Genetic testing and genomic profiling

You may have heard the words "genetics" and "genomics" used in breast cancer care and the difference between them matters. In this video - I will explain what each one is, how testing works, and what the results mean for you. These two terms sound alike, but they describe quite different things in breast cancer care. Genetics looks at the genes you inherited; while genomics looks at the genes inside the cancer cells themselves. Cancer genetics focuses on the inherited genes, that can increase your risk of developing breast cancer over your lifetime. The best-known are BRCA1 and BRCA2, which significantly raise the lifetime risk of breast and ovarian cancer. Other genes such as PALB2; CHEK2; and ATM also contribute to inherited breast cancer risk in some families. A genetic test usually involves a simple blood sample, analysed in a laboratory for inherited gene changes. Results are normally discussed with you in person, alongside specialist counselling where this is appropriate. Genetic testing may be offered when your personal or family history suggests an inherited risk of breast cancer. It is particularly considered if you were diagnosed at a young age; or if several close relatives have been affected by breast or ovarian cancer. If a high-risk gene change is found, this can affect both your treatment choices and the support we offer your wider family. Close relatives can be offered targeted testing for the same change. Your care plan may also include extra screening, risk-reducing medication, or in some cases preventive surgery. Cancer genomics looks at something quite different from your inherited genetics; and it has its own important role. It examines the DNA of the tumour itself, including changes that the cancer cells have acquired during their growth. In hormone receptor positive early breast cancer; tests such as Oncotype DX or EndoPredict, analyse specific genes in your tumour. They estimate the risk of recurrence and help us decide whether chemotherapy is likely to add real benefit to your treatment plan. In metastatic breast cancer, genomic profiling identifies specific tumour changes that may open up new treatment options. For example, a mutation in the PIK3CA gene may allow us to use a targeted treatment such as alpelisib. Also, tumours that carry a very high number of genetic faults may also respond well to immunotherapy. Together, genetics and genomics allow us to personalise your care in ways that were not possible even a decade ago. They guide both treatment choices and the support offered to your family, and they are now a routine part of modern breast cancer care. Thank you for watching. If you would like to discuss genetic testing or genomic profiling; please contact my team, and they will talk you through the options.