by Jason Wasserman MD PhD FRCPC
March 29, 2026
If your pathology report or genetic test results mention BRCA1 or BRCA2, these refer to two genes that play a critical role in repairing damaged DNA. In ovarian cancer, BRCA testing is one of the most important molecular tests performed — not just because a mutation in either gene helps predict how the cancer will respond to certain treatments, but because the result can have significant implications for you and your blood relatives. Understanding what BRCA testing involves and what a positive result means takes some explanation, but it is information worth having.
What the test looks for
BRCA1 and BRCA2 are tumour suppressor genes — genes whose normal job is to help cells repair serious breaks in their DNA. When DNA is damaged in a healthy cell, the proteins made by BRCA1 and BRCA2 work together with other proteins to identify and fix the damage before the cell divides. This process is called homologous recombination repair.
When the BRCA1 or BRCA2 gene is mutated — meaning its instructions are altered in a way that prevents the protein from functioning — the cell loses one of its main tools for repairing DNA. Over time, DNA damage accumulates, and this creates conditions that favour cancer development.
In ovarian cancer, BRCA testing looks for mutations in these two genes. Depending on the type of testing ordered, the laboratory may look at tumour tissue, a blood or saliva sample, or both. What the test finds — and what the result means for treatment — depends on which sample was used and what type of mutation is identified.
Why is the test done
BRCA testing in ovarian cancer serves two distinct but related purposes: guiding treatment decisions and identifying hereditary cancer risk.
On the treatment side, ovarian tumours that carry BRCA mutations behave differently from those that do not. They tend to be more sensitive to a class of drugs called PARP inhibitors, which exploit the DNA repair defect caused by the BRCA mutation. Tumours with BRCA mutations are also generally more responsive to platinum-based chemotherapy — the backbone of first-line ovarian cancer treatment. Knowing whether a BRCA mutation is present can therefore directly influence the treatment plan from the time of diagnosis.
On the hereditary side, a BRCA mutation found in the blood or saliva — rather than just in the tumour — means the mutation was inherited and is present in every cell in the body. This type of result has implications that extend beyond the person with ovarian cancer. It means biological relatives may have inherited the same mutation, and those who have it face elevated lifetime risks for ovarian, breast, and other cancers. Identifying families with hereditary BRCA mutations enables relatives to access surveillance and prevention options that can significantly reduce their risk.
For these reasons, major clinical guidelines — including those from ASCO, ESMO, and the Society of Gynecologic Oncology — recommend BRCA testing for all patients with high-grade serous ovarian carcinoma, as well as for patients with other ovarian cancer types where BRCA mutations occur. In practice, this means BRCA testing should be considered for essentially all patients with a new diagnosis of ovarian cancer, regardless of family history or age at diagnosis.
Who should be tested
BRCA testing is recommended for all patients diagnosed with epithelial ovarian cancer — particularly high-grade serous carcinoma, the most common subtype, where BRCA mutations are found in approximately 20–25% of all cases. Testing is also appropriate for patients with endometrioid, clear cell, and other less common ovarian cancer subtypes, though mutation rates are lower in these groups.
The recommendation to test all patients — rather than limiting testing to those with a family history of cancer — reflects a well-established finding: a significant proportion of people who carry a BRCA mutation have no family history that would suggest it. Restricting testing to those with a known family history would miss many patients who could benefit from targeted treatment and whose families would benefit from cascade genetic testing.
Access to BRCA testing varies by where you live and where you receive care. In some countries and regions, germline testing is offered to all ovarian cancer patients as a routine part of cancer care; in others, it may require a referral to a genetics clinic or may not be publicly funded. If you have not been offered BRCA testing and are not sure whether it has been done, it is worth asking your oncologist or gynaecologic oncologist directly.
Germline versus somatic mutations: an important distinction
Before explaining how BRCA testing is performed and how results are reported, it is essential to understand the difference between the two types of BRCA mutations, because this distinction affects both the treatment implications and the implications for your family.
- Germline mutation. A germline mutation is one that was inherited — it was present in the egg or sperm cell at the time of conception, and as a result, it exists in every cell in the body, including cells that are not part of the tumour. Germline mutations are hereditary. If you carry one, each of your biological children has a 50% chance of having inherited it, and your siblings and parents may also carry it. Germline BRCA mutations are the reason some families have multiple members affected by ovarian and breast cancer across generations.
- Somatic mutation. A somatic mutation develops in tumour cells during a person’s lifetime — it was not present at birth and is not carried in normal cells elsewhere in the body. Somatic mutations are not inherited and cannot be passed to children. They arise from the same accumulation of errors that drives cancer development more broadly. In ovarian cancer, approximately 6–8% of BRCA mutations are somatic, found in the tumour but not in the blood.
The distinction matters because a germline mutation triggers a cascade of recommendations for the patient and their family that a somatic mutation does not. Both types of mutation, however, have similar implications for treatment of the ovarian cancer itself — tumours with either germline or somatic BRCA mutations are eligible for PARP inhibitor therapy.
How the test is performed
BRCA testing may be performed on different sample types, and in many cases, both are performed.
Germline testing (blood or saliva)
Germline testing — which looks for inherited mutations — is performed on a blood or saliva sample. The DNA extracted from this sample represents the patient’s constitutional genetic makeup. In most centres, a blood draw or saliva collection is arranged through a genetics clinic, a medical oncology clinic, or a gynaecologic oncology programme.
In many cancer programmes, germline BRCA testing is now initiated by the treating oncologist at the time of diagnosis, without requiring a prior genetics referral. A genetics referral is still arranged afterward to discuss the results in full, particularly when a mutation is found.
Tumour (somatic) testing
Tumour testing looks for BRCA mutations present in the cancer cells themselves. It is performed on the tumour tissue collected during surgery or biopsy. The laboratory extracts DNA from the tumour and analyses it using next-generation sequencing (NGS) — a technology that reads the tumour’s genetic code to detect specific mutations.
Tumour testing detects both germline and somatic mutations, because germline mutations are present in the tumour cells just as they are in every other cell. For this reason, a mutation identified through tumour testing requires follow-up germline testing (in blood or saliva) to determine whether it is germline or somatic in origin. If a mutation is found in the tumour but not in the blood, it is classified as somatic.
Some centres perform tumour testing first (because tumour tissue is already available after surgery) and then arrange germline testing as a follow-up step. Others perform germline testing first. The approach depends on local resources and institutional practice.
How results are reported
BRCA test results are typically reported in one of several ways, depending on the laboratory and the type of testing performed.
Pathogenic or likely pathogenic variant detected
This means a mutation in BRCA1 or BRCA2 has been identified that is known or strongly expected to impair the protein’s function. This is a positive result. The report will specify which gene is affected (BRCA1 or BRCA2), describe the specific mutation, and may indicate whether it is germline or somatic, or flag that germline testing is needed to make that determination.
No pathogenic variant detected
This means the test did not identify a mutation in BRCA1 or BRCA2 that would impair protein function. This is often called a negative result. It does not rule out all hereditary cancer risk — other genes involved in DNA repair (such as PALB2, RAD51C, RAD51D, and BRIP1) can also increase ovarian cancer risk and may be tested separately, either on a panel or as part of a broader hereditary cancer assessment.
Variant of uncertain significance (VUS)
In some cases, the test identifies a change in the BRCA1 or BRCA2 gene that has not yet been classified as definitely harmful or definitely harmless. This is called a variant of uncertain significance (VUS). A VUS result is neither positive nor negative. It should not be used to make treatment decisions, and it does not trigger the same recommendations as a pathogenic variant. VUS results are re-evaluated over time as more data accumulate, and the classification may change. Your genetic counsellor will explain what a VUS means for your specific situation.
BRCA1 versus BRCA2
The result will specify which gene carries the mutation. While both BRCA1 and BRCA2 mutations confer sensitivity to PARP inhibitors and platinum chemotherapy, there are some differences between the two in the spectrum of cancers they are associated with and in certain nuances of treatment response. Your oncologist will discuss the specific significance of a BRCA1 versus a BRCA2 result in the context of your cancer.
What the result means
BRCA mutation detected (pathogenic or likely pathogenic variant)
A positive BRCA result — whether the mutation is in BRCA1 or BRCA2, and whether it is germline or somatic — means the tumour lacks a functioning copy of one of its main DNA repair genes. This has direct implications for treatment.
Ovarian tumours with BRCA mutations respond well to platinum-based chemotherapy — the combination of carboplatin and paclitaxel used as standard first-line treatment — and response rates are generally higher than in tumours without BRCA mutations. More significantly, BRCA-mutated tumours are eligible for maintenance therapy with PARP inhibitors after chemotherapy.
PARP inhibitors — including olaparib, niraparib, and rucaparib — are oral medications that work by blocking a DNA repair enzyme called PARP. In cells that already lack functional BRCA1 or BRCA2, blocking PARP creates a level of DNA damage that the cell cannot survive. This mechanism — called synthetic lethality — makes PARP inhibitors highly effective against BRCA-mutated tumours while sparing most normal cells, which still have intact BRCA function.
In patients with a BRCA mutation, maintenance olaparib after response to first-line platinum-based chemotherapy has been shown in large randomised trials to delay disease progression significantly. In the SOLO-1 trial, patients with newly diagnosed advanced BRCA-mutated ovarian cancer who received olaparib maintenance had a median progression-free survival of approximately 56 months, compared to approximately 14 months in those who received a placebo. At seven years of follow-up, approximately 45% of patients in the olaparib group had not progressed or died, compared to approximately 20% in the placebo group.
PARP inhibitors are also used in the recurrent setting — in patients whose cancer has returned after initial treatment. Approval varies by country and by specific drug and clinical scenario; your oncologist will advise you on what is available and appropriate in your case.
No BRCA mutation detected (negative result)
A negative result means no pathogenic BRCA1 or BRCA2 mutation was found in the sample tested. This does not mean PARP inhibitors are definitively off the table. Some patients with ovarian cancer have a broader pattern of DNA repair deficiency, called homologous recombination deficiency (HRD), that extends beyond BRCA mutations and can still predict benefit from PARP inhibitors. HRD testing, which measures the genomic fingerprint of DNA repair failure across the whole tumour, may be performed in addition to BRCA testing. That test is explained in a separate article on this site.
A negative germline BRCA result provides meaningful reassurance regarding hereditary risk. However, it does not eliminate all hereditary cancer risk — genetic testing panels that include other ovarian cancer risk genes may be offered through a genetics clinic.
Variant of uncertain significance (VUS)
A VUS result does not change treatment decisions and does not carry the same implications for family members as a pathogenic variant. However, it should be discussed with a genetic counsellor, who can explain how VUS classification works and arrange follow-up if the classification changes over time.
Implications for family members
If your BRCA mutation is confirmed to be germline — meaning it was identified in your blood or saliva, or was found in the tumour and confirmed in blood — it means the mutation is hereditary and may be present in your biological relatives.
Each first-degree relative (parent, sibling, or child) has a 50% chance of having inherited the same mutation. Those who carry a germline BRCA1 mutation face a lifetime risk of ovarian cancer of approximately 40–50%, compared to a general population risk of approximately 1–2%. The lifetime breast cancer risk is approximately 70–80%. Carriers of a germline BRCA2 mutation face a lifetime ovarian cancer risk of approximately 15–25% and a lifetime breast cancer risk of approximately 60–70%.
Relatives who are found to carry the mutation can access surveillance programmes — including enhanced breast imaging (MRI and mammography) and discussions about risk-reducing surgery — that substantially reduce these risks. Risk-reducing salpingo-oophorectomy (surgical removal of the ovaries and fallopian tubes) reduces ovarian cancer risk by approximately 80% and also reduces breast cancer risk in premenopausal carriers. For relatives who do not carry the mutation, their risk returns to the general population level, and they do not require enhanced surveillance.
This process — where a positive result in one family member is used to test other relatives — is called cascade genetic testing. Your genetic counsellor will explain how to share this information with your family and how relatives can access testing.
If you are concerned about discussing genetic results with family members, or if you are uncertain about family members’ reactions, your genetic counsellor can help you navigate these conversations. This is a common and important part of hereditary cancer care.
What happens next
If a BRCA mutation is found in your tumour — whether through tumour testing or germline testing — your oncologist will incorporate this into your treatment plan. In most cases, this means you will be offered PARP inhibitor maintenance therapy after completing platinum-based chemotherapy, provided you have responded to chemotherapy.
If a germline BRCA mutation is identified (or if tumour testing finds a mutation and germline confirmation has not yet been done), a referral to a genetic counsellor or medical geneticist is the standard next step. The genetic counsellor will review your personal and family history, explain the implications of the result in detail, and discuss options for your relatives. You do not need to navigate these conversations alone.
If your BRCA result is negative, your oncologist may discuss HRD testing to determine whether you might still benefit from PARP inhibitors based on a broader DNA repair deficiency. If HRD testing has not already been performed, it is worth asking whether it is appropriate in your situation.
If you have received a VUS result, no immediate action is needed beyond arranging a discussion with a genetic counsellor. Follow-up over time is appropriate, as VUS reclassifications do occur.
Questions to ask your doctor
- Has BRCA testing been performed on my tumour, my blood, or both — and if only one, will the other be done?
- Is my BRCA mutation germline (inherited) or somatic (acquired in the tumour only)?
- Am I eligible for PARP inhibitor maintenance therapy, and which drug and dosing schedule would you recommend?
- If my BRCA result is negative, should HRD testing be performed to determine whether I might still benefit from PARP inhibitors?
- Will I be referred to a genetic counsellor, and how should I approach sharing this information with my family?
- How will my BRCA result influence my treatment if the cancer recurs in the future?
- Are there clinical trials I should be aware of based on my BRCA result?
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