High Tech Lymphedema Surveillance Helps Prevent Progression

Roxanne Nelson, RN, BSN

May 08, 2019

A new technique may help in the diagnosis of lymphedema, a dreaded complication that can develop after breast cancer surgery that includes the removal of lymph nodes in the armpit.

When the complication develops, the chronic swelling of the arm can be debilitating, reducing both range of motion and quality of life.

At present, lymphedema is usually diagnosed by measuring the arm circumference with a tape measure, but once it has developed to the point that it can be detected this way, it is often irreversible.

A new technique could lead to earlier diagnosis, and allow earlier instigation of treatment, say a group of researchers reporting on the use of bioimpedance spectroscopy (BIS), a device that uses electrical current to measure intercellular fluid volume.

In the study, women who were assessed by BIS and were referred for early treatment had a 9.8% absolute and a 67% relative reduction in clinically diagnosed lymphedema when compared with women who were assessed with a tape measure. Both groups of patients received the same treatment with compression therapy.

This is the first study of its type, said lead author Sheila Ridner, RN, PhD, from Vanderbilt University School of Nursing in Nashville, Tennessee.

She presented the findings at the 20th Annual Meeting of the American Society of Breast Surgeons, held recently in Dallas, and summarized the results for journalists in a webcast held by the society ahead of the meeting.

The findings suggest that BIS is a highly effective tool for pinpointing patients who are at risk, as fewer women went on to develop clinical lymphedema when referred for therapy using BIS as compared to standard assessment, she said.

"Despite advances in breast-conserving surgery, radiation protocols, and chemotherapy, breast cancer-related lymphedema remains a major source of morbidity and concern in the patient population," Ridner commented at the press briefing.

Less Progression with BIS

Ridner and colleagues conducted a randomized controlled trial that compared progression rates of lymphedema that was detected with BIS with lymphedema that was detected by using volume measurements calculated from tape measure-acquired arm circumference.

A total of 508 patients were included in the planned interim analysis that was presented at the meeting. All patients had been followed for least 12 months post-surgery (median, 17.8 months; interquartile range [IQR], 13–23), and had stage I-III invasive breast cancer or ductal carcinoma in situ that had been treated with at least one of the following: mastectomy; axillary treatment (axillary lymph node dissection; sentinel lymph node biopsy with greater than 6 nodes; axillary radiation), or taxane-based chemotherapy.

Patients who were selected for intervention had experienced a change from pre-surgical baseline of either ≥ 5% volume by tape measure or ≥ 6.5 units by lymphedema index (L-Dex BIS), and were prescribed a compression sleeve and gauntlet to be used for 4 weeks.

The primary endpoint was the rate of lymphedema progression of 10% or greater above baseline and one that required complex decongestive physiotherapy.

The median age of the study participants was 58.8 years, and the majority of the cohort was white (77%) with a median body mass index (BMI) of 27.9 (IQR, 24–33). Close to half reported comorbid cardiovascular disease (44%, n = 223).

Most patients had been diagnosed with stage I breast cancer (56.7%, n = 288) with 39% (n = 198) having stage II/III breast cancer at baseline.

At baseline, the median BIS measurement was 0.0 (IQR: -3 -+3.0) L-Dex units, while arm volume was 1943.2 mL (IQR, 1685–2344) in the at-risk group and 1949.6 mL (IQR, 1667–2335) in the non-at-risk group.

From the 508 participants in the trial, 109 (21.9%) women triggered pre-threshold interventions (68 in the tape measure [TM] group, 41 in the BIS group).

As compared with women in the tape measure group, those measured by BIS had a lower rate of triggering (15.8% BIS vs 28.5% TM; P < .001) as well as a longer time to triggering (9.5 months BIS vs 2.8 months TM; P = .002).

A total of 12 patients progressed to requiring complex decongestive physiotherapy, which included 10 in the tape measure group (14.7%) and 2 in the BIS group (4.9%).

This extrapolated to a 67% relative reduction and a 9.8% absolute reduction (P = .130) in the need for more intensive therapy.

Even though more patients using the tape measure received early intervention, a higher number also developed clinical lymphedema. Ridner commented that assessment with a tape measure leaves more room for human error, while BIS relies on electrical current to gauge fluid resistance between cells, providing extremely specific and precise measurement. BIS is a relatively low cost and non-invasive assessment tool, she added.

"Interim results may support the concept of posttreatment surveillance using BIS for early detection of subclinical lymphedema coupled with early intervention," said Ridner.  "We believe that the 10% reduction is clinically significant for this population."

Area of Interest

Asked to comment for Medscape Medical News, Sarah P. Cate, MD, assistant professor of breast surgery at the Icahn School of Medicine at Mount Sinai in New York City, noted that since the results did not reach statistical significance, it is "unclear if the sample size wasn't large enough or if early intervention does make a difference."

"It's an interesting concept, but I would like to see if they looked at risk factors," she said. The authors did indicate that cardiovascular comorbidity affected 44% of trial participants, as well as a median BMI, but there were no details on patient characteristics.

"We don't know how many women were obese, or how many women had diabetes or an axillary lymph node infection — and developed lymphedema," Cate pointed out. "It would be important for these factors to be teased out."

Cate also emphasized that lymphedema is a very "hot" topic in breast cancer surgery right now, with intense interest into how to be more proactive and how to prevent it. "This is on everyone's mind, so this is an area of interest," she said.

The study was funded by ImpediMed Inc with in-kind donations of garments from medi, and REDCap data capture system funded by the National Institutes of Health. Ridner is employed by Vanderbilt University. She serves as principal investigator for studies funded by ImpediMed Inc and Tactile Medical through contractual agreements between the companies and Vanderbilt University. Cate has disclosed no relevant financial relationships.

20th Annual Meeting of the American Society of Breast Surgeons: Abstract: Interim Analysis Lymphedema "PREVENT" Trial. Presented May 2, 2019.

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