Endocrine control mechanisms team

55,000 people are diagnosed with breast cancer in the UK every year. Up to 80% of these cancers are oestrogen receptor positive (ER-positive). Many lobular breast cancers are also ER-positive. Lobular breast cancer is a type that can be harder to diagnose and treat than other types of breast cancer. It is harder to detect by mammography and physical examination.

ER-positive breast cancers are usually treated with hormone therapy. But even with treatment, the disease can return many years later in other parts of the body. When this happens, it’s called secondary (metastatic) breast cancer, and there’s currently no cure for it.

Until now, it’s been difficult to study how ER-positive tumours develop. Professor Cathrin Brisken is creating better laboratory models of the disease that are similar to the disease in people. This will help to develop new and more effective treatments for ER-positive breast cancers, including lobular breast cancer.

Cathrin and her team are focusing on 2 areas:

1. Developing improved models of lobular and ER-positive breast cancer
   
   To better understand more difficult to treat ER-positive breast cancers, Cathrin and her team have been developing new ways to study these cancers in mice.
   
   Using innovative methods, they’ll create breast cancers that are very similar to those that develop in people. It means they can study how cancer cells leave the breast and move into other organs, where the disease becomes incurable.
   
   Cathrin and her team have also worked out how to grow lobular breast cancer cells in the lab. It allows them to study tissue samples donated by people with this type of breast cancer. They’ll use these samples to test drugs that interfere with proteins in lobular breast cancer, to see if they have potential as a future treatment. They’ll also look for ways to tell which people will benefit from these drugs.
   
   
2. Investigating the role of the progesterone receptor
   
   For this project, Cathrin’s team is working with chemistry researchers in the Institute of Cancer Research, London. Many ER-positive cancers have a protein that can interact with the hormone progesterone, called the progesterone receptor. Cathrin and her team have found that in mice, abnormal levels of progesterone receptors in some cases can help ER-positive breast cancer to grow and spread.
   
   Now, they want to investigate this further. So they’re developing a drug targeting the progesterone receptor. This drug will use the natural recycling system inside the cells to break down the progesterone receptor. They’re testing and refining a selection of drugs that can achieve this. Then they can look at whether these drugs work against ER-positive breast cancer.

This research aims to develop new ways to treat ER-positive and lobular breast cancers. Cathrin also hopes the research will find out how hormones such as oestrogen and progesterone affect healthy breast cells, as well as ER-positive breast cancer cells. Doing this could help us find new ways to prevent the disease.