Risk factors for lymphedema and method of assessment in endometrial cancer: a prospective longitudinal multicenter study.

ABSTRACT

OBJECTIVE: The aim of the study was to determine risk factors for lymphedema of the lower limbs, assessed by four methods, 1 year after surgery for endometrial cancer. METHODS: A prospective longitudinal multicenter study was conducted in 14 Swedish hospitals. 235 women with endometrial cancer were included; 116 underwent surgery including lymphadenectomy, and 119 had surgery without lymphadenectomy. Lymphedema was assessed preoperatively and 1 year postoperatively objectively by systematic circumferential measurements of the legs, enabling volume estimation addressed as (1) crude volume and (2) body mass index-standardized volume, or (3) clinical grading, and (4) subjectively by patient-reported perception of leg swelling. In volume estimation, lymphedema was defined as a volume increase ≥10%. Risk factors were analyzed using forward stepwise logistic regression models and presented as adjusted odds ratio (aOR) and 95% confidence interval (95% CI). RESULTS: Risk factors varied substantially, depending on the method of determining lymphedema. Lymphadenectomy was a risk factor for lymphedema when assessed by body mass index-standardized volume (aOR 14.42, 95% CI 3.49 to 59.62), clinical grading (aOR 2.11, 95% CI 1.04 to 4.29), and patient-perceived swelling (aOR 2.51, 95% CI 1.33 to 4.73), but not when evaluated by crude volume. Adjuvant radiotherapy was only a risk factor for lymphedema when assessed by body mass index-standardized volume (aOR 15.02, 95% CI 2.34 to 96.57). Aging was a risk factor for lymphedema when assessed by body mass index-standardized volume (aOR 1.07, 95% CI 1.00 to 1.15) and patient-perceived swelling (aOR 1.06, 95% CI 1.02 to 1.10), but not when assessed by crude volume or clinical grading. Increase in body mass index was a risk factor for lymphedema when estimated by crude volume (aOR 1.92, 95% CI 1.36 to 2.71) and patient-perceived swelling (aOR 1.36, 95% CI 1.11 to 1.66), but not by body mass index-standardized volume or clinical grading. The extent of lymphadenectomy was strongly predictive for the development of lymphedema when assessed by body mass index-standardized volume and patient-perceived swelling, but not by crude volume or clinical grading. CONCLUSION: Apparent risk factors for lymphedema differed considerably depending on the method used to determine lymphedema. This highlights the need for a 'gold standard' method when addressing lymphedema for determining risk factors.