Factors Influencing Patient-Reported Symptom Outcomes in Women with Metastatic Breast Cancer

Background Utilization of targeted agents and immunotherapy led to improved survival in women with metastatic breast cancer (MBC). However, a knowledge gap remains about the side effects and symptom burden associated with these therapies that are not fully described for people living with MBC. We examined patient-reported symptom severity, interference and symptom burden related to MBC cancer treatments and identified correlated sociodemographic and clinical factors. Methods Women with MBC on systemic cancer treatment recruited from oncology clinics and advocacy organizations, completed a survey from February to September 2024. We used the MD Anderson Symptom Inventory (MDASI) Immunotherapy module to describe symptom severity and interference of 20 symptoms and symptom burden. We conducted descriptive statistics and stepwise multiple linear regression to identify sociodemographic and clinical factors correlated with symptom severity, interference, and symptom burden. Results In the sample of 209 participants, the mean age was 50.1 years (SD = 14.11), 76.6% were White. Most were HR+/HER2- subtype, with an average time of 4.35 years since MBC diagnosis. Fatigue, sleep disturbance, forgetfulness, drowsiness, and sadness were the most prevalent symptoms. Participants identified as non-White, have completed more lines of treatments reported higher symptom severity, interference and total symptom burden. However, having dependent children (β = 0.32, 95% CI [0.04, 0.60], P = 0.027) was associated with more severe symptom interference. Conclusion The type and number of treatments, being non-White and caring dependent children were associated with higher symptom burden. Symptom management interventions should be tailored for specific MBC subgroup and to improve overall well-being for MBC population.