Objectives: To compare the smear histories of women with microinvasive squamous cell carcinoma (SCC) of the cervix to those of women with cervical intraepithelial neoplasia grade 3 (CIN3).
Design: Retrospective case-control study.
Setting: A large public hospital gynaecology unit. Sample Twenty-nine consecutive women with microinvasive SCC FIGO stage 1A1 (cases). Fifty-five age-matched controls with histologically confirmed CIN3 (controls).
Methods: The cases and controls were selected from institutional databases; smear histories and other information was retrieved from hospital notes or following consent from other records.
Main outcome measures: The time from index smear to prior screening smear and participation in the National Screening Programme (NCSP).
Results: Only 35% of cases compared with 78% controls had a smear in the last 3 years (P = 0.00008.) Cases had a longer median interval between the abnormal smear that resulted in diagnosis and the previous screening smear (4 years) compared with controls (2 years). Cases were less likely to be enrolled in the NCSP (65%) prior to their index smear than controls (85%).
Conclusion: Delayed interval screening was more frequent in women with 1A1 SCC than CIN3.