The number of patients with papillary thyroid cancer has been rising since the mid 1970’s. Initially, this was attributed to more frequent use of neck ultrasound and CT scans which could identify new cases of thyroid cancer that would not have otherwise been found. More frequent neck imaging can certainly account for the increase in incidence of small, early stage papillary thyroid cancers; however, it cannot explain a reported rise in the incidence of large (>4 cm) papillary thyroid cancers as well as increase in death from thyroid cancer. As such, it is likely that other environmental factors may also be contributing to the changing incidence of papillary thyroid cancer.
The epidemic of obesity over this period mirrors the rise in papillary thyroid cancer; therefore, there may be a positive relationship between thyroid cancer and obesity. In fact, recent studies have shown a relationship between one’s fat mass and diagnosis of papillary thyroid cancer. Further, obesity has already been linked to many other types of cancers such as gastrointestinal, breast, kidney and endometrial cancers.
The goal of the current study was to quantify the impact of rising rates of obesity on the incidence of papillary thyroid cancer.
THE FULL ARTICLE TITLE
Kitahara CM et al. 2019, Impact of overweight and obesity on U.S. papillary thyroid cancer incidence trends (1995–2015) J Natl Cancer Inst. Epub 2019 Oct 22.
SUMMARY OF THE STUDY
The authors used data from a large US study called the National Institutes of Health (NIH)—AARP diet health study, which started in 1995 when members of the American Association of Retired Persons (AARP) between ages 51-70 completed a questionnaire about health and lifestyle characteristics which included questions about weight and body mass index (BMI) . Then, using local cancer registries and databases they identified 604 people from the study that were diagnosed with new papillary thyroid cancer between 1995-2005.