Tumor stage, vascular invasion and the percentage of poorly differentiatedcancer: Independent prognosticators for inguinal lymph node metastasis in penile squamous cancer

Purpose: We determine if histopathological factors of the primary penile tu mor can stratify the risk of the development of inguinal lymph node metasta ses. Materials and Methods: Clinical records of 48 consecutive patients with squ amous cell carcinoma of the penis who underwent resection of the primary le sion and either inguinal lymph node dissection or were observed for signs o f recurrence (median followup 59 months) were reviewed. Parameters examined included pathological tumor stage, quantified depth of invasion and tumor thickness, histological and nuclear grade, percentage of poorly differentia ted cancer in the primary tumor, number of mitoses and presence or absence of vascular invasion. Variables were compared in 18 lymph node positive and 30 lymph node negative cases. Results: Pathological tumor stage, vascular invasion and presence of greate r than 50% poorly differentiated cancer were the strongest predictors of no dal metastasis on univariate and multivariate regression analyses. None of 15 pT1 tumors exhibited vascular invasion or lymph node metastases. Of 33 p atients with pT2 or greater tumors 21 (64%) had vascular invasion and 18 (5 5%) had metastases. Only 4 of 25 patients (15%) with 50% or less poorly dif ferentiated cancer in the penile tumor had metastases compared with 14 of 2 3 patients (61%) with greater than 50% poorly differentiated cancer (p = 0. 001). No other variables tested were significantly different among the pati ent cohorts. Conclusions: Pathological stage of the penile tumor, vascular invasion and greater than 50% poorly differentiated cancer were independent prognostic f actors for inguinal lymph node metastasis. Prophylactic lymphadenectomy in compliant patients with pT1 lesions without vascular invasion and 50% or le ss poorly differentiated cancer does not appear warranted.