Occult axillary lymph node metastases do not appear to affect overall or recurrence-free survival in patients with early-stage breast cancer, according to research published in the March 15 issue of Cancer.
Yun Wu, M.D., Ph.D., of the University of Texas M.D. Anderson Cancer Center in Houston, and colleagues conducted a study involving 267 patients with early-stage breast cancer who had undergone axillary lymph node dissection (ALND) and were classified as being lymph node negative using routine pathologic evaluation, and who, consequently, did not receive systemic chemotherapy or hormone therapy. Samples were re-evaluated using a more sensitive pathologic method involving serial sectioning with hematoxylin and eosin staining plus immunohistochemical staining to detect occult axillary lymph node metastases.
The researchers note that, using the enhanced detection methods, 15 percent who had been classified as lymph node negative on routine evaluation were found to have occult axillary lymph node metastases. Of these, 20 percent were macrometastases, 40 percent were micrometastases, and 40 percent consisted of isolated tumor cells. However, neither the presence nor size of occult metastases appeared to affect overall or recurrence-free survival in this patient population.
"In summary, for the current study, we reviewed a cohort of patients with early-stage breast cancer who had ALND specimens that were lymph node negative on initial evaluation and did not receive systemic therapy. Enhanced pathologic processing identified occult axillary lymph node metastases in a small subset of those patients (15 percent). Although these patients did not receive systemic chemotherapy or hormone therapy, there were very low recurrence rates in both the occult lymph node metastasis group and in the group without occult metastasis," the authors write.