Abstract P1-09-09: Determination of the first evidence-based diagnosis of secondary upper limb lymphedema

Abstract

Abstract Background: The incidence of secondary upper limb lymphedema after treatment for breast cancer is unclear due to the wide variety of measurement tools and diagnostic thresholds that are used in both the literature and clinical practice. Furthermore, this lack of clarity in what constitutes lymphedema or not has prevented the progression of the field of lymphedema. Many of the thresholds have been chosen for ease of use only and have no evidence base to support them. The aim of this study, therefore, was to determine which clinical diagnostic threshold for unilateral upper limb lymphedema has the best sensitivity and specificity when compared to diagnosis by lymphoscintigraphy. Methods: Women with and without a history of secondary upper limb lymphedema were assessed using lymphoscintigraphy, bioimpedance spectroscopy (BIS) as well as volume and circumference measurements using the perometer. Dermal backflow score was determined as the diagnostic criteria for the lymphoscintigraphy and was assessed by an experienced nuclear medicine physician. Determination of the presence of lymphedema by lymphoscintigraphy was compared with diagnosis by both commonly-used and normatively-determined diagnostic thresholds for circumference, volume and bioimpedance. Normatively-and commonly-used diagnostic thresholds examinedWhole arm volumeCircumferenceWhole arm BISNormatively-determined thresholds examined3SD perometry threshold*Single elevated circ (3SD threshold)*3SD Cornish, 20012SD perometry threshold*Adjacent raised circ (3SD threshold)*2SD Cornish, 20013SD frustrum threshold*Single raised threshold (2 SD)*3SD, Ward 20112SD frustum threshold*Adjacent raised circ (2SD threshold)*2SD, Ward 2011 3SD SOAC* 2SD SOAC* Commonly-used thresholds examined200 ml interlimb difference2 cm single interlimb difference 10% differenceAdjacent 2 cm interlimb difference 5 cm SOAC * Dylke et al, 2012; Sum of arm circumferences (SOAC); Circumference measure (Circ) Results: For those with widespread dermal backflow, any clinical diagnostic criteria could differentiate between those with and without lymphedema. In contrast, for those with mild to moderate dermal backflow, only the normatively-determined threshold, set at 2 standard deviations above the norm, for arm circumference and full arm bioimpedance (Cornish et al 2001) had adequate sensitivity and specificity. Both of these thresholds had clinically relevant positive (23 and 10 respectively) and negative (0.2 and 0.3) likelihood ratios. Conclusion: Evidence-based diagnostic thresholds have been established for the diagnosis of secondary upper limb lymphedema. In determining if lymphoedema is present in those with mild lymphedema, normatively-determined circumference and bioimpedance thresholds that account for limb dominance should be used. Adoption of these evidence-based criteria will allow, for the first time, comparison between studies, clarifying the incidence and risk factors for lymphedema, allowing the field to make meaningful progress forward in determining who is at-risk for lymphedema and how to prevent it from developing. Acknowledgements: Cancer Australia and National Breast Cancer Foundation. Citation Format: Sharon L Kilbreath, Elizabeth S Dylke, Geoff P Schembri, Leigh C Ward, Dale L Bailey, Deborah Black, Elizabeth A Bailey, Jane M Beith, Kathryn M Refshauge. Determination of the first evidence-based diagnosis of secondary upper limb lymphedema [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-09.