Partial nephrectomy underutilized for small renal tumors

SAN FRANCISCO—Women, older patients, and patients with cerebrovascular disease who have small renal tumors are more likely to undergo radical nephrectomy of the affected kidney than partial nephrectomy, according to a retrospective study presented at the 2008 Genitourinary Cancers Symposium (abstract 387).

“Just as lumpectomy can be less invasive but as effective as mastectomy for treating breast cancer, people with kidney cancer should be aware that partial nephrectomy is not only an option, but may be a better option than radical nephrectomy in many circumstances because it may help preserve kidney function in patients with renal tumors,” said lead author William Huang, MD, assistant professor of urologic oncology, New York University School of Medicine.

The incidence of renal tumors has been rising steadily for several decades, largely due to the incidental finding of these small tumors during imaging procedures for other reasons, Dr. Huang said at a press conference.

Using SEER data from 1995 through 2002, the investigators identified patients with small renal tumors (4 cm or less): 2,547 of these patients (81%) underwent radical nephrectomy and 556 (19%) had partial nephrectomy. These data were linked to Medicare claims to analyze preoperative factors that might influence surgical choice.

They found that patients who had partial nephrectomy were more likely to be younger, male, married, and treated at a later date during the study period, which may mean that the prevalence of partial nephrectomy is slowly increasing, Dr. Huang said.

Women, older patients, and those with cerebrovascular disease were less likely to have partial nephrectomy. For example, 20.5% of men and 22.4% of patients aged 66 to 69 had partial nephrectomy, compared with 16% of women and 7.1% of patients aged 85 and older.

There were no differences in the type of surgery based on geographical location, economic level, or race.

Why the preference?

Dr. Huang speculated that surgeons may prefer radical nephrectomy over partial nephrectomy because it is technically less challenging to perform and has a lower risk of complications. For these reasons, surgeons may believe that the procedure is a better option for older patients and those with cerebrovascular disease in the postoperative period. But in the long run, he said, these patients may have worsened kidney function after radical nephrectomy, resulting in serious long-term consequences.

At a press briefing, Howard M. Sandler, MD, of the University of Michigan Health System, Ann Arbor, commented: “The main rationale of partial nephrectomy is to preserve as much kidney function as possible, because as we get older, we’ll need as much kidney function as we can get.”

The bias toward radical nephrectomy in women is less clear, Dr. Huang said, but may be based on the way surgeons interpret preoperative laboratory tests that may suggest women have better renal function than they actually do.

At the meeting, Dr. Huang also presented data on morbidity and mortality with radical vs partial nephrectomy, using the same patient cohort (abstract 366). Adjusting for 15 preoperative demographic and comorbid variables, radical nephrectomy was associated with an increased risk of mortality (HR 1.38, P = .002), he reported.

“Partial nephrectomy continues to be underutilized for small renal tumors, and is not even offered to all subpopulations of patients,” Dr. Huang concluded. “Increased education and training in partial nephrectomy is needed to reverse this trend.”