Influence of tumor extent on central lymph node metastasis in solitary papillary thyroid microcarcinomas: a retrospective study of 1092 patients

Abstract

BackgroundThe morbidity of papillary thyroid microcarcinomas is increasing worldwide. Surgery is the main treatment for papillary thyroid microcarcinomas, and the choice of surgical method partly depends on the T stage of the tumor. However, according to the American Joint Commission on Cancer staging system (7th edition), the T stage of papillary thyroid microcarcinomas with different tumor extent is unclear. We aimed to study the effect of tumor extent and other factors on central lymph node metastasis to explore the relationship between tumor extent and T stage and to identify the risk factors predicting central lymph node metastasis in papillary thyroid microcarcinomas.MethodsWe included 1092 patients diagnosed with solitary papillary thyroid microcarcinomas between July 2011 and April 2016. The tumor extent and other central lymph node metastasis risk factors were retrospectively analyzed.ResultsUnivariate analysis revealed that capsule invasion and extracapsular extension (P = 0.013, <0.001; respectively) were significantly correlated with central lymph node metastasis. On multivariate analysis, extracapsular extension was independent central lymph node metastasis predictors (odds ratio 3.092, 95% CI 1.744–5.484), while capsule invasion was not (odds ratio 1.212, 95% CI 0.890–1.651). In addition, multivariate analysis revealed that male sex, tumor size >5 mm, and age <45 years were independent central lymph node metastasis predictors (odds ratio 2.072, 2.356, 2.302; 95% CI 1.483–2.894, 1.792–3.099, 1.748–3.031; respectively).ConclusionsThis study supported that capsule invasion and tumor limited to the thyroid in papillary thyroid microcarcinomas were suitable for the lower T1, that is, capsule invasion in papillary thyroid microcarcinomas might not belong to the minimal extrathyroid extension included in T3 of TNM staging. In addition, patients with risk factors of extrathyroid extension, male sex, age <45 years, or tumor size >5 mm in papillary thyroid microcarcinomas should consider a more aggressive surgical treatment.

Clinical and ultrasonographic features of medullary thyroid microcarcinomas compared with papillary thyroid microcarcinomas: a retrospective analysis

“…Our results showed that there was significantly different in lymph node metastases between MTMCs group and PTMCs group. In PTMCs group, 21 (20.19%) patients had lymph node metastases, the incidence of which was similar to those in previous reports [14][15][16]. MTMCs were more likely to have lymph node metastases, which indicated the strong invasive characteristics of MTCs.…”

Clinical and ultrasonographic features of medullary thyroid microcarcinomas compared with papillary thyroid microcarcinomas: a retrospective analysis

“…Our results showed that there was a significant difference in lymph node metastases between the MTMC group and the PTMC group. In the PTMC group, 21 (20.19%) patients had lymph node metastases, which is similar to the incidence in previous reports [14][15][16]. MTMC patients were more likely to have lymph node metastases, which indicates the strong invasive characteristics of MTCs.…”

Risk factors for cervical lymph node metastasis in papillary thyroid microcarcinoma: a study of 1,587 patients

“…In this retrospective study, we evaluated the risk factors for CLNM and LLNM in 1,587 patients with PTMC. In previous reports, the prevalence of CLNM ranged from 24.1% to 64.1% [2][3][4][5] , and that for LLNM ranged from 3.7% to 44.5% 2 . In the present study, the prevalence of CLNM and LLNM was 30.9% (491 of 1,587) and 4.6% (73 of 1,587), respectively.…”

“…Although PTMC has an indolent course, many cases have demonstrated highly aggressive clinical features, such as extrathyroidal extension and cervical lymph node metastasis. The incidences of central lymph node metastasis (CLNM) (24.1%-64.1%) [2][3][4][5] and lateral lymph node metastasis (LLNM) (3.7%-44.5%) 2 for PTMC are comparable with those of PTC.…”