By Kristina Rebelo
SAN DIEGO -- April 15, 2008 -- A device that measures arm oedema in breast cancer patients is an accurate method for documenting either post-treatment lymphoedema or those at risk for chronic lymphoedema after breast cancer treatment, according to a study released here at the American Society of Breast Disease (ASBD) 32nd Annual Symposium.
Upper-extremity lymphoedema following treatment for breast cancer is not well understood. "We're trying to approach lymphoedema from a rigorous scientific viewpoint, because it hasn't been done before," said study coauthor Colleen D. Murphy, MD, Breast Surgery Fellow, Department of Surgical Oncology, Massachusetts General Hospital, Boston, Massachusetts. To date, there has not been a standard definition of post-treatment lymphoedema, and the more traditional methods of limb measurement (eg, tape measure) are often poorly reproducible.
In Dr. Murphy's ongoing study, a device called a Perometer is used to measure arm volumes of women undergoing sentinel node biopsy (SNB) or axillary lymph node dissection (ALND) for primary breast cancer. Preoperative arm measurements are compared with measurements taken postoperatively and then again at 6-month intervals. At each point in time, the relative volume change (RVC) of the treated arm is calculated using volume ratios of the treated to the nontreated side compared with a preoperative baseline measurement.
Of 433 patients evaluated preoperatively to date, 177 have at least 2 postoperative measurements or 1 postoperative measurement and 6 months or more of follow-up (35.6% after ALND and 64.4% after SNB).
At a median follow-up of 9.8 months, an RVC of 10% or greater developed in 1 of the 114 SNB patients and in 4 of the 63 ALND patients. An RVC of 5% to 9% developed in 10 of the 114 patients undergoing SNB and 8 of the 63 patients undergoing ALND.
The median time to development of lymphoedema was 5.6 months for those in the RVC 10%-or-greater category, and 6.3 months for those in the RVC 5%-to-9% category.
In 10 patients, a transient RVC increase of 5% or greater occurred at a median follow-up of 1.4 months; however, only 2 of these patients developed a persistent lymphoedema measurement of 5% or greater at 9.8 months.
Of 5 patients with RVC 10% or greater, 3 had mastectomy plus ALND, 1 had lumpectomy plus ALND, and 1 had lumpectomy plus SNB. Four of these patients received radiation therapy, including 2 with supraclavicular fields and 1 with supraclavicular plus axillary fields.
"Previously, a large number of [lymphoedema] patients were unrecognised," Dr. Murphy said in a poster presentation on April 11. "This method gives us more accuracy."
One important finding, added Dr. Murphy, was that many patients have unequal arm volumes prior to surgery. At baseline there was a mean volume difference of 3.2% between an individual patient's left and right arm, with 18.4% of patients having over a 5% difference in mean volume between arms.
"Our goal is to develop treatment [for lymphoedema] after identifying risk factors, such as blood pressure variations or even air travel."
The Perometer is produced by Pero-System Messgerate GmbH, Wuppertal, Germany.
[Presentation title: Prospective Evaluation of Arm Edema in Breast Cancer Patients After Axillary Surgery Using the Perometer. Poster F-24.]
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