Various tests – ranging from a tape measure to sophisticated imaging technology – show only low to moderate agreement in diagnosing breast cancer-related lymphedema (BRCL), reports a study in Rehabilitation Oncology, official journal of APTA Oncology, an academy of the American Physical Therapy Association (APTA).

The journal is published in the Lippincott portfolio by Wolters Kluwer.

"For years, the lack of a standardised assessment for BRCL has been recognised as an impediment to research and clinical practice," comments lead author Cheryl L.Brunelle, PT, MS, CCS, CLT, of Massachusetts General Hospital.

"Our findings highlight the unacceptably low levels of agreement between different tests for recognising this complication, and the urgent need to establish standardised diagnostic criteria."

No ’gold standard’ for diagnostic tests for lymphedema

Breast cancer-related lymphedema is a sequela of breast cancer surgery and lymph node radiation, characterised by uncomfortable swelling in the trunk, breast, or arm on the side of surgery.

Early and accurate diagnosis is needed to enable effective treatments for BRCL.

Although various tests and diagnostic criteria have been used, there is still no "gold standard" test for identifying patients with lymphedema.

The authors’ hospital has introduced routine lymphedema screening for women undergoing breast and lymph node surgery – including measurements of arm volume performed before and after surgery.

In the new study, the researchers compared the performance of different tests and diagnostic criteria for lymphedema.

Tests included relative and absolute differences in arm volume – assessed using a tape measure – including comparison of the treated and untreated sides, and with optoelectronic limb volumetry, which uses infrared light.

The researchers also utilised bioimpedance spectroscopy (BIS), which uses very low-strength electrical current to characterise extracellular fluid levels.

'Clinically unacceptable' differences between tests for BRCL

Of the 57 patients studied, 21 were diagnosed with BCRL, based on a 10% increase in relative volume change (RVC) from before breast surgery.

This high incidence was anticipated as participants with BCRL were actively accrued.

Whether preoperative baseline measures were integrated into BCRL diagnosis or not, diagnostic agreement was "poor and insignificant.”

In other comparisons evaluating RVC versus optoelectronic limb volumetry or varying diagnostic cutoff points, agreement was "statistically moderate at best." Ms. Brunelle and coauthors write: "Clinically, this is unacceptable as it would result in 40% to 60% diagnostic disagreement utilising different diagnostic thresholds."

Test performance varied based on the presence of physical signs and symptoms of lymphedema – specifically, swelling or a feeling of "heaviness" in the arm, However, "every participant reporting heaviness or swelling met the diagnostic criteria for BCRL," the researchers write.

They believe that diagnosis of BRCL should incorporate patient-reported symptoms and clinical examination findings.

"The proportion of women diagnosed with BCRL after breast cancer treatment varies greatly depending on the measurement tool and the diagnostic criteria utilised," Ms. Brunelle and coauthors conclude.

They emphasise the need for rigorously designed studies to develop standardised guidelines for BRCL diagnosis – including integration of preoperative baseline measurements.

Source: Wolters Kluwer Health