Background: A number of different classification schemes, with generally similar but not identical criteria, exist to describe the different stages of lymphedema. Criteria may include both subjective and objective assessments. The present study investigated whether bioelectrical impedance parameters had utility in staging breast cancer-related lymphedema. Methods and Results: Hierarchical agglomerative cluster analysis was used to assign women (n = 221) at risk of or with clinically ascribed lymphedema to clusters sharing similar impedance characteristics. Five clusters could be identified with each cluster containing proportions of participants that closely aligned with staging allocation, according to International Society of Lymphology criteria, at initial presentation. The use of cluster analysis for tracking of lymphedema progression or response to treatment is demonstrated. Conclusions: No single assessment provides definitive assignment of a patient to lymphedema stage. Staging is usually achieved by identifying and allocating a patient to a lymphedema stage shared by a group of patients with similar clinical signs. Cluster analysis of impedance data provides similar groupings of patients and could provide a useful adjunct objective assessment for staging lymphedema.
Keywords: bioelectrical impedance spectroscopy (BIS); cluster analysis; impedance parameters; staging.