SUPPORTIVE CARE IN CANCER, no.7, 2024 (SCI-Expanded)
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.