ASCO Breast Cancer Guidelines Again Favor of Sentinel Node Biopsy, But Differences in Practice Exist

ASCO Breast Cancer Guidelines Again Favor of Sentinel Node Biopsy, But Differences in Practice Exist

The American Society of Clinical Oncology (ASCO) recently updated its guidelines for early stage breast cancer treatment, reaffirming a 2014 recommendation of a “less-is-more” approach that favors a sentinel lymph node biopsy for evaluating and treating patients who may have malignant disease. But a researcher with a key role in these guidelines reports that many surgeons in the U.S. are still routinely performing full lymph node dissections on patients.

“The new guidelines, first established in 2014, seem to have been embraced within academic centers and larger hospitals and cancer centers, but compliance is still quite variable elsewhere,” Gary Lyman, a  breast cancer oncologist at the Fred Hutchinson Cancer Research Center in Seattle, Washington, said in a press release. Lyman, co-director of the Hutchinson Institute for Cancer Outcomes Research (HICOR), is first author of the recommendations, published this  month in the ASCO Journal of Clinical Oncology.

The guidelines reaffirm the more conservative approach of sentinel node biopsy for evaluating breast cancer patients to stage their cancer, to determine if the malignancy has infiltrated the lymph node systems — a common signal of cancer spread — and in planning treatment regimens.

In a major shift in 2014, ASCO guidelines advised surgeons to not routinely harvest all lymph nodes even if a malignancy is detected in one or two sentinel nodes. In contrast, guideline issued in 2005 advised surgeons to use sentinel node biopsies to stage the cancer, and then, if disease is found in the sentinel node, do an axillary lymph node dissection in which all lymph nodes under the patient’s arm  are removed.

Gary H. Lyman, MD, MPH

“In smaller hospitals, particularly in rural areas, many women are still being told they need a full axillary dissection. There are economic issues, geographic issues and education issues for both clinicians and patients,” Lyman said.

Under the new guidelines surgeons are advised to in most cases to forego routine axillary lymph node dissection in women presenting with no evidence of cancer on sentinel node biopsy or when malignancy is detected in only one or two sentinel nodes.

Consequently, most women undergoing lumpectomy and whole breast radiation will be able to avoid having a full lymph node dissection. And this is mostly advantageous because axillary lymph node dissection often has a dramatic negative effect on a patient’s quality of life, with potential side effects that may include infections, pain, lymphedema, and reduced range of limb motion.

“There are cautions. The sentinel node biopsy has to be well-conducted, the tumor should not be greater than 5 centimeters in size, and there should be no other major risk factors. However, approximately two thirds of women meet these criteria,” Lyman said. “Full removal is always an option, and some women want to have all of the lymph nodes taken out.

“But given the down side of the full axillary dissection in terms of quality of life and possible complications, many women who have a lower risk say, ‘I want to avoid those problems,'” said Lyman, who helped pioneer sentinel lymph node biopsy in breast cancer patients 20 years ago and remains influential in shaping ASCO policy for breast cancer treatment.