No Need for Additional Pathology of Occult Metastases of Lymph Nodes Initially Found Negative

 

As part of the National Surgical Adjuvant Breast and Bowel Project, researchers evaluated paraffin-embedded tissue blocks of initially negative sentinel nodes from patients with breast cancer. Using routine staining and immunohistochemical staining for cytokeratin, they looked for micrometastases deeper in the tissue than the initial evaluation. Their findings were not used in clinical decision making.

 

In 3887 patients, researchers identified occult metastases in 15.9% (95% confidence interval [CI], 14.7-17.1). Comparing patients in whom occult metastases were found with those in which they were not, researchers found a significant decrease in overall survival (P = .03), disease-free survival (P = .02), and distant-disease–free interval (P = 004). Adjusted hazard ratios were 1.40 (95% CI, 1.05-1.86) for death, 1.31 (95% CI, 1.07-1.60), for any outcome event, and 1.30 (95% CI, 1.02-1.66) for distant disease.

 

 

“The take-home message for women is that the micrometastases are so small, they have very little impact on outcome—only 1.2% at 5 years,” said lead author Donald L. Weaver, MD, in a press release regarding the study, “Pathologists shouldn’t continue to look for micrometastases when the initial evaluation is negative, and oncologists shouldn’t treat patients any differently or change therapy exclusively based on micrometastases.”