Real-world treatment outcomes of patients with penile cancer in the Kyushu-Okinawa area of Japan in the pre-guideline era.

ABSTRACT

OBJECTIVES: To understand the real-world outcomes for patients with penile cancer in the Kyushu-Okinawa area before the introduction of practice guidelines in Japan. METHODS: We retrospectively collected medical information on patients with penile squamous cell carcinoma and penile intraepithelial neoplasia at 12 university hospitals and their affiliated hospitals in the Kyushu-Okinawa area from January 2009 to December 2020. Patients with unknown clinical stage were excluded. Patient background characteristics and survival, as well as pretreatment factors involved in survival, were investigated. RESULTS: A total of 196 patients were included. Patients with clinical stage 0, I, IIA, IIB, IIIA, IIIB and IV comprised 9.7, 26.0, 22.4, 2.6, 10.7, 14.3 and 14.3%, respectively. The median follow-up was 26 months, and the mean 5-year overall survival and cancer-specific survival rates were 74.3 and 79.8%, respectively. On univariate analysis, tumor diameter ≥ 30 mm, penile shaft tumor, Eastern Cooperative Oncology Group performance status ≥ 1, cT ≥ 3, cN ≥ 2 and cM1 were associated with significantly poorer cancer-specific survival. On multivariate analysis, pretreatment factors of cN ≥ 2 (hazard ratio, 32.5; 95% confidence interval, 5.08-208; P = 0.0002), Eastern Cooperative Oncology Group performance status ≥ 1 (4.42; 1.79-10.9; P = 0.0012) and cT ≥ 3 (3.34; 1.11-10.1; P = 0.0319) were identified as independent prognostic factors. CONCLUSIONS: The study revealed basic data for future penile cancer treatment and research, including survival rates according to clinical stages, and identified cN ≥ 2, Eastern Cooperative Oncology Group performance status ≥ 1 and cT ≥ 3 at initial diagnosis as independent prognostic factors. Evidence for penile cancer in Japan is particularly scarce, and future large-scale prospective studies are warranted.