New findings opens door for breast cancer researchers

Queensland scientists have found vital clues suggesting how breast cancer cells evade recognition by the immune system and are able to progress into life threatening tumours. This discovery has the potential to result in a new treatment for breast cancer, a disease affecting one in 12 Australian women.

Scientists at The Queensland Institute of Medical Research (QIMR) have been studying Dendritic Cells (DC), which play a crucial role in the immune system by constantly seeking out those cells that have been invaded by pathogens or are undergoing pre-cancerous changes. DCs instruct the body’s defences to destroy cells infected with viruses and bacteria – the same defences that kill tumours.

Early detection of abnormal cells by DCs allow the immune system to eliminate pre-cancerous cells before they develop into a cancer. Based at QIMR’s Clive Berghofer Cancer Research Centre, Associate Professor Alejandro Lopez and his colleagues discovered – by studying patients with breast cancer – that tumours can cause the death of DCs. Their results were recently presented in a highly accessed publication of the journal Breast Cancer Research.

“Compared to healthy women, we found that patients with breast cancer demonstrated a higher percentage of dying DCs,” said Associate Professor Lopez. “This means that the body is unable to effectively suppress tumour progression because the DCs die before they can trigger an immune response.”

A further study showed a molecule naturally produced by the body (CD40L) can protect DCs from dying prematurely and may enhance the effectiveness of immunotherapy. (CD40L belongs to a group of proteins produced by white blood cells that act as chemical messengers between cells – they also have the ability to modulate the activity of immune cells such as DCs).

These findings give a better understanding of the complexities behind breast cancer development and will be instrumental in adding this disease to the experimental DC-based immunotherapy treatment, currently being trialled by QIMR and its collaborators on melanoma, prostate cancer and brain tumours.

Immunotherapy uses DCs to teach the immune system to target and kill only cancer cells, with little to no negative side effects, unlike chemotherapy and radiotherapy. These trials began at QIMR in 1996 with patients with stage 4 melanoma, in whom cancers had progressed beyond a treatable state and immunotherapy was their only hope. These treatments have been shown to be effective in around 10% of the stage 4 patients treated.

Breast cancer is the most common cancer occurring in Australian females and results in 2,500 deaths each year. Increased funding will provide the resources to advance this immunotherapy to make it applicable for patients with breast cancer, in the future.

For more information about QIMR research or to make a donation, visit www.qimrberghofer.edu.au or call toll-free 1800 993 000.