Easing the ordeal of biopsies

Removing and examining lymph nodes is a routine part of surgery for invasive breast cancer. Determining whether cancer cells have spread to the lymph system helps doctors “stage” the disease -- assess how extensive it is -- and then decide whether additional therapy, such as chemotherapy and radiation, is necessary.

Traditionally, doctors perform a procedure called axillary (meaning underarm) lymph node dissection. The technique is highly accurate in revealing whether the cancer has spread, but it’s plagued by complications, including lymphedema, which is chronic swelling in the arm. A newer technique removes only one or a few lymph nodes -- called the sentinel nodes -- that are most likely to be the first to come into contact with cancer cells as they leave the breast tumor and start to spread.

A new study has found that this procedure is not only a useful way to determine whether the cancer has spread, but that it dramatically reduces discomfort after surgery.

The study, performed at the Mayo Clinic in Rochester, Minn., contributes to a growing body of evidence that sentinel node biopsy is accurate and much easier for women although it too is not complication-free.

Researchers followed 685 women who had sentinel lymph node biopsy and 164 who had both the sentinel nodes removed and the traditional axillary lymph node dissection. Far more women with axillary node dissection suffered lymphedema compared to those having only sentinel node biopsy (34% compared to 6%); they also had more pain (38% compared to 14%) as well as more infection.

“Sentinel node biopsy is currently taking over as the gold standard for staging breast cancer,” said Dr. D. Kay Blanchard, the study’s lead author. “But one of the surprises in this study is that patients [receiving the sentinel node biopsy] still have a fair amount of pain. There are a number of nerves that go through that area of the sentinel nodes. We are trying to increase our awareness of some of these smaller nerves to try to avoid them.”

After more than two years of follow-up, in only one of the 685 women receiving just sentinel lymph node biopsy did the cancer spread to the axillary nodes.

“There haven’t been that many long-term studies. So I think this validates what we’ve been doing with sentinel lymph node biopsy,” says Blanchard. “It really does work.”

The National Cancer Institute is currently overseeing two large, long-term studies comparing the two staging techniques, for breast cancer, however. Preliminary results are expected in about two years.

Meantime, many breast surgeons already offer sentinel lymph node biopsy, Blanchard said. She advises women to ask their doctors which staging procedure they use and how many sentinel lymph node biopsies they have performed. Doctors must inject a dye or radioactive marker to locate the sentinel node, and the procedure takes practice to perfect.

The study was published in the May 12 issue of the Archives of Surgery.