Clifford A. Hudis, MD, Chief, Breast Cancer Medicine Service, Memorial Sloan-Kettering Cancer Center, discusses the utility of detailed information on the axillary lymph node status for the management of early-stage breast cancer.
Historically, physicians have been taught that the prognosis will worsen as the number of nodes involved increases, which denotes a higher risk for recurrence and warrants the use of chemotherapy. The idea behind this method is a relative risk reduction when giving chemotherapy; the higher the risk the greater the measureable benefit.
Chemotherapy is not always effective and is unique in regards to risks and benefits. Hudis provides tamoxifen as an example; in estrogen receptor (ER)-positive breast cancer tamoxifen is very successful and demonstrates a large benefit, however ER-negative patients do not receive any benefits. The effects are independent of anatomy and are derived from biology and the presence of a biomarker.
A tumors susceptibility to chemotherapy is also based on certain biological subtypes. Some cancers are more sensitive than others. Chemotherapy sensitivity is driven by biological states, not anatomy. Hudis notes that this conclusion results in it no longer being necessary to have extremely accurate historical lymph node status information to make a treatment decision.
In the last decade, there have been tremendous improvements in the treatment of HER2-positive breast cancer with new HER2-targeted agents improving survival in both the adjuvant and metastatic settings.