DNA “Barcoding” and Mouse Avatars to Push Personalised Breast Cancer Care
Cambridge is pushing for the use of genetic testing to transform treatment of breast cancer. They are using genomics to predict responses to treatment and to reveal clues about how cancer becomes resistant to treatment too.
Women diagnosed with breast cancer and have opted to be part of the Personalised Breast Cancer Programme have a sample of their tumour and of their blood sent for sequencing, with the full results coming back within 12 weeks.
Carlos Caldas, Prof of Cancer Medicine and programme director at Cancer Research UK Cambridge Institute, said: “By sequencing the tumour we have something like a barcode which gives us the pattern of mutations in that cancer.
Using sequencing, they are able to test for inherited mutations in BRCA1 & 2 genes, both known for increasing the risk of breast and ovarian cancer. These results have wider implications on their family members who may also need to be notified.
Researchers are able to catalogue the mutations that have occurred in the cancer cells by comparing the germline genome to the tumour sequencing results. This comparison allows enables clinicians to predict individual responses to treatment
Targeted therapies are then prescribed to those who have specific mutations that are driving tumour growth.
But it’s not always as straight forward as that. Elizabeth Benns, 61, joined the study after she was diagnosed with inflammatory breast cancer last year. Like other patients, she had surgery, chemotherapy and radiotherapy. Despite this extensive treatment, her cancer returned and is now incurable, but Elizabeth remains optimistic: “Being part of research gives you are feeling of control and being part of something.”
She told BBC News “It’s reassuring knowing that I don’t have to keep going back for biopsies because they have my genetic code and that of my cancer; it’s banked and hopefully it will mean that first one targeted drug trial and then another will come along that I will be eligible for.”
Cambridge is also taking the approach of offering patients to take part in research involving mouse models known as mouse avatars. This approach hopes to identify the most promising course of treatment for patients by monitoring responses in mice. The mice are injected with tumour cells from the patients and so mimic the exact cancer of each individual that opts into the research.
Dr Alejandra Bruna, molecular biologist, Cancer Research UK Cambridge Institute told me: “We want to reduce the number of toxic drugs that we give to patients, and where possible treat them with targeted therapies with fewer side effects.”
The patients’ tumours are also grown in cells lines, enabling the majority of drug testing to be done in laboratory dishes, so minimising the number of animal tests.
The movement towards using research directly to influence clinical decisions is a promising one. However, the project is still in its early research phases meaning it will need to be further validated before it can be implemented into the clinic.