Sparing the Scalpel in Lymph Node Biopsies

Breast cancer patients have sentinel lymph node (SLN) biopsies to determine if the cancer has spread to the lymph nodes. This is a surgical procedure and has its risks. A new method being investigated may not require a scalpel.

Investigators have found that a new molecular fluorescent imaging technique can illuminate two cell markers that show up when breast cancer has spread to the lymph nodes.

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Researchers at Moffitt Cancer Center and other institutions have developed probes that use this new imaging technology to non-invasively detect lymph node - technically known as axillary nodal (ALN) metastasis.

"Because of the unreliability of the SLN biopsy and its potential for adverse effects, a noninvasive, more accurate method to assess lymph node involvement is needed," corresponding author David L. Morse, Ph.D., an associate member at Moffitt, said.

SNLs, the authors note, don't detect 5-10 percent of ALN disease and complications after the surgery can range from lymphedema (swelling of the arm) to nerve injury.

Researchers from Moffitt, the University of Arizona and University of Florida, used two cell markers that promote tumor growth - CAIX and CAXII - that are seen in lymph node metastasis and missing from normal tissues.

They then developed agents that latch onto and bind with the markers. The fluorescent imaging probes were able to detect ALN in mouse models of metastasized breast cancer.

“The imaging probes detected tumor cells in ALNs with high sensitivity,” explained Morse. “Either CAIX or CAXII were expressed in 100 percent of the breast cancer lymph node metastasis samples we surveyed in this study.”

Patrick D. Maguire, M.D., a radiation oncologist in North Carolina and author of When Cancer Hits Home: An Empowered Patient is the Best Weapon Against Cancer, told dailyRx, "The potential for detecting potential lymph node metastasis non-invasively for patients diagnosed with breast cancer using molecular probes is exciting, albeit very preliminary.

"The testing of the CAXI and CAXII probes in a clinical setting, in comparison to the current" gold standard" of sentinel lymph node  biopsy may be valuable," said Dr. Maguire, who was not involved in the study.

He goes on to dispute the characterization of SLN biopsies. "I would argue with the authors, however, regarding the efficacy and toxicity of SLN biopsy. An accuracy rate of about 95% is hard to match (tough job for these new probes), and the side effects from SLN are usually minor in experienced surgeons' hands."

This research published in a recent issue of Clinical Cancer Research, a publication of the American Association for Cancer Research.