Most Neuroendocrine Tumors Produce Opioid Peptides
All neuroendocrine tumors tested (100%) produced opioid peptides, and even 33-73% of non-neuroendocrine tumors like breast and colon cancer stained positive.
Quick Facts
What This Study Found
Using a "pan-opioid" antibody that detects all opioid peptides, researchers screened 108 tumors. Every adrenal pheochromocytoma (15 of 15), thyroid medullary carcinoma (6 of 6), and pituitary adenoma (5 of 5) stained positive for opioid peptides.
Most parathyroid adenomas (8 of 9), pancreatic islet-cell tumors (7 of 10), and carcinoid tumors (18 of 26) also stained positive.
Zero non-neuroendocrine tumors showed opioid staining. Lung small-cell carcinomas, skin Merkel-cell tumors, and neuroblastomas were all negative.
The same opioid peptides were found in normal versions of these tissues (adrenal medulla, pancreatic islets, pituitary), suggesting the tumors simply overproduce a normal cellular product.
Key Numbers
How They Did This
Immunohistochemistry study of 108 tumors using avidin-biotin immunoperoxidase technique. A monoclonal pan-opioid antibody (3-E7) detected the common opioid sequence Tyr-Gly-Gly-Phe. Polyclonal antibodies identified specific opioid subtypes: alpha-endorphin, met-enkephalin, and dynorphin B.
Why This Research Matters
This study established opioid peptides as reliable markers for neuroendocrine differentiation in tumors. For pathologists trying to classify unclear tumors, opioid peptide staining could help identify their origin. Published in the New England Journal of Medicine, this was a high-impact finding.
The Bigger Picture
Tumor-produced opioid peptides could contribute to cancer pain, immune evasion, or tumor growth. This finding opened a research avenue into opioid peptides as cancer biomarkers or therapeutic targets.
What This Study Doesn't Tell Us
This was a descriptive study. It did not determine whether opioid peptide production by tumors has any functional consequences (like pain modulation or hormone effects). The sample sizes for individual tumor types were small.
Questions This Raises
- ?Do tumor-derived opioid peptides suppress local immune responses?
- ?Could opioid receptor blockers serve as cancer therapy?
- ?Do opioid peptide levels correlate with tumor aggressiveness?
Trust & Context
- Key Stat:
- 100% of neuroendocrine tumors Produced opioid peptides detected by pan-opioid antibody
- Evidence Grade:
- Moderate cross-sectional study with a large tumor panel (108) and rigorous immunohistochemistry methodology.
- Study Age:
- Published in 1987 — established that opioid peptide production by tumors is widespread.
- Original Title:
- Expression of opioid peptides in tumors.
- Published In:
- The New England journal of medicine, 317(23), 1439-43 (1987)
- Authors:
- Bostwick, D G, Null, W E, Holmes, D, Weber, E, Barchas, J D, Bensch, K G
- Database ID:
- RPEP-00040
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Why would tumors make opioid peptides?
Tumors may use opioid peptides to suppress local immune responses, promote blood vessel growth, or stimulate their own growth. They may also inherit opioid production from their tissue of origin.
Does this explain cancer pain?
Partly. Tumor-produced opioid peptides can bind to pain receptors but their role is complex — they may sometimes suppress and sometimes contribute to pain depending on the specific peptides released.
Read More on RethinkPeptides
Cite This Study
https://rethinkpeptides.com/research/RPEP-00040APA
Bostwick, D G; Null, W E; Holmes, D; Weber, E; Barchas, J D; Bensch, K G. (1987). Expression of opioid peptides in tumors.. The New England journal of medicine, 317(23), 1439-43.
MLA
Bostwick, D G, et al. "Expression of opioid peptides in tumors.." The New England journal of medicine, 1987.
RethinkPeptides
RethinkPeptides Research Database. "Expression of opioid peptides in tumors." RPEP-00040. Retrieved from https://rethinkpeptides.com/research/bostwick-1987-expression-of-opioid-peptides
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.