The identification of a variant (mutation) in the ESR1 gene in circulating tumour DNA (ctDNA) from a patient with metastatic ER-positive, HER2-negative breast cancer who has progressed on endocrine therapy has implications for the clinical management of the current cancer.

The identification of a constitutional (germline) pathogenic variant in the ATM gene in a patient with breast cancer may have implications for the clinical management of the current cancer, as well as for the patient’s future cancer risk. It should also trigger cascade testing in the wider family.

The identification of a somatic (tumour) AKT1 variant in a patient with metastatic oestrogen receptor-positive, human epidermal growth factor receptor-2-negative breast cancer who has progressed on endocrine therapy may have implications for the clinical management of the current cancer.

The identification of a constitutional (germline) pathogenic variant in the PALB2 gene in a patient with breast cancer has implications for the clinical management of the patient’s current cancer, as well as for their future cancer risk. It should also trigger cascade testing in the wider family.

Patients with a pathogenic variant in the ATM gene have an increased risk of cancer, which may include the rare condition ataxia telangiectasia.

Genomic testing in carcinoma of unknown primary may have implications for the clinical management of the patient’s current cancer, as well for their family members.

The identification of a somatic (tumour) PIK3CA gene variant in a patient with metastatic oestrogen receptor (ER)-positive, human epidermal growth factor receptor-2 (HER2)-negative breast cancer who has progressed on endocrine therapy has implications for the clinical management of the current cancer.

Advice for patients with cancer whose constitutional (germline) genomic testing results are uninformative should be guided not just by their negative result, but also by their personal and family history. The patient and their relatives may still require enhanced cancer screening.

Genomic testing in breast cancer may affect clinical management of the current cancer, as well as of the patient’s future cancer risk and that of their relatives. 

Genomic testing in breast cancer may affect clinical management of the current cancer, as well as of the patient’s future cancer risk and that of their relatives.