Abstract / Summary
Abstract Background Lymphoedema of the breast is a potential consequence of breast cancer treatment. Questionnaires exist to quantify breast symptoms but evidence for measurement properties is limited. This study aimed to evaluate measurement properties of breast lymphoedema questionnaires and report on frequency and severity of breast symptoms in women with breast cancer. Methods Women following breast conserving surgery and radiotherapy were recruited. Four questionnaires, Breast Lymphoedema Severity Symptom questionnaire (BLYSS), European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire - Breast Symptom Subscale (EORTC-QLQ-BSS), Lymphoedema Symptom Intensity and Distress scale–Trunk (LSIDS-T) and Breast Oedema Bother scale (BOB), were completed three and nine-months after radiotherapy. Measurement properties and breast symptoms were evaluated. Results Questionnaires were completed by 164 women at three-months, and 152 at nine-months post radiotherapy. Internal consistency was strong for all questionnaires (McDonald’s Omega and Cronbach’s ⍺ ≥0.7). Correlation between BLYSS and EORTC-QLQ-BSS and BOB visual analogue scale (BOB-VAS) met the hypothesised level (r s ≥ 0.7) demonstrating construct validity. Exploratory factor analysis demonstrated single factors for individual tools and four factors when all four questionnaires were combined: pain, swelling, breast sensations and hardness. Responsiveness was high for BLYSS and moderate for EORTC-QLQ-BSS and BOB-VAS. Over half the women experienced symptoms ≥twice/week at mild-extreme severity. Breast pain, hardness, oversensitivity and swelling were most reported symptoms. Conclusion The BLYSS demonstrated the strongest measurement properties among the PROMs evaluated with strong internal consistency, construct validity and responsiveness. Breast symptoms were commonly experienced by women after breast cancer treatment.