AUTHOR=Sun Wei , Zhuang Shaohui , Cheng Minghua , Qiu Zeting 

TITLE=Mu opioid receptor mRNA overexpression predicts poor prognosis among 18 common solid cancers: A pan-cancer analysis

JOURNAL=Frontiers in Oncology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2023.1134744

DOI=10.3389/fonc.2023.1134744

ISSN=2234-943X

ABSTRACT=<sec><title>Background</title><p>Opioids are widely used for patients with solid tumors during surgery and for cancer pain relief. We conducted a pan-cancer genomic analysis to investigate the prognostic features of Mu opioid receptor (<italic>MOR</italic>) mRNA expression across 18 primary solid cancers.</p></sec><sec><title>Methods</title><p>All the data of cancer with <italic>MOR</italic> mRNA were retrieved from cBioPortal for Cancer Genomics. Logistic regression was used to determine the associations between <italic>MOR</italic> mRNA expression and clinicopathological features. Log-rank test and Cox regression was used for survival analysis. Subgroup analysis and propensity score matching were also carried out.</p></sec><sec><title>Results</title><p>7,274 patients, including 1,112 patients with positive <italic>MOR</italic> mRNA expression, were included for data analyses. Positive <italic>MOR</italic> mRNA expression was associated with more advanced stage of T (adjusted Odds ratio [OR], 1.176; 95% confidence interval [CI], 1.022-1.354; <italic>P</italic>=0.024), M (adjusted OR, 1.548; 95% CI, 1.095-2.189; <italic>P</italic>=0.013) except N (adjusted OR, 1.145; 95% CI, 0.975-1.346; <italic>P</italic>=0.101), and worse prognosis for overall survival (Hazard ratio [HR] 1.347, 95% CI 1.200-1.512, <italic>P</italic>&lt;0.001), progression-free survival (HR 1.359, 95% CI 1.220-1.513, <italic>P</italic>&lt;0.001), disease-free survival (HR 1.269, 95% CI 1.016-1.585, <italic>P</italic>&lt;0.001) and disease-specific survival (HR 1.474, 95% CI 1.284-1.693, <italic>P</italic>&lt;0.001). Patients with positive <italic>MOR</italic> mRNA expression tended to be classified as tumor microenvironment immune types II, representing low PD-L1 and low CD8A expression.</p></sec><sec><title>Conclusion</title><p><italic>MOR</italic> mRNA overexpression is associated with poor prognosis and poor response to PD-L1 therapy.</p></sec>