The extent of extranodal extension as a prognostic indicator in papillary thyroid cancer

Extranodal extension (ENE) is acknowledged as a significant prognostic factor associated with recurrence, distant metastasis, and reduced disease-specific survival in patients with papillary thyroid carcinoma. However, the impact of the extent of extranodal extension on the clinical outcomes of these patients remains insufficiently understood. This study aimed to estimate the risk of detecting distant metastasis in patients with varying degrees of ENE according to a novel stratification method.

This retrospective study utilizes medical records and slide reviews of papillary thyroid cancer patients who underwent therapeutic neck dissection. A new stratification system was developed, based on the circumferential rupture of the lymph node capsule. It is defined as Focal ENE when less than one-third of the lymph node capsule is ruptured and as Diffuse ENE when one-third or more of the capsule is involved.

Eighty-nine patients participated in the study, with 19% diagnosed with distant metastasis within a 96-month follow-up period. The presence of diffuse extranodal extension was associated with a risk approximately six times higher than in patients without ENE for the detection of distant metastasis at 96 months, after adjustment for age group (HR = 6.41; 95% CI: 1.7-23.8; p = 0.006).

A greater extent of extranodal extension is linked to a heightened risk of detecting distant metastasis and should thus be considered in the therapeutic decision-making process.