The new TNM-based staging of breast cancer

Abstract

This review describes the changes that have been implemented in the Tumor-Node-Metastasis (TNM)-based staging of breast cancers by the new, 8th editions of the relevant Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) publications. After giving a background for TNM being the common language of cancer staging and related activities like cancer treatment and registration, it summarizes not only the changes but reviews some highlights important for pathologists, and lists and comments on the differences between the publications and diagnostic practices based on them. A section is dedicated to the prognostic stages of breast carcinomas introduced in the AJCC Cancer Staging Manual, but not mentioned in the UICC TNM classification of malignant tumors. A few issues that are not appropriately covered by TNM according to the authors' view (e.g., multifocal tumors, larger lymph node metastases identified by molecular methods, the heterogeneous prognosis of M1-defined stage IV disease) close the review with the final thoughts raising the vision of a potential loss of the common staging language.

Impact of biomarkers and genetic profiling on breast cancer prognostication: A comparative analysis of the 8th edition of breast cancer staging system

“…The proportions of HER2+ BCs also differ: in the MD Anderson cohort, 9.2% of BCs were HER2+, in contrast to 14.0% BCs in NYULMC cohort. Even though HER2+ BCs are a biologically aggressive subgroup, and carry a poor prognosis, HER2‐targeted therapy has dramatically improved the outcome of HER2+ BCs(). Currently, HER2+ BCs are regarded as a “favorable” subgroup, provided that the patients receive appropriate anti‐HER2‐targeted treatment.…”

“…Triple negative (TN) BCs constitute 10%‐17% of BCs and, in general, carry a poor prognosis . Because of their intrinsic aggressive behavior, and the lack of targeted therapy, TN status has a global upstaging effect in the TNM + Biomarkers system across all stage groups as seen in our study and several other published studies . The TNM + Biomarkers system considers all TNBCs as one homogenous group of BCs with equally poor prognosis .…”

“…Estrogen‐ and progesterone‐positive BCs tend to have lower histologic grade than ER−/PR− BCs and respond well to hormonal therapy . In general, the TNM + Biomarkers system downstages N0‐1M0, ER+/PR+ BCs . For example, T2N1M0/T3N0M0 BCs fall in TNM stage group IIB, but using the TNM + Biomarkers system, the ER+/PR+ status shifts the tumors to either stage IA or IIA, depending on the histologic grade .…”

The American Joint Commission Cancer 8th Edition Prognostic Stage Including Oncotype DX® Recurrence Score: Impact on Staging of Early Breast Cancer

“…Difficulties with the proposed PS include the complex nature of the staging system with potential for lack of reproducibility [38]. Realisation that certain tumour profiles could not be assigned a PS has been addressed in a recent update [39].…”

Relationship between Ribosomal Protein S6-pS240 Expression and other Prognostic Factors in Non-Special Type Invasive Breast Cancer

“…Numerous established prognostic markers of breast cancer (NST) exist, such as grade of differentiation, tumor size, regional lymph node status, histological type, proliferation index, and HER2/ neu amplification or expression of hormone receptors [6][7][8][9] . Multiple unfavorable genetic events and subsequent molecular alterations may trigger tumor progression.…”