[Disease burden of thyroid cancer in the Chinese population, in 1990 and 2013]

Current Iodine Nutrition Status and Morbidity of Thyroid Nodules in Mainland China in the Past 20 Years

The aim of this study was to comprehensively assess the prevalence of goiter and thyroid nodules (TNs) in relation to China's iodine nutrition level over the past 20 years and provide an effective reference for developing health policies. PubMed, EMBASE, Chinese National Knowledge Infrastructure, Chongqing VIP, and Chinese Wan Fang databases were searched for relevant studies from Jan 1996 to Feb 2020. Two reviewers extracted valid data from the eligible citations to determine the morbidity of TNs in different urinary iodine concentrations (UICs) and in patients of different genders, of different ages, who live in different geographic regions, and who live at different altitudes, as well as the P values of interactions between groups. There were 26 articles (34 studies) included in this analysis. The overall morbidity of TNs in mainland China was 23.4%. Morbidity was higher in urban areas (P < 0.001) than in rural and mixed areas. Coastal areas (P < 0.001), female patients (P < 0.001), high-altitude areas (P < 0.001), and residence in south China (P < 0.001) were all associated with higher morbidity of TNs. The lowest morbidity value of TNs, 16%, was in the more-than-adequate iodine subgroup. The highest morbidity, 27.2%, was in the adequate iodine subgroup. The morbidity of TNs increases with age, and women are more likely to have TNs. We also need to perform more epidemiological studies, and in the future, we should cultivate better understanding of the relationship between other thyroid diseases and provide more comprehensive and useful information for other researchers.

circCCDC66 promotes thyroid cancer cell proliferation, migratory and invasive abilities and glycolysis through the miR-211-5p/PDK4 axis

Cancer metastasis is the main cause of death in cancer patients, including patients with thyroid cancer (TC). TC is the most common malignant endocrine tumour. In the recent years, increasing evidence has demonstrated that circular RNAs (circRNAs) serve a significant role in the development of many types of human cancer. However, the function and underlying mechanism of circCCDC66 in TC remain unclear. The present study aimed to explore the role of circCCDC66 in TC. To do so, reverse transcription quantitative PCR was used to detect the expression level of circCCDC66. Cell viability, migratory and invasive abilities, and glucose consumption were evaluated by cell counting kit 8, Transwell and glucose consumption assays, respectively. The association between circCCDC66 or pyruvate dehydrogenase kinase 4 (PDK4) and miR-211-5p was verified by dual-luciferase reporter assay. The results demonstrated that circCCDC66 expression was significantly increased in TC tissues and cell lines. Furthermore, silencing circCCDC66 inhibited TC cell proliferation, migratory and invasive abilities and glycolysis in vitro. Further validation demonstrated that circCCDC66 directly interacted with the microRNA (miR) miR-211-5p. Subsequently, the activity of circCCDC66 was attenuated by miR-211-5p. In addition, the results demonstrated that circCCDC66 may promote papillary thyroid cancer progression by sponging miR-211-5p and increasing expression of PDK4. In conclusion, the present study demonstrated that circCCDC66 could promote TC cell proliferation, migratory and invasive abilities and invasion and glycolysis through the miR-211-5p/PDK4 axis. These findings suggested that targeting circCCDC66 may be considered as a promising therapeutic strategy for TC.

Review of Factors Related to the Thyroid Cancer Epidemic

Thyroid cancer is the most common endocrine cancer, of which the incidence has dramatically increased worldwide in the past few decades. The reasons for the observed rapid increase still are not fully understood, but evidence suggests that overdiagnosis, with the advancement in detection methods and screening policies, is not the sole driver of the substantial increase of the incidence. However, the effect of environmental/lifestyle factors remains speculative other than that of radiation exposure at a young age. This review tries to give a balanced view of debated factors leading to the thyroid cancer epidemic, to offer some alternatives in understanding the controversies, and to suggest potential directions in the search of modifiable risk factors to help reduce thyroid cancer.