Objective: Regional variation in thyroid cancer incidence in Belgium, most pronounced for low risk cancer, was previously shown to be related to variation in clinical practice, with higher thyroid surgery rates and lower proportions of preoperative fine-needle aspiration (FNA) in regions with high thyroid cancer incidence (period 2004–2006). The objective of this study was to investigate regional thyroid cancer incidence variation in relation with variation in thyroid surgery threshold in a more recent Belgian thyroid cancer cohort. Methods: A population-based cohort of thyroid cancer patients that underwent a (near) total thyroidectomy in the period 2009–2011 (n = 2,329 patients) was identified and studied by linking data from the Belgian cancer registry and the Belgian health insurance companies, and case-by-case study of the pathology protocols. The execution of preoperative FNA and the thyroid resection specimen weight were compared between high and low thyroid cancer incidence regions. Thyroid weight in the pT1a-restricted group was studied as a proxy for surgical threshold for benign nodular goiter. Furthermore, time trend analyses were performed for the execution of FNA for the period 2004–2012. Results: Although a lower proportion of FNA in the high thyroid cancer incidence region persisted in the period 2009–2011 (41.2% [31.9–50.9] vs. 72.9% [64.9–79.7] in the low-incidence region (LIR), p < 0.001), a positive time trend was observed for the period 2004–2012. The median thyroid surgical specimen weight was lower in the high incidence region compared to the LIR (27.0 g [IQR 18.0–45.3] vs. 36.0 g [IQR 22.0–73.0], p < 0.0001), and this finding was corroborated in the pT1a-restricted group. Conclusion: Interregional differences in use of FNA and surgical thyroid specimen weight are consistent with an inverse relation between thyroid cancer incidence and thyroid surgery threshold, carrying risk for overdiagnosis.
Background Large scale observational studies are crucial to study thyroid cancer incidence and management, known to vary in time and place. Combining cancer registry data with other data sources enables execution of population-based studies, provided data sources are accurate. The objective was to compare thyroid tumour and treatment information between the available data sources in Belgium. Methods We performed a retrospective national population-based cohort study. All patients with thyroid cancer diagnosis in Belgium between 2009 and 2011 (N = 2659 patients) were retrieved from the Belgian Cancer Registry database, containing standard patient and tumour characteristics. Additionally, information was obtained from the following sources: a) detailed pathology reports b) the health insurance company database for reimbursed performed therapeutic acts (both available for N = 2400 patients) c) registration forms for performed and/or planned treatments at the time of the multidisciplinary team meeting (available for N = 1819 patients). More precisely, information was retrieved regarding characteristics of the tumour (histologic subtype, tumour size, lymph node status (source a)) and the treatment (thyroid surgery (a,b,c), lymph node dissection (a,b), postoperative administration of radioactive iodine (b,c)). Results High concordance in histological cancer subtype (> 90%), tumour size (96.2%) and lymph node involvement (89.2%) categories was found between the cancer registry database and the pathology reports. Tumour subcategories (such as microcarcinoma, tumor ≤1 cm diameter) were more specified in the pathology reports. The therapeutic act of thyroid surgery as mentioned in the pathology reports and health insurance company database was concordant in 92.7%, while reports from multidisciplinary team meetings showed 88.5% of concordance with pathology reports and 86.1% with health insurance data. With regard to postoperative radioiodine administration, reports from multidisciplinary teams and health insurance data were concordant in 76.8%. Conclusion Combining registered and/or administrative data results in sufficiently accurate information to perform large scale observational studies on thyroid cancer in Belgium. However, thorough and continuous quality control and insight in strengths and limitations of each cancer data source is crucial.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.