Clinical Features, Microbial Epidemiology, and Recurrence Risk of Cellulitis in Breast Cancer-Related Lymphedema.

[BACKGROUND] Cellulitis, resulting from impaired lymphatic function, is a debilitating complication of breast cancer-related lymphedema (BCRL) that contributes to lymphedema progression. However, the clinical presentation and microbiologic profile of BCRL-associated cellulitis remain poorly defined. This study investigated the prevalence, clinical features, and treatment outcomes of cellulitis in BCRL, aiming to identify risk factors for recurrence and inform evidence-based treatment strategies.

[METHODS] A retrospective review was conducted of cellulitis episodes among 2920 patients with BCRL treated at a single institution between 2000 and 2024. Demographic, clinical, microbiologic, and treatment data were analyzed. Univariate and multivariable Cox proportional hazards models were used to evaluate risk factors associated with recurrent cellulitis.

[RESULTS] A total of 418 cellulitis episodes were documented among 231 patients with BCRL, indicating a prevalence of 7.9% (231/2920) and a recurrence rate of 39.0% (90/231). Blood cultures were obtained in 255 (61.7%) episodes, of which 33 (12.9%) were positive. Streptococcus agalactiae was the most frequently isolated pathogen (8/33; 24.2%). Risk factors independently associated with recurrence included any radiotherapy (hazard ratio [HR] 2.15; 95% confidence interval [CI] 1.24-3.72; P < 0.01), axillary lymph node dissection (HR 1.96; 95% CI 1.05-3.68; P < 0.05), and shorter time from BCRL diagnosis to the initial cellulitis episode (HR 0.99; 95% CI 0.99-0.99; P < 0.01).

[CONCLUSIONS] Cellulitis is a significant complication of BCRL with a high recurrence rate. Radiotherapy, axillary lymph node dissection, and early cellulitis onset are associated with recurrence. These findings support proactive surveillance and risk-stratified prevention strategies to reduce infection burden and improve outcomes in this high-risk population.