Validation of a breast cancer nomogram to predict lymphedema in a Chinese population.

ABSTRACT

BACKGROUND: Upper arm lymphedema (LE) is a common complication after axillary lymph node dissection (ALND) in breast cancer patients. This retrospective cohort study aimed to validate a published nomogram to predict the risk of LE in the Chinese breast cancer patients. METHODS: A total of 409 breast cancer patients who underwent breast cancer surgery and ALND (level I and II) were identified. Cox regression analysis was used to identify the risk factors for LE. The nomogram predictive of LE of breast cancer was evaluated by receiver-operating curve analysis, calibration plots, and Kaplan-Meier analysis in our study population. RESULTS: With a median follow-up of 68 months, the 5-year cumulative incidence of LE was 22.3%. Higher body mass index (hazard ratio [HR] = 1.06, 95% CI 1.00-1.13), neoadjuvant chemotherapy (HR = 3.76, 95% CI 2.29-6.20), larger extend of axillary surgery (level I/II/III versus level I/II HR = 2.39, 95% CI 1.30-4.37), and radiotherapy (HR = 4.90, 95% CI 1.90-12.5) were independently associated with LE. The AUC value of the nomogram was 0.706 (95% CI 0.648-0.752). A high-risk subgroup of patients defined by nomogram had significantly higher cumulative risk of LE than those in the low-risk subgroups (P < 0.01). The calibration plots revealed that the nomogram was well calibrated (Hosmer-Lemeshow test, P = 0.0634). CONCLUSIONS: The nomogram to predict the risk of LE in breast cancer patients with ALND has been validated to be discriminative and accurate. More studies are needed to evaluate the impact of other factors (lifestyle, behaviors, and so forth) on the performance of the nomogram.