Elsevier

Obstetrics & Gynecology

Volume 92, Issue 5, November 1998, Pages 737-744
Obstetrics & Gynecology

Original Articles
A randomized clinical trial of cryotherapy, laser vaporization, and loop electrosurgical excision for treatment of squamous intraepithelial lesions of the cervix

https://doi.org/10.1016/S0029-7844(98)00246-4Get rights and content

Abstract

Objective: To compare cryotherapy, laser vaporization, and loop electrical excision for treatment of squamous intraepithelial lesions (SILs).

Methods: Women at least 18 years old with biopsy-proven SIL, negative pregnancy tests, negative findings on endocervical curettage, satisfactory colposcopy examinations, and congruent Papanicolaou smear and biopsy results were assigned randomly to treatment after stratification by SIL grade, endocervical gland involvement, and lesion size; they were evaluated 1, 4, 8, 12, 16, 20, and 24 months after treatment. Data were analyzed using χ2 statistics, logistic regression analysis, and the Cox proportional hazards model.

Results: Of 498 patients assigned, 108 were excluded (most because of inadequate follow-up), leaving 390 (139 cryotherapy, 121 laser vaporization, 130 loop excision) for analysis. All were followed 6–37 months (mean 16). There were no statistically significant differences in complications, persistence (disease present less than 6 months after treatment), or recurrence (disease present more than 6 months after treatment). Risk of persistent disease was higher among women with large lesions (risk ratio [RR], 18.9; 95% confidence interval [CI], 3.2, 110.6). Recurrence risk was higher among women aged 30 years and older (RR, 2.1; 95% CI, 1.2, 4.3), those with human papillomavirus type 16 or 18 (RR, 2.1; 95% CI, 1.1, 4.0), and those who had had prior treatment (RR, 2.1; 95% CI, 1.1, 3.9).

Conclusion: The data support a high success rate with all three modalities. No significant difference in success rates was observed between the three treatments in our population. Additional attention and research should be directed toward the higher risk patients identified above.

Section snippets

Study protocol

The study population was drawn from women referred to the University of Texas M. D. Anderson Cancer Center Colposcopy Clinic with the diagnosis of SIL, then called cervical intraepithelial neoplasia (CIN), between March 1992 and April 1994. Patients were eligible if they 1) were at least 18 years of age, 2) were using contraception, 3) had a negative pregnancy test, 4) had a biopsy-proven CIN lesion, 5) had negative findings on endocervical curettage, 6) had a satisfactory colposcopy

Results

Four hundred ninety-eight patients were assigned randomly to receive one of the three treatments. A total of 108 were excluded from analysis (four because they did not present for treatment, one because of other illness, one because of physician error in assignment, and 102 because they did not complete 4 months of follow-up), leaving 390 patients for analysis (139 cryotherapy, 121 laser vaporization, 130 loop electrosurgical excision procedure). No differences in age (P = .88) or grade (P =

Discussion

Previous nonrandomized and randomized studies of these treatments in the literature were not stratified by prognostic variables; thus, differences in these variables could have accounted for differences in failure rates. The case series that have reported on patients treated with these modalities have high dropout rates, and none were analyzed using statistical methods accounting for the amount of time patients were followed. The nonrandomized and randomized studies have short follow-up (Table

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The authors thank Robert Barr, MD, for helpful comments and the Business and Professional Women’s Association of Houston, Texas, for financial support.

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