Radiation Oncology/Thyroid/Staging

Thyroid Cancer Staging

AJCC Staging
AJCC 7th Edition (2009) Primary tumor
 * T0 - No evidence of primary tumor
 * T1 - Tumor 2 cm or less, limited to the thyroid
 * T1a - Tumor 1 cm or less
 * T1b - Tumor >1 cm but <= 2 cm
 * T2 - Tumor >2 cm but <=4 cm, limited to the thyroid
 * T3 - Tumor >4 cm, limited to the thyroid, or any tumor with minimal extrathyroidal extension (e.g. extension to sternothyroid muscle or perithyroid soft tissues)
 * T4a - Tumor extending beyond the thyroid capsule to invade subcutaneous soft tissues, larynx, trachea, esophagus, or recurrent laryngeal N
 * T4b - Tumor invades prevertebral fascia or encases carotid artery or mediastinal vessels

Anaplastic carcinoma: All anaplastic carcinomas are considered T4 tumors
 * T4a - Intrathyroidal anaplastic carcinoma
 * T4b - Anaplastic carcinoma with gross extrathyroid extension

Nodes
 * N0 - no regional lymph node metastasis
 * N1 - regional lymph node metastasis
 * N1a - Metastasis to Level VI (pretracheal, paratracheal, and prelaryngeal/Delphian lymph nodes)
 * N1b - Metastasis to unilateral, bilateral, or contralateral cervical (Levels I-V) or retropharyngeal or superior mediastinal lymph nodes (Level VII)

Distant Metastasis
 * M0 - none
 * M1 - yes

Stage grouping
 * Papillary or follicular
 * (Age under 45 years)


 * Stage I - Any T, Any N, M0
 * Stage II - Any T, Any N, M1
 * Papillary or follicular
 * (45 years and older)


 * Stage I - T1 N0 M0
 * Stage II - T2 N0 M0
 * Stage III - T3 or N1a
 * Stage IVA - T4a or N1b
 * Stage IVB - T4b, Any N, M0
 * Stage IVC - M1


 * Medullary carcinoma (all age groups)


 * Stage I - T1 N0 M0
 * Stage II - T2-T3 N0 M0
 * Stage III - T1-3 N1a M0
 * Stage IVA - T4a or N1b
 * Stage IVB - T4b, Any N, M0
 * Stage IVC - M1


 * Anaplastic carcinoma

All anaplastic carcinomas are considered Stage IV
 * Stage IVA - T4a, Any N, M0
 * Stage IVB - T4b, Any N, M0
 * Stage IVC - M1

Changes from 6th edition
 * Subdivided T1 into T1a and T1b

Other Staging Systems

 * See also: Thyroid cancer prognostic indices (e.g. AMES, AGES, MACIS)

National Thyroid Cancer Treatment Cooperative Study (NTCTCS) Staging Classification