Cross-cultural adaptation and comparative psychometric evaluation of four patient-reported outcome measures for breast cancer-related lymphedema: measurement properties and clinical discrimination.

Background: Breast cancer-related lymphedema (BCRL) can substantially impair health-related quality of life. Patient-reported outcome measures (PROMs) may complement objective limb measurements by capturing symptoms, functional limitations, and psychosocial consequences; however, comparative evidence on BCRL-specific PROMs and validated Chinese versions remains limited. This study aimed to cross-culturally adapt four BCRL-specific PROMs and compare their classical and Rasch measurement properties, known-groups validity, and exploratory discrimination relative to a circumference-based reference classification. Methods: The Upper Limb Lymphedema 27 (ULL-27), Lymphedema Quality of Life Questionnaire for Upper Limbs (LYMQOL-ARM), Lymphedema Functioning, Disability and Health Questionnaire for Upper Limb Lymphedema (Lymph-ICF-UL), and Lymphedema Life Impact Scale Version 2 (LLIS) were translated and culturally adapted according to international standards. In total, 204 Chinese women treated for breast cancer participated: 104 completed ULL-27 and LYMQOL-ARM, and 100 completed Lymph-ICF-UL and LLIS. Content validity, internal consistency, construct validity, known-groups validity across BCRL stages, and Rasch measurement properties were evaluated. Exploratory receiver operating characteristic (ROC) analyses assessed discrimination relative to the study reference classification. PROM scores were also compared between axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB) recipients who did not meet the circumference-based BCRL criterion. Results: The four PROMs were generally comprehensible and culturally relevant. All subscales demonstrated adequate weighted likelihood estimation reliability (0.730-0.921) and high internal consistency (Cronbach's α >0.90). Of 93 items, 79 (84.9%) showed acceptable fit, and all response-category thresholds were ordered. Evidence generally supported essential unidimensionality, although local dependence, floor effects, and selected measurement-invariance concerns were identified. LLIS and Lymph-ICF-UL scores differed most consistently across BCRL stages. The largest area under the curve (AUC) estimates were observed for Lymph-ICF-UL Symptoms [0.734; 95% confidence interval (CI): 0.633-0.834], LLIS Physical (0.725; 95% CI: 0.625-0.825), and LLIS total score (0.680; 95% CI: 0.573-0.787); no pairwise AUC difference remained significant after Holm adjustment. Among circumference-negative participants, LLIS total, Physical, and Psychosocial scores and Lymph-ICF-UL Symptoms and Mental Function scores were significantly higher after ALND than after SLNB. Conclusions: The Chinese versions of the four PROMs showed generally supportive but nonuniform measurement properties. LLIS and Lymph-ICF-UL performed comparatively well in distinguishing clinically defined BCRL stages, while LLIS Physical and Lymph-ICF-UL Symptoms showed favorable lower-end targeting and the largest exploratory AUC estimates. These PROMs may complement clinical evaluation and objective limb assessment by capturing patient-reported burden not fully reflected by circumference measurements. Because the ROC analyses used an imperfect reference classification and the study was cross-sectional, diagnostic and predictive validity cannot be established. Larger, prospectively powered longitudinal studies incorporating more sensitive objective assessments are required.