Trends in the presentation, treatment, and survival of patients with medullary thyroid cancer over the past 30 years

Abstract

Background: The impact of recent medical advances on disease presentation, extent of operation, and disease-specific survival for patients with medullary thyroid cancer is unclear.

Methods: We used the Surveillance, Epidemiology, and End Results registry to compare trends over 3 time periods, 1983-1992, 1993-2002, and 2003-2012.

Results: There were 2,940 patients diagnosed with medullary thyroid cancer between 1983 and 2012. The incidence of medullary thyroid cancer increased during this time period from 0.14 to 0.21 per 100,000 population, and mean age at diagnosis increased from 49.8 to 53.8 (P < .001). The proportion of tumors ≤1 cm also increased from 11.4% in 1983-1992, 19.6% in 1993-2002, to 25.1% in 2003-2012 (P < .001), but stage at diagnosis remained constant (P = .57). In addition, the proportion of patients undergoing a total thyroidectomy and lymph node dissection increased from 58.2% to 76.5% during the study period (P < .001). In the most recent time interval, 5-year, disease-specific survival improved from 86% to 89% in all patients (P < .001) but especially for patients with regional (82% to 91%, P = .003) and distant (40% to 51%, P = .02) disease.

Conclusion: These data demonstrate that the extent of operation is increasing for patients with medullary thyroid cancer. Disease-specific survival is also improving, primarily in patients with regional and distant disease.

Figure 1. Study Cohort Inclusion and Exclusion Flowchart

This diagram depicts how the final study cohort was defined.

Figure 2. Age-adjusted Incidence of Medullary Thyroid Cancer

The incidence of Medullary Thyroid Cancer increased overall (top) and across all stages of disease (bottom).

Figure 3. Trend in Lymph Node Dissections at the time of Total Thyroidectomy

This histogram demonstrates that the proportion of patients who underwent a total thyroidectomy with a lymph node dissection increased from 58.2% to 69.2% to 76.5% in the last 30 years (p < 0.001).

Figure 4. Disease Specific Survival for patients with Medullary Thyroid Cancer based on Time Interval

The four Kaplan-Meier survival curves demonstrate improved disease specific survival (DSS) for all patients (top left) and for those patients with regional (bottom left) and distant (bottom right) disease, but not with localized disease (top right).