Human papillomavirus, lichen sclerosus and penile cancer: a study in Belgium

The prevalence of penile cancer varies between 1.5 (industrialized countries) and 4.5 per 100,000 men (non-industrialized countries). Predominant histological subtype is squamous cell carcinoma (SCC). Human papillomavirus (HPV) is found in 40-46% of cases: penile cancer is considered to behave as vulvar cancer. Non HPV related risk factors are lack of circumcision, phimosis, chronic inflammation, and smoking. The role of lichen sclerosus (LS) is unclear. Clinical diagnosis is difficult and treatment often mutilating. Preventive measures can be taken since the risk factors are known: the use of the prophylactic HPV vaccines may contribute. We measured the prevalence of HPV and LS in penile cancer in Belgium.

We found 76 samples of penile lesions in the archives of the departments of Histology of four university hospitals in Belgium. Real-time PCR of type-specific HPV DNA was performed targeting 18 HPV types.

Patients with penile intraepithelial neoplasia (PeIN) were 56.1 years of age: patients with invasive penile cancer (IPC) 68.5 (p=0.009). Fifty-five samples (55/76) were adequate for HPV targeting. Overall HPV DNA was 70.9%: 89.5% in samples of PeIN (n=19) and 61.1% in samples of IPC (n=36). Invasive penile cancer samples were less likely to be HPV infected (p=0.028). HPV 16 was most prevalent: 48.3%: 20% PeIN, and 28.3% IPC. HPV DNA of the types, included in the prophylactic vaccines, was found in 33% of PeIN and 31.7% of IPC samples. Thrice, low risk HPV (lrHPV) types 6 (1 IPC) and 11 (1 PeIN, 1 IPC) were solely present. There was no difference in the presence of LS between HPV positive and HPV negative samples (p=0.944).

Prevalence of HPV DNA in penile lesions in Belgium is high. However, the prophylactic vaccines may contribute to primary prevention of only a subset of cases. The role of LS remains unclear.