Craniocaudal retroperitoneal node length as a risk factor for relapse from clinical stage I testicular germ cell tumor.

363 Background: To investigate if retroperitoneal craniocaudal nodal length (CCNL) or nodal volume (NV) predicts relapse risk in clinical stage I testicular cancer. Methods: This institutional review board-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant study retrospectively reviewed 826 patients with testicular cancer. One hundred eighteen out of 826 patients forming the analytic cohort had stage I disease and either more than or equal to 2 years surveillance or retroperitoneal lymph node dissection with no adjuvant chemotherapy. 3D NVs and CCNL were measured by two attending physicians in consensus. Association between relapse risk and CCNL/NV was evaluated using univariable/multivariable logistic regression analysis adjusted for known prognostic factors. Results: Sixty six out of 118 patients (56%) had nonseminomatous germ cell tumor (NSGCT) and 52 (44%) had seminomatous germ cell tumor (SGCT). Twenty one percent (25 out of 118) of patients relapsed: 24% (16 out of 66) for NSGCT and 17% (9 out of 52) for SGCT. Eighty percent of relapses were limited to the retroperitoneum; 90% of these were at the site of the largest lymph node. CCNL proved to be an independent risk factor in NSGCT using a multivariable logistic regression model adjusting for other potential known risk factors of embryonal predominance (EP) and lymphovascular invasion (LVI). For every 3 mm increase in CCNL, the risk of relapse increased by 52% (odds ratio [OR]=1.52; 95% CI=1.03- 2.25). For patients with SGCT, only the primary tumor size was an independent risk factor for relapse (OR=1.34; 95% CI=1.02-1.75). Conclusions: In NSGCT, CCNL was shown to be associated with increased risk of relapse independently of other known risk factors. If validated in a larger cohort, CCNL could provide important additional information used to inform management decisions in these patients.