Medullary thyroid carcinoma with nodular goiter carries an excellent prognosis

In our institution, patients with medullary thyroid carcinoma (MTC) concurrent with nodular goiter (NG) have a nearly 100% survival rate, but the reasons and characteristics are unclear.

Eighty patients with MTC who underwent surgery in our center between 1971 and 2011 were reviewed.

A total of 21 MTC/NG and 59 MTC only patients were identified. The stage of the two groups had no significant difference (P = 0.13). The MTC/NG group had lower preoperative serum calcitonin (CT) levels (914.7 ng/L vs. 1162.6 ng/L, P = 0.003), lower postoperative serum CT levels (371.4 ng/L vs. 582.5 ng/L, P < 0.001), lower carcinoembryonic antigen levels (18.3 ng/ml vs. 130.5 ng/ml, P < 0.001), a lower propensity toward lymph node metastasis (40.0% vs. 66.7%, P = 0.07), and a lower proportion of multifocality (19.1% vs. 42.4%, P = 0.06), capsular invasion (9.5% vs. 25.4%, P = 0.21), and vascular invasion (4.8% vs. 10.1%, P = 0.67). The mean tumor diameter of the two groups was similar (20.3 mm vs. 22.1 mm, P = 0.6). Overall 15-year survival in MTC/NG versus MTC only groups was 100% versus 57.0% (P = 0.03).

MTC with NG is an indolent disease and has an excellent prognosis. The only independent predictor of survival was the TNM stage of disease.