Prognostic factors of penile cancer and the efficacy of adjuvant treatment after penectomy: Results from a multi-institution study

Background: Penile cancer is a rare malignancy associated with high rates of mortality and morbidity. Currently, the efficacy of adjuvant treatment (AT), including radiotherapy and chemotherapy, for penile cancer remains unclear. Therefore, we investigated the prognostic factors for treatment outcomes and the efficacy of AT in consecutive patients who underwent penectomy for penile cancer at multiple Korean institutions between 1999 and 2013. Methods: AT was defined as the administration of chemotherapy, radiotherapy, or both within 12 months after initial treatment. All patients were divided into two groups according to the AT status. Results: Forty-three patients (median age 67.0 years) with a median follow-up after penectomy of 26.4 (interquartile range: 12.0-62.8) months were enrolled. Patients with AT had a significantly higher pathologic stage. However, no differences in age, histologic grade, or type of surgery were identified according to the presence of AT. The 3- and 5-year cancer-specific survival (CSS) rates were 79.0% and 33.0%, respectively. In a multivariate analysis, American Joint Committee on Cancer (AJCC) stage ≥ III disease was an independent predictor of CSS and recurrence-free survival (RFS). However, AT was not associated with CSS and RFS. The type of primary surgical treatment and inguinal lymph node dissection at diagnosis were also not significantly associated with overall survival, CSS, or RFS. Conclusion: AJCC stage ≥ III disease, which mainly reflects lymph node positivity, is a significant prognosticator in patients with penile cancer. By contrast, AT does not seem to affect CSS and RFS.