Ultrasound targets lymph node recurrence in breast cancer

Ultrasound is an effective way to monitor lymph node recurrence after breast cancer surgery, South Korean researchers report.

Regional lymph node recurrence (LNR) affects just 2% to 16% of patients with any stage of breast cancer but is difficult to manage and associated with poor prognosis. One version, supraclavicular LNR, is associated with concurrent or subsequent distant metastasis.

LNR detection remains challenging. Physical exams result in a high false-negative rate (39%), and mammography's field-of-view doesn't cover the entire axilla.

The Korean study included 1817 patients, all imaged with ultrasound. Thirty-nine of them (2.1%) had LNR; for 11 of them the LNR was ipsilateral (Radiol 2009;252:673-681). Nine lesions were palpable.

The LNR findings were confirmed by cytopathologic results, clinical follow-up, and imaging studies like CT, MR, or FDG-PET. Ultrasound sensitivity was 76.9% and specificity was 98.7%. Distant metastases were found more frequently in patients with ipsilateral LNR (62%) than in those without (2.3%).

"On the basis of this result, imaging surveillance for distant metastases should be performed when ipsilateral LNR is detected at screening ultrasound," said lead author Dr. Hee Jung Moon, from the radiology department at the Research Institute of Radiological Science in Seoul, South Korea.

In Korea, ultrasound examinations of the bilateral axillary and supraclavicular lymph node areas are routinely included for patients with a history of mastectomy or breast conservation therapy. A clinical exam is performed every six months for the two to three years after such procedures and annually thereafter.

Standard practice in the U.S. at this time is not to monitor for lymph node recurrence in asymptomatic patients, according to Dr. Cherie Kuzmiak, an associate professor of radiology at the Lineberger Comprehensive Cancer Center, University of North Carolina-Chapel Hill.

"The yield for ultrasound is extremely low for lymph node recurrence, which limits the value of this study," she said.

Currently, most patients in the U.S. undergo sentinel node sampling. If the sample is negative, then the probability is low there is LNR in the axilia, she said.

But ultrasound could prove useful for asymptomatic patients, she said.

"If I can find something in a patient who is asymptomatic, it will better their survival rate than if I found it after chemotherapy was initiated," she said.

Ultrasound could prove useful for imaging LNR in the future, and this study in particular opens up the topic for further discussion in the U.S., according to Kuzmiak.