E. Snyder; and Andrew J. Vickers, PhD of MSKCC and Andrew S. Levey, MD, of Tufts-New England Medical Center. Funding was provided in part, by a grant from the National Institutes of Health.
Memorial Sloan-Kettering Cancer Center is the world's oldest and largest institution devoted to prevention, patient care, research, and education in cancer. Our scientists and clinicians generate innovative approaches to better understand, diagnose, and treat cancer. Our specialists are leaders in biomedical research and in translating the latest research to advance the standard of cancer care worldwide. For more information, go to http://www.mskcc.org/.
Contact: Joanne Nicholas
Memorial Sloan-Kettering Cancer Center
Death Rate Rises Despite Better Kidney Cancer Detection And Early Treatment
The number of cases of kidney cancer has been rising over the last two decades, and new research from the University of Michigan Comprehensive Cancer Center shows that this increase is driven largely by the detection of small, presumably curable, kidney masses. But even though the rising incidence has been paralleled by greater use of surgery for kidney cancer, this trend has not led to fewer people dying.
"With increased early detection and treatment of small tumors, we would expect to see a decrease in mortality associated with kidney cancer," says senior author Brent K. Hollenbeck, M.D., assistant professor of urology at the U-M Medical School. "Surprisingly, that's not what we found. Our research shows that an increase in detection and treatment is not leading to a reduction in the kidney cancer mortality rate."
The study - published in the Sept. 20 issue of the Journal of the National Cancer Institute - includes data from nine of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registries. In all, the researchers examined data from 34,503 patients with kidney cancer.
Over the study period (1983 to 2002), researchers observed a rise in the occurrence of kidney cancer (also known as renal cell carcinoma) for tumors of all sizes. But the greatest increases in kidney cancer incidence were among tumors 4 centimeters or smaller. Tumors of this size, often found in patients without any clinical signs or symptoms, are being detected more and more with the widespread use of abdominal imaging studies, such as MRIs and CAT scans. These small kidney tumors are considered curable by surgery, which has led to a rise in surgery for kidney cancer.
Even as early detection and surgical treatment increased, however, mortality rates caused by kidney cancer during the time period rose dramatically, from 1.2 to 3.2 deaths per 100,000 people in the United States.
These seemingly contradictory findings can be explained, in part, through the rising incidence of larger, more lethal tumors, says lead author John M. Hollingsworth, M.D., fifth-year surgery resident with the Department of Urology at the U-M Medical School. "While more and more small, detectable kidney tumors are being treated, the absolute number of patients with larger, lethal masses has not decreased. And it is these larger, lethal masses that seem to mainly affect mortality," Hollingsworth says.
The researchers say the data also suggest something else: A proportion of these smaller, incidentally found kidney tumors may not merit surgical removal.
"We're not saying that surgery for patients with small renal masses is inappropriate," Hollingsworth says. "Our findings, however, show that their increased treatment has not diminished kidney cancer mortality. This calls to question the effectiveness of our current treatment strategy. Perhaps there are some patients with small kidney tumors for whom surgery is not the best option."
Kidney cancer is the third most common malignancy of the genitourinary system (the reproductive system and urinary system). The American Cancer Society estimates there will be about 38,890 new cases of kidney cancer (24,650 in men and 14,240 in women) in the United States this year, and about 12,840 people (8,130 men and 4,710 women) will die from the disease.
This study included data from 34,503 kidney cancer patients, including age at diagnosis, race, gender and information about the tumor. During the years 1983-2002, researchers found, the overall incidence of kidney cancer rose from 7.1 to 10.8 cases per 100,000 people in the United States, an increase of 52 percent. The largest increase was among people with tumors 2 to 4 centimeters in size (the second-smallest category of tumors in the study), an increase of 1.0 to 3.3 cases per 100,000 people in the United States.
Mortality rates also increased, most notably among people with the largest group of tumors (greater than 7 centimeters). Deaths caused by cancer in this group rose from 0.3 to 1.4 per 100,000 people in the United States.
"What this shows us is that, despite more frequent surgeries for smaller kidney cancers, mortality among patients with kidney cancer has continued to increase," Hollingsworth says. "So even while detection and treatment are increasing and more tumors have become detectable, this study suggests a disconnect because we are not decreasing mortality rates."
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In addition to Hollingsworth and Hollenbeck, researchers on the study were David C. Miller, M.D., clinical lecturer in the Department of Urology; and Stephanie Daignault, M.S., a biostatistician with the U-M Comprehensive Cancer Center.
The research was supported by a training grant from the National Institutes of Health, and funding from the Johan and Suzanne Munn Endowed Research Fund of the University of Michigan Comprehensive Cancer Center.
Citation: Journal of the National Cancer Institute, Sept. 20, 2006, "Rising Incidence of Small Renal Masses: A Need to Reassess Treatment Effect."
Contact: Katie Gazella
University of Michigan Health System
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