Tumor, Node, Metastasis (TNM) staging classification for breast cancer
- Daniel F Hayes, MD
Daniel F Hayes, MD
- Section Editor — Breast Cancer
- Professor of Medicine
- University of Michigan School of Medicine
- Section Editor
- Anees B Chagpar, MD, MSc, MA, MPH, MBA, FACS, FRCS(C)
Anees B Chagpar, MD, MSc, MA, MPH, MBA, FACS, FRCS(C)
- Section Editor — Breast Surgery
- Associate Professor, Department of Surgery
- Yale University School of Medicine
The Tumor, Node, Metastasis (TNM) staging system for breast cancer is an internationally accepted system used to determine the disease stage. This disease stage is used to determine prognosis and guide management. It is also used to facilitate discussions about treatment and prognosis between collaborating providers, as well as between providers and patients.
The TNM staging system correlates important tumor characteristics with survival data to help estimate and follow outcomes. It is based upon a retrospective analysis of survival in diverse samples of patients representing all stages of disease. It reflects the clinical evaluation methods and treatments that are applied to the particular study population. While an individual patient's clinical course and outcome cannot be predicted with certainty, available survival data can help direct treatment decisions and provide an estimate of the likely prognosis.
Periodic revisions are necessary because advanced imaging techniques and treatments evolve and impact survival. The eighth edition of the TNM staging system, which will be effective as of January 1, 2018, includes anatomic stage groups (table 1) as well as prognostic stage groups, which incorporate biomarker testing (table 2) . Staging has traditionally relied on tumor size, involvement of lymph nodes, and presence of metastatic disease. The eighth edition incorporates biologic markers, which improve prognostic discrimination over anatomic staging alone. All newly diagnosed cases through December 31, 2017 should be staged with the seventh edition (table 3) , although the scientific content of the eighth edition manual, summarized below, is valid at this time . However, outside of the United States, the Union for International Cancer Control (UICC) has implemented the eighth edition changes as of January 1, 2017.
The rationale and data supporting the eighth edition of the TNM staging system are discussed here. The initial evaluation, clinical manifestations, diagnosis, treatment, and prognosis of breast cancer are reviewed elsewhere. (See "Overview of the treatment of newly diagnosed, non-metastatic breast cancer" and "Clinical features, diagnosis, and staging of newly diagnosed breast cancer".)
REVISIONS IN STAGING FROM THE SEVENTH TO THE EIGHTH EDITIONS
The eighth edition of the American Joint Committee on Cancer (AJCC) staging manual, going into effect January 1, 2018, outlines a new prognostic staging system that relies not only on the anatomic extent of disease, but also on prognostic biomarkers. In areas in which biomarker testing is performed, prognostic stage groups should be utilized. Although the prognostic staging system provides refined information regarding outcomes, the anatomic staging was retained to allow a common lexicon for patients treated worldwide who may not have access to biomarker testing. Additionally, the anatomic staging system provides a link to cases treated historically, staged using previous editions of the TNM system.
- AJCC (American Joint Committee on Cancer) Cancer Staging Manual, 8th edition, Amin MB, Edge SB, Greene FL et al. (Eds), Springer, Chicago 2017.
- AJCC (American Joint Committee on Cancer). Cancer Staging Manual, 7th edition, Edge SB, Byrd DR, Compton CC, et al (Eds), Springer-Verlag, New York 2010. p.347.
- 8th Edition Implementation Project https://cancerstaging.org/8thEdImplementation/Pages/default.aspx (Accessed on December 05, 2016).
- Sparano JA, Gray RJ, Makower DF, et al. Prospective Validation of a 21-Gene Expression Assay in Breast Cancer. N Engl J Med 2015; 373:2005.
- REVISIONS IN STAGING FROM THE SEVENTH TO THE EIGHTH EDITIONS
- Incorporation of biologic prognostic factors
- THE EIGHTH EDITION TNM STAGING SYSTEM
- Clinical versus pathologic staging
- Primary tumor classification
- - Changes in tumor (T) classification
- Regional lymph nodes (N)
- - Clinical classification of regional lymph nodes
- - Pathologic classification of regional lymph nodes
- - Changes in nodes (N) classification
- Distant metastasis (M)
- - Changes in metastases (M) classification
- Clarifications regarding postneoadjuvant staging
- Anatomic stage groupings
- Prognostic stage groupings
- THE SEVENTH EDITION TNM STAGING SYSTEM
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS