To evaluate whether surveillance can reduce unnecessary excisions in patients with cervical intraepithelial neoplasia grade 2 (CIN 2) without increasing short-term cancer or CIN 3+ risk.
Approach:
Study Design: Target trial emulation using electronic health record data from Kaiser Permanente Northern California, analyzing 12,012 patients diagnosed with CIN 2 between 2017 and 2023.
Treatment Definitions: Immediate treatment defined as excision within 6 months without interim surveillance; delayed treatment involved continued surveillance or excision at least 6 months after diagnosis.
Outcomes Measured: Primary outcomes included 3-year risks for invasive cervical cancer and CIN 3+; excision outcomes were also evaluated.
Key Findings:
3-year risk for cervical cancer was 0.39% with immediate treatment and 0.43% with delayed treatment.
3-year risk for CIN 3+ was 9% with immediate treatment and 10% with delayed treatment.
36% of immediate treatment patients had excision specimens showing less severe disease than CIN 2.
Estimated 3-year probability of potentially unnecessary excision was 8% for delayed treatment.
Interpretation:
Limitations:
Observational study design may introduce residual confounding.
Cancer outcomes were uncommon, limiting precision.
