Comparison of Diagnostic Accuracy of Clinical Measures of Breast Cancer–Related Lymphedema: Area Under the Curve

Smoot BJ, Wong JF, Dodd MJ. Comparison of diagnostic accuracy of clinical measures of breast cancer–related lymphedema: area under the curve.ObjectiveTo compare diagnostic accuracy of measures of breast cancer–related lymphedema (BCRL).DesignCross-sectional design comparing clinical measures with the criterion standard of previous diagnosis of BCRL.SettingUniversity of California San Francisco Translational Science Clinical Research Center.ParticipantsWomen older than 18 years and more than 6 months posttreatment for breast cancer (n=141; 70 with BCRL, 71 without BCRL).InterventionsNot applicable.Main Outcome MeasuresSensitivity, specificity, receiver operator characteristic curve, and area under the curve (AUC) were used to evaluate accuracy.ResultsA total of 141 women were categorized as having (n=70) or not having (n=71) BCRL based on past diagnosis by a health care provider, which was used as the reference standard. Analyses of ROC curves for the continuous outcomes yielded AUC of .68 to .88 (P<.001); of the physical measures bioimpedance spectroscopy yielded the highest accuracy with an AUC of .88 (95% confidence interval, .80–.96) for women whose dominant arm was the affected arm. The lowest accuracy was found using the 2-cm diagnostic cutoff score to identify previously diagnosed BCRL (AUC, .54–.65).ConclusionsOur findings support the use of bioimpedance spectroscopy in the assessment of existing BCRL. Refining diagnostic cutoff values may improve accuracy of diagnosis and warrant further investigation.