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 NTCTCS Staging adapted from PMID 9731906 (Sherman SI, Cancer 1998) Papillary Carcinoma Follicular Carcinoma Age < 45 Age ≥ 45 Age < 45 Age ≥ 45 Primary tumor size (cm) <1 I I I II 1-4 I II I III >4 II III II III Primary tumor characteristics Microscopic multifocal I II I III Macroscopic multifocal or Macroscopic tumor capsule invasion I II II III Microscopic extraglandular invasion I II I III Macroscopic extraglandular invasion II III II III Poorly differentiated NA NA III III Metastases Cervical lymph node metastases I III I III Extracervical (distant) metastases III IV III IV