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

Outcomes of penile sarcomatoid squamous cell carcinoma from a single tertiary referral centre: a matched cohort study

OBJECTIVE

To report the oncological survival outcomes of men with penile sarcomatoid squamous cell carcinoma (sSCC).

PATIENTS AND METHODS

A retrospective analysis of men with penile sSCC diagnosed between January 2010 and January 2020 in a single centre was conducted. Disease-specific (DSS), recurrence-free (RFS) and metastasis-free (MFS) survival were evaluated. Outcomes were compared with a non-sarcomatoid penile SCC cohort matched to age, type of surgery and tumour stage. Kaplan-Meier plots were used to estimate survival outcomes.

RESULTS

In all, 1286 men were diagnosed with penile SCC during the study period and of these 38 (3%) men had sSCC. The median (interquartile range) age and follow-up was 70 (57-81) years and 16 (7-44) months, respectively. Operations performed included: circumcision, one (2.6%); wide local excision, four (10.5%); glansectomy, 11 (29%); partial penectomy, 10 (26%); subtotal/total penectomy, 12 (32%). The Kaplan-Meier estimated 12-, 24- and 36-month DSS was 62% (vs non-sarcomatoid, 67%), 43% (vs non-sarcomatoid, 67%) and 36% (vs non-sarcomatoid, 67%), respectively (P = 0.03). The Kaplan-Meier estimated 12- and 24-month RFS was 47% (vs non-sarcomatoid, 60%) and 28% (vs non-sarcomatoid, 55%), respectively (P = 0.01). The MFS was 52% (vs non-sarcomatoid, 62%) at 12 months and 37% (vs non-sarcomatoid, 57%) at 24 months (P = 0.04).

CONCLUSIONS

Sarcomatoid differentiation was associated with a lower DSS, RFS and MFS. Due to the rarity of its incidence and aggressiveness, expert histological review and multidisciplinary management is required in a specialist penile cancer centre.

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

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.

HPV infection and 5mC/5hmC epigenetic markers in penile squamous cell carcinoma: new insights into prognostics

BACKGROUND

Penile cancer is one of the most aggressive male tumors. Although it is preventable, the main etiologic causes are lifestyle behaviors and viral infection, such as human papillomavirus (HPV). Long-term epigenetic changes due to environmental factors change cell fate and promote carcinogenesis, being an important marker of prognosis. We evaluated epidemiological aspects of penile squamous cell carcinoma (SCC) and the prevalence of HPV infection using high-risk HPV (hrHPV) and p16^INK4A expression of 224 participants. Global DNA methylation was evaluated through 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC).

RESULTS

The incidence of HPV was 53.2% for hrHPV and 22.32% for p16^INK4a. hrHPV was not related to systemic or lymph node metastasis and locoregional recurrence, nor influenced the survival rate. P16^INK4a seems to be a protective factor for death, which does not affect metastasis or tumor recurrence. Lymph node and systemic metastases and locoregional recurrence increase the risk of death. An increased 5mC mark was observed in penile SCC regardless of HPV infection. However, there is a reduction of the 5hmC mark for p16^INK4a + (P = 0.024). Increased 5mC/5hmC ratio (> 1) was observed in 94.2% of penile SCC, irrespective of HPV infection. Despite the increase in 5mC, it seems not to affect the survival rate (HR = 1.06; 95% CI 0.33-3.38).

CONCLUSIONS

P16^INK4a seems to be a good prognosis marker for penile SCC and the increase in 5mC, an epigenetic mark of genomic stability, may support tumor progression leading to poor prognosis.