NEW YORK (Reuters Health) – Removing more lymph nodes from patients with lymph node positive renal cell carcinoma meant fewer died of the disease, according to a new study in The Journal of Urology.

The findings suggest that lymphadenectomy should be considered for those at high risk for nodal disease – but that requires better ways to identify nodes before surgery and determine who lymphadenectomy might work for, the authors said.

The current study, led by Dr. Jared Whitson of the University of California, San Francisco examined the cases of 9,586 renal cell carcinoma patients in the Surveillance, Epidemiology and End Results (SEER) database that were treated with radical or partial nephrectomy with lymphadenectomy. Node status was negative in 8,321 patients and positive in 1,265. Median follow-up was 3.5 years.

Five-year disease specific survival (DSS) was 80% in patients with lymph node negative disease and 36% for those with lymph node positive disease. In patients with positive lymph nodes, having more positive nodes was associated with a lower chance of survival (HR = 1.1, 95% CI: 1.0-1.2, P = 0.001 for each additional positive node.)

How many lymph nodes were removed during lymphadenectomy did not influence DSS in patients with lymph node negative disease (HR = 1.0, 95% CI: 0.9-1.1, P = 0.93).

But survival was increased in patients with positive lymph nodes who had more nodes removed during surgery, regardless of their actual number of positive nodes (HR = 0.8, 95% CI: 0.7-1.0, P = 0.04 per 10 nodes removed). The five-year predicted probability of DSS was 49% in node-positive patients who had 15 nodes removed during lymphadenectomy, compared to 39% in those who had 5 lymph nodes removed.

The authors said that lymphadenectomy may improve survival by removing micrometastatic disease that would otherwise not be picked up. They also note that removing more nodes may improve staging accuracy.

Regional or extended lymphadenectomy should be considered in patients who are at risk of nodal disease, Whitson and his colleagues said.

They added, “Future efforts should focus on improved imaging modalities and on the development of prediction tools which use clinical variables to suggest who is likely to benefit from regional or extended lymphadenectomy.”

J Urol.