Lymph node counts are a measure of quality assurance and are associated with prognosis for numerous malignancies. To date, investigations of lymph node counts in testis cancer are lacking.
Using the Memorial Sloan-Kettering Testis Cancer Database, we identified 255 patients treated with primary retroperitoneal lymph node dissection (RPLND) for nonseminomatous germ cell tumors (NSGCT) between 1999 and 2008. Features associated with node counts, positive nodes, number of positive nodes, and risk of positive contralateral nodes were evaluated with regression models.
Median (IQR) total node count was 38 (27–53) and was 48 (34 – 61) during the most recent 5 years. Features associated with higher node count on multivariate analysis included high volume surgeon (p=0.034), clinical stage (p=0.036), and more recent year of surgery (p<0.001) while pathologist was not significantly associated with node count (p=0.3). Clinical stage (p<0.001) and total node count (p=0.045) were significantly associated with finding positive nodes on multivariate analysis. The probability of finding positive nodes were 23%, 23%, 31%, and 48% if the total node count was <21, 21 – 40, 41 – 60, and >60, respectively. With a median follow-up of 3.0 years all patients were still alive and 16 patients relapsed while no patient relapsed in the paracaval, interaortocaval, paraaortic, or iliac regions.
Our results suggest that >40 lymph nodes removed at RPLND improves the diagnostic efficacy of the operation. These results will be useful for future trials comparing RPLND, especially when assessing the adequacy of lymph node dissection.