Overdiagnosis of thyroid cancer
Menée en Corée du Sud à partir de données portant sur un échantillon représentatif de la population incluant 5 796 patients atteints d'un cancer de la thyroïde diagnostiqué en 1999, 2005 ou 2008, cette étude analyse l'évolution de l'incidence de la maladie sur la période 1999-2008 ainsi que l'effet des méthodes de détection utilisées (examen clinique, examen de dépistage) sur le stade et la taille de la tumeur au diagnostic
Non-lethal cancers picked up by screening are probably responsible Thyroid cancer incidence has increased dramatically in many countries in the developed world over the past three decades.1 Papillary thyroid cancer, which has been responsible for virtually the entire increase, is rarely lethal. The 20 year survival rate is greater than 90%, and approaches 100% for the smallest cancers.2 The increasing incidence is most likely due to overdiagnosis—the detection of subclinical cancers never destined to cause harm.3 4 This conclusion has been reached because the incidence has been primarily due to the detection of small papillary cancers, mortality due to thyroid cancer has not changed significantly, and small foci of papillary thyroid cancer are commonly found at autopsy in people who died of other causes. Overdiagnosis is a problem because it exposes people to the potential side effects of treatment, but without an equal expectation of benefit, because the cancer is unlikely to advance.In a linked article in The BMJ,5 Park and colleagues extend our understanding of the issue in South Korea, which has seen a 15-fold increase in incidence over the past 10 years,6 …
BMJ , éditorial, 2015