title: Endpoints for screening thyroid cancer in the Republic of Korea: thyroid specialists' perspectives.
abstract: Cancer screening is aimed primarily at reducing deaths from the specific cancer. Thyroid-specific cancer mortality may be the most ambitious endpoint for obtaining estimates of screening effect. Numerous observations have accumulated over the years, indicating that thyroid cancer mortality endpoint has been difficult to study and is confounded by population heterogeneity, provision of randomization, and requirement of large cohorts with sufficiently long follow-up due to the excellent prognosis of the cancer. Accordingly, it may be important to reconsider how to best measure thyroid cancer screening efficacy. Recommendations against thyroid cancer screening should be based upon trials designed to evaluate its effectiveness not only in significant reduction in cancer mortality, but also of other distinct endpoints. It is desirable to evaluate derivative endpoints that can reliably predict reductions in mortality. The term "derivative" means a variable that is related to the true endpoint and is likely to be observable before the primary endpoint. Derivative endpoints may include thyroid cancer incidence, the proportion of early-stage tumors detected, more treatable stage, the identification of small tumors (to maintain in observation), decrease in the number of people who develop metastatic disease, the increased chance of lesser extent surgery, and the application of minimally invasive approaches, as well as no need for lifelong thyroid replacement therapy, a consistent follow-up, low-dose or no RAI administration and risk factor assessments where case findings should be continuous. The Korean guidelines for thyroid cancer national-level screening were published by a relevant group of multidisciplinary thyroid experts. It was concluded that the evidence is insufficient to balance the benefits and harms of thyroid cancer screening. However, the paper seems to raise the necessary investments in future research and demand a complete analysis for derivative endpoints, and offer screening participants with complete information necessary to make decisions that will provide them with the most value when a small thyroid cancer is screen-identified.
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, KUMC Thyroid Center, Korea University College of Medicine, Seoul, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: An
authors.affiliation: Department of Surgery, KUMC Thyroid Center, Korea University College of Medicine, Seoul, Korea. hoonyubkim@korea.ac.kr.
authors.forename: H Y
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, KUMC Thyroid Center, Korea University College of Medicine, Seoul, Korea. k50367@korea.ac.kr.
authors.forename: S G
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Section of Endocrine Surgery, Department of General, Visceraland Vascular Surgery, University Hospital Essen, Essen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Dralle
authors.affiliation: Division of Thyroid and Parathyroid Surgery, Harvard Medical School, Boston, MA, USA.
authors.forename: G W
authors.initials: GW
authors.lastname: Randolph
authors.affiliation: Division of Endocrinology, Department of Clinical and Experimental Medicine, University of Insubria, Varese, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Piantanida
authors.affiliation: Division of Endocrinology, Department of Clinical and Experimental Medicine, University of Insubria, Varese, Italy.
authors.forename: M L
authors.initials: ML
authors.lastname: Tanda
authors.affiliation: 1st Division of General Surgery, Department of Surgical Sciences and Human Morphology, Research Center for Endocrine Surgery, University of Insubria (Varese-Como), via Guicciardini 9, 21100, Varese, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Dionigi
mesh_terms: D055088:Early Detection of Cancer; D006801:Humans; D015994:Incidence; D010820:Physicians; D011379:Prognosis; D056910:Republic of Korea / Q000453:epidemiology; D013038:Specialization; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control
keywords: Epidemiology; RAI; Screening; Surgery; Thyroid cancer