Detection of variable genotypes in common human papillomavirus-associated invasive penile squamous cell carcinomas: a study of 177 human papillomavirus-positive cases

Abstract

Human papillomavirus (HPV) is detected in 30-50% of invasive penile carcinomas, and it is frequently associated with basaloid and warty morphological features. Based on this heterogeneity and different clinical behaviors, we hypothesized a variation in their HPV genotypic composition. To test this, we evaluated 177 HPV-positive cases: basaloid (114), warty-basaloid (28), and warty (condylomatous) (35) invasive carcinomas. HPV DNA detection and genotyping was performed using the SPF-10/DEIA/LiPA₂₅ system. Nineteen HPV genotypes were detected. High-risk HPVs predominated (96%), and low-risk HPVs were rarely present. Most common genotype was HPV16 followed by HPVs 33 and 35. According to the genotypes identified, 93% of the cases would be covered with current vaccination programs. There was a significant variation in the distribution of HPV16 and non-HPV16 genotypes according to histological subtype. HPV16 was significantly frequent in basaloid (87%) and was less frequent in warty carcinomas (61%). This molecular difference, along with their distinctive macro-microscopic and prognostic features, makes basaloid and warty carcinomas unique. The gradual decreasing frequency of HPV16 demonstrated in basaloid, warty-basaloid, and warty carcinomas suggest that the basaloid cell, present in those types in decreasing proportions, may be responsible for the differences.

Keywords: Basaloid carcinoma; Human papillomavirus; Penile squamous cell carcinoma; Warty carcinoma; Warty-basaloid carcinoma.