Prediction For Occult Carcinoma In Patients With Unilateral PTMC And Contralateral Nodules:A Meta-analysis

Objective:In this study,we aimed to define clinical factors that could be indicators for malignancy in nodules in the contralateral thyroid lobe,which could aid the clinician in selecting the appropriate operation approach.Methods:The literatures published from January 2000 to December 2018 were systematic searched in PubMed?Cochrane Library?Embase?CBM?CNKI and WanFang database(up to the date of December,2018),included the literatures related to risk factors for unilateral PTMC complicated with contralateral lobar nodules,evaluated their methodological quality and extracted data.The odds ratio(OR)and95%CI were used to describe the screened binary variable data(RevMan 5.3).Heterogeneity among studies was tested by Q and I~2 test;publication bias was detected by Harbord method(Stata 14.0 software).The overall occult carcinoma rate of the contralateral nodules in literature was calculated by Meta analysis of a single rate.Results:A total of 2541 literatures were searched,10 literatures were finally included in this study,a total of 2042 patients with unilateral PTMC and contralateral benign nodules were enrolled,513 patients were confirmed to have malignancy in the contralateral lobe.The results of random effect model Meta analysis showed that the occult carcinoma rate of contralateral benign nodules in patients with unilateral PTMC was 0.24(95%CI:0.22-0.26).Meta-analysis showed that the OR and 95%CI of age,gender,primary lesion size,ipsilateral central lymph node metastasis and multifocal contralateral thyroid lobe were 0.98[0.77,1.25]?0.98[0.74,1.31]?1.31[0.88,1.95]?1.25[0.96,1.62],1.77[0.94,3.33],respectively.Z test showed that there were no statistical differences(P>0.05).While the OR and 95%CI of multifocal primary carcinomas involvement,capsular invasion and Hashimoto's thyroiditis were 4.25[2.88,6.28]?1.55[1.13,2.11]?1.56[1.18,2.06],respectively.Z test showed that there were statistical differences,suggested that multifocal primary carcinomas involvement,capsular invasion and Hashimoto's thyroiditis predicted a high incidence of occult contralateral carcinoma.Conclusions:According to our findings,the rate at which contralateral carcinomas are preoperatively misdiagnosed as benign is 24.0%.The risk factors of occult contralateral carcinoma include multifocal primary carcinomas involvement,capsular invasion and Hashimoto's thyroiditis.When frozen section examination shows the above risk factors,comply with the principle of individualized treatment,further total/subtotal thyroidectomy should be considered to avoid misdiagnosis as much as possible.