How accurately do Solsona and European Association of Urology risk groups predict for risk of lymph node metastases in patients with squamous cell carcinoma of the penis?

OBJECTIVES: To compare the prognostic accuracy of the Solsona and European Association of Urology (EAU) risk groups in the identification of lymph node involvement in a cohort of patients with squamous cell carcinoma of the penis. METHODS: The clinical and pathologic data of 175 patients who had undergone surgery for squamous cell carcinoma of the penis from 1980 to 2002 at 11 urologic centers of northeastern Italy were retrospectively collected. RESULTS: According to the EAU risk group, 25 patients were categorized as at low (15.1%), 23 (13.9%) as intermediate, and 118 (71.1%) as high risk of lymph node metastasis. Similarly, using the criteria of the Solsona risk group stratification, 25 (15.1%), 55 (33.1%), and 86 patients (51.8%) were categorized as at low, intermediate, and high risk. At the median follow-up of 26 months, lymph node involvement was observed in 71 (40.6%) of 175 patients. Receiver operating characteristic curve analysis showed that both the EAU risk group (area under the curve = 0.632) and Solsona risk group (area under the curve = 0.697) had a low accuracy for predicting lymph node involvement. Both risk groups were independent predictors of lymph node involvement, as well as the clinical stage of lymph node involvement and the presence of vascular and/or lymphatic embolization. CONCLUSIONS: The Solsona and EAU risk groups were both independent predictors of lymph node involvement, although the receiver operating characteristic curve analysis showed that both risk groups had low predictive accuracy.