[Thyroid cancer screening: is it useful?]

Abstract

Differentiated thyroid cancer has a good overall prognosis, however, unfavourable evolution may be observed in cases discovered at an advanced stage. Thyroid cancer incidence has increased in occidental countries over the last 20 years without any significant change in mortality. This has been partially related to changes in diagnostic procedures with an increased detection of small cancers. Indeed, microcarcinomas (less than 10mm diameter), frequently incidentally discovered are now, the most frequent form of thyroid cancer, representing around 40 % of cases. Their prognosis is excellent and the benefit of their surgical management remains to be demonstrated. Unexpectedly, the proportion of large thyroid cancer at diagnosis has remained stable representing around 20 % of cases. These forms are responsible of most of the thyroid cancer specific mortality and an intensification of their clinical screening is necessary. By contrast, a systematic ultrasonographic screening of thyroid nodules should increase the proportion of small thyroid cancers without evidence of an earlier diagnosis of advanced forms and the ratio cost-benefit of such a strategy should be properly evaluated.