The relationship between the extent of extrathyroidal extension and lymph node metastasis based on propensity score...

Extrathyroidal extension (ETE) and lymph node metastasis (LNM) are significant factors influencing the prognosis of papillary thyroid carcinoma (PTC). However, their relationship remains controversial. This study explores the connection between ETE and LNM by using propensity score matching (PSM) to guide individualized treatment.

A retrospective analysis was conducted on 1,045 PTC patients who underwent surgery between January 2023 and June 2024. PSM at a 1:1 ratio was used to balance confounding factors based on univariate and multivariate analyses to investigate the relationship between ETE and LNM.

Among the 1,045 patients, 55.8% had LNM, and 16.1% had ETE. Univariate analysis showed that male sex, age <45 years, tumor size ≥8 mm, ETE, and multifocal were associated with LNM (P<0.05). Multivariate analyses identified male sex, age <45 years, tumor size ≥8 mm, and multifocal as independent risk factors for LNM (P<0.05). After PSM in the present data set, the difference in LNM rates between ETE and non-ETE groups did not reach statistical significance (P>0.05). Similarly, the relationship between LNM and ETE was analyzed. Univariate analysis showed that age <45 years, tumor location, tumor diameter ≥8 mm, multifocal and LNM were risk factors for ETE (P<0.05). Multivariate analysis indicated that age <45 years, tumor located at the isthmus, tumor diameter ≥8 mm and LNM were independent risk factors for ETE (P<0.05). After PSM, no significant difference in ETE was found between patients with and without LNM (P>0.05).

In this single-center, retrospective PSM cohort, we did not observe a significant association between the extent of ETE and LNM in patients with PTC. ETE does not appear to be a reliable indicator for guiding the extent of lymph node dissection. For patients with concurrent ETE, the lymph node dissection range should be personalized.