Predictive factors from cold knife conization for residual cervical intraepithelial neoplasia in subsequent hysterectomy

OBJECTIVE: The optimal management of cervical intraepithelial neoplasia after cold knife conization remains controversial. Reliable predictors of residual dysplasia in the cervix after cold knife conization have not been consistently identified. This study was initiated to examine the accuracy of the traditional factors used to predict residual dysplasia in hysterectomy specimens after cold knife conization. STUDY DESIGN: A retrospective 10-year chart review identified a cohort of 1272 patients who underwent cold knife conization, of whom 311 had a subsequent hysterectomy within 1 year of conization. Residual disease was defined as cervical intraepithelial neoplasia or cancer in the hysterectomy specimen. All cone specimens were completely submitted for pathologic examination, and the following factors were analyzed for their predictive value: degree of dysplasia, margin involvement, endocervical gland involvement, and status of the endocervical curettage. The predictive value of age, race, gravidity, parity, socioeconomic status, cigarette smoking, and marital status were also examined. The χ² test, t test, and logistic regression were used for statistical analysis. RESULTS: Dysplasia or cancer was identified in 1066 (84%) of the 1272 patients who underwent cold knife conization. Of the 311 patients having a subsequent hysterectomy, 106 (34%) had residual disease in their hysterectomy specimen. By multivariate analysis only increasing age and degree of dysplasia were predictive of residual disease. The odds ratio of residual disease in the hysterectomy specimen for a 25-year-old woman was 2.7 (95% confidence interval 1.6 to 4.4) compared with a 40-year-old woman whose odds ratio was 4.9 (95% confidence interval 2.2 to 10.8). The presence of dysplasia in the cold knife conization specimen conferred an odds ratio of 12.1 (95% confidence interval 2.7 to 54.5) of identifying residual disease. Dysplasia involving the ectocervical margin, endocervical margin, and endocervical glands was not predictive of disease in the hysterectomy specimens. Endocervical curettage was not performed in 44% of the patients, preventing reliable statistical evaluation. Further analysis indicated that residual disease was found in 32% of the hysterectomy specimens with negative margins, in 31% with no endocervical gland involvement, and in 23% with a negative endocervical curettage sample. CONCLUSIONS: The presence or absence of dysplasia in the cold knife conization ectocervical margin, endocervical margin, and endocervical glands was not predictive of residual dysplasia in post-cold knife conization hysterectomy specimens. Increasing age and severity of disease in the cone specimen were the only factors that accurately predicted residual dysplasia. The traditional factors used to justify hysterectomy after cold knife conization may not be valid on the basis of these results.