Progression and regression of low-grade epithelial abnormalities of the cervix.

The records of 738 women with low-grade cervical epithelial abnormalities were examined for changes in degree of cervical disease and lesion size, as well as sociodemographic and behavioural factors which influence the development of invasive cancer of the cervix. Survival analysis was used to determine the predictors and rates of progression and regression. The results suggest that about 80% of the low-grade epithelial abnormalities of the cervix will not progress within 2 years. The only predictors of progression were a biopsy diagnosis of CIN 1 and the size of the lesion. Predictors of regression were older age, older age at first intercourse, greater parity, fewer sexual partners, and absence of a past history of genital herpes. Although progression rates of low-grade abnormalities of the cervix were very low, CIN 1 lesions were 2.4 times (95% CI: 1.6 to 3.7) more likely to progress than lower-grade lesions and large lesions (> 1/2 ectocervix) were 2.0 times (95% CI: 1.2 to 3.3) more likely to progress than small ones (< 1/4 ectocervix).