PROFILE: Freya Leif, breast cancer researcher

My name is Freya Leif and I’m a second-year Ph.D. student at the University of Leeds, UK. I research breast cancer and cell receptors, trying to find new therapy options for people with a particularly difficult to treat breast cancer subtype.

Types of breast cancer

Breast cancer is not a simple disease – there any several different types of breast cancer and which type someone has will determine what treatment they get.

One way of categorising breast cancers is by the receptors that are found in breast cancer cells. Receptors are proteins found in cells and when certain substances bind to them they send signals telling the cells what to do.

Hormone positive breast cancer

These are tumours that have receptors for the hormones estrogen and/or progesterone. Although these hormones have normal functions in the body in some cases they can encourage cancer cells to grow. About 70% of breast cancers are positive for the estrogen receptor.

HER2 positive breast cancer

These are tumours that have too much of the HER2 receptor and this sends signals to make the cells grow and divide much quicker than they would normally. Around 15-20 per cent of breast cancers are positive for the HER2 receptor.

Triple-negative breast cancer

These tumours do not have receptors for estrogen, progesterone, or HER2. This subtype is particularly aggressive and tends to affect younger women than the other types. Triple-negative breast cancer accounts for around 15 per cent of all breast cancers.

Treatments for breast cancer

Most patients with breast cancer will have surgery as part of their treatment, either to remove just the area of the cancer or the whole breast. Radiation therapy may be used after surgery to help stop the cancer from coming back.

Drugs also form a part of breast cancer treatment plans. These could be conventional chemotherapy drugs or targeted therapies. Targeted therapies bind to a receptor and block it from sending signals that encourage the cell to grow. These include Tamoxifen which stops estrogen binding to the estrogen receptor in hormone-positive breast cancers and Trastuzumab (Herceptin) which binds to HER2 preventing it from sending growth signals in HER2+ breast cancers.

My research

Triple-negative breast cancer has a worse survival rate than other types of breast cancer. It is more difficult to treat because it does not have hormone or HER2 receptors and there are no targeted therapies available currently, leaving chemotherapy as the only drug option. My work looks at the glucocorticoid receptor, which is related to the estrogen and progesterone receptors. I am trying to understand what its function is in triple-negative breast cancer cells and see if using drugs to block it can stop cancer cells from growing.