ORLANDOData from a massive pathologic reanalysis of breast cancer
patients with apparently negative lymph nodes show that women with occult
micrometastases have shorter disease-free survival and are more likely to die
from breast cancer than are women whose nodes are negative on
Lee K. Tan, MD, who led the Memorial Sloan-Kettering research team,
presented the study at the 38th Annual Meeting of the American Society of
Clinical Oncology (abstract 146). Dr. Tan emphasized that this was not a study
of sentinel lymph nodes only, but a reanalysis of multiple nodes removed by
The widespread use of hematoxylin & eosin (H&E) serial sections and
immunohistochemical (IHC) staining for cytokeratin has greatly increased
detection of occult or micrometastatic breast cancer. This has decreased the
false-negative rate in sentinel lymph node biopsy but sparked new concerns
about the importance of the abnormalities detected with these tools.
"Debate has intensified due to sentinel lymph node biopsy. Are we
identifying a subset of patients at risk for recurrence, or are we just
upstaging them with the risk of over-treatment?" Dr. Tan said.
To answer that question, Dr. Tan and her colleagues conducted an in-depth
pathologic reanalysis of specimen blocks from 368 unselected patients with
apparently node-negative breast cancer who had been treated with mastectomy and
axillary lymph node dissection from 1976 to 1978. The analysis included an
average of 17 nodes per patient. Median follow-up among surviving patients was
17.6 years. None had been treated with adjuvant chemotherapy.
A total of 2,470 axillary lymph node blocks were sectioned at two deeper
levels 50 µm apart and stained with H&E and IHC. This generated nearly
10,000 slides, the analysis of which formed the basis for Dr. Tan’s report.