Biopsy of Internal Nodes May Aid Breast Cancer Patients

Researchers in The Netherlands are pioneering the practice of taking biopsies from lymph nodes behind the sternum at the same time they take biopsies of the nodes under the armpits. They believe this will enable doctors to detect more accurately where cancer cells have metastasized and to select more appropriate treatment, which could lengthen survival.

While axillary lymph nodes are routinely checked in women with breast cancer, the internal mammary nodes are not. However, the status of the internal mammary (IM) lymph nodes is known to be an important prognostic factor, since women with IM metastases usually do less well. The internal mammary sentinel node (IM-SN) can be identified by a scan following injection of a radioactive tracer into the patient.

The IM-SN biopsy is more difficult to perform than an axillary SN biopsy. The biopsy involves making a small cut (2-2.5 cm) over the area adjacent to the breast bone, through which the radioactive IM-SN is removed surgically. IM-SN biopsy is successful in 65% of cases, according to Dr. van der Ent, a senior surgeon at Maaslandziekenhuis, in Sittard (The Netherlands), who presented the procedure at the 3rd European Breast Cancer Conference in Barcelona (Spain).

Dr. van der Ent and his colleagues have performed axillary and IM-SN biopsies on 470 breast cancer patients to date and have found metastases in 20-25% of them. In a small proportion (5%) of patients, the biopsies revealed no metastases in the axillary nodes but only metastases in the IM-SNs. Thus, if no biopsy had been performed on the IM-SN, these few patients might then have had less appropriate treatment because doctors would have presumed there were no metastases at all.

"We believe that IM-SN biopsy, by improving nodal staging, recognizes high-risk patients,” said Dr. van der Ent. "By incorporating the diagnostic information of IM-SN in future trials, we could develop more individualized treatment protocols, which in turn might lead to a survival advantage.”