Risk factors for lymphedema in breast cancer survivors, the Iowa Women's Health Study.

Risk factors for lymphedema and related arm symptoms in breast cancer (BC) survivors have not been examined using a large prospective population-based cohort. The Iowa Women's Health Study (IWHS) collected self-reported data for diagnosed lymphedema in 2004, and data for cancer diagnosis, treatment, behavioral and health characteristics between 1986 and 2003. We studied 1,287 women, aged 55-69 at baseline, who developed unilateral BC: n = 104 (8%) with diagnosed lymphedema, n = 475 (37%) with arm symptoms but without diagnosed lymphedema, and n = 708 without lymphedema. Age- and multivariate-adjusted logistic regression models examined risk factors for lymphedema and related arm symptoms (OR [95% confidence interval]). The mean time between BC and the 2004 survey was 8.1 ± 5.0 (mean ± SD) years. After multivariate adjustment, the following cancer characteristics were positively associated with lymphedema: tumor stage (regional vs. in situ: 3.92 [1.61-9.54]), number of excised nodes (highest vs. lowest quintile: 3.52 [1.32-9.34], P (trend) = 0.003), tumor-positive nodes (yes vs. no 2.12 [1.19, 3.79]), and adjuvant chemotherapy (yes vs. no: 3.05 [1.75-5.30]). Several health characteristics were positively associated with lymphedema: baseline body mass index (highest vs. lowest tertile: 3.24 [1.70-6.21]), waist and hip circumference, and general health (fair/poor vs. excellent: 3.44 [1.30-9.06]). Positive associations with arm symptoms were number of excised nodes (highest vs. lowest quintile: 2.38 [1.41-4.03], P (trend) = 0.007), axillary radiation (yes vs. no: 1.72 [1.15-2.57]), and baseline general health (fair/poor vs. excellent: 4.27 [2.60-7.00]). In the IWHS, obesity, poorer general health, and markers of more advanced cancer were risk factors for lymphedema and related arm symptoms in BC survivors.