From Surveillance to Intervention in Breast Cancer-Related Lymphedema: Clinical Thresholds, Longitudinal Monitoring, and Actionable Care Pathways.

Breast cancer-related lymphedema (BCRL) is a common and potentially progressive complication of breast cancer treatment. Although lymphatic dysfunction may precede clinically apparent swelling, uncertainty remains regarding how surveillance findings should be translated into confirmation, intervention, and follow-up. This review synthesized evidence on early detection and prospective surveillance for BCRL, focusing on the transition from measurement to clinical action. A systematic search of PubMed/MEDLINE, Embase, the Cochrane Library, KoreaMed, and KMbase from inception through March 2026 included 57 unique studies addressing diagnostic modalities, intervention thresholds and early management, patient-centered monitoring and self-management, and prospective surveillance strategies. Serial bioimpedance spectroscopy and limb-volume assessment referenced to individual baseline measurements were the most extensively evaluated approaches for identifying clinically meaningful changes before overt BCRL. A lymphedema index increase of at least 6.5 units and a relative limb-volume increase of 5% to 10% were most appropriately interpreted as triggers for confirmatory assessment and consideration of early conservative intervention rather than as stand-alone diagnostic criteria. Ultrasonography and indocyanine green lymphography provided complementary tissue and anatomical information but were better suited to selected clinical assessment than routine surveillance. Evidence supporting patient self-monitoring and health-system implementation remained limited. The clinical value of prospective surveillance depends on linking baseline-based longitudinal monitoring to confirmation of meaningful change, timely intervention, response reassessment, and escalation when necessary. An actionable care pathway integrating objective measurements, symptoms, clinical context, and patient participation may support earlier and more consistent BCRL management throughout breast cancer survivorship.