Cancer treatment for people with inherited ATM mutations

People with an inherited ATM mutation who have been diagnosed with cancer may have different treatment options than people without a mutation. You may also consider enrolling in a clinical trial studying which treatments work best for people with an inherited ATM mutation. To learn more about standard of care treatment options for specific types of cancer, visit our section on Cancer Treatment by Cancer Type. 

If you have an inherited ATM mutation, have been diagnosed with cancer and any of the situations below apply to you, you may want to speak to your doctor about your medical options.

• You have metastatic prostate cancer
• You have advanced ovarian cancer
• You are making breast cancer surgical decisions
• You have cancer and need radiation therapy

Regardless of diagnosis and situation, people with an ATM mutation may qualify for clinical trials looking for more effective treatments for cancer.

PARP inhibitors

PARP inhibitors are a type of targeted therapy that work by blocking a protein used to repair damaged DNA. They were initially developed to treat cancers in people with an inherited BRCA1 or BRCA2 mutation. Since then, research and additional FDA approvals have expanded use of PARP inhibitors to more situations. People with an ATM mutation who have been diagnosed with cancer may want to ask their doctor about whether they might benefit from PARP inhibitor therapy or a PARP inhibitor research study. 

PARP inhibitors for metastatic prostate cancer

The PARP inhibitor, Lynparza (olaparib) has received FDA-approval to treat men with metastatic, castration-resistant prostate cancer, who have a mutation in ATM or another gene linked to a certain type of DNA damage repair. Lynparza has been approved to treat men whose prostate cancer has progressed on enzalutamide (Xtandi) or abiraterone (Zytiga). 

PARP inhibitors for advanced ovarian, fallopian tube or primary peritoneal cancer

Several PARP inhibitors have been approved to treat ovarian cancers at different stages of the disease. In some situations, a tumor biomarker test known as an HRD test ("hemologous recombination deficiency") can help women with advanced ovarian cancer learn if they may benefit from a PARP inhibitor.

Maintenance therapy after first-line treatment

• HRD testing can help women with advanced ovarian cancer learn if they may benefit from the PARP inhibitor Lynparza (olaparib) in combination with Avastin (bevacizumab) as maintenance therapy after first-line platinum chemotherapy.
• Zejula is approved for maintenance therapy in women with advanced ovarian, fallopian tube, or primary peritoneal cancer who had a complete or partial response to first-line platinum-based chemotherapy. Zejula for maintenance therapy does not require an HRD test. 

Maintenance therapy after treatment of recurrent cancer

• Zejula, Rubraca (rucaparib) and Lynparza are all approved for maintenance therapy in women with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in a complete or partial response to platinum based chemotherapy. In this setting, none of these drugs requires an HRD test. 

Breast cancer surgical decisions 

Because of the high risk for a second breast cancer diagnosis, women who are diagnosed with breast cancer who test positive for an inherited mutation in ATM may choose bilateral mastectomy rather than lumpectomy and radiation. Mutation carriers who undergo mastectomy are less likely to develop a second breast cancer. 

Radiation therapy in people with an ATM mutation 

Based on research in people who have a mutation in both copies of their ATM gene (see our Other Considerations section), there have been some questions raised about the safety of radiation therapy to treat cancer in people with a single ATM mutation. According to experts, cancer patients with a single ATM mutation can undergo radiation therapy to treat their cancer as recommended by their oncologist.