Risks of cervical intraepithelial neoplasia grade 3 or invasive cancers in ASCUS women with different management: a population-based cohort study

OBJECTIVE: To investigate the progression risk of atypical squamous cells of undetermined significance (ASCUS) with different clinical managements. METHODS: Women with their first diagnosis of ASCUS cytology were retrieved from the national cervical cancer screening database and linked to the national health insurance research database to identify the management of these women. The incidences of developing cervical intraepithelial neoplasia grade 3 and invasive cervical cancer (CIN3+) were calculated, and the hazard ratios (HRs) were estimated using a Cox proportional hazards model. This study was approved by the Research Ethics Committee of the National Taiwan University Hospital and is registered at ClinicalTrials.gov (Identifier: NCT02063152). RESULTS: There were total 69,741 women included. Various management strategies including colposcopy, cervical biopsies and/or endocervical curettage, and cryotherapy, failed to reduce the risk of subsequent CIN3+ compared with repeat cervical smears. Loop electrosurgical excision procedure/conization significantly decreased risk of subsequent CIN3+ lesions (HR=0.22; 95% confidence interval [CI]=0.07–0.68; p=0.010). Women in their 40s–50s had an approximately 30% risk reduction compared to other age groups. Women with a previous screening history >5 years from the present ASCUS diagnosis were at increased risk for CIN3+ (HR=1.24; 95% CI=1.03–1.49; p=0.020). CONCLUSION: In women of first-time ASCUS cytology, a program of repeat cytology can be an acceptable clinical option in low-resource settings. Caution should be taken especially in women with remote cervical screening history more than 5 years.