Characteristics of penile cancer in Japan: An analysis of nationwide hospital-based cancer registry data.

Abstract

To investigate the clinical characteristics of patients with penile cancer in Japan using the nationwide hospital-based cancer registry database. Using hospital-based cancer registry data, we described the distribution of age, pathology, tumor-node-metastases classification, and first-course treatment in patients treated between 2012 and 2015. We compared the patterns of first-line treatment between elderly and non-elderly patients. A total of 1012 patients were diagnosed with squamous cell carcinoma among 1773 patients with penile tumors who registered under topography code C60. The median age at diagnosis was 74years, and 85.9% of patients were aged >60years. The most common pathology was usual-type squamous cell carcinoma (91.9%), followed by verrucous carcinoma (5.0%), sarcomatoid carcinoma (1.1%), papillary carcinoma (0.7%), basaloid carcinoma (0.6%), adenosquamous carcinoma (0.4%), warty carcinoma (0.2%) and mixed carcinoma (0.1%). A total of 61.3% of patients were diagnosed with localized disease. In contrast, the proportions of patients with lymph node and distant metastases were 27.5% and 2.1% at diagnosis, respectively. The proportion of patients who were treated with chemotherapy as the first-course treatment was significantly lower among elderly patients (≥80years) with clinical stageIII (27.6% vs 7.1%, P=0.0312) and clinical stageIV (53.2% vs 14.3%, P=0.0086). Most penile cancer patients in Japan are diagnosed with usual-type squamous cell carcinoma, and those with human papilloma virus-related squamous cell carcinomas are <1%. Chemotherapy for advanced penile cancer is administered less in Japanese elderly (≥80years) patients.