Anatomic Stage III Breast Cancer AJCC v8

**Semantic type:** Neoplastic Process

**Definition:** Stage III includes: IIIA: (T0, N2, M0); (T1, N2, M0); (T2, N2, M0); (T3, N1, M0); (T3, N2, M0); IIIB: (T4, N0, M0); (T4, N1, M0); (T4, N2, M0); IIIC: (Any T, N3, M0). T0: No evidence of primary tumor. T1: Tumor measuring 20 mm or less in greatest dimension. T2: Tumor measuring more than 20 mm, but not more than 50 mm in greatest dimension. T3: Tumor measuring more than 50 mm in greatest dimension. T4: Tumor of any size with direct extension to the chest wall and/or to the skin (ulceration or macroscopic nodules); invasion of the dermis alone does not qualify as T4. N0: No regional lymph node metastasis is identified or isolated tumor cell clusters (ITCs) are identified only. N1: Tumor with micrometastases; or metastases in 1-3 axillary lymph nodes; and/or clinically negative internal mammary nodes with micrometastases or macrometastases by sentinel lymph node biopsy. N2: Tumor with metastases in 4-9 axillary lymph nodes; or positive ipsilateral internal mammary lymph nodes by imaging in the absence of axillary lymph node metastases. N3: Tumor with metastases in 10 or more axillary lymph nodes; or in infraclavicular (level III axillary) lymph nodes; or positive ipsilateral internal mammary lymph nodes by imaging in the presence of one or more positive level I, II axillary lymph nodes; or in more than three axillary lymph nodes and micrometastases or macrometastases by sentinel lymph node biopsy in clinically negative ipsilateral internal mammary lymph nodes; or in ipsilateral supraclavicular lymph nodes. M0: No clinical or radiographic evidence of distant metastases. Imaging studies are not required to assign the M0 category. (AJCC 8th ed.)

**Synonyms:** - Anatomic Stage III Breast Carcinoma AJCC v8 - Stage III Breast Cancer