Staging of Breast Cancer
| Primary Tumor (T) | |||
| T0 | No evidence of primary tumor | ||
| TIS | Carcinoma in situ | ||
| T1 | Tumor ≤2 cm | ||
| T1a | Tumor >0.1 cm but ≤0.5 cm | ||
| T1b | Tumor >0.5 but ≤1 cm | ||
| T1c | Tumor >1 cm but ≤2 cm | ||
| T2 | Tumor >2 cm but ≤5 cm | ||
| T3 | Tumor >5 cm | ||
| T4 | Extension to chest wall, inflammation, satellite lesions, ulcerations | ||
| Regional Lymph Nodes (N) | |||
| PN0(i-) | No regional lymph node metastasis histologically, negative IHC | ||
| PN0(i+) | No regional lymph node metastasis histologically, positive IHC, no IHC cluster >0.2 mm | ||
| PN0(mol-) | No regional lymph node metastasis histologically, negative molecular findings (RT-PCR) | ||
| PN0(mol+) | No regional lymph node metastasis histologically, positive molecular findings (RT-PCR) | ||
| PN1 | Metastasis in one to three axillary lymph nodes, or in internal mammary nodes with microscopic disease detected by sentinel lymph node dissection but not clinically apparent | ||
| PN1mi | Micrometastasis (>0.2 mm, none >2 mm) | ||
| PN1a | Metastasis in one to three axillary lymph nodes | ||
| PN1b | Metastasis in internal mammary nodes with microscopic disease detected by sentinel lymph node dissection but not clinically apparent a | ||
| PN1c | Metastasis in one to three axillary lymph nodes and in internal mammary lymph nodes with microscopic disease detected by sentinel lymph node dissection but not clinically apparent.a (If associated with greater than three positive axillary lymph nodes, the internal mammary nodes are classified as pN3b to reflect increased tumor burden.) | ||
| pN2 | Metastasis in four to nine axillary lymph nodes, or in clinically apparent internal mammary lymph nodes in the absence of axillary lymph node metastasis | ||
| pN3 | Metastasis in 10 or more axillary lymph nodes, or in infraclavicular lymph nodes, or in clinically apparenta ipsilateral internal mammary lymph nodes in the presence of one or more positive axillary lymph nodes; or in more than three axillary lymph nodes with clinically negative microscopic metastasis in internal mammary lymph nodes; or in ipsilateral subcarinal lymph nodes | ||
| Distant Metastasis (M) | |||
| M0 | No distant metastasis | ||
| M1 | Distant metastasis (includes spread to ipsilateral supraclavicular nodes) | ||
| Stage Grouping | |||
| Stage 0 | TIS | N0 | M0 |
| Stage I | T1 | N0 | M0 |
| Stage IIA | T0 | N1 | M0 |
| T1 | N1 | M0 | |
| T2 | N0 | M0 | |
| Stage IIB | T2 | N1 | M0 |
| T3 | N0 | M0 | |
| Stage IIIA | T0 | N2 | M0 |
| T1 | N2 | M0 | |
| T2 | N2 | M0 | |
| T3 | N1, N2 | M0 | |
| Stage IIIB | T4 | Any N | M0 |
| Any T | N3 | M0 | |
| Stage IIIC | Any T | N3 | M0 |
| Stage IV | Any T | Any N | M1 |
aClinically apparent is defined as detected by imaging studies (excluding lymphoscintigraphy) or by clinical examination.
Abbreviations: IHC, immunohistochemistry; RT-PCR, reverse transcriptase/polymerase chain reaction.
Source: Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, 7th ed. New York, Springer, 2010; www.springeronline.com.