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 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.

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.

The identification of a constitutional (germline) pathogenic variant in the BRCA1 or BRCA2 genes in a patient with breast cancer has 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.

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

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