Long term follow up of women with borderline cervical smear test results: effects of age and viral infection on progression to high grade dyskaryosis.

OBJECTIVE

To follow up and assess the significance of borderline change in cervical smears.

DESIGN

Retrospective study of women undergoing routine cervical cytological screening in 1981.

SETTING

Avon Cervical Screening Programme, covering 250,000 women in Bristol and Weston super Mare.

SUBJECTS

437 women showing borderline cervical changes in 1981 and 437 age matched controls with normal results in 1981.

MAIN OUTCOME MEASURES

Cytological progression to high grade dyskaryosis (cervical intraepithelial neoplasia grade III or invasive carcinoma).

RESULTS

During follow up ranging from 13 to 106 months 98 of the 437 women (22.4%) with borderline cytological changes on routine cervical cytology screening had a subsequent smear test showing high grade dyskaryosis compared with three of the 437 women (0.9%) in the control group. The risk of progression was greater in women aged 20 to 39 than in those aged 40 and over. Human papillomavirus infection had initially been diagnosed cytologically in 101 of the 437 (23%) women with borderline results. Significantly fewer of these women developed high grade dyskaryosis (13/98 (13%) v 88/339 (26%), p less than 0.05).

CONCLUSIONS

Women with borderline smear test results are at increased risk of developing high grade dyskaryosis, particularly if the borderline changes occur without cytological features of human papillomavirus infection. Progression occurs within three years in 50% of cases, although a linearly increasing risk was sustained over the nine years of follow up and was greatest in women aged 20 to 39. Careful follow up of these women is indicated.