Opioid use after breast cancer in Denmark: a nationwide study of social and clinical factors

Abstract Background Pain is a common long-lasting effect of breast cancer treatment. However, adequate pain management can be a challenge in survivorship care. Opioids remain important for acute and chronic pain, yet prolonged use carries risks of dependence and overdose. Denmark has historically had high opioid prescription rates, but the duration, strength, and intensity of use among breast cancer survivors is not well described. Methods We conducted a nationwide registry-based study of 84,610 Danish women diagnosed with stage I–III breast cancer (1997 − 2020). We described temporal trends in opioid-prescribing and examined associations between sociodemographic and clinical characteristics and five potentially harmful opioid-related outcomes after breast cancer new and prolonged use, long-term use, long-term strong use, concurrent use with sedative-hypnotics, and diagnosed substance-related disorder or overdose. Results Within one year of diagnosis, 18% of women filled at least one opioid prescription; this proportion declined steadily after 2015. Codeine, the most common initial opioid in the late 1990s, was gradually replaced by tramadol, morphine, and oxycodone. Across the cohort, 6.1% had long-term use, 2.0% long-term strong use, 3.6% concurrent opioid and sedative-hypnotic use, and 0.4% developed an substance-related disorder or overdose. Among 74,771 opioid-naïve patients, 1.7% became new and prolonged users. Odds of these opioid-related behaviors were higher among women with socioeconomic hardships, psychiatric morbidity, comorbidity, and advanced disease. Discussion Opioid use after breast cancer was uncommon and declined over time in Denmark. Nonetheless, social and clinical disparities persisted, highlighting the importance of survivorship care that balances safe prescribing with adequate pain management.