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

ABSTRACT

OBJECTIVE: Medullary thyroid carcinoma (MTC) has varying clinical course. We assessed trends in MTC presentation during the last 34 years. DESIGN: Retrospective study. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.