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

Abstract

Introduction. Papillary thyroid cancer (PTC) is one of the most prevalent endocrine malignancies that has increased in recent decades around the world. Although the indicator for navigating the surgical extent in PTC patients is still in debate, a key issue is how to predict that there are undetected preoperative tumors in the contralateral thyroid lobe. This study aims to find risk factors for contralateral occult papillary thyroid cancer (COPTC) to facilitate more accurate surgical decisions made for patients with PTC. Materials and Methods. In our study, we included 229 patients who underwent total thyroidectomy plus central and ipsilateral lateral lymph nodes dissection from January 1, 2019, to September 1, 2021. Univariate and multivariate logistic regression analyses were conducted to assess the association between COPTC and clinical-pathological characteristics, as well as the relation between the diameter of the occult lesions and predictors. The forest plot was plotted to visualize the prediction factors from the output of the multivariate regression analysis. A ROC curve was used to evaluate the combining potency of all the risk factors. Results. Of the 229 patients included in our study, 46 with COPTC were assigned to the case group, representing 20.1% in this study. Multifocality in one lobe (OR = 2.21, P = 0.03 ), intact capsule (OR = 2.54, P = 0.01 ), central lymph node metastasis (OR = 3.00, P = 0.02 ), and Hashimoto’s thyroiditis (OR = 2.08, P = 0.04) are more prone to present contralateral occult papillary thyroid carcinoma. The ROC curve of the aggregate potency of the risk factors presents AUC = 0.701 ( P < 0.001 ), and the best cutoff value was 2.02, with a sensitivity of 78.3% and specificity of 55.2%. Furthermore, there was no statistical correlation between the diameter of the occult tumor and the four obtained variables. Conclusion. Patients with multifocality in one lobe, intact capsule, central lymph node metastasis, and HT may harbor contralateral papillary thyroid carcinoma. It is essential to be prudent to make a surgical or follow-up decision on these patients. In addition, more clinical rather than postoperative pathological indicators need to be revealed in the future.

Pathological multifocality is not a prognosis factor of papillary thyroid carcinoma: a single-center, retrospective study

“…In the guideline of the American Thyroid Association published in 2015, CTx is recommended for multifocal PTC treated with non-TTx to achieve complete resection of multifocal disease and to allow for efficient RAI therapy [ 3 ]. Pathologically multifocal PTC in the unilateral lobe increases the possibility of clinically undetected PTC in the remnant thyroid [ 7 , 8 , 10 – 16 ]. Some studies have reported that lymph node metastasis is more often observed in multifocal PTC than in unifocal PTC, although none of them distinguished cN and pN [ 26 – 31 ].…”

“…In such cases, PTC not detected clinically might be left in the remaining thyroid tissue. Multifocality in the ipsilateral lobe is a risk factor of cancer presence in the opposite lobe that the rate accounts for 16.7–58% [ 7 – 16 ]. The European Society of Endocrine Surgeons recommends total or near-total thyroidectomy for apparent multifocal PTC as the initial treatment to reduce local recurrence risk [ 6 ].…”