“The take home message for clinicians is that, whenever feasible from a technical perspective, partial nephrectomy appears to be the best treatment option for patients with early-stage kidney cancer who choose surgical treatment,” Dr. David C. Miller from University of Michigan in Ann Arbor, who worked on the study, told Reuters Health by email.
“Our data suggest that by judiciously expanding the use of partial nephrectomy, clinicians can optimize survival outcomes for this growing population of patients,” he added.
In a report in the Journal of the American Medical Association April 18, Dr. Miller and colleagues note that while partial nephrectomy is the preferred treatment for many patients with early-stage kidney cancer, a recent clinical trial from Europe demonstrated better survival for patients treated with radical nephrectomy.
This has “generated new uncertainty regarding the comparative effectiveness of these treatment options,” they say, and prompted their study – a retrospective comparative analysis of long-term survival after partial and radical nephrectomy among a contemporary cohort of 7138 Medicare beneficiaries with clinical stage T1a kidney cancer.
Of the 7138 patients, 1925 (27%) had partial nephrectomy and 5213 (73%) had the radical surgery. The researchers say they used an instrumental variable approach to account for measured and unmeasured differences between the groups.
During a median follow-up of 62 months, fewer patients who had partial nephrectomy than radical nephrectomy died from any cause – 487 (25.3%) vs 2164 (41.5%). Kidney cancer was the cause of death for 37 patients (1.9%) treated with partial nephrectomy and 222 patients (4.3%) treated with radical nephrectomy.
According to the researchers, the risk of dying during follow-up was 46% lower in patients who had partial nephrectomy (hazard ratio, 0.54). “This corresponded with a predicted survival increase with partial nephrectomy of 5.6, 11.8, and 15.5 percentage points at 2, 5, and 8 years following surgery (p<0.001). “Based on a predicted survival difference of 15.5 percentage points at 8-year follow-up, 1 life would be saved for every 7 patients treated with partial rather than radical nephrectomy,” Dr. Miller and colleagues say. “Accordingly, our findings support partial nephrectomy as the preferred treatment option for the ever-expanding pool of patients with kidney tumors measuring 4 cm or smaller,” they conclude. [discpar3] The results of a subgroup analysis suggest that partial nephrectomy may be most beneficial for patients younger than age 75 years and those with significant comorbidity. The clinicians “acknowledge that partial nephrectomy remains a technically challenging operation with potentially significant complications (eg, hemorrhage, urinary fistula that are seen less frequently with radical nephrectomy. This concern cannot be ignored when making treatment decisions,” they say. “Indeed, the benefits of partial nephrectomy must always be weighed against the risk of acute surgical morbidity. In certain scenarios, some patients may be better served with an uncomplicated radical nephrectomy. Likewise, alternative treatment options, including active surveillance and ablative therapies, maybe particularly prudent for patients in whom the benefits of surgical removal are less apparent,” the study team writes. JAMA 2012;307:1629-1635.