# Gene expression profiling as a potential predictor between normal and cancer samples in gastrointestinal carcinoma

Source: https://onco.cc/key-papers/paper-apostolou-rgcc-pbmc-gastrointestinal-oncotarget-2019/  
OnCo record `paper-apostolou-rgcc-pbmc-gastrointestinal-oncotarget-2019` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

RGCC researchers separated a very small set of colorectal cancer and healthy blood samples using gene-expression clustering. The study was exploratory and does not validate multi-cancer screening in people without symptoms.

## Summary

RGCC researchers measured expression of more than 50 genes in peripheral blood mononuclear cells and commercial gastrointestinal cancer cell lines. The human normal-versus-cancer analysis contained four healthy donors and six people with colorectal cancer. Additional comparisons used nine colorectal patient samples and commercial cell lines.

The clustering methods separated the small groups used to develop and illustrate the approach. There was no independent prospective screening cohort, prespecified population threshold, diagnostic work-up, stage-specific performance analysis or clinical-outcome endpoint. RGCC links this study from its Onco-D-Clare page, but the study does not validate a pan-cancer screening test or a population accuracy claim.

## Fields

- Kind: Key paper
- Last checked: 2026-11-04
- Tags: rgcc; screening; proof-of-concept; evidence:limited
- Journal: Oncotarget
- Year: 2019
- DOI: 10.18632/oncotarget.26913
- Authors: Apostolou P, Iliopoulos AC, Parsonidis P, Papasotiriou I
- Findings: The primary human normal-versus-cancer comparison used four healthy donors and six people with colorectal cancer.; Two clustering methods separated those ten samples after the number of groups was fixed at two.; Further analyses compared patient samples with commercial cell lines rather than testing an independent screening population.
- What it means: The paper is early proof of concept for a gene-expression method. It cannot establish screening sensitivity, specificity, tissue of origin, mortality reduction or clinical utility for Onco-D-Clare.
- Caveats: Tiny exploratory dataset with no independent prospective validation cohort.; All authors were affiliated with Research Genetic Cancer Centre S.A.; Known colorectal cancer samples and healthy controls do not represent an asymptomatic screening population.; The study did not test whether screening reduced late-stage diagnosis or cancer deaths.

## Sources

- PubMed Central full text: https://pmc.ncbi.nlm.nih.gov/articles/PMC6534363/
- PubMed: https://pubmed.ncbi.nlm.nih.gov/31164955/
- Publisher article: https://doi.org/10.18632/oncotarget.26913

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/)
- technologies: [Multi-cancer early detection (MCED)](https://onco.cc/technologies/mced/)
- companies: [RGCC International](https://onco.cc/companies/rgcc-international/)

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