Risks of central lymph node metastasis in papillary thyroid carcinoma with or without multifocality in at least one lobe: A multi-center analysis

Abstract

Purposes: To quantitatively predict central lymph node metastasis (CLNM) risks by comparing the clinicopathological features of different multifocal manifestations in papillary thyroid carcinomas (PTC) patients.

Methods: A total of 998 PTC patients from three medical centers were retrospectively analyzed.

Results: PTC patients with multifocal lesions in at least one thyroid lobe (MF group) yielded significantly higher CLNM rates than those with unifocal lesions in one or both lobes (UF group). Multifocality in at least one lobe rather than bilateral presence was confirmed to be an independent risk factor of CLNM for PTC patients. Four (age, gender, maximum tumor diameter, and thyroid capsular invasion (TCI)) and three (age, gender, and TCI) factors were proven to be independent risk factors of CLNM for patients within UF and MF groups, respectively. Predictive nomograms were established for these patients based on their respective high-risk factors. The accuracy and validity of these newly-created models were verified using C-index and calibration curves. Patients within UF and MF groups possessing significantly different CLNM risks based on individualized nomogram risk scores were further classified into different subgroups. A detailed CLNM risk stratification flow chart covering all PTC patients was then established.

Conclusion: A meticulous evaluating system that quantifiesCLNM risk for PTC patients with unifocal lesions in one or both lobes and multifocal lesions in at least one lobe was established.

Keywords: Bilaterality; Central lymph node metastasis; Multifocality; Papillary thyroid carcinoma; Risk stratification.