Risk of cervical intraepithelial neoplasia 2+ among women with a history of previous treatment for cervical intraepithelial neoplasia: ASCUS and LSIL Pap smears after treatment.

Objective: The objective of the current study was to describe outcomes among women with low-grade abnormalities on cervical cytology screening in the setting of previous excisional or ablative treatment for cervical intraepithelial neoplasia (CIN).

Methods: Study participants were recruited into the Study to Understand Cervical Cancer Early Endpoints and Determinants. At enrollment, the patient's previous cytology results, previous colposcopic biopsy results, and previous cervical procedures were recorded. Study procedures included collection of biospecimens followed by colposcopy and biopsy. From clinical records, additional information regarding previous treatment for CIN was collected.

Results: Two hundred seventy-four women had an atypical squamous cells of uncertain significance (ASCUS) referral Pap and 532 women had a low-grade squamous intraepithelial lesion (LSIL) referral Pap. For patients with an ASCUS referral Pap, previous treatment was associated with an odds ratio for CIN 2+ (45.0% vs 28.2% of untreated patients) of 2.08 (95% confidence interval = 1.05-4.13, p = .04). For patients with an LSIL referral Pap, 33.3% of those women with previous treatment had CIN 2+ compared with 16.7% of those patients enrolled with no previous treatment (odds ratio = 2.49, 95% confidence interval = 1.12-5.51, p = .03).

Conclusions: Patients with a history of previous treatment for CIN have a 2-fold risk of CIN 2+ at the time of colposcopy referral for ASCUS or LSIL cervical cytology.