| BackgroundThyroid cancer(TC)is one of the most common malignant tumors of the endocrine system.The incidence of TC has been increasing rapidly in recent decades all over the world.The most common type of TC is differentiated thyroid carcinoma(DTC),which is further divided into papillary thyroid carcinoma(PTC)and follicular thyroid carcinoma(FTC),of which the former accounts for more than 80%-85%.Surgery is the most reliable way to treat PTC.The purpose of surgery is to remove the lesions,reduce the tumor recurrence rate,and provide the basis for postoperative risk stratification and the conditions for subsequent iodine therapy,if necessary.In 2016,the American Thyroid Association(ATA)recommended total thyroidectomy for patients with tumors larger than 4cm in diameter,with severe extrathyroidal extension,central lymph nodes or distant metastasis;then,unilateral lobectomy or total thyroidectomy is acceptable for papillary carcinoma confined to a unilateral lobe if the lesion is less than 4cm in diameter and without lymph node or distant metastasis.Meanwhile,in recent years,many studies have reported the existence of contralateral occult papillary thyroid carcinoma(COPTC)not detected by preoperative imaging,especially in patients with unilateral thyroid cancer.The presence of contralateral occult papillary thyroid carcinoma is not uncommon.Obviously,unilateral lobectomy is not sufficient in these patients.Therefore,it is a topic worth exploring to identify patients with unilateral papillary thyroid cancer who should undergo bilateral total thyroidectomy for precise and individualized surgical treatment based on the reliable predictors of COPTC in patients with unilateral papillary thyroid cancer.ObjectiveBased on preoperative imaging,serological and clinicopathological indicators,to investigate the risk factors for contralateral occult papillary thyroid carcinoma in patients with clinical unilateral papillary thyroid carcinoma and evaluate their potency of prediction,providing the basis for refined and individualized treatment for related patients.MethodsTwo hundred and twenty-nine patients who underwent total thyroidectomy plus central lymph nodes dissection in The First Affiliated Hospital of Zhengzhou University from January 1,2019 to September 1,2021 were enrolled in this study.The sample size was determined after strict implementation of exclusion criteria,and patients with contralateral occult carcinoma were defined as the COPTC group and the remaining patients as the control group according to postoperative pathological results.The differences in clinicopathological and demographic characteristics between the two groups were analyzed,and the correlation between the indicators and contralateral occult papillary thyroid carcinoma was evaluated by univariate and multivariate binary logistic regression analysis.According to the regression results,the forest plot,and nomogram were drawn to visualize the respective and comprehensive prediction effectiveness of each predictor;then,the receiver operating characteristic curve(ROC),calibration curve,and decision curve analysis(DCA)were used to evaluate the prediction model.ResultsAmong 229 included thyroid cancer patients,postoperative pathology confirmed the presence of occult cancer foci on the opposite side of the primary lesion in 46 patients,accounting for 20.1%.Multifocality in one lobe(OR=2.21,95%CI=1.11-4.40,p=0.03),intact capsule(OR=2.54,95%CI=1.24-5.19,p=0.01),lymph node metastasis in the central region of the neck(OR=3.00,95%CI=1.21-7.49,p=0.02),and Hashimoto’s thyroiditis(OR=2.08,95%CI=1.02-4.23,p=0.04)were more likely to harbor occult papillary carcinoma in the contralateral thyroid gland.In the following ROC analysis,the area under the curve(AUC)was 0.701(95%CI=0.620-0.782,p<0.001),and the optimal cut-off value was 2.02 according to the Youden index.At this time,the sensitivity of the combined prediction of the four predictors was 78.3%and the specificity was 55.1%.In DCA,when the threshold probability of COPTC diagnosis was between nearly 0.1 and 0.6,the benefit curve of the model was significantly higher than the two reference lines.In the subgroup analysis of patients without Hashimoto’s thyroiditis,multivariate logistic regression analysis showed that there was still statistical differences in the correlation between multifocality in one lobe(OR=2.91,95%CI=1.16-7.31,p=0.02),intact capsule(OR=3.36,95%CI=1.29-8.75,p=0.01),central lymph node metastasis(OR=4.70,95%CI=1.02-21.60,p=0.04)and COPTC.Subsequently,the ROC curve and nomogram were drawn.The results showed that AUC was 0.721(95%CI=0.623-0.819,p<0.001)in the ROC curve and when the Youden index was 0.408,the model had the best cutoff value,with a sensitivity of 76.9%and specificity of 63.9%.ConclusionMultifocality in one lobe,intact capsule,central lymph nodes metastasis,and Hashimoto’s thyroiditis were independent predictors of contralateral occult papillary thyroid carcinoma,and the clinical risk prediction model based on these risk factors has sufficient predictive performance.As a result,for these patients,the choice of surgical options should be more careful.In addition,more preoperative clinical rather than postoperative pathological factors should be explored to guide the precise and individualized treatment of patients with unilateral papillary thyroid cancer,to reduce the recurrence rate and the likelihood of reoperations. |
PDF Full Text Request