Isolated Breast Cancer Cells In Sentinel Lymph Node Associated With Non-Sentinel Lymph Node Metastases

Numerous studies have examined the risk of metastatic tumors in other lymph nodes associated with isolated tumor cells in a sentinel lymph node. However, the results from those studies have been inconsistent, and no standard recommendations regarding the use of axillary lymph node dissection have been made.

To better understand the relationship between isolated tumor cells in the sentinel lymph node and the likelihood of disease spread to other lymph nodes, Paul van Diest, M.D., Ph.D., of the University Medical Center Utrecht in The Netherlands and colleagues reviewed 29 published studies that included 836 patients.

The overall pooled risk estimate was 12.3 percent. The pooled risk was marginally higher than the risk of a false-negative sentinel lymph node biopsy but marginally lower than the risk of non-sentinel lymph node metastases in patients with micrometastases, who are currently eligible for axillary lymph node dissection. Not all of the original studies provided information on the size of the non-sentinel lymph node tumors, but in 10 studies that classified the non-sentinel lymph node metastases according to size, 36 of the 56 women (64 percent) with isolated tumor cells had macrometastases, greater than 2 mm in diameter.

"In conclusion, results on isolated tumor cells in the sentinel lymph node are somewhat controversial, and there is still doubt about the need for axillary lymph node dissection after finding isolated tumor cells in the sentinel lymph node," the authors write. A wait-and-see approach may be appropriate for some women, while axillary lymph node dissection may be appropriate for women if they are unsure about whether to undergo adjuvant systemic therapy.

This research was published in the Journal of the National Cancer Institute November 11, 2008.