To Örebro University

Background & objectives: HPV-positive penile tumours have been associated with higher survival rates. However, HPV analysis is unavailable in many low-income countries. We investigated if histological assessment of penile squamous cell carcinoma subtypes can replace HPV testing in determining HPV-related/non-HPV-related tumour status.

Methods: We reviewed paraffin-embedded tumour tissue from 345 penile cancer patients, surgically treated between 2009 and 2018 at Örebro University Hospital, Sweden. The histological subtype of squamous cell carcinoma was assessed according to the WHO criteria and ISUP recommendations. HPV-DNA genotyping was performed using the PCR method Anyplex II HPV28. Concordance was assessed by calculating Cohen’s kappa (κ).

Results: A good concordance was found between histological subtype of squamous cell carcinoma and HPV tumour-status with a Cohen’s kappa (κ) of 0,72 corresponding to 86,6% agreement. Of the 46 discordant cases, five had HPV-related histology (mixed subtypes) but were HPV-negative. The remaining 41 cases had non-HPV- related histology (85% usual subtype, 15% mixed subtypes) but were HPV-positive. Noteworthy is that in 21 of the cases with non-HPV-related histology, foci of undifferentiated PeIN was found. In addition, four cases with both undifferentiated PeIN and lichen sclerosus et atrophicus in the tumour margin, 14 cases with both differentiated PeIN and lichen sclerosus et atrophicus and two cases without preneoplastic lesion were identified.

Conclusion: Good concordance between histological subtype of penile squamous cell carcinoma and HPV genotyping shows that when necessary, histological assessment is a good alternative, at least in less resourceful settings, to PCR-based HPV analysis in determining if penile tumours are HPV or non-HPV-related. Discordant cases most likely depend on subjectivity in histological assessment but can also suggest a HPV infection in a non-HPV-related tumour.