Staging of breast cancer

  Clinical stage of breast cancer
  Stage 0: No lymph nodes in the ipsilateral axilla, tumor diameter less than 2cm
  Stage I: active lymph nodes in the ipsilateral axilla, with or without metastasis, tumor diameter 2-5cm, Zhang Chenguang, Breast Surgery Department, Xinjiang Cancer Hospital
  Stage II: ipsilateral axillary lymph nodes fused into a block and adhered to other tissues, tumor diameter greater than 5cm
  Stage III: Metastasis in ipsilateral supraclavicular, infraclavicular or axillary lymph nodes or edema in upper limbs. The metastatic lymph nodes are fused and hard.
  Stage IV: metastasis in other distant sites
  Pathological classification (pTNM)
  T primary tumor
  TX primary tumor cannot be identified (e.g., resected)
  T0 primary tumor not detected
  Tis primary carcinoma in situ
  Tis(DCIS) ductal carcinoma in situ
  Tis(LCIS) lobular carcinoma in situ
  Tis(Paget) papillary Paget’s disease without tumor
  Note: Paget’s disease with masses is staged according to the size of the masses
  T1 tumor maximum diameter ≤2cm
  T1mic microinvasive carcinoma with maximum diameter ≤0.1cm
  T1a maximal diameter >0.1cm, ≤0.5cm
  T1b maximal diameter >0.5cm, ≤1.0cm
  T1c maximal diameter >1.0cm, ≤2.0cm
  T2 maximum diameter>2.0cm, ≤5.0cm
  T3 maximum diameter >5.0cm
  T4 direct invasion of chest wall or skin regardless of tumor size (chest wall includes ribs, intercostal muscles, and anterior serratus, but not pectoral muscles)
  T4a Invasion of chest wall
  T4b Skin edema (including orange peel-like changes), ulceration or satellite nodules on the affected breast
  T4c coexistence of T4a and T4b
  T4d inflammatory breast cancer
  N-region lymph nodes
  Nx-area lymph nodes cannot be analyzed (e.g., cleared)
  N0 regional lymph nodes without metastasis
  N1 ipsilateral axillary lymph nodes metastatic and mobile
  N2 ipsilateral axillary lymph nodes fused to each other or fixed to other tissue; or clinically significant internal breast lymph node metastasis in the absence of clinical evidence of axillary lymph node metastasis
  N2a ipsilateral axillary lymph nodes fused to each other or fixed to other tissues
  N2b clinically significant internal mammary lymph node metastasis in the absence of clinical evidence of axillary lymph node metastasis
  N3 ipsilateral subclavian lymph node metastasis; or clinically significant internal mammary lymph node metastasis in the presence of clinical evidence of axillary lymph node metastasis; or ipsilateral supraclavicular lymph node metastasis with or without axillary or internal mammary lymph node metastasis
  N3a ipsilateral subclavian lymph node metastasis and axillary lymph node metastasis
  N3b ipsilateral internal mammary lymph node and axillary lymph node metastasis
  N3c ipsilateral supraclavicular lymph node metastasis
  pN regional lymph nodes
  pNx regional lymph nodes cannot be analyzed (surgery did not include this site or it was removed in the past)
  pN0Histology without regional lymph node metastasis, no separate examination of isolated tumor cells
  pN0(i-) histology without regional lymph node metastasis, immunohistochemically negative
  pN0(i+) histology without regional lymph node metastasis, positive immunohistochemistry, tumor foci ≤0.2mm
  pN0(mol-) no regional lymph node metastasis on histology, negative molecular assay (RT-PCR)
  pN0(mol+) no regional lymph node metastasis on histology, positive molecular assay (RT-PCR)
  pN1mi presence of micrometastases, maximum diameter >0.2mm, ≤2.0mm
  pN1 ipsilateral 1 to 3 axillary lymph node metastases, or microscopic metastases in the anterior lymph nodes of the internal breast that are not clinically evident
  pN1a ipsilateral 1 to 3 axillary lymph node metastases
  pN1b microscopic metastasis of the internal breast sentinel lymph node that is not clinically significant
  pN1c ipsilateral 1 to 3 axillary lymph node metastases, ipsilateral internal mammary sentinel lymph node microscopic metastases, and clinically insignificant
  pN24 to 9 axillary lymph node metastases, or clinically significant internal breast lymph node metastases without axillary lymph node metastases
  pN2a4 to 9 axillary lymph node metastases with at least one tumor focus >2.0mm
  pN2b clinically significant internal breast lymph node metastasis without axillary lymph node metastasis
  pN310 or more axillary lymph node metastases, or subclavian lymph node metastases, or clinically significant ipsilateral internal breast lymph node metastases in case of axillary lymph node metastases; or 3 or more axillary lymph node metastases with clinically negative microscopic internal breast lymph node metastases; or ipsilateral supraclavicular lymph node metastases
  pN3a10 or more axillary lymph node metastases (at least one tumor focus >2.0mm), or subclavian lymph node metastases
  pN3b 3 or more axillary lymph node metastases with clinically negative but microscopic internal breast lymph node metastases on biopsy of anterior lymph nodes
  pN3c ipsilateral supraclavicular lymph node metastasis
  M distant metastasis
  Mx no distant metastases could not be assessed
  M0 without distant metastasis
  M1 with distant metastasis
  Description.
  Clinically evident: means detected by clinical physical examination or imaging (except lymph nuclei visualization).
  pN classification is based on the results of axillary lymph node dissection with or without prior sentinel lymph node biopsy; if only sentinel lymph node biopsy is performed without subsequent axillary lymph node dissection, the sentinel lymph node is indicated by (sn), e.g., pN0(i+)(sn).
  Isolated tumor cells refer to single cells or small cell clusters less than 0.2 mm, usually detected by immunohistochemical or molecular techniques and identified by conventional histology, isolated tumor cells do not necessarily show metastatic activity, such as proliferation or interstitial reaction.
  Clinically inconspicuous: refers to a condition that cannot be detected by clinical physical examination or imaging (except lymph nuclein imaging).
  Clinical staging
  Stage O TisN0M0
  Stage I T1N0M0
  Stage IIA T0N1M0
  T1N1M0
  T2N0M0
  Phase IIB T2N1M0
  T3N0M0
  Phase IIIA T0N2M0
  T1N2M0
  T2N2M0
  T3N1~2M0
  Phase IIIB T4N0M0
  T4N1M0
  T4N2M0
  Phase IIIC any TN3M0
  Stage IV any T any NM1
  Histopathological grading (G)
  Gx cannot determine the degree of differentiation.
  G1 highly differentiated.
  G2 moderately differentiated.
  G3 hypodifferentiated.
  Classification of the presence or absence of residual tumors after surgical treatment (R)
  Rx cannot determine the presence or absence of residual tumors.
  R0 no residual tumor.
  R1 microscopically visible residual tumor.
  R2 Visible to the naked eye.