# Germline BRCA test → adjuvant PARP inhibitor

Source: https://onco.cc/pairings/germline-to-parp/  
OnCo record `germline-to-parp` (Pairing). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A blood test for inherited BRCA mutations unlocks a year of olaparib after surgery, which improves survival.

## Summary

This diagnostic-therapeutic pairing links Germline (hereditary) testing for inherited BRCA1 / BRCA2 (HRD) mutations to a year of adjuvant Olaparib, one of the PARP inhibitors, after surgery. The rationale is synthetic lethality confined to BRCA-deficient cells, so the drug is only worth giving once the inherited mutation is confirmed. The phase 3 OlympiA trial showed that adjuvant olaparib improved invasive disease-free survival and overall survival in this population. Because the treatment depends on the test, every patient with Triple-negative breast cancer (TNBC) or high-risk HR-positive / HER2-negative breast cancer needs germline testing at diagnosis, which is why the pairing is linked from the TNBC and Germline testing entries.

## Fields

- Kind: Pairing
- Last checked: 2026-09-04
- Pairs: Germline (hereditary) testing + PARP inhibitors
- Type: diagnostic-therapeutic
- Rationale: Synthetic lethality confined to BRCA-deficient cells.
- Evidence: Phase 3 OS benefit.

## Sources

- ClinicalTrials.gov NCT02032823: OlympiA: https://clinicaltrials.gov/study/NCT02032823

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- targets: [BRCA1 / BRCA2 (HRD)](https://onco.cc/targets/brca/)
- drugs: [Olaparib](https://onco.cc/drugs/olaparib/)
- trials: [OlympiA](https://onco.cc/trials/olympia/)
- technologies: [Germline (hereditary) testing](https://onco.cc/technologies/germline-testing/), [PARP inhibitors](https://onco.cc/technologies/parp-inhibitor/)
- roadmaps: [Pancreatic cancer roadmap: from Whipple's operation to gemcitabine, FOLFIRINOX, adjuvant chemotherapy, PARP inhibition, KRAS inhibition, vaccines and the surveillance question](https://onco.cc/roadmaps/pancreatic-roadmap/), [Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem](https://onco.cc/roadmaps/tnbc-roadmap/)
- ideas: [Surveillance for every germline carrier found by universal testing, inside a registry rather than a research exception](https://onco.cc/ideas/idea-pdac-surveillance-for-every-germline-carrier/)

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JSON: https://onco.cc/api/v1/entities/germline-to-parp.json