Review Article

To Treat or Not to Treat: The Role of Adjuvant Radioiodine Therapy in Thyroid Cancer Patients

Table 2

AJCC staging, 7th ed., for well-differentiated thyroid cancer based on TNM descriptors [2].

T1 Tumor diameter ≤ 2 cm, limited to the thyroid
T2 Primary tumor diameter > 2 cm to 4 cm, limited to the thyroid
T3 Primary tumor diameter > 4 cm, limited to the thyroid or with minimal extrathyroidal extension
T4a Tumor of any size extends beyond thyroid capsule to invade subcutaneous soft tissues, larynx, trachea, esophagus, or recurrent laryngeal nerve
T4b Tumor invades prevertebral fascia or encases carotid artery or mediastinal vessels
TX Primary tumor size unknown, but without extrathyroidal invasion

N0 No regional lymph node metastasis
N1a Metastasis to level VI (pretracheal, paratracheal, and prelaryngeal/Delphian lymph nodes)
N1b Metastasis to unilateral, bilateral, contralateral, cervical, or superior mediastinal lymph nodes
NX Nodes not assessed at surgery

M0 No distant metastases
M1 Distant metastases
MX Distant metastases not assessed

Patient age < 45 yearsPatient age ≥ 45 years

Stage IAny T, any N, M0T1, N0, M0
Stage IIAny T, any N, M1T2, N0, M0
Stage IIIT3, N0, M0
T1, N1a, M0
T2, N1a, M0
T3, N1a, M0
Stage IVAT4a, N0, M0
T4a, N1a, M0
T1, N1b, M0
T2, N1b, M0
T3, N1b, M0
T4a, N1b, M0
Stage IVBT4b, Any N, M0
Stage IVCAny T, Any N, M1