ABSTRACT
One major advantage of molecular assays for human papillomavirus (HPV) DNA detection is that these assays can be performed on self-collected samples unlike cytology or visual inspection with acetic acid (VIA). This cross-sectional study was carried out between March 2017 and April 2019 to compare the diagnostic performance in self-collected urine and vaginal samples for HPV DNA detection. Viral DNA was extracted from processed samples using a Qiagen viral DNA extraction Kit (QIAamp DNA Mini Kit). To detect four common high-risk HPV types (16, 18, 31, 45), multiplex real-time polymerase chain reaction (PCR) targeting the LCR/E6/E7 region of the HPV genome was performed in ABI 7500 cycler (Applied Biosystems). The negative samples were screened by conventional PCR targeting the L1 capsid region to exclude other HPV types. The overall agreement between the two self-collecting sampling methods was 64.04% with a κ value of 0.29 pointing towards a fair agreement (P < .01). The sensitivity of HPV DNA detection in urine samples was 57.95% (47.52%, 67.72), and specificity was 84.6% (66.47%, 93.85%) when compared with vaginal samples. The study concludes that self-collected vaginal HPV DNA testing is more sensitive than unpreserved-urine samples for HPV DNA detection in a hospital-based setting.
ABSTRACT
OBJECTIVES: To assess the efficacy of self-collected vaginal samples compared with physician-collected cervical samples for the detection of HPVDNA. METHODS: A hospital-based cross-sectional study was carried out among patients with newly diagnosed cervical cancer attending the Gynecologic Oncology Division, Department of Obstetrics and Gynecology and Radiation Oncology Department at Government Medical College, Kozhikode, Kerala between March 2017 and April 2019. Consenting patients collected their vaginal samples, followed by cervical sample collection by the clinician. The paired samples were transported at 4-8 °C to the laboratory. Amplification of LCR/E6/E7 regions of the HPV genome was done by polymerase chain reaction (PCR). The agreement level between paired samples was assessed by the Kappa index. RESULTS: Among the 114 cervical cancer patients enrolled in the present cross-sectional study, the prevalence of HPV DNA was 78.1% (95% confidence interval [CI] 69.2%-85%) in cervical samples and 77.2% in vaginal samples (95% CI 68.7%-83.9%). The overall agreement between the two sampling methods was 93.9% and the kappa value was 0.82 (P<0.001). The sensitivity of HPV detection using vaginal samples was 98.9% (95% CI 93.9%-99.8%) and the specificity was 100% (95% CI 86.7%-100%) with cervical sampling as the gold standard. By Kappa index, an almost perfect agreement for HPV DNA detection between self-collected and physician-collected samples was observed. CONCLUSION: Self-collection of vaginal samples ensures equity of cervical cancer screening in low-income countries such as India.
