#1697456 Incident Predictors of Thyroid Cancer Subtypes: An analysis of the NCCR Database

To analyze and compare population data for papillary and follicular thyroid cancer. The NCCR database identified patients diagnosed with thyroid cancer from 1975-2020. Demographic, pathologic subtype, and survival trends were analyzed followed with a thorough literature review for discussion. Calculated Annual percent change for Follicular Thyroid Cancer found a noticeable difference in incidence rate between 1997-2009 amongst male and female patients with net 7.5% difference in reported rate per 100,000 with men (12.1%) more than doubling the reported rate for women (4.6%). Analysis for papillary thyroid cancer however found no significant difference between male and female rates with a slight difference of 0.3% favoring men (10.9%) over women (10.6%). When analyzed along racial or age demographic lines no variations between historic annual percent changes to analyzed data sets were observed. Annual percent change amongst age groups all increased with the demographic of 65+ having the largest annual percent change of 16.6%. Comparing the incidence rates between both papillary and follicular subtypes of thyroid cancer revealed an asymmetric distribution between gender for reported cases of Follicular thyroid cancer whereas no significant difference between gender or race was reported for the papillary subtype incidence rate. Both subtypes share the same risk factors of family history, genetic family syndromes and radiation exposure, with radiation therapy at young age being the leading risk factor for both cancer subtypes. Despite the shared risk factors between subtypes only the Follicular subtype favored an increased incidence amongst women suggesting additional factors at play. New publications have studied the potential link between obesity and the rise of follicular thyroid cancer. If applicable, the obesity trends would be expected to parallel the annual percent change noted in the SEER data, and a global study of obesity prevalence trends did find a ratio of 3 obese women for every 2 obese men. Another potential risk factor suspected was a decreasing incidence of cigarette smoking among women as smoking trends have been on the decline and interestingly smoking has consistently been shown to be associated with a 30-40% reduced risk in developing thyroid cancers. Taken together, the likelihood of the social exposure trends being the cause for the gender discrepancy remains in question and would benefit from additional epidemiologic studies. Additionally, a more comprehensive report on the genetic analysis of reported follicular thyroid cancers might elucidate a better understanding of the underlying heritable factors that might also be playing a role in this observed gender gap. A final takeaway from these finding is that there is a statistically significant discrepancy in the incidence rate of follicular thyroid cancer diagnoses amongst women when compared to men and more epidemiologic studies are warranted to determine the root cause of these worrying trends.