Colorectal cancer patients had significantly higher serum substance P and their tumors overexpressed the NK-1 receptor compared to normal tissue, suggesting a role in tumor growth.
P=0.001 elevated SPSerum substance P was significantly higher in colorectal cancer patients than healthy controls
What the researchers found
Serum substance P was significantly elevated in CRC patients (P=0.001) and tumor tissues overexpressed NK-1R compared to adjacent normal tissue (P=0.01).
Why it matters
NK-1 receptor antagonists (like aprepitant, used for nausea) already exist. If SP/NK-1R drives colorectal cancer, these drugs could potentially be repurposed as cancer therapies.
The numbers in context
SP elevated in serum (p=0.001); NK-1R higher in tumor vs adjacent tissue (p=0.01); no correlation with tumor size or lymph nodes
How the study worked
Observational study: 38 CRC patients; serum substance P by ELISA (cases vs healthy controls); NK-1R immunohistochemistry in tumor vs adjacent normal tissue; correlation with tumor size and lymph node status.
Who was studied
38 patients newly diagnosed with colorectal cancer and a healthy control group
What this study cannot tell us
Small sample (38 patients); no correlation with clinical outcomes (survival); observational design — cannot prove causation; NK-1R expression didn't correlate with tumor characteristics.
How to read the evidence
Low-moderate — statistically significant findings in a small observational study without functional validation or outcome data.
When this study was published
Published in 2020; substance P/NK-1R as a cancer target is gaining research interest.
The bigger picture
Substance P's role in cancer extends beyond pain — it may actively promote tumor growth through the NK-1R. This adds colorectal cancer to the list of malignancies where neuropeptide signaling may be targetable.
Questions still open
- Would NK-1 receptor antagonists (aprepitant) slow colorectal cancer growth?
- Can serum substance P serve as a screening biomarker for CRC?
- Does substance P promote CRC through angiogenesis, proliferation, or immune evasion?
Common questions
What is substance P's role in cancer?
Could anti-nausea drugs help fight colon cancer?
Read the original research
Evaluation of serum level of substance P and tissue distribution of NK-1 receptor in colorectal cancer.
Molecular biology reports, 47(5), 3469-3474
Citation
Lorestani, Shima; Ghahremanloo, Atefeh; Jangjoo, Ali; Abedi, Maedeh; Hashemy, Seyed Isaac. (2020). Evaluation of serum level of substance P and tissue distribution of NK-1 receptor in colorectal cancer.. Molecular biology reports, 47(5), 3469-3474. https://doi.org/10.1007/s11033-020-05432-4