The Role of Tumor and Lymph Node Size and Extension in Papillary Thyroid Cancer Staging

Excerpt

In this issue, two interesting studies are published by Ito et al. in an attempt to subclassify thyroid cancer T and N staging. The AJCC 8th edition defines T staging by size and by extent of extrathyroidal extension (intraoperative findings) and N staging by compartment involvement (N1a—central, and N1b—lateral) [1]. The authors used a large cohort of thyroid cancer patients treated at a tertiary well-known center in Japan to further evaluate subgroups of patients that warrant re-staging. With regard to T staging, the authors suggest that T4a should be subdivided into two: T4a1 (invasion to trachea, esophagus, recurrent laryngeal nerve, and tracheal muscles) and T4a2 (invasion to tracheal/esophagus mucosa, large vessels, sternocleidomastoid muscle, and subcutaneous tissue) [2]. The suggested N staging included size (3 cm cutoff) and lymph node extension (LNEx) to other organs (e.g., trachea, esophagus, recurrent laryngeal nerve, neck muscles, jugular vein) [2, 3]. …