Cold-knife conization versus loop electrosurgical excision for cervical adenocarcinoma in situ: a retrospective cohort study

The purpose of this study was to compare the efficacy of cold-knife conization (CKC) and loop electrosurgical excision procedure (LEEP) in treating cervical adenocarcinoma in situ (AIS) and identify relevant risk factors within a recent cohort from a tertiary hospital in China. We conducted a retrospective chart review of patients who underwent a conization procedure with a preoperative or postoperative diagnosis of AIS of the cervix from January 2021 to July 2024. Clinicopathological data and follow-up results were collected, with recurrence-free survival (RFS) as the primary endpoint. Among the 251 patients included, 161 (64.14%) underwent LEEP and 90 (35.86%) underwent CKC as primary treatment. Overall, 29.9% (75/251) underwent eventual hysterectomy. Median follow-up was 36 months. The positive margin rate was lower in the CKC group than in the LEEP group (16.7% vs. 31.7%, P < 0.001). Multivariate analysis showed that LEEP (aOR 2.28, 95% CI 1.13–4.58, P = 0.021), TZ type 2 or 3 (aOR 2.00, 95% CI 1.12–3.58, P = 0.019), and AIS with concurrent HSIL (aOR 2.07, 95% CI 1.13–3.78, P = 0.018) were independently associated with positive margins. Greater cone depth was associated with lower risk (per 1 mm increase: aOR 0.73, 95% CI 0.55–0.97, P = 0.031) when conization type was excluded due to collinearity. Among patients who underwent hysterectomy, positive conization margin was the only predictor of residual disease (aOR 9.12, 95% CI 1.07–77.8, P = 0.043). Kaplan–Meier analysis showed a significant difference in RFS among the three groups (P = 0.018), but pairwise comparison did not reveal a significant difference between the LEEP and CKC groups (P = 0.109). In this retrospective cohort, CKC achieved lower positive margin rates than LEEP for AIS. However, short-term RFS did not differ significantly between the two techniques, suggesting that margin status alone may not fully predict oncologic outcomes. Positive margin was a predictor of residual disease at hysterectomy, but this finding requires validation. For fertility-seeking patients, CKC is preferred to optimize margins, though LEEP may be acceptable when CKC is not feasible.