Analysis of the related risk factors of inguinal lymph node metastasis in patients with penile cancer: A cross-sectional study

PURPOSE: To determine independent predictors of inguinal lymph node (ILN) metastasis in patients with penile cancer. PATIENTS AND METHODS: We retrospectively analyzed all patients with penile cancer who underwent surgery at our medical center in the last ten years (n=157). Using univariate and multivariate logistic-regression models, we assessed associations with age, medical-history, phimosis, onset-time, number and maximum diameter of involved ILNs measured by imaging, pathological T stage, degree of tumor differentiation and/or cornification, lymphatic vascular infiltration (LVI), nerve infiltration, and ILN metastases. Interaction and stratified analyses were used to assess age, phimosis, onset time, number of ILNs, cornification, and nerve infiltration. RESULTS: A total of 110 patients were included in the study. Multiple logistic regression analysis showed that the following factors were significantly correlated with ILN metastasis: maximum diameter of enlarged ILNs, T stage, pathological differentiation, and LVI. Among patients with a maximum ILN diameter ≥1.5cm, 50% had lymph node metastasis whereas 30.6% patients with a maximum ILN diameter <1.5cm showed LNM. Among 44 patients with stage Ta/T1, 10 showed ILN metastases, while 47.0% patients with stage T2 showed ILN metastases. Among 40 patients with highly differentiated penile-cancer, eight showed ILN metastasis, while 47.1% patients with low-to-middle differentiation showed ILN metastases. The rate of LNM was 33.3% in the LVI-free group and 64.3% in the LVI group. CONCLUSION: Our single-center results suggested that maximum ILN diameter, pathological T stage, pathological differentiation, and LVI were independent risk factors for ILN metastases.