Optimal cervical cytology mass screening interval for cervical cancer

To identify the optimal interval for repeat cervical cytology testing for screening of cervical cancer and dysplasia in healthy female adults.

A retrospective cohort study was conducted on 3,804 apparently healthy females without known cervical cancer at baseline from 2005 to 2010. Participants underwent annual health checkups, including cervical cytology testing. This data did not contain human papillomavirus status. Participants with cytological abnormality underwent further examination, including biopsy, to check for cervical cancer. The generalized estimating equation (GEE) was performed to analyze the longitudinal data.

In the groups <40, 40-49, 50-59 and ≥60 years old, the 5-year cumulative incidences (95 % CI) of cytological abnormality were 11.2 % (8.8-13.9 %), 7.6 % (6.2-9.3 %), 4.4 % (3.3-5.7 %) and 2.8 % (1.8-4.2 %), respectively, and the cumulative incidences of cervical cancer were 0.9 % (0.3-2.0 %), 0.1 % (0.0-0.4 %), 0.1 % (0.0-0.5 %) and 0 %, respectively. The odds ratios of the incidence for cervical cancer and cervical dysplasia per year, with GEE models, were 1.5 (95 % CI:1.1-2.0), 1.2 (95 % CI:0.8-1.9), 2.2 (95 % CI:0.5-10.3) and 0 for cervical cancer, and 1.3 (95 % CI:1.2-1.5), 1.3 (95 % CI:1.2-1.5), 1.3 (95 % CI:1.1-1.5) and 1.4 (95 % CI:0.9-2.0) for cervical dysplasia, respectively.

For patients under 40 years old, the screening for cervical cancer every 2 years should be considered, while for patients of 40-59 years old screening every 2 or 3 years should be considered. Females over 60 years old may only need repeat screening every 5 years.