The impact of malnutrition on chemotherapy toxicity and quality of life in advanced breast cancer patients.

349 Background: Sarcopenia has not been recognized as a problem in breast cancer. There was still limited data whether sarcopenia related to chemotherapy toxicity and impacted to quality of life. The aim is to know the role of sarcopenia on chemotherapy toxicity and changed of quality of life after breast cancer patients underwent 3 cycles of chemotherapy. Methods: This prospective cohort study was conducted in Siloam Lippo Village since October 2024 until February 2025. Breast cancer women patients with age 18- to 59-year-old who underwent chemotherapy will be evaluated for malnutrition using malnutrition screening tool (MST) questionnaire. Evaluation of chemotherapy toxicity and quality of life with National cancer institute common toxicity criteria and European Organization for research and treatment of cancer care quality of life 30 and BRE-23. Results: A total of 55 breast cancer subjects with median age 47(25-59) year old, 38 (14.5%) in metastatic stage, 61.6% with before menopause, 61.6% got taxeme based chemotherapy. Malnutrition was found in 18(32.7%) cases. Three of eighteen subjects had body mass index less than 18.5 kg/m2. Malnutrition before chemotherapy associated with toxicities after first, second, and third cycles of chemotherapy with adjusted OR 1.53(0.62-4.56); 2.34(1.54-41.19); and 1.98(1.1-14.01), respectively. Malnutrition associated with changed of quality-of-life scores of loss of appetite, constipation, and financial loss domains with adjusted OR 2.23(0.27- 18.63), 3.42(0.75-15.50), and 5.50(1.41-21.42) respectively after underwent three cycles of chemotherapy. Conclusions: Malnutrition before chemotherapy associated with chemotherapy toxicity and decreased quality of life score for several domain of symptom scales. Further studies need should focus on the intervention of malnutrition and the impact on quality of life. Awareness about malnutrition screening should be done in advanced breast cancer.