PracticeUpdate Editorial Team
July 28, 2014, New York–Results of a systematic review of literature from 1966 of the natural history of papillary thyroid microcarcinoma (PTMC) revealed that the condition is being over-diagnosed and over-treated.
The review was presented Sunday at the Fifth World Congress of the International Federation of Head and Neck Oncologic Societies (IFHNOS) held in New York, NY, from July 26 to 30, 2014.
Thyroid cancer is the most common endocrine malignancy, with a rising incidence. Wider access to imaging has increased the detection of asymptomatic thyroid nodules known as “incidentalomas.” This, combined with the introduction of thyroid cancer screening programs in certain countries, has led to a surge in the diagnosis of PTMC. PTMC generally follows an indolent course and carries an excellent prognosis.
George Garas, MD, from Imperial College, London, assessed whether all confirmed thyroid cancers require surgery or certain forms, such as incidentally detected PTMC, can be managed conservatively.
Dr. Garas’s team conducted a systematic review of the Cochrane Controlled Trials Register, MEDLINE, EMBASE, and Google Scholar databases dating from 1966.
The results suggested over-diagnosis and over-treatment. Two large trials (Ito et al, n=1995; and Davies et al, n=35,663, over 32 years), found, respectively, that no patients in the surveillance groups died, and no significant difference in death rates from thyroid cancer occurred in patients who did not receive immediate surgery for low-risk PMTC vs those who did.
Dr. Garas noted that the most compelling evidence that patients with low-risk cancers are being over-treated is that, despite a threefold increase of papillary thyroid cancer over the past 30 years, the death rate has remained stable (0–5/100,000 in 1979; 0.5/100,000 in 2009). Nevertheless, the number of thyroidectomies in the US has increased by 60% over the past 30 years.
Dr. Garas concluded that, “Until a definitive answer is obtained by a large randomized controlled trial, patients should be informed about the uncertainties surrounding PTMC. Those who are poor surgical candidates due to advanced age, synchronous malignancies, or significant comorbidities should be advised of the option of watchful waiting with serial ultrasound and clinical examination.”
References
Garas G, Qureishi A, Palazzo F, et al. Should We Be Operating on All Thyroid Cancers? The Paradigm of Papillary Thyroid Microcarcinomas. Paper presented at: the Fifth World Congress of the International Federation of Head and Neck Oncologic Societies; July 26-30, 2014; New York, New York. Abstract P0085.