Re: Cervical intraepithelial neoplasia outcomes after treatment: long-term follow-up from the British Columbia Cohort Study

Low recurrence rate of high-grade cervical intraepithelial neoplasia after successful excision and routine colposcopy during follow-up

The aim of the present cohort study was to assess the long-term (follow-up period up to 22 years) recurrence rate of preinvasive disease and the newly detected invasive disease rate in a cohort of women treated with excisional methods for high-grade cervical intraepithelial neoplasia (CIN).Women treated with large loop excision of the transformation zone (LLETZ) and cold knife conization (CKC) for histologically proven high-grade CIN were followed up for up to 22 years. Surgical specimens underwent histological examination and the status of endocervical as well as ectocervical margins was recorded. Follow-up protocol included conventional Pap test, colposcopy and pelvic examination at 3, 6, and 12 months after the initial treatment, and every 12 months thereafter, provided that the results were normal. In case of high-grade cytological findings and/or atypical colposcopic impression, multiple punch biopsies were taken in order to verify or exclude recurrent disease.In total, 804 women were followed for a mean time of 77.1 months (range: 6-266). LLETZ was used in 569 (70.7%) and CKC in 235 cases (29.2%). No woman developed invasive cervical cancer. Recurrent high-grade disease, developed in 9 women (1.1%, 95% confidence interval 0.5-2.2). Median treatment-to-recurrence time was 46.5 months (range: 6-235.3). One woman treated for squamous CIN2 on clear margins developed adenocarcinoma in situ 59.2 months post-treatment.Women having undergone excisional treatment for high-grade CIN indicate a very low risk for recurrent disease and potentially negligible risk for invasive cancer, provided that a strict and vigorous follow-up is offered after treatment.

Risk of cervical cancer after completed post-treatment follow-up of cervical intraepithelial neoplasia: population based cohort study

OBJECTIVE

To compare the risk of cervical cancer in women with histologically confirmed cervical intraepithelial neoplasia who returned to routine screening after having completed post-treatment follow-up with consecutive normal smear test results with women with a normal primary smear test result.

DESIGN

Population based cohort study using data from a nationwide pathology register.

SETTING

The Netherlands, 1994 to 2006.

POPULATION

38,956 women with histologically confirmed intraepithelial neoplasia grades 1 to 3 with completed follow-up after treatment.

INTERVENTION

Routine post-treatment follow-up of cervical intraepithelial neoplasia, recommending smear tests at six, 12, and 24 months.

MAIN OUTCOME MEASURE

Incidence of cervical cancer in the period from completed follow-up with negative test results after cervical intraepithelial neoplasia to the next primary test. 10-year hazard ratios were compared with periods after normal results for the primary smear test, adjusted for year in follow-up.

RESULTS

20 cervical cancers were diagnosed during 56,956 woman years after completed follow-up of cervical intraepithelial neoplasia, whereas 1613 cervical cancers were diagnosed during 25,020,697 woman years after a normal primary smear test result. The incidence of 35.1 (95% confidence interval 21.4 to 54.2) per 100,000 woman years and 6.4 (6.1 to 6.8) per 100,000 woman years, respectively, led to an adjusted hazard ratio of 4.2 (95% confidence interval 2.7 to 6.5) for periods after completed follow-up compared with periods after normal primary smear test results. This hazard ratio was increased for all ages. No significant difference in risk of cervical cancer was observed by grade of cervical intraepithelial neoplasia.

CONCLUSIONS

An excess risk of cervical cancer previously observed for women treated for cervical intraepithelial neoplasia was also observed in the subgroup of women who completed their post-treatment follow-up with three consecutive normal smear test results. The overall corrected risk of cervical cancer in these women was increased fourfold 35 cases per 100,000 woman years) compared with women with normal primary smear test results (6 per 100,000 woman years).