HPV genotyping with LBC trumps cytology for cervical screening in SG
Human papillomavirus (HPV)+16/18 genotyping with reflex liquid-based cytology, compared to cytology, detects more cervical intraepithelial neoplasia grade 3 or worse (≥CIN3) and is cost-effective for cervical screening in Singapore, suggests a recent study.
A total of 1,866 women were included in the study; of these, 167 (8.9 percent) had abnormal cytology (≥ASCUS [atypical squamous cells of undetermined significance]) and 171 (9.2 percent) tested positive for high-risk HPV.
There were 23 CIN detected. Of the 10 ≥CIN3 cases, three had negative cytology but positive HPV-16.
Compared to cytology, HPV genotyping detected more ≥CIN3 (odds ratio, 1.43). Furthermore, HPV+16/18 genotyping with reflex LBC was superior to LBC with reflex HPV in terms of cost-effectiveness, both for disease detection rate and cost per case of ≥CIN2 detected.
Researchers retrospectively analysed women who were ≥25 years old and undertook cotesting with LBC and HPV-genotyping for HPV-16, HPV-18 and 12 high-risk HPV types in a single institution. A single cervical smear in ThinPrep PreservCyt solution was separated for tests in independent cytology and molecular pathology laboratories.
A designated gynaecologist reviewed the results based on institutional clinical management protocols. Those who tested positive for HPV-16 and/or HPV-18 (regardless of cytology results), cytology showing low-grade squamous intraepithelial lesions (SIL) or high-grade SIL, or ASCUS with positive 12 high-risk HPV types were referred for colposcopy.
A colposcopist determined cervical biopsy, either directed punch biopsies or excisional biopsy, and a gynaecologic pathologist reviewed the ≥CIN3 diagnosis.
Epidemiological, clinical and financial input data form Singapore were used to analyse the cost-effectiveness of HPV-based screening in terms of disease and financial burden.