Patient-reported lower limb edema after primary radiotherapy for prostate cancer

Abstract

Background Secondary lymphedema is a known side effect to radiotherapy (RT), but limited information regarding prevalence and risk factors for lower limb edema (LLE) after curative radiotherapy in patients with prostate cancer (PCa) is available. This study provides a descriptive analysis of patient-reported LLE with analysis of risk factors in a cohort of patients with PCa treated with curative RT. Material and methods A total of 302 patients with PCa with prospective registration of patient-reported LLE (EORTC QLQ-PR25 (Question 46)) were included. Analysis of LLE was done with the calculation of prevalence rates and Kaplan-Meier statistics. Risk factors for LLE were analyzed multivariate with Cox regression analysis. Results At a median follow-up of 15 (3–51) months, the overall crude incidence of patients reporting ‘quite a bit’ or ‘a lot’ of LLE was 49 (16.2%) and 21 (7.0%), respectively. The baseline prevalence rate of ‘quite a bit’ and ‘a lot’ of LLE was 5.0% and 0.8%, respectively. During follow-up the prevalence rate for ‘quite a bit’ or ‘a lot’ of LLE increased significantly and remained constant from 6 months where 11.5% (±1.7%) reported ‘quite a bit’ and 2.9% (±0.5%) reported ‘very much’ LLE (p < 0.001), respectively. Significant risk factors (p < 0.10) for LLE in univariate analysis included lymph node irradiation (HR:2.325), baseline Body Mass Index (BMI) (HR:1.100), Charlson Comorbidity Index (HR:1.227), Androgen Deprivation Therapy (HR:2,979), and Performance Status (HR:0.594). Only high BMI (HR:1.091) remained significant in multivariate analysis with a three-fold increase in LLE in patients with BMI ≥ 30 compared to normal weight patients. Conclusion Severe patient-reported LLE after curative RT for PCa is rare. Significantly more patients with a high BMI report ‘quite a bit’ or ‘very much’ LLE compared to patients with a normal BMI. Obese PCa patients could be offered a rehabilitation program for early detection and management of LLE.