LAS VEGAS – About half of breast cancer patients without palpable lymphadenopathy but with preoperative ultrasound-guided, biopsy-proven axillary lymph node metastases have N1 disease, according to a review of 129 women.
Among the 30 women with a primary tumor 2 cm or smaller and only one abnormal lymph node on axillary ultrasound, 22 (73%) had metastases limited to the one lymph node, suggesting that such patients “may undergo ... sentinel lymph node biopsy” instead of a complete axillary lymph node dissection (ALND), the investigators concluded.
M. Alexander Otto/Frontline Medical News
Dr. Rubie Sue Jackson
The problem that has come up in clinical practice is that axillary ultrasound is now a routine part of breast cancer workup, but the original trial didn’t address ultrasound, said senior investigator Rubie Sue Jackson, MD, at the annual meeting of the American Society of Breast Surgeons. As a result, “surgeons don’t know what to do with an ultrasound-detected suspicious node. I think a lot of surgeons, if they detect a positive lymph node by ultrasound, even if it’s nonpalpable, would not consider the patient a candidate for sentinel lymph node biopsy. Our data suggest that many of these patients are being overtreated if they have an upfront axillary lymph node dissection,” she said.
The 129 women had 1-3 suspicious, nonpalpable nodes on ultrasound that turned out to have metastatic disease on needle biopsy. They all had subsequent ALNDs.
On final pathology, 67 women (52%) had only one metastatic node. For those women, a sentinel lymph node biopsy was likely all that they required. “They probably did not benefit from having an ALND,” said Dr. Jackson, a breast surgeon at the Anne Arundel Medical Center in Annapolis, Md. The other 62 women (48%) had N2-3 disease.
A primary tumor sized 2 cm or smaller (P = .012); nonlobular histology (P = .013), and having only one suspicious nonpalpable node on ultrasound (P = .008) were all associated with NI disease. Of the women who met the criteria, only eight (27%) had N 2-3 disease (P = .007).
“Patients meeting the three criteria are particularly unlikely to have three or more positive sentinel lymph nodes” and require subsequent ALND. “You don’t need to do a complete axillary lymph node dissection upfront, as long as they are getting a lumpectomy and whole breast radiation,” Dr. Jackson said.
These days at Anne Arundel, “we do the axillary ultrasound, we biopsy the lymph node if it looks suspicious, but we don’t feel forced to do an ALND. If a patient has tumor biology that’s likely to be highly responsive, we do upfront chemotherapy. If they have luminal tumor biology that’s not going to be very responsive to neoadjuvant therapy,” with one or two suspicious nodes, “and they are planning to get breast conserving therapy, I would do a sentinel lymph node biopsy and x-ray the specimen to make sure that I’ve retrieved the clip,” she said.
Dr. Jackson didn’t have any disclosures, and there was no industry funding for the work.