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HRD (homologous recombination deficiency) testing: what it means for you

Waiting on test results can feel like one more hard thing, for you and the people who love you. Here's what the HRD (homologous recombination deficiency) test looks for and how it can help your care team pick the treatment most likely to work for you.

ℹ️ General information to help you and your loved ones talk with your care team, not medical advice. Read our disclaimer.

Matters most in: Ovarian cancer, Prostate cancer, Breast cancer

Why it matters

In ovarian cancer, HRD-positive tumors tend to benefit more from PARP inhibitor maintenance. In prostate cancer, HRR gene changes can point to PARP inhibitors.

Treatments it can point to

• PARP inhibitors such as Lynparza (sometimes with Avastin) or Zejula (Lynparza (olaparib), Zejula (niraparib), Avastin (bevacizumab))

Only your care team can say which treatment fits you. Drug approvals depend on cancer type, stage and prior treatment.

Tissue vs. blood testing

Tumor tissue; prostate testing can also use blood.

Most tests use a piece of tumor tissue from a biopsy or surgery. Some can also use a blood sample (a 'liquid biopsy') that looks for tumor DNA floating in the blood. Blood tests are easier and faster, but they can miss a change that a tissue test would find, so a negative blood test is often followed by a tissue test.

❓ Questions you and your loved ones can ask

• Is my tumor HRD-positive?
• Would a PARP inhibitor help me after chemo?
• When will my results be back, and will treatment wait for them?
• Will my insurance cover this test?

Written by the Cancer Side Effects Guide team from FDA labels and leading cancer centers. Not medical advice. · Last updated: October 15, 2026 · How we write