Impact of opioid analgesics on survival in cancer patients receiving immune checkpoint inhibitors

Purpose: This study aimed to assess the effects of concurrent opioid analgesic (OA) use with immune checkpoint inhibitors (ICIs) on progression-free survival (PFS) and overall survival (OS). Methods: In this observational retrospective study, we included advanced cancer patients who received ICIs at Hacettepe University Hospital’s Department of Medical Oncology between June 2018 and January 2023. Results: Our study included 375 recurrent or metastatic cancer patients treated with ICIs in the first, second line, or beyond. There were no significant differences between the OA-treated and OA-untreated groups regarding median age, age group, gender, primary tumor location, ICI type, or the presence of baseline liver and lung metastases. However, the OA-treated group exhibited a significantly higher proportion of patients who had received three or more prior treatments before initiating ICIs (p = 0.015). OA-Untreatment was significantly correlated with prolonged mPFS (6.83 vs. 4.30 months, HR 0.59, 95% CI 0.44–0.79, p < 0.001) and mOS (17.05 vs. 7.68 months, HR 0.60, 95% CI 0.45–0.80, p < 0.001). Conclusions: Our study demonstrates an association between the concurrent use of OAs and reduced OS and PFS in patients treated with ICIs. While OA treatment serves as a surrogate marker for higher disease burden, it may also suggest a potential biological relationship between opioids and immunotherapy efficacy.