Correlation of Prognostic Nutritional Index To Quality of Life Of Breast Cancer Patients Undergoing Chemotherapy

Breast cancer is the most common cancer and a leading cause of cancer-related death among women worldwide. Chemotherapy, a vital treatment for breast cancer, can alter energy expenditure and decrease physical activity, negatively impacting quality of life. The Prognostic Nutritional Index (PNI) has been identified as a prognostic marker for various solid tumors, including breast cancer. This prospective cohort observational study assessed PNI and quality of life in 37 breast cancer patients at Hasanuddin University Hospital and Wahidin Sudirohusodo Hospital, Makassar, from September 2024 to March 2025. PNI was measured through blood tests, and quality of life was evaluated using the EORTC QLQ-BR45 questionnaire. Paired t-test analysis showed a significant decrease in PNI from 52.45 ± 6.04 before chemotherapy to 49.74 ± 6.69 after chemotherapy (p = 0.012). Total lymphocyte count (TLC) also declined significantly from 2048.76 ± 697.95 cells/mm³ to 1543.05 ± 1354.27 cells/mm³ (p = 0.024). Symptom scale scores increased from 19.24 ± 11.93 to 25.51 ± 18.52 (p = 0.039). Protein intake increased to 47.97 ± 17.17 grams on day 18 post-chemotherapy (p < 0.001). Spearman correlation analysis revealed positive associations between PNI and symptom scale after chemotherapy (r = 0.342, p = 0.038) and changes in PNI and symptom scale (r = 0.583, p < 0.001). A negative correlation was found between protein intake on day 18 and symptom scale changes (r = -0.333, p = 0.044). These findings suggest chemotherapy reduces PNI and TLC, with nutritional status influencing symptom severity.