High diagnostic concordance between vulvar and cervical samples for human papillomavirus detection: a cross-sectional...

Low compliance with clinician-collected cervical sampling and implementation barriers in resource-limited settings limit human papillomavirus (HPV)-based cervical cancer prevention. Vulvar sampling is non-invasive and easier to perform, but its agreement with cervical HPV testing remains insufficiently defined. We retrospectively analyzed 719 paired vulvar and cervical specimens tested by clinically validated fluorescence PCR to evaluate concordance between sampling sites and the potential utility of vulvar HPV testing. High-risk HPV (hrHPV) positivity was 47.98% (345/719) in vulvar samples and 43.53% (313/719) in cervical samples, with strong site-to-site concordance (κ = 0.821). The negative predictive value of vulvar hrHPV testing for concurrent cervical hrHPV positivity was 95.72%. Concordance was highest for HPV18 (κ = 0.892; negative predictive value [NPV] = 99.41%), followed by HPV16 (κ = 0.839), and low-risk HPV6/11 (κ = 0.746). Among five biopsy-confirmed cervical intraepithelial neoplasia cases, vulvar and cervical HPV results were fully concordant. Age-stratified analysis showed peak hrHPV infection in women younger than 30 years. In women aged 40-49 years, vulvar hrHPV positivity exceeded cervical positivity (56.52% vs 45.65%). Agreement was lower among women aged ≥40 years for hrHPV and lrHPV testing. Among discordant cases, 93.75% (15/16) of vulvar-negative/cervical-positive cases had prior HPV-related treatment, whereas non-HPV16/18 types predominated in vulvar-positive/cervical-negative cases (91.67%, 44/48). Vulvar HPV testing showed high concordance with paired cervical testing and may help identify women at low likelihood of concurrent cervical hrHPV positivity. These findings support prospective evaluation of vulvar sampling as a non-invasive adjunct for HPV testing, particularly for women with low acceptance of cervical sampling or limited access to conventional screening.IMPORTANCEConventional cervical human papillomavirus (HPV) screening remains inaccessible to some women because of discomfort, perceived invasiveness, privacy concerns, and implementation barriers. This study shows that HPV testing with vulvar swabs, a truly non-invasive sampling site, has high concordance with paired cervical testing (κ = 0.821). The high negative predictive value of vulvar high-risk HPV (hrHPV) testing for concurrent cervical hrHPV negativity (95.72%) suggests that a negative vulvar result may identify women at low likelihood of cervical hrHPV positivity, potentially reducing unnecessary referrals. These findings are relevant for older and postmenopausal women, in whom cervical atrophy may decrease the sensitivity of HPV detection. Overall, our results provide preliminary support for prospective evaluation of vulvar sampling as a patient-friendly adjunct to HPV testing, particularly for women with low acceptance of cervical sampling or limited access to conventional screening. Population-based validation with cytological and histological endpoints is required before broader implementation.