Medullary thyroid carcinoma: the influence of policy changing in clinical characteristics and disease progression

Abstract

Medullary thyroid carcinoma (MTC) has varying clinical course. We assessed trends in MTC presentation during the last 34 years. Retrospective study. One hundred and fifty one patients (44.4% males) were followed for 0.934 years. Patients were classified according to year of diagnosis: group 1, 1977-2000 (n=53) and group 2, 2001-2011 (n=98). Extent of disease at diagnosis, during follow-up, number of surgeries, and pre- and postoperative calcitonin levels were recorded. In total, 48.34% reported family history of MTC. Group 1 had larger tumors (median 1.70 (intraquartile range (IQR) 1.7) vs 1.1 (1.2) cm, P=0.045, Mann-Whitney), they presented less frequently micro-MTCs (27.8 vs 46.1%, P=0.045), and underwent more multiple surgeries (63.3 vs 20.0%, P<0.001). Group 1 had more frequently progressive disease (35.8 vs 12.2%, P=0.003) and distant metastasis at follow-up (39.7 vs 17.4%, P=0.017). Chronological group (HR 0.15, 95% CI 0.03-0.68, P=0.015) and distant metastases at follow-up (HR 0.07, 95% CI 0.015-0.30, P=0.001) were independently associated with 10-year disease progression (P<0.001). In sporadic cases, cervical lymph node invasion and distant metastases at diagnosis were more frequent in group 1 (72.7 vs 45.5%, P=0.032 and 27.3 vs 5%, P=0.019 respectively); disease stage at diagnosis was more advanced (P=0.004). They underwent more multiple surgeries (P<0.001), presented more frequently distant metastasis at follow-up (67.7 vs 20.0%, P=0.002), had less frequently remission, and more frequently progressive disease (21.4 vs 58.0% and 64.3 vs 14.0% respectively, P<0.001). Postoperative calcitonin levels were higher (P=0.024). Recently, an increase in micro-MTCs is observed, while indices of invasiveness and persistence of disease are better. Increased awareness in familial cases, routine calcitonin measurements, and improved surgical procedures could be responsible.