# Differential Plasma Expression of sTNF-R, TNF-α, PDGF-AA, IL-17A, and IL-1β Across the Colorectal Neoplasia Spectrum

## TL;DR

The study found that plasma levels of certain inflammatory proteins differ across stages of colorectal neoplasia, with PDGF-AA showing the strongest differences.

## Contribution

This exploratory study identifies differential inflammatory mediator levels in colorectal neoplasia, highlighting PDGF-AA as a potential marker.

## Key findings

- PDGF-AA levels showed the strongest differences between healthy controls and neoplastic groups.
- IL-17A levels were slightly higher in early-onset CRC compared to late-onset CRC.
- TNF-α and IL-1β showed no significant differences across groups.

## Abstract

Colorectal cancer (CRC) remains one of the most important causes of cancer-related mortality worldwide, underscoring the need to better understand systemic inflammatory pathways across the colorectal neoplasia spectrum. In this exploratory case–control study, we characterized plasma levels of key inflammatory mediators in healthy individuals and patients with colorectal polyps or CRC. Healthy controls (n = 10), patients with colorectal polyps (CP, n = 16), early-onset CRC (EO-CRC, n = 11), and late-onset CRC (LO-CRC, n = 51) were prospectively enrolled. Plasma levels of sTNF-R, total TNF-α, PDGF-AA, IL-17A, and IL-1β were measured by ELISA. Group comparisons used Kruskal–Wallis tests with epsilon-squared effect sizes. PDGF-AA showed the strongest differences between controls and all neoplastic groups (ε2 ≥ 0.15), and these comparisons remained significant after Benjamini–Hochberg false discovery rate correction. IL-17A levels were slightly higher in EO-CRC than in LO-CRC; however, this difference did not remain significant after adjustment for multiple testing. TNF-α and IL-1β showed no significant differences across groups. Overall, this study primarily provides descriptive and hypothesis-generating evidence of differential inflammatory patterns across colorectal neoplasia, with PDGF-AA emerging as the most robust signal in this exploratory dataset. These findings do not support immediate diagnostic application and require validation in larger, prospectively recruited cohorts.