HPV16 E6 Gene Transcripts in Primary Type II Endometrial Carcinomas

Abstract

Background/Aim: Data on the prevalence of human papilloma virus (HPV) DNA in different subtypes of endometrial carcinomas (EC) are limited. Patients and Methods: We investigated the incidence of HPV16 DNA E6/E7 transcripts in 47 type I (endometrioid-type) tumors and eight type II (non-endometrioid-type) uterine neoplasms applying PCR-based technology. Immunohistochemical staining in HPV16 positive cases was also performed, and seven lymph node metastases were examined for the presence of HPV16 DNA E6/E7. Results: None of the type I ECs was positive for HPV16 E6 gene transcripts; however, four out of 8 (50%) type II ECs (two out of four papillary-serous and two out of four clear-cell carcinomas) were positive for HPV16 E6 transcripts. The difference in HPV16 E6 transcripts between endometrioid and non-endometrioid neoplasms was statistically significant (p=0.0011). Apart from the cancer subtype, none of the EC clinicopathological features were related to HPV16 E6 positivity. None of 55 ECs contained an HPV16 E7 gene transcripts. All slides from gene-positive samples revealed intense immunostaining reactions. Interestingly, the virus was not detected in any of seven lymph node metastases, including four from HPV16-positive primary tumors. Conclusion: HPV16 E6 gene transcripts may be present in ECs, primarily in the non-endometrioid (type II) uterine cancer subtypes. HPV E6/E7 DNA transcripts were not found in lymph node metastases, even when the primary tumors harboured HPV DNA.