Detection of variable genotypes in common HPV-associated invasive penile squamous cell carcinomas. A study of 177 HPV positive cases

Abstract

HPV is detected in 30 to 50% of invasive penile carcinomas and it is frequently associated with basaloid and warty morphological features. Based on this heterogeneity and different clinical behavior, 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 with PCR using 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 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.