# Gene-expression prognostic assays

Source: https://onco.cc/technologies/gene-expression-prognostic-assays/  
OnCo record `gene-expression-prognostic-assays` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Tests that measure a set of genes in a removed tumour to estimate how likely it is to come back, so patients with low scores can safely skip chemotherapy.

## Summary

Multigene expression assays run on resected tumour tissue estimate recurrence risk and, for some, chemotherapy benefit. Oncotype DX (21 genes) and MammaPrint (70 genes) are the best known in breast cancer, where the TAILORx and MINDACT trials showed that most women with low scores gain nothing from chemotherapy; Prolaris and Decipher serve the same purpose in prostate cancer. They are recommended in major guidelines and reimbursed in many systems.

## Fields

- Kind: Technology
- Status: approved
- Last checked: 2026-09-04
- Principle: RNA is extracted from fixed tumour tissue and the expression of a fixed gene panel is measured by RT-PCR or microarray and combined into a validated risk score.
- Strengths: Prospective trial evidence for de-escalating chemotherapy; Standard of care in early hormone-positive breast cancer; Adds to clinical and pathological factors
- Limitations: Cost and turnaround; Validated mainly in specific subtypes and stages; Scores near thresholds remain hard to act on

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Oncotype_DX
- Wikipedia: https://en.wikipedia.org/wiki/Oncotype_DX

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- fronts: [Diagnostics & Biomarkers](https://onco.cc/fronts/diagnostics/)
- drugs: [MammaPrint (70-gene signature)](https://onco.cc/drugs/mammaprint/), [Oncotype DX](https://onco.cc/drugs/oncotype-dx/), [Prolaris](https://onco.cc/drugs/prolaris/)

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