An Ethical Issue After the Nuclear Accident in Fukushima: Young People’S Perspectives of Thyroid Cancer Screening and its Harms

Background Overdiagnosis of thyroid cancer has become a major global medical issue. Ultrasound-based thyroid cancer screening has promoted overdiagnosis, and recently international recommendations indicate that such screening should not be conducted, even after a nuclear accident. The Fukushima thyroid cancer screening program was initiated in 2011 as a health policy after the nuclear accident, although the risk for radiation-induced thyroid cancer was unlikely given the low radiation levels. However, the thyroid cancer screening program has continued at 2-year intervals with a relatively high participation rate and is now in its fifth round. Therefore, it is crucial to clarify whether those targeted for screening understand the disadvantages of screening and identify factors that influenced their decision to participate. Methods We conducted an anonymous mail-based questionnaire that included young people from Fukushima (subjects) and a neighboring prefecture that was not targeted for screening (non-subjects). We asked them about the significance of the thyroid cancer screening in Fukushima, the reasons for taking or not taking a screening, their perception of the harms of screening, and their opinions on thyroid examination at school. Then we compared the results of the questionnaire between subjects and non-subjects and examinees (who accepted screening) and non-examinees (who declined screening). Results Only 16.5% of respondents were aware of the harms associated with thyroid cancer screening, with most perceiving that the benefits outweighed the harms. Comparison of subjects’ and non-subjects’ responses showed there were no significant differences between subjects and non-subjects. In addition, among subjects, there were no differences of responses between examinees and non-examinees. The most common reason for participation in screening was that the screening was conducted in schools and perceived as obligatory. Conclusions These results highlighted a serious ethical issue in that school-based screening leads to making young people think that it is mandatory screening in an opt-out and default setting manner, with a lack of knowledge about the disadvantages of screening. Based on the autonomy of the subjects and the ethical principle of the post-disaster, surveys after a nuclear disaster should be conducted in an opt-in style without an opt-out style such as school-based screening.

Spatial distribution and determinants of thyroid cancer incidence from 1999 to 2013 in Korea

We evaluated the spatial variation in thyroid cancer incidence and its determinants in Korea considering its importance in cancer prevention and control. This study was based on the ecological design with cancer incidence data by administrative district from the National Cancer Center and regional characteristics generated from the Korea Community Health Survey Data. We identified spatial clusters of thyroid cancer incidences based on spatial scan statistics. Determinants of regional variation in thyroid cancer incidence were assessed using the Besag-York-Mollie model with integrated nested Laplace approximations. Spatial clusters for low and high thyroid cancer incidences were detected in the northeastern and southwestern regions, respectively. Regional variations in thyroid cancer incidence can be attributed to the prevalence of recipients of basic livelihood security (coefficient, − 1.59; 95% credible interval [CI], − 2.51 to − 0.67), high household income (coefficient, 0.53; 95% CI, 0.31 to 0.76), heavy smoking (coefficient, − 0.91; 95% CI, − 1.59 to − 0.23), thyroid dysfunction (coefficient, 3.24; 95% CI, 1.47 to 5.00), and thyroid cancer screening (coefficient, 0.38; 95% CI, 0.09 to 0.67). This study presented the spatial variations in thyroid cancer incidence, which can be explained by the prevalence of socioeconomic factors, thyroid cancer screening, thyroid dysfunction, and smoking.

Stress-Induced Differential miR-4633-5p Expression in Thyroid Cancer Health Disparities

Filipino Americans (FA) are known to have higher rates of thyroid cancer incidence and disease recurrence compared to European Americans (EA). FA are also known to be two times more likely to die of thyroid cancer compared to EA. Epidemiological studies in California have shown that thyroid cancer is the second most common cancer among FA women. Currently, there are no studies that demonstrate the mechanism behind these discrepancies. Evidence shows a strong correlation between obesity and more aggressive forms of thyroid cancer; obesity has an increased frequency in FA populations. The exact connection between the mechanisms of obesity and cancer is poorly understood. This epigenetic phenomenon may be due to microRNAs (miRNAs), which post-transcriptionally regulate gene expression. Dysregulated miRNA profiles have been associated with various diseases including obesity and cancer. MiRNAs are linked to different types of cancer; tumor suppressor genes and oncogenes are subject to modulation by dysregulated miRNAs. No study elucidates the association of miRNAs to tumor staging or prognosis in thyroid cancer health disparities. In this study, we determined miRNA expression profiles and found significant differences in the miRNA profiles between FA and EA thyroid cancer patients. Our pilot study showed several dysregulated miRNAs, from which we chose to assay dysregulated miR-4633-5p segments that are known to be associated with thyroid cancer signaling. We used QIAGEN’s miRNA extraction kit to obtain high-quality miRNA from paraffin-embedded thyroid tissues. We performed next-generation miRNA sequencing using equal number of FA and EA samples and identified the top ten significantly up- and down-regulated miRNAs from the pool of differentially expressed miRNAs by qPCR assays. Our investigation demonstrated a 1.5-2-fold higher expression of an upregulated miR-4633-5p in FA versus EA miRNA samples (n=70) after normalized to controls. In contrast, miR-323b-3p showed no difference between FA and EA after normalized to controls. For our future work, we plan to analyze multiple up- and down-regulated miRNAs by qPCR, determine whether the miRNA signatures are consistent between samples from FA versus EA, and explore the use of these miRNA signature differentials for affordable and rapid thyroid cancer screening and prognosis.

A COMPARATIVE EXPECTED VALUE ANALYSIS STUDY TO DETERMINE IF THE ECONOMIC BENEFITS OF SCREENING AND EARLY DIAGNOSIS TREATMENT OF THE MOST COMMON TYPES OF CANCER IN THE UNITED STATES PROVIDE ECONOMIC VALUE

Breast, colorectal and skin cancer screening and early diagnosis with treatment provides economic value, while lung cancer screening and early diagnosis with treatment came close to providing economic value. Bladder, endometrial, kidney, leukemia, non-Hodgkin lymphoma, pancreatic, prostate and thyroid cancer screening and early diagnosis with treatment were not found to have provided economic value.

THE ROLE OF ULTRASOUND SCREENING FOR THYROID CANCER IN PATIENTS WITH FAMILIALADENOMATOUS POLYPOSIS SYNDROME

Familial adenomatous polyposis (FAP) is an inherited disease that is characterised by multiple recurrent cancers of the colon (large intestine). Thyroid nodules and thyroid cancer are among the few extraintestinal manifestations of FAP, with a prevalence of 35-80% and 3-12% respectively. The incidence of thyroid cancer is higher in FAP patients than in the general population. However, routine thyroid cancer screening is not consistently performed by most practitioners when managing patients with FAP. We sought to assess the frequency of thyroid cancer screening among patients with FAP and the prevalence of thyroid cancer among these patients. We performed a retrospective chart review of all adult patients with FAP, between January 2000 and December 2016 at our center. 51 patients were identified with a confirmed diagnosis of FAP based on colonoscopy and pathology criteria. Of the 51 patients with FAP syndrome, only 14 patients had thyroid ultrasound performed, and 3 patients were found to have thyroid cancer. With limited data, our analysis showed a reduced prevalence of thyroid cancer of 5% when compared to historical data. Most adult FAP patients did not get thyroid cancer screening and this could be due to lack of awareness in medical providers on the increased incidence of thyroid cancer and FAP. Every clinician managing FAP patients should be educated on the increased risk of thyroid cancer in FAP and the role of thyroid ultrasound screening for early detection of thyroid cancer.