Development and validation of a nomogram to predict the risk of breast cancer-related lymphedema among Chinese breast cancer survivors

Purpose Breast cancer-related lymphedema (BCRL) is a major long-term complication for post-surgery breast cancer survivors. Although several risk factors have been identified, lifestyle characteristics have been neglected in previous studies. The aim of this study was to develop and validate a nomogram for estimating this population's risk of developing lymphedema, taking into consideration their demographic, clinical, and personal lifestyle behaviors. Methods In a cross-sectional study, we collected data from 775 post-operative breast cancer survivors who had attended a follow-up session in the recent 10 years (primary cohort). Lymphedema was assessed using the Norman telephone questionnaire, self-reported by patients. Multiple logistic regression was used to identify risk factors for lymphedema, including demographic, clinical, and lifestyle-related factors. A nomogram was constructed based on those factors and was validated using a separate group of 314 breast cancer patients (validation cohort). Results The factors independently associated with lymphedema were higher body mass index (BMI), modified radical mastectomy (MRM), postsurgical infection, chemotherapy, radiotherapy, exercise of the affected arm, and the active participation in physical activity (P<0.05). The area under the curve (AUC) values of the primary and the validation cohorts were 0.721 (95% confidence interval: 0.685-0.756) and 0.702 (95% confidence interval: 0.646-0.759), respectively. Conclusions BCRL risk factors include MRM, radiotherapy, chemotherapy, and higher BMI, while the active physical activity behavior of patients appears to be a factor against lymphedema. The nomogram incorporating the patients' clinical and lifestyle factors might be useful for predicting lymphedema in breast cancer survivors.