Opioid Receptor Expression in Colorectal Cancer: A Nested Matched Case-Control Study.

Area of Science:

• Oncology
• Anesthesiology
• Molecular Biology

Background:

• Perioperative anesthetic management's impact on cancer progression is under investigation.
• The role of perioperative opioids in cancer recurrence remains controversial.
• This study investigates opioid receptor expression in colorectal cancer tissues.

Purpose of the Study:

• To assess differential expression of µ-opioid receptor (MOR) and Opioid Growth Factor Receptor (OGFR) between healthy and tumor tissues in stage II/III colorectal cancer patients.
• To explore the relationship between opioid receptor expression and cancer recurrence.
• To analyze the cAMP-PKA pathway and validate findings using TCGA-GTEx databases.

Main Methods:

• Retrospective cohort study with propensity-score matched case-control analysis.
• Immunohistochemistry (IHC) to measure MOR and OGFR expression in tumor and healthy tissues.
• Analysis of cAMP, PKA, and in silico data from TCGA-GTEx.

Main Results:

• Significantly higher MOR and OGFR expression in tumor tissues compared to healthy tissues (P<0.001).
• No significant differences in MOR, OGFR, cAMP, or PKA expression based on recurrence status.
• TCGA-GTEx data confirmed increased MOR and OGFR expression in tumor samples, with a skewed MOR distribution.

Conclusions:

• MOR and OGFR expression are significantly increased in stage II/III colorectal cancer tissues.
• Increased MOR and OGFR expression in tumor tissues do not correlate with cancer recurrence.
• The cAMP-PKA pathway is not differentially expressed between tumor and healthy tissues or by recurrence status.