- Title
- The Importance of Evaluating the Lateral Neck in Patients with Papillary Thyroid Microcarcinomas
- Creator
- Rowe, Christopher W.; O'Neill, Christine J.
- Relation
- Clinical Thyroidology® Vol. 35, Issue 10, p. 429-431
- Publisher Link
- http://dx.doi.org/10.1089/ct.2023;35.429-431
- Publisher
- Mary Ann Liebert
- Resource Type
- journal article
- Date
- 2023
- Description
- Background: Papillary thyroid carcinomas less than 10 mm in size are referred to as microcarcinomas (PTMCs) and are common, particularly with increasing age. Most PTMCs are considered indolent and are managed with either active surveillance or limited surgery (i.e., hemithyroidectomy), and they may be considered for early discharge from follow-up with a specialist. However, a subgroup of PTMCs can metastasize and recur, and patients with these PTMCs may benefit from more intensive management. Identifying higher-risk PTMC patients at the time of diagnosis is important in order to allow appropriate treatment and follow-up. Methods: Ruan and colleagues report a retrospective surgical series of 5241 patients with PTMC from China between 1997 and 2016 (1). The methods do not explicitly state that PTMC was identified preoperatively, although this appears likely, as most (if not all) patients in this series underwent routine central neck dissection as per Chinese guidelines for thyroid cancer. Although lateral lymph node metastases were identified in 130 patients, it is unclear how many patients underwent lateral neck dissection or how they were selected. Aggressive histologic subtypes (e.g., tall-cell, hobnail, and other variants) and patients with less than 1 year of follow-up were excluded, but the number of patients who met these criteria was not given. Patients were monitored for disease recurrence using serum thyroglobulin levels and neck ultrasonography. Nodal recurrences were confirmed either pathologically or by a positive radioiodine (I-131) whole-body scan. The aim of the study was to evaluate the association between AJCC TNM N1b disease (lateral neck lymph node metastases) in patients with PTMC and future risk of recurrence and to identify factors predictive of N1b metastases at the time of initial surgery. Results: This PTMC cohort was predominantly female (76%) and young (79% were less than 55 years of age), and the mean (±SD) tumor size was 0.58±0.26 cm. Nodal metastases were present in the central neck (AJCC TNM N1a disease) in 26% cases and in the lateral neck (N1b disease) in 2.5% of cases. There were 3.6% cases with a T3/T4 primary tumor due to gross extrathyroidal extension. Median postoperative follow-up was 60 months (interquartile range, 44–81). During follow-up, recurrence occurred in 114 of 5241 (2.2%) patients. Sites of recurrence were the thyroid bed (n = 41), lymph nodes (n = 69) and distant sites (n = 3). There were 24 patients who died; one of these deaths was associated with PTMC (0.05%). The 5-year disease-free survival, stratified by initial nodal status, was 98.9% for N0/Nx (no lymph node metastases), 96% for N1a, and 87% for N1b. In multivariate analysis, the presence of nodal metastases at initial surgery was the only significant predictor of recurrence. The odds ratio for any recurrence following initial N1a disease was 3.0 (95% CI, 2.0–4.6; P<0.001) and 11.1 following initial N1b disease (95% CI, 6.3–19.8; P<0.001). Age, sex, tumor size, multifocality, and gross extrathyroidal extension were not significantly associated with recurrence risk. The risk of initial N1b disease was associated with increasing tumor size, multifocality and bilaterality, gross extrathyroidal extension, and N1a disease in multivariate analysis. Age and sex were not significant associations. The strongest association with initial N1b disease was N1a disease (odds ratio, 5.1; 95% CI, 3.4–7.7; P<0.001). There was a linear relationship between the number of involved central compartment lymph nodes and the risk of N1b disease, with a dichotomized threshold of ≤5 central compartment nodes identifying a lower-risk cohort (4.2% vs. >23.7% risk of incident N1b disease). Conclusions: A small number of PTMCs may recur, and the presence of involved lymph nodes at diagnosis is a predictive factor. In this study, the presence of N1b disease at diagnosis was the strongest predictor of future recurrence. However, N1a disease, especially with >5 involved N1a nodes, was also predictive.
- Subject
- papillary thyroid carcinomas; patients; disease; treatment
- Identifier
- http://hdl.handle.net/1959.13/1505973
- Identifier
- uon:55798
- Identifier
- ISSN:2329-9711
- Language
- eng
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