Aggressiveness Of Papillary Thyroid Cancer With Peripheral Nerve Invasion And Its Therapeutic Efficacy With Radioactive Iodine:A Propensity Scorematching Study

ObjectivesTo analyze the invasiveness of papillary thyroid cancer(PTC)with peripheral nerve invasion(PNI).To investigate the short-term and long-term efficacy of radioiodine therapy(RAI)for PTC with PNI.Materials and MethodsPatients with PTC who were treated with radioactive iodine(RAI)for the first time in the Department of Nuclear Medicine,Zhujiang Hospital of Southern Medical University from January 2016 to November 2017 were retrospectively analyzed.All of these patients underwent total or near-total thyroidectomy.Patients were divided into two groups according to the presence or not of invasive characteristics.Logistic regression analysis was used to determine the relationship between the clinicopathological features and the invasiveness of PTC.The efficacy evaluation of RAI therapy for PTC included short-term efficacy one year after RAI therapy and long-term efficacy of disease persistence/progression survival.Logistic regression analysis was used to determine the relationship between clinicopathological factors and short-term efficacy.Survival analysis and Cox regression analysis were used to determine the difference in survival between PNI group and non-perineural invasion(nPNI)group,as well as the influence of clinicopathological factors on the long-term efficacy.After propensity scorematching method(PSM)was used to equalize the data bias,then the above steps were repeated to further clarify the impact of PNI on the efficacy of PTC.ResultsIn this study,991 patients with PTC were included for invasive evaluation,there are 79(8.0%)PNI-positive patients.Compared with nPNI group,Patients with PNI had higher TNM stage,recurrence risk stratification and clinical stage,and extradular invasion,vascular cancer thrombus and more lymph node metastasis were observed more patient distribution.After adjusting for age,sex,pathological subtypes,PNI,pathological subtypes,and vascular cancer thrombus,we found atypical(OR=7.420,95%CI:2.263-24.326,P=0.003),PNI(OR=5.257,95%CI:2.375-11.636,P=0.000)and vascular cancer thrombus(OR=2.366,95%CI:1.381-4.054,P=0.002)was higher risk factors for PTC invasiveness,and female was a protective factor for PTC invasiveness(OR=0.037,95%CI:0.544-0.981,P=0.002).Efficacy was assessed in 842 patients with a median follow-up of 57 months.PNI was at significantly greater risk for PTC persistence/progression than nPNI before propensity scorematching(P=0.000).Besides,male,higher recurrence risk stratification,vascular cancer thrombus and more lymph node metastases were the influencing factors of poor long-term efficacy,while higher N stage,clinical stage and more lymph node metastases were the influencing factors of poor short-term efficacy.Although PNI was positively correlated with poor short-term efficacy and long-term efficacy,the effect was not significant.According to PSM method,63 cases were matched in PNI group and nPNI group respectively.After efficacy analysis of the PSM,it was found that there was no difference in persistence/progression survival between PNI and nPNI group(P=0.88),which was still not an independent factor of short-term and long-term efficacy,while male patients were significantly associated with worse short-term and long-term efficacy.ConclusionPeripheral nerve invasion was a predictor of higher aggressive disease status at the time of assessment,but was not independent predictor factor of short-term or long-term outcome.