Longitudinal analysis of cancer symptom clusters and inflammatory biomarkers: Insights into quality of life in Brazilian breast cancer patients undergoing chemotherapy.

Abstract

e24045 Background: Chronic inflammation and cancer share a complex relationship. Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), Monocyte-to-Lymphocyte Ratio (MLR), and C-reactive protein (CRP) are reliable biomarkers linked to inflammation and cancer prognosis. Elevated levels correlate with poorer quality of life (QoL). Research on cancer symptom clusters (CSC) may elucidate mechanisms and improve symptom management, particularly regarding QoL. This study assessed associations between inflammatory biomarkers, CSCs, and QoL in Brazilian breast cancer (BC) patients under chemotherapy (CT). Methods: A longitudinal study at a southeastern Brazil cancer center (2022-2024) included newly diagnosed women (≥18 years) with stage I-III BC under outpatient CT. Exclusion criteria: palliative care and >1 primary tumor. Data collection occurred before CT-infusion including: blood samples for inflammatory biomarker analysis, CSC data (MSAS), and QoL scores (EQ-5D-3L) were collected across six 21-day CT-cycles. Descriptive, bivariate, and multivariate analyses were held. Results: Fifty BC patients (mean age: 53.3±11.4) were followed. Diagnoses included invasive ductal carcinoma (IDC) (50%) and non-IDC (50%), with stages I (16%), II (62%), and III (22%). Adjuvant therapy regimens for breast cancer included anthracycline in 42% of patients, while 58% received nonanthracycline therapy . Effect sizes (Glass' delta) were large for NLR (0.83 [0.03-1.62]) and PLR (0.92 [0.25-1.57] and moderate for MLR (0.59 [0.22-0.96]). NLR (p=0.013), PLR (p<0.001), and MLR (p=0.001) increased significantly during CT1-CT6 cycles, indicating inflammation and poor prognosis. Differences emerged between IDC and non-IDC for PLR at CT3 (p=0.042) and CT4 (p=0.042), and NLR at CT5 (p=0.05). QoL averaged was 79.36 (p=0.219). MLR impacted D5-Anxiety/Depression at CT3 (p=0.028) and D3-Usual Activities at CT6 (p=0.019). Predominant CSCs during CT1-CT5 included: Cluster-1 (emotional): concentration issues-nervousness-insomnia-sadness-worry-irritability; and Cluster-2 (somatic): pain-fatigue-dry mouth. At CT6, Cluster-2 persisted, joined by Cluster-4 (gastrointestinal): nausea-appetite loss-taste changes-bloating-weight loss-diarrhea. Cluster-1 impacted D2 (p<0.001), D3 (p<0.001), and D5 (p<0.001). Cluster-2 affected D4 (p<0.001) and D5 (p<0.001). Clusters-2 and 4 worsened all QoL domains at CT6 (p<0.001). Conclusions: Emotional, somatic, and gastrointestinal CSCs significantly impaired QoL during CT. Inflammatory biomarkers progressively increased, reflecting poor prognosis and QoL impact. CSC and biomarker research may provide insights into the complex biological networks underpinning cancer symptoms, supporting personalized care, enabling early interventions to manage CT side effects.