Risk Factors for Contralateral Occult Carcinoma in Patients With Unilateral Papillary Thyroid Carcinoma: A Retrospective Study and Meta-Analysis

Abstract

BackgroundBilateral lesions are common in papillary thyroid carcinoma (PTC). For patients with unilateral PTC, occult carcinoma that is not detected preoperatively, but pathologically after surgery, might remain in the contralateral lobe. In this situation, inadequate surgical extent could cause relapse and even lead to re-operation. Here, we explore the frequency and investigate the risk factors of contralateral occult PTC in unilateral PTC through a retrospective study conducted by our team and published articles online, respectively.MethodsWe collected the patients’ clinical data in our hospital, whose cancer was determined to be confined to the unilateral lobe by preoperative image examination (N = 204). These patients underwent initially total or near-total thyroidectomy and included their clinical data in the meta-analysis. We searched related literature in the PubMed, Embase, MEDLINE, Cochrane, and Web of Science databases until December 7, 2020, in order to perform a meta-analysis. The relevant articles were examined and the eligible studies were included to assess the association between clinicopathologic factors and contralateral occult PTC.ResultsThe meta-analysis included nine studies (involving 4347 patients). Of these, eight studies were from the databases, and one study was our retrospective data. The meta-analysis showed that the prevalence of contralateral occult PTC was 26.6% in all patients. A tumor size > 1 cm, ipsilateral multifocality, contralateral benign nodule, and central lymph node metastasis were significantly associated with contralateral occult PTC. In contrast, sex, age, ETE, capsular invasion, BRAF mutation, Hashimoto thyroiditis, and lateral lymph node metastasis were insignificantly associated with contralateral occult PTC.ConclusionThe meta-analysis identified a tumor size > 1 cm, ipsilateral multifocality, contralateral benign nodule, and CLNM as being significant risk factors for contralateral occult PTC. These findings may guide the extent of surgery in unilateral PTC patients.

Risk Factors for Contralateral Occult Papillary Thyroid Carcinoma in Patients with Clinical Unilateral Papillary Thyroid Carcinoma: A Case-Control Study

“…Previous studies showed that encapsulation was correlated with multifocality and CNM [ 16 , 33 , 34 ]; therefore, we established a linear regression model based on these three variables to eliminate collinearity (VIF = 1.006 and 1.009, respectively). Furthermore, there were also studies [ 14 , 25 , 27 ] , showing that capsular invasion was related to COPTC, which is contrary to our conclusion. That is interesting because some scholars defined multifocality as PTC with intrathyroidal extension with a hypothesis considering that the multiple foci result from a single primary lesion via intrathyroidal lymphatics [ 15 ].…”

“…In our study, the incidence of contralateral occult thyroid cancer is 20.1%. We found that multifocality of the ipsilateral lobe was an independent risk factor of the presence of COPTC in unilateral clinical PTC, meeting the same conclusion from some studies [25][26][27][28]. However, dissimilar to several previous studies [14,26], we excluded all the patients with contralateral nodules indicated by preoperative ultrasound, even those with TI-RADS < 3, for the reason of the limitation of the US to differentiate malignancies from benign nodules [29], which may lead to bias, and patients with occult contralateral benign nodules confirmed by postoperative pathology were assigned to control group.…”

Bilateral follicular variant of papillary thyroid cancer with different RAS mutations detected with next‐generation sequencing: Report of an unusual case and literature review

“…Papillary thyroid carcinoma (PTC) accounts for approximately 80%–90% of all thyroid malignancies 1 . PTC often presents with two or more anatomically separate foci, with the prevalence of multifocality ranging from 18%–87%, 2–4 in most cases as microscopic disseminations discovered during examination of the surgical pathology sample. Bilaterality―a specific subtype of multifocality―is discovered in 13%–56% of thyroidectomy specimens 5,6 …”

Integrating BRAFV600E mutation, ultrasonic and clinicopathologic characteristics for predicting the risk of cervical central lymph node metastasis in papillary thyroid carcinoma

“…Hashimoto’s thyroiditis was identified as a negatively predictive factor by multivariate logistic analysis. Tumor size is a critical factor estimated for the biological features of PTC, because tumor size can be readily obtained by preoperative US examination [ 32 ]. Malignant-looking PTC was more prevalence with extrathyroidal extension, cervical CLNM, and advanced stage than benign-looking PTC, especially when tumor diameter more than 10 mm [ 33 ].…”