CALCA and medullary thyroid gland carcinoma: When the MTC lesion diameter of the two groups > was 1 cm, the preoperative calcitonin level of the combined group was lower compared with the simple group [206.4 (61.7, 585.0) vs 491.5 (171.8, 833.5), P = 0.021]; the differences in other aspects were not statistically significant (P > 0.05), as shown in Table 4.