Meta-analysis of the prognosis of medullary thyroid carcinoma patients with biochemical recurrence and the determination of optimal cut-off value of calcitonin for predicting postoperative structural recurrence / 肿瘤研究与临床

ABSTRACT

Objective:To summarize the prognosis of medullary thyroid carcinoma (MTC) patients with biochemical recurrence (the increase of postoperative calcitonin and no abnormal imaging) and to investigate the optimal cut-off value of calcitonin for postoperative structural recurrence (with imaging abnormality).Methods:Literature retrieval was conducted for PubMed, CNKI, EMbase, Web of Science, Cochrane and other databases, and literatures related to the increase of calcitonin after MTC surgery were included. Review Manager 5.4 software was used for Meta-analysis of the recurrence and death. SPSS 23.0 software was used and receiving operating characteristic (ROC) curve was used to analyze the rising folds of postoperative calcitonin level in comparison with the maximum value of experiment detection, and to predict the outcome of biochemical recurrence transforming to structural recurrence, and then the optimal cut-off value could be worked out.Results:A total of 7 studies including 1 005 MTC patients (276 cases of biochemical recurrence and 542 cases of biochemical cure). Meta-analysis showed that structural recurrence rate in postoperative biochemical recurrence group [40.6% (112/276) vs. 2.2% (12/542); OR = 27.99, 95% CI 14.57-53.78, P < 0.001] and mortality [10.0% (19/190) vs. 0.96% (3/312); OR = 7.26, 95% CI 2.42-21.84, P < 0.001] were higher than those in the biochemical cure group (normal postoperative calcitonin level and no disease state). The data of 89 MTC patients with biochemical recurrence were collected in another 4 studies. ROC curve analysis showed that area under the curve of the rising folds of postoperative calcitonin level in predicting structural recurrence was 0.825; according to the cut-off value at all sections, the optimal cut-off value of the increased postoperative calcitonin was 50 times, the sensitivity was 66. 7%, the specificity was 88.6%. Conclusions:MTC patients with postoperative biochemical recurrence have higher structural recurrence rate and mortality compared with patients with normal postoperative calcitonin. The postoperative elevation of calcitonin more than 50 times the maximum value of the laboratory detection can be taken as the critical diagnostic value, when more than 50 times is prone to structural recurrence.