# therascreen companion diagnostic kits (KRAS, EGFR, PIK3CA, FGFR, BRAF)

Source: https://onco.cc/drugs/therascreen-cdx/  
OnCo record `therascreen-cdx` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A family of quick single-gene tests that decide who can have several bowel, lung, breast and bladder cancer drugs.

## Summary

Qiagen's therascreen kits were among the first PCR companion diagnostics: therascreen KRAS RGQ (PMA P110030, 6 July 2012) identifies KRAS wild-type colorectal cancers eligible for cetuximab and panitumumab; therascreen EGFR RGQ (2013) was the companion for afatinib; therascreen PIK3CA RGQ (2019) selects alpelisib for PIK3CA-mutant, hormone-receptor-positive breast cancer from tissue or plasma; therascreen FGFR RGQ RT-PCR (2019) detects FGFR3 mutations and FGFR2/3 fusions for erdafitinib in urothelial cancer; therascreen BRAF V600E RGQ (2020) is the companion for encorafenib with cetuximab in colorectal cancer. Single-gene PCR is cheap and fast but is being displaced by panels where many genes must be checked from one small biopsy.

## Fields

- Kind: Treatment
- Status: approved
- Last checked: 2026-09-10
- Tags: test
- Brand: therascreen
- Modality: Real-time PCR companion diagnostic test family
- Mechanism: Scorpions and ARMS allele-specific real-time PCR kits run on the Rotor-Gene Q, each detecting a defined set of hotspot mutations or fusions from tumour tissue (and plasma for PIK3CA).
- Approvals: US 2012: therascreen KRAS: cetuximab and panitumumab eligibility in metastatic colorectal cancer; US 2013: therascreen EGFR: afatinib in EGFR-mutant NSCLC; US 2019: therascreen PIK3CA (tissue and plasma): alpelisib in breast cancer; therascreen FGFR: erdafitinib in urothelial cancer; US 2020: therascreen BRAF V600E: encorafenib plus cetuximab in colorectal cancer

## Notes

- What a result means: for bowel cancer, a KRAS or NRAS mutation means the EGFR antibodies will not work; for breast cancer, a PIK3CA mutation opens the door to a PI3K inhibitor.
- Colorectal cancer: the RAS companion diagnostic family. The threshold the assays must reach is extended RAS, KRAS and NRAS exons 2, 3 and 4, because 17% of KRAS exon 2 wild-type patients carry another RAS mutation and gain nothing from an EGFR antibody (Douillard 2013, Sepulveda 2017).

## Sources

- FDA PMA P110030: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpma/pma.cfm?id=P110030
- Qiagen therascreen portfolio: https://www.qiagen.com/us/product-categories/diagnostics-and-clinical-research/oncology

## Connected records

- cancers: [Bladder & urothelial cancer](https://onco.cc/cancers/urothelial/), [Colorectal cancer](https://onco.cc/cancers/colorectal/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/)
- technologies: [Companion diagnostics](https://onco.cc/technologies/companion-diagnostic/)
- targets: [BRAF](https://onco.cc/targets/braf/), [EGFR](https://onco.cc/targets/egfr/), [FGFR2](https://onco.cc/targets/fgfr2/), [KRAS](https://onco.cc/targets/kras/), [PIK3CA / PI3K-alpha](https://onco.cc/targets/pik3ca/)
- drugs: [Afatinib](https://onco.cc/drugs/afatinib/), [Alpelisib](https://onco.cc/drugs/alpelisib/), [Cetuximab](https://onco.cc/drugs/cetuximab/), [Encorafenib](https://onco.cc/drugs/encorafenib/), [Erdafitinib](https://onco.cc/drugs/erdafitinib/), [Panitumumab](https://onco.cc/drugs/panitumumab/)
- companies: [QIAGEN](https://onco.cc/companies/qiagen/)
- terms: [Companion diagnostic](https://onco.cc/terms/companion-diagnostic-term/)
- trials: [EGFR/HER2 Dual-Target CAR-NK Cells for Recurrent or Metastatic HNSCC](https://onco.cc/trials/nct07617805/)
- key papers: [K-ras mutations and benefit from cetuximab in advanced colorectal cancer](https://onco.cc/key-papers/paper-karapetis-kras-cetuximab-colorectal-nejm-2008/), [Panitumumab-FOLFOX4 treatment and RAS mutations in colorectal cancer (PRIME)](https://onco.cc/key-papers/paper-douillard-prime-panitumumab-ras-nejm-2013/)
- biomarkers: [BRAF V600E (and V600K)](https://onco.cc/biomarkers/braf-v600e/), [EGFR exon 19 deletion](https://onco.cc/biomarkers/egfr-exon-19-deletion/), [FGFR3 alteration (mutation or fusion)](https://onco.cc/biomarkers/fgfr3-alteration/), [KRAS G12C](https://onco.cc/biomarkers/kras-g12c/), [KRAS G12D (and other non-G12C KRAS mutations)](https://onco.cc/biomarkers/kras-g12d/), [PDGFRA exon 18 mutation (D842V)](https://onco.cc/biomarkers/pdgfra-exon-18-d842v/), [PIK3CA mutation](https://onco.cc/biomarkers/pik3ca-hotspot-mutation/), [RAS wild-type (extended KRAS and NRAS testing)](https://onco.cc/biomarkers/ras-wild-type/)
- roadmaps: [Diagnostics roadmap: stains → gene panels → blood tests that decide treatment](https://onco.cc/roadmaps/diagnostics-roadmap/)

---
JSON: https://onco.cc/api/v1/entities/therascreen-cdx.json