Human papillomavirus and p16 in squamous cell carcinoma and intraepithelial neoplasia of the vagina

We estimated the overall and type-specific prevalence of human papillomavirus (HPV) and p16 overexpression in vaginal cancer and vaginal intraepithelial neoplasia (VaIN). We conducted a systematic search of PubMed, Embase and Cochrane Library to identify studies published between 1986 and 2017 using PCR-based or Hybrid Capture 2 tests to evaluate the presence of HPV DNA and/or using any method to detect p16 overexpression in VaIN, vaginal squamous cell carcinoma (VaSCC), or other types of vaginal cancer. Applying a random effects model, we estimated the pooled prevalence of HPV and p16 overexpression along with 95% confidence intervals (CIs). The I² statistic was used to assess heterogeneity. We included 26 studies, reporting HPV prevalence and six studies evaluating p16 overexpression. The pooled HPV prevalences in VaSCC (n = 593) and VaIN (n = 1,374) were 66.7% (95% CI = 54.7-77.8) and 85.2% (95% CI = 78.2-91.0), respectively. Substantial inter-study heterogeneity was observed, and analyses stratified on geographic region, type of tissue, HPV detection method or PCR primer type did not fully explain the observed heterogeneity. The most predominant HPV type among the HPV positive VaSCC and VaIN cases was HPV16, followed by HPV33, and HPV45 (in VaIN) and HPV18, and HPV33 (in VaSCC). In pooled analyses, 89.9% (95% CI = 81.7-94.6) of HPV positive and 38.9% (95% CI = 0.9-90.0) of HPV negative vaginal cancers were positive for p16 overexpression. Our findings suggest that vaccination against HPV might prevent a substantial proportion of vaginal neoplasia and highlight the need for further studies of the possible clinical value of p16 testing in these patients.

hrHPV positivity in ASC-US Papanicolaou tests from women with treated HPV- and non-HPV-related gynecologic malignancies

INTRODUCTION

Although the utility of high-risk human papillomavirus (hrHPV) testing is established in the triage of ASC-US Papanicolaou tests from the general population, its role in women who have been treated for cervical cancer and other HPV-related cancers is less clear.

MATERIALS AND METHODS

Records of patients with ASC-US Papanicolaou tests and HPV testing results submitted by our gynecologic oncology service with a history of malignancy between 2006 and 2012 were reviewed.

RESULTS

Thirty-nine women with a history of treatment for HPV-related cancer and ASC-US Papanicolaou tests who had undergone hrHPV testing were identified. hrHPV was detected in the in specimens from 12 of the 39 patients. Among the 12 patients with ASC-US/hrHPV+ Papanicolaou tests, 2 had a subsequent Papanicolaou test with high-grade squamous intraepithelial lesion (HSIL) and 1 had a cervical biopsy that showed invasive squamous cell carcinoma. Among the 27 patients with ASC-US/hrHPV- Papanicolaou tests with pathologic follow-up, none had HSIL or worse. In patients with treated non-HPV-related cancers, hrHPV was detected in cervical/vaginal cytology specimens from 11 of 47 patients. Of 11 patients with ASCUS/hrHPV+ Papanicolaou tests, 1 had an HSIL Papanicolaou test and a negative vaginal biopsy within 18 months. None of the 36 patients with ASC-US/hrHPV- Papanicolaou tests had HSIL or worse on follow-up.

CONCLUSION

The rates of hrHPV positivity in ASC-US Papanicolaou tests from women treated for both HPV-related (31%) and non-HPV-related (23%) gynecologic malignancies were similar to those reported in women older than 45 years. hrHPV testing identified all women with ASC-US Papanicolaou tests who subsequently developed HSIL or worse.