Abstract PS1-05-21: Socioeconomic disparities in opioid use and harm among Danish breast cancer survivors

Abstract Background: Opioids are frequently prescribed to manage pain after a breast cancer diagnosis, but prolonged use can lead to serious harm, including dependence and overdose. Socioeconomic position (SEP), often defined by income, education, and employment, may influence access to care, prescribing patterns, and the likelihood of long-term opioid use. Although Denmark provides universal healthcare, it is unclear whether SEP-related differences in opioid use persist after diagnosis. Methods: We identified all patients assigned female at birth who were diagnosed with non-metastatic breast cancer at age 18 or older between 1997 and 2020 using the Danish Cancer Registry. Patients with opioid use or a hospital history of opioid use disorder in the year before diagnosis were excluded. To be eligible, patients had to survive and reside in Denmark for at least one year after diagnosis. SEP was measured at diagnosis using household income, education level, and employment status. We defined three outcomes from the time of diagnosis: any opioid use (≥1 prescription within 6 months), prolonged use (≥1 prescription in the first 6 months and ≥2 in months 6-12), and opioid-related disorder or overdose within 5 years. Associations between SEP and each outcome were estimated using logistic regression, reporting crude odds ratios (OR) and 95% confidence intervals (CI). Results: Among 77,261 one-year breast cancer survivors, 52,321 (68%) redeemed an opioid prescription within six months of diagnosis, 992 (1.3%) became prolonged users, and 204 (0.3%) experienced an opioid-related disorder or a fatal/non-fatal overdose. Patients with low income were more likely to receive any opioid in the first six months after diagnosis compared with those with high income (OR: 1.40, 95% CI: 1.34, 1.46), with similar patterns observed across other measures of SEP. Among those who received opioids, there were no SEP differences in the type or strength prescribed. Unemployed patients were more likely to become prolonged users compared with those employed at diagnosis (OR: 1.68, 95% CI: 1.47, 1.93), and patients with a high-school education had higher odds of opioid-related disorder or overdose compared with those with a tertiary-level education (OR: 1.74, 95% CI: 1.21, 2.50). Discussion: In this nationwide study of breast cancer survivors, socioeconomic differences in opioid use and harms emerged despite universal healthcare. Although initial prescribing practices appeared equitable among users, patients with lower SEP were more likely to receive opioids, become prolonged users, and experience opioid-related harm. These findings highlight the need for equity-focused pain management and survivorship care in breast cancer. Because this was a descriptive study, we reported crude estimates to reflect overall patterns. Future work could build on these findings by exploring potential mechanisms or points for intervention. Citation Format: K. M. Woolpert. Socioeconomic disparities in opioid use and harm among Danish breast cancer survivors [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-05-21.