Comparison of the GenoFlow human papillomavirus (HPV) test and the Linear Array assay for HPV screening in an Asian population

Abstract

High-risk human papillomavirus (HR-HPV) DNA detection in cervical cytology samples is useful for primary screening of cervical cancer and for triage of patients with equivocal cytological findings. The GenoFlow HPV array test (GF assay; Diagcor Bioscience Inc., Hong Kong) was recently developed to detect 33 HPV genotypes by a "flowthrough" hybridization technology. In this study, we assessed the analytical sensitivity and reproducibility of the GF assay and compared its genotyping results with those of the Linear Array (LA) assay (Roche Molecular Diagnostics, Indianapolis, IN), using 400 archived liquid-based cytology samples representing the full range of cytology findings. Genotyping findings of the GF and LA assays were concordant or compatible for 93.44% of tested samples, with a good (κ = 0.797) to very good (κ = 0.812) strength of agreement for assay-common and oncogenic HPV types, respectively. The two assays showed good (κ = 0.635) agreement in detecting infections with multiple HPV genotypes. The lowest detection limits of the GF assay for HPV16 and HPV18 were 25 copies and 20 copies, respectively. Repeat testing of 60 samples by use of two different lots of the GF assay revealed no discordant results, suggesting good reproducibility of the assay. Both assays achieved approximately 80% and 100% sensitivity for identifying cases of atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesions (LSIL) with subsequent detection of LSIL+ and high-grade squamous intraepithelial lesions or higher (HSIL+) in 2 years, respectively. Among ASC-US samples, the GF assay achieved the highest specificity (23.08%) for indicating subsequent identification of HSIL compared with the LA (19.23%) and Hybrid Capture 2 (HC2) (8.97%) assays. The GF and LA assays showed significant discrepancy in detecting HPV genotypes 11, 26, 39, 52, and 66. More sensitive detection of HPV52 by GF assay offers an advantage in regions where HPV52 is more prevalent. The sensitivity of the GF assay for detecting patients with HSIL+ was noninferior to that of the LA assay.