Background: Patients with thyroid cancer often have distinctive characteristics that change as the cancer progresses to stage IV and warrants varied treatment. A Surveillance, Epidemiology, and End Results-based study reported that men with thyroid cancer of follicular cell origin are more likely to present with advanced disease compared with that of female patients. This is the largest study to evaluate stage IV thyroid cancer.
Methods: A population-based study was conducted using the National Cancer Database (NCDB), which captures nearly 70% of incident cancers in the U.S. For the accession years 2000 to 2012, NCDB took epidemiologic information for a sample of 343,386 thyroid cancer cases and used data from the 2012 U.S. census. The diagnosis of stage IV disease represented 6.88% (23,613) of the total patient population. The demographics of stage IV patients were compared with patients with all other stages using the chi-square test.
Results: There was an increased incidence of stage IV thyroid cancer in Medicare, lower high school graduation rates, annual median household income < $44,000, aged ≥ 70 years, male, more comorbidities, and further distance from a treatment facility (P < .0001). Ethnicity/race had little impact on the incidence of stage IV disease. Stage IV cancer incidence is higher in males (12.14%) compared with that of females (5.15%), and stage IV patients are more likely have Medicare (14.60%) or be uninsured (8.72%) than have private insurance (4.63%). Patients with ≥ 2 comorbidities (14.23%) are more than twice as likely to have stage IV as those without comorbidities (6.77%). Medullary and anaplastic cancers (20.08%) are much more likely to be stage IV than papillary (5.76%) or follicular cancers (3.94%, P < .0001).
Conclusions: Patients with the following characteristics are more likely to present with stage IV thyroid cancer: Medicare, less education, low income, older age, male, comorbidities, far from a treatment facility, and medullary or anaplastic thyroid cancer.
