# A blood test for the pre-metastatic niche

Source: https://onco.cc/ideas/idea-bio2-premetastatic-niche-assay/  
OnCo record `idea-bio2-premetastatic-niche-assay` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Before cancer spreads, distant organs are changed to become welcoming. A test for those changes would show which organ is at risk while a person still looks cancer-free.

## Summary

Pre-metastatic niche formation involves tumour-derived exosome integrins, S100A8 and S100A9 induction, myeloid mobilisation and fibronectin deposition in the target organ. Candidate readouts exist (plasma S100A8/A9, exosomal integrin profiles, circulating LOX activity, neutrophil trajectories) but nobody has assembled them into a validated organ-specific risk assay.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: A multi-analyte niche score measured after curative surgery predicts organ-specific relapse (lung versus liver versus bone) with a c-statistic above 0.75, independently of and additively to ctDNA.
- Rationale: Exosomal integrin patterns predicted lung and liver organotropism respectively in mouse and human samples. Organ-specific prediction would let prevention be targeted to one organ, which a single ctDNA yes-or-no answer cannot do.
- Proposed test: Nested case-control study in two existing adjuvant trial biobanks with known relapse sites; lock the score, then validate it prospectively in a third cohort.
- Maturity: speculative
- Actor: research

## Sources

- Bottleneck evidence (Metastasis is understood least and studied last): Dillekås et al., Are 90% of deaths from cancer caused by metastases? (Cancer Medicine 2019): https://doi.org/10.1002/cam4.2474

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/)
- technologies: [Liquid biopsy (ctDNA)](https://onco.cc/technologies/liquid-biopsy/), [Proteomics & phosphoproteomics](https://onco.cc/technologies/proteomics/)
- bottlenecks: [Biomarkers are not validated or standardised](https://onco.cc/bottlenecks/b-biomarker-validation/), [Dormant cells and minimal residual disease](https://onco.cc/bottlenecks/b-dormancy-mrd/), [Metastasis is understood least and studied last](https://onco.cc/bottlenecks/b-metastasis-biology/)
- key papers: [Are 90% of deaths from cancer caused by metastases?](https://onco.cc/key-papers/paper-dillekas-cancer-med/)

---
JSON: https://onco.cc/api/v1/entities/idea-bio2-premetastatic-niche-assay.json