Changing trends in well differentiated thyroid carcinoma over eight decades.

INTRODUCTION: The incidence of well differentiated thyroid cancer (WDTC) is rising in the USA. The objective of this study is to present the changes in incidence, presentation, management and outcomes of WDTC within our institution over the past 8 decades.
METHODS: 2797 patients managed between 1932 and 2005 at Memorial Sloan Kettering Cancer Center were identified from our institutional database.
RESULTS: There has been an increase in the number of patients managed per decade. Although the median age was 45 years, patients managed post-1985 were more likely to be over 45 years (53% versus 44%, p < 0.001). The percentage of women increased from 68% to 72% (p = 0.026), and the percentage of papillary carcinomas also increased, from 78% to 92%, p < 0.001. An increase in early stage tumors was observed with pT1 lesions increasing from 19% to 48%. Patients in the latter cohort were less likely to have thyroid lobectomy (29% versus 72%, p < 0.001). There was a significant change in the use of RRA, with 8% of the early versus 44% of the latter group receiving post-operative RRA (p < 0.001). Since the introduction of risk group stratification disease specific survival (DSS) has not changed significantly. With a median follow up of 90 months, 10 year DSS rates were below 90% in the cohort managed prior to the 1970s, which rose to >95% thereafter (p < 0.001).
CONCLUSIONS: Older patients with earlier stage disease present an increasing workload for surgical oncologists. Excellent outcomes remain unchanged despite increasingly aggressive surgical and medical management.