Clinical and Ultrasonic Risk Factors for Lateral Lymph Node Metastasis in Papillary Thyroid Microcarcinoma: A Systematic Review and Meta-Analysis

Abstract

Background: Clinical and ultrasonic risk factors for lateral lymph node metastasis (LLNM) in papillary thyroid microcarcinoma (PTMC) are not well-defined. Herein, a systematic review and meta-analysis was conducted to investigate clinicopathologic and ultrasonic risk features for LLNM in PTMC. Methods: A systematic search of electronic databases (PubMed, Embase, Cochrane Library, and Web of Science) for studies published until April 2019 was performed. Case-control studies and randomized controlled trials that studied clinical and ultrasonic risk factors of LLNM in PTMC were included. Results: Fourteen studies (all retrospective studies) involving 43,750 patients met final inclusion criteria. From the pooled analyses, younger age<45 (OR, 1.

Bilateral multifocality, a marker for aggressive disease, is not an independent prognostic factor for papillary thyroid microcarcinoma: A propensity score matching analysis

“…However, it is necessary to investigate the clinical and prognostic implications of multifocality on PTMC, based on the consensus that PTMC has different genetic characteristics, 21 biological behaviour and corresponding clinical management compared with PTC 10,11 . In fact, some studies have focused on the role of multifocality and its bilaterality in the aggression and prognosis of PTMC 7,8,12,13,16,17 . However, some confounding factors, such as sample selection bias and poor matching of baseline characteristics, affect the reliability of the results.…”

“…In this PTMC cohort, several baseline factors were different between the MFD and UFD groups. These factors and BRAF V600E mutations have been considered to be related to tumour aggression 6,8,12,22 . Thus, there are obvious confounding factors or biases in analysing whether multifocality affects the invasive behaviour of PTMC.…”

“…The American Thyroid Association (ATA) guideline included multifocal PTMC without ETE in the low‐risk category, while ETE was included in the intermediate‐risk category 11 . However, recent studies have shown that multifocality is associated with aggressive progression of the disease (ETE and/or LNM) and impacts the prognosis 7,8,12,13 . Several studies on PTMC and papillary thyroid carcinoma (PTC) have shown that bilateral multifocality accounted for the majority of multifocal cases, 8,9,14,15 and it was an independent predictor for LNM and should be treated aggressively 16,17 .…”

“…11 However, recent studies have shown that multifocality is associated with aggressive progression of the disease (ETE and/or LNM) and impacts the prognosis. 7,8,12,13 Several studies on PTMC and papillary thyroid carcinoma (PTC) have shown that bilateral multifocality accounted for the majority of multifocal cases, 8,9,14,15 and it was an independent predictor for LNM and should be treated aggressively. 16,17 In addition, one study suggested that patients with bilateral multifocality had more aggressive features and shorter disease-free survival than patients with PTC and unilateral multifocality.…”

A Nomogram Predicting Central Lymph Node Metastasis for Patients with Papillary Thyroid Cancer

“…Despite a favorable long-term prognosis 4,5 , a minority of patients with central lymph node metastasis (CLNM) and even lateral lymph node metastasis (LLNM) showed relatively poor prognosis 6 . Currently, great achievements have been made in a range of works in determining the risk factors in the progression of PTC [7][8][9] . Especially, many clinical characteristics including but not limited to the male gender, younger age, larger tumor size, multifocal lesions, and extracapsular spread were regarded as the independent risk factors involving in the lymph node metastasis of PTC.…”