Breast malignant, males, children
Staging of breast carcinoma (AJCC 8th Edition)

Author: Emily S. Reisenbichler, M.D.

Revised: 7 February 2018, last major update October 2017

Copyright: (c) 2002-2018,, Inc.

PubMed Search: Staging[title] breast carcinoma[title]
Cite this page: Reisenbichler, E.S. Staging of breast carcinoma (AJCC 8th Edition). website. Accessed February 20th, 2018.

Pathologic TNM staging of breast carcinoma, AJCC 8th edition
Definition / general
Changes from the 7th edition
  • Use of IHC for important tumor markers (ER, PR and HER2) and tumor grade are incorporated into staging to refine prognosis
  • Genomic assays (such as Oncotype DX, MammaPrint, EndoPredict, PAM50 (Prosigna) and Breast Cancer Index) are used to downstage some estrogen receptor positive, lymph node negative tumors
  • LCIS is no longer classified as Tis because it is considered a risk factor, not a malignancy
  • Summary of changes in the 8th edition is listed in Table 1
Primary tumor (pT)
  • See Table 2
  • Notes:
    • Measure invasive component only, not DCIS
    • T classification traditionally assumes there was no prior treatment; can stage after preoperative (neoadjuvant, primary) chemotherapy but should indicate that prior treatment was received (J Natl Cancer Inst 2005;97:1137)
    • Report tumor size in mm and round to the nearest mm (except when between 1.0 and 1.4 mm, then round up to 2.0 mm to avoid mistakenly classifying these as microinvasive)
    • Do not attempt to add dimensions on the needle biopsy to residual measurements in the excision; use the maximum dimension in either the needle or excision specimen for T categorization (invasive tumor extent is reportedly larger on needle biopsy than in subsequent excision in 12% of cases, Am J Surg Pathol 2013;37:739)
    • If multiple excisions, may want to report "at least pT_, a more accurate estimate may be based on imaging studies"
    • If there are multiple simultaneous, macroscopically measurable, ipsilateral invasive tumors, use largest size, do not sum sizes (but add a comment)
    • If there are multiple invasive carcinomas, the size, grade, histologic type and results of ER, PgR and HER2 should pertain to largest invasive carcinoma; if smaller invasive carcinomas differ in any of these features, include this information in comments
    • Tumor in pectoralis muscle should be measured with the breast tumor to determine the tumor size and T category
    • Grade corresponds to largest area of invasion; if there are smaller foci of invasion of a different grade, include this information under "additional pathologic findings"
    • Margin status is "positive" if there is ink on carcinoma (i.e. the distance is 0 mm); if the margin is not positive, then a distance from the margin may be listed; distances can be specific measurements or expressed as greater than or less than a measurement
Regional lymph nodes (pN)
  • See Table 3
  • Notes:
    • ITC means "isolated tumor cells"
    • Like primary invasive measurement, measure only the largest contiguous focus of metastatic tumor cells; adjacent satellites are not added 
    • Direct extension of tumor into an intramammary lymph node is included as a positive regional lymph node
    • Rounded tumor nodules without nodal tissue present in a nodal drainage area should be considered lymph nodes completely replaced with tumor unless a vascular wall is present
    • "Clinically detected" is defined as detected by imaging studies (excluding lymphoscintigraphy) or by clinical examination and having characteristics highly suspicious for malignancy or a presumed pathologic macrometastasis based on fine needle aspiration biopsy with cytologic examination
    • Lymph node ratio (LNR, the ratio of positive over excised lymph nodes) has been suggested as an alternative to pN staging (J Clin Oncol 2009;27:1062)
Distant metastasis (M)
  • See Table 4
  • Notes:
    • Categories for pathologic stage (pM) are the same as for clinical staging (cM)
    • Designation pM0 is not a valid category; all cases must be cM0 if no evidence of metastases
    • Stage designation may be changed postsurgery if:
      1. Imaging studies within 4 months of diagnosis reveal the presence of distant metastases,
      2. there has been no disease progression, and
      3. no preoperative therapy was given.
Postneoadjuvant considerations (yp)
  • ypT
    • Measurement of the largest single contiguous focus, not including the intervening fibrous tumor bed
    • Treatment often results in multiple residual foci within a tumor bed, requiring use of the (m) modifier
  • ypN
    • Like the primary tumor, measure only the largest contiguous focus of metastatic deposit; do not add separate tumor deposits within the node or include intervening fibrosis / treatment effect
  • Notes:
    • If a patient is M1 (therefore stage IV) prior to neoadjuvant chemotherapy, they remain stage IV regardless of treatment response
    • If a patient was classified as having inflammatory (cT4d) carcinoma prior to neoadjuvant chemotherapy, this remains classified as inflammatory breast carcinoma, regardless of treatment response
    • Pathologic complete response (pCR) requires absence of invasive carcinoma in the breast and lymph nodes; the presence of residual tumor within lymphatics or ITCs in lymph nodes precludes a designation of pCR
TNM anatomic stage groups
  • See Table 5
  • Note: this table should only be used in global regions where biomarker tests are not routinely available; cancer registries in the US must use the prognostic stage group table described in the article (Table 8)
Diagrams / tables

Images hosted on other servers:

Various possible difficulties

Additional references
Board review question #1
What are the tumor features used to assign prognostic stage groups in breast cancer?

  1. pTNM, ER, PR, HER2 status and Oncotype score
  2. pTNM, proliferative rate and Oncotype score
  3. pTNM, proliferative rate, ER, PR and HER2 status
  4. pTNM, tumor grade, ER, PR and HER2 status
  5. pTNM, tumor grade, Ki67
Board review answer #1
D. pTNM, tumor grade, ER, PR and HER2 status. The new prognostic stage group incorporates biomarkers (ER, PR, HER2) and tumor grade in addition to traditional anatomic pTNM stage factors to more accurately group patients into prognostic groups based on their specific tumor biology. This staging system results in 41% of cases being classified into a better or worse prognostic group.