The greater the number of nodes removed, the better the outcome. Even with negative nodes, the prognosis is better. This is because in one-third of histological negative lymph nodes there are molecularly detectable metastatic cells. The pathologic assessment of lymph nodes benefits from submitting lymph node packets, as the pathologist will do more diligent evaluation. The number of lymph nodes collected increases with an extended lymph node dissection and translates into better survival. For example, the 5-year survival in pT3 patients increases from 19% to 63% with an extended vs. limited LND. Injection of radioisotope followed by SPECT-CT permits identification of specifically positive nodes. The next day LND identified these nodes and confirmed them by gamma counting. This helped to delineate the boundaries of the LND. 8% of nodes are superior to the bifurcation of the common iliac artery. The incidence of positive LNs increases from 36% to 47% with this “super extended” dissection. However, survival does not seem to be improved, so the standard extended LND suffices.
They followed a similar LN distribution for prostate cancer (CaP) patients. In low-risk CaP patients, there is a 6.8% incidence of positive LNs. Most often, the positive LNs are in patients with upgrading from prostate biopsy to prostatectomy. Those with a single positive LN benefit most, with good long term survival and, and they often avoid requiring additional therapy. 40% of patients with LN positive disease have recurrence-free survival at 10-years. In a SEER analysis, even those with negative LN have better survival, he referenced. Isotope choline PET-CT and DW iron-oxide (USPIO) imaging improves the detection of positive LNs. However, these technologies may still miss micrometastasis and an extended PLND is mandatory for prostate and bladder cancer, he concluded.
Presented by Urs E. Studer, MD at the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.