Comparison of diagnostic accuracy of clinical measures of breast cancer-related lymphedema: area under the curve

Abstract

Objective: To compare diagnostic accuracy of measures of breast cancer-related lymphedema (BCRL).

Design: Cross-sectional design comparing clinical measures with the criterion standard of previous diagnosis of BCRL.

Setting: University of California San Francisco Translational Science Clinical Research Center.

Participants: Women older than 18 years and more than 6 months posttreatment for breast cancer (n=141; 70 with BCRL, 71 without BCRL).

Interventions: Not applicable.

Main outcome measures: Sensitivity, specificity, receiver operator characteristic curve, and area under the curve (AUC) were used to evaluate accuracy.

Results: A 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).

Conclusions: Our 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.

Fig 1

Classification of lymphedema based on the NQ.

Fig 2

ROC curve for continuous variables.