Objective:

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.
• Follow-up duration was limited to 3 years.
• Analysis conducted within a single health system.

Conclusion:

Sources:

• Annals of Internal Medicine