Correlation Between Serum Calcitonin And Clinicopathological Characteristics And Prognosis Of Medullary Thyroid Carcinoma

Objective: To explore the correlation between serum calcitonin（Ctn）and the clinicopathological characteristics and prognosis of medullary thyroid carcinoma（MTC）,in order to further improve the diagnosis and treatment of MTC and the prognostic evaluation system,for the precise chemical diagnosis and treatment of MTC Provide theoretical basis.Methods: A total of 92 MTC patients who underwent surgical treatment and calcitonin monitoring in the thyroid surgery department of the China-Japanese Union Hospital of Jilin University from June 2008 to June 2020 were collected.Retrospective analysis of its clinicopathological characteristics and prognostic data.Through Mann-Whitney U,Kruskal-Wallis H,and Chi-square test,it was single-factor analysis,and the correlation between Ctn and MTC was analyzed by establishing multiple linear regression model and logistic regression model.Result:（1）Correlation analysis of preoperative serum Ctn,CEA and clinicopathological characteristics of MTC patients: The higher the preoperative serum Ctn and CEA,the larger the tumor diameter（P < 0.001）and the more likely to have lateral cervical lymph node metastasis（P < 0.001）,and spearman correlation analysis proved that preoperative serum Ctn were positively correlated with MTC tumor burden.Similarly,preoperative serum CEA levels showed similar correlations with tumor burden and lymph node metastasis.By drawing the ROC curve,the preoperative serum Ctn cut-point value for predicting cervical lymph node metastasis in MTC patients was 45.88 pg/ml,the area under the curve was 0.760,the sensitivity was 85.1%,and the specificity was 47.3%.The optimal preoperative serum Ctn cut-point value for predicting lateral cervical lymph node metastasis in MTC patients was 167 pg/m L,the area under the curve was 0.842,the sensitivity was85.3%,and the specificity was 77.6%.（2）Correlation analysis of postoperative serum Ctn prognosis Based on the dynamic changes of postoperative serum calcitonin,this study divided patients into remission group,stable group and progress group.By the K-M curve,the results proved: Compared with the remission group and the stable group,MTC patients in the progression group were more likely to relapse（P <0.001）.The line chart of postoperative serum Ctn changes in MTC patients in the progressive group showed that.It was found that the serum Ctn level of most patients remained stable within 12 months after surgery,but a sudden increase occurred during 12-36 months after surgery.（3）Correlation between preoperative serum Ctn and postoperative serum Ctn progression Univariate analysis found that patients with multiple cancer foci（P = 0.025）,bilateral cancer foci（P = 0.008）,and high TNM stage（P < 0.001）were more likely to develop postoperative serum Ctn levels.The higher the preoperative serum Ctn level（P < 0.001）and the higher the CEA level（P = 0.05）,the greater the possibility of the patient’s postoperative Ctn level progression.Multivariate logistic analysis showed that TNM staging and preoperative serum Ctn level were independent factors influencing the progression of postoperative serum Ctn.The risk of postoperative serum Ctn progression in patients with TNM III stage was 9.7 times higher than that of patients with TNMI/II stage（P = 0.021）.For every increase of preoperative serum Ctn by 1 unit,the risk of postoperative serum Ctn progression increased by 1.004 times（P = 0.008）.Conclusion: 1.Preoperative serum Ctn can predict tumor load and lymph node metastasis.The higher the preoperative serum Ctn,the larger the tumor diameter and the more likely lymph node metastasis will occur.2.Preoperative serum Ctn level of 167.0 pg/ml is the critical value for predicting the risk of lateral neck lymph node metastasis in MTC patients.3.Postoperative serum Ctn progresses,that is,MTC patients with a doubling time greater than 150 pg/ml or less than 12 months have a worse prognosis.4.Dynamic monitoring of postoperative serum Ctn can evaluate the postoperative disease state of MTC patients,and should be closely observed in 12-36 months.5.Higher preoperative serum Ctn and TNM staging are independent risk factors for postoperative serum Ctn progression.