Thyroid Cancer: Evidence-based Optimal Management and the Search for a Cure

‘Where is the wisdom we have lost in knowledge

where is the knowledge we have lost in information?’

TS Eliot [1]

The treatment of thyroid cancer remains controversial because of its relative rarity, long natural history with generally good outcome, and lack of randomised trials. However, research in thyroid cancer has been progressing rapidly in recent years. This necessitated a revision of the American Thyroid Association’s guidelines [2], and also publication of special issues such as this which expands on the conceptual basis of some selected aspects of management of this cancer.

This issue focuses on clinical management with the practising clinician in mind. Unfortunately, one issue is not enough to cover all aspects of thyroid cancer, and no attempt has been made to cover translational research in thyroid cancer or the increasing number of ongoing thyroid studies and trials.

Differentiated thyroid cancer is an interesting tumour model, with conservation of highly specialised cellular functions such as active transport of iodine [by the membrane-bound sodium iodide symporter protein (NIS) which makes targeted cellular radiotherapy with radioiodine possible] and thyroglobulin production despite neoplastic transformation in most cases. Moreover, these functions remain responsive to exogenous and endogenous thyroid-stimulating hormone modulation, which is routinely exploited for treatment, monitoring during follow-up and diagnosis of recurrence which is probably unique in solid tumour oncology.

Large ongoing randomised trials in Europe and America, as well as a multitude of other studies involving molecular approaches and molecular targeted therapy studies detailed on www.cancer.gov, will provide more reliable grades of recommendation for management in the future. Progress in molecular diagnostics and predictors in thyroid cancer, definition of the role of thyroid stem cells in cancer, the continued search for susceptibility loci of non-medullary thyroid cancers, and advances in thyroid tumour proteomics are significant developments. Investigations into the use of the NIS gene in gene therapy and biotherapy, and the finding of an NIS repressor with poly(ADP-ribose) polymerase-1 components are demonstrating possibilities for the development of new curative treatment strategies for thyroid cancer and other conditions [3], [4], [5], [6], [7], [8].

Against this background and following the evidence base for optimal management within this issue, many more patients in the future may expect to be cured of thyroid cancer.