Staging of Differentiated Thyroid Carcinoma: Standardizing Rational Thought

Excerpt

In the current edition of the Journal, Lang et al.1 studied a population of 760 patients with well-differentiated thyroid cancer who were retrospectively restaged on the basis of the updated criteria of the 6th edition of the AJCC Cancer Staging Manual. 1,2 In the updated staging system, the designation of a T1 tumor has been increased from ≤ 1 cm to ≤ 2 cm; T2 tumors are now > 2 cm and ≤ 4 cm; T3 tumors now include those with minimal extrathyroidal extension; and T4 tumors have been subcategorized into T4a (invading subcutaneous tissues, larynx, trachea, esophagus, or recurrent laryngeal nerve) and T4b (invading prevertebral fascia or encasing carotid artery or mediastinal vessels). These changes more than doubled the percentage of T1 tumors, with a reciprocal diminution in T2 tumors. The frequency of T3 tumors increased from 10% to 33.7%, and the frequency of T4 tumors decreased from 31.6% to 7.9%.1 …