RISK OF RESIDUAL INVASIVE DISEASE IN WOMEN WITH MICROINVASIVE SQUAMOUS CANCER IN A CONIZATION SPECIMEN

Objective: To quantify the risk of residual invasion when cervical con ization reveals microinvasive squamous carcinoma and to determine whet her any factors affect this risk. Methods: We reviewed the charts and histopathology slides of 87 women who underwent a conization that cont ained microinvasive squamous carcinoma, followed by either a repeat co nization or hysterectomy. Depth of invasion, number of invasive foci, and status of the internal margin and post-conization endocervical cur ettage (ECC) were assessed. The findings were correlated with the pres ence of residual invasion. Results: Significant predictors of residual invasion included status of the internal margin (residual invasion pr esent in 22% of women with an involved margin versus 3% with a negativ e margin; P < .03) and the combined status of the internal margin and post-conization ECC (residual invasion in 4% of patients if both negat ive, 13% if one positive, and 33% if both positive; P < .015). Depth o f invasion and number of invasive foci in the conization specimen were not significant. The power of this study to detect a 25% difference i n the risk of residual invasion was 73% for depth of invasion and 75% for number of invasive foci. Conclusion: Women with microinvasive squa mous carcinoma in a conization specimen in which both the internal con ization margin and post-conization ECC are negative have a low risk of residual invasion and are candidates for follow-up or simple hysterec tomy. If either the internal margin or the post-conization ECC contain s dysplasia or carcinoma, the risk of residual invasion is high and wa rrants repeat conization before definitive treatment planning. (C) 199 7 by The American College of Obstetricians and Gynecologists.