A network analysis of symptoms in women with metastatic breast cancer undergoing systemic therapy.

e13107 Background: Women with metastatic breast cancer (MBC) experience various concurrent symptoms during cancer treatment that impact quality of life. Previous studies identified symptom clusters, but findings were inconsistent, and the interactome of these co-occurring symptoms remain unclear. Network analysis is a novel approach to identify and visualize interconnected relationships between multiple symptoms. We sought to explore the symptom network among core cancer symptoms in women with MBC receiving systemic therapy. Methods: Women with MBC (N = 209) were recruited between February and September 2024, from Yale Smilow Cancer Center and five MBC patient advocacy groups in the U.S. Participants completed the MD Anderson Symptom Inventory (MDASI) measuring 13 core cancer symptoms: pain, fatigue, nausea, disturbed sleep, distress, shortness of breath, difficulty remembering, lack of appetite, drowsiness, dry mouth, sadness, vomiting and numbness/tingling. Symptom severity was rated from 0 (not present) to 10 (most severe). We conducted a symptom network analysis by estimating a mixed graphical model via elastic-net regularized neighborhood regression. The estimated symptom network properties were examined by analyzing centrality indices: strength (weight of direct connection between symptoms), closeness (influence of symptoms on other symptoms), and betweenness (bridges of symptoms to one or more symptoms). Results: Of 209 women, 76.6% identified as White and 65.1% had HR+/HER2- breast cancer, with an average age of 50.1 years (SD = 14.1). The average time since MBC diagnosis was 4.4 years (SD = 3.9). The mean symptom score was 3.9 (SD = 2.2) with fatigue (mean = 5.8, SD = 2.7) and disturbed sleep (mean = 5.1, SD = 3.1) rated as the most severe symptoms. The network analysis illustrated three distinct subnetworks: neurological symptoms (“fatigue-drowsiness”), gastrointestinal symptoms (“nausea-lack of appetite-vomiting”), and psychological symptoms (“distress-sadness”). Shortness of breath (strength = 0.88, closeness = 0.01, betweenness = 35) demonstrated the highest centrality indices, and connected to lack of appetite, vomiting, dry mouth, numbness/tingling, and difficulty remembering. Conclusions: Network analysis revealed interconnected symptom patterns. In addition to well-recognized symptom clusters such as fatigue-sleep disturbance, shortness of breath may function as a key connector symptom. Future research is needed to determine the role and contribution of shortness of breath in overall symptom burden among women with MBC.