Preoperative predictors of occult central lymph node metastasis in clinically node-negative papillary thyroid carcinoma: a common data model-based retrospective cohort study.

PURPOSE: In papillary thyroid carcinoma (PTC), central lymph node metastasis (CLNM) is frequently detected only after surgery, even when preoperative ultrasonography (USG) and CT show no suspicious lymph nodes. Identifying readily available clinical factors associated with occult CLNM may guide the decision for prophylactic central neck dissection in clinically node-negative (cN0) PTC. We investigated factors associated with CLNM using a Common Data Model (CDM)-based cohort. METHODS: Patients who underwent thyroid surgery for PTC between 2013 and 2022 and had no suspected nodal metastasis on preoperative USG or CT were included. Demographic and laboratory variables were extracted from the CDM database. Univariable and multivariable logistic regression analyses were performed to identify factors independently associated with CLNM. RESULTS: A total of 1,020 patients (246 males, 774 females) were included. The mean age was 50.1 ± 13.2 years. CLNM was identified in 313 patients (30.7%). On multivariable analysis, male sex (adjusted odds ratio [aOR], 1.548; 95% confidence interval [CI], 1.138-2.106; P = 0.005) was independently associated with CLNM, whereas age ≥55 years was inversely associated (aOR, 0.687; 95% CI, 0.515-0.915; P = 0.010). Compared with tumors ≤1 cm, tumor size 1-2 cm (aOR, 2.231; 95% CI, 1.649-3.018; P < 0.001) and >2 cm (aOR, 2.739; 95% CI, 1.711-4.383; P < 0.001) were associated with higher odds of CLNM. CONCLUSION: In cN0 PTC, male sex, younger age, and larger tumor size were independently associated with occult CLNM. These factors may help identify patients who warrant closer consideration for central neck management despite negative preoperative imaging.