Dr. Mittendorf Discusses Rationale for Updating the AJCC Staging System

Elizabeth Mittendorf, MD, PhD, Robert and Karen Hale Distinguished Chair in Surgical Oncology, director, Breast Immuno-Oncology Program, Director of Research, Breast Surgical Oncology, Dana-Farber/Brigham and Women’s Cancer Center, discusses the rationale for updating the AJCC staging system in patients with breast cancer. This system was originally developed in the 1970s but is still used today.

For decades, the staging of breast cancer has been based off the anatomic extent of the disease. This looked at the primary tumor, evidence of disease in lymph nodes, and distant metastases, in what’s known as TNM staging.

Since then, a number of different subtypes have been discovered, subtypes dictated by tumor biology, according to Mittendorf. However, the TNM staging did not account for tumor biology, which influences many treatment decisions today. Because of this, the staging system was very dated.