The researchers have identified immune cell types that could be targeted to create particular immunotherapies for chemotherapy-resistant breast tumours. Researchers from King’s College London and The Institute of Cancer Research, London, with support from Breast Cancer Now, have performed a deep dive into the different immune markers within tumour tissues and blood samples of early breast cancer patients whose cancer failed to respond to chemotherapy given to them prior to surgery.

The research, published in Clinical Cancer Research, a journal of the American Association for Cancer Research, gives insight into the function of immune cells in patients with chemotherapy-resistant breast cancers. While chemotherapy may not kill cancer cells in these high-risk patients, immunotherapy, a type of treatment that helps the immune system to attack cancer cells, may provide a benefit.

To investigate the immune environment that surrounds these chemotherapy-resistant tumours, researchers employed multiple and novel complementary technologies looking at proteins and genes on both pre-treatment and post-treatment breast cancer tissue. They also measured how 1,330 cancer and immune-related genes within cancer tissues were affected by chemotherapy.

They found that chemotherapy-resistant cancer cells had very few immune cells around them, but chemotherapy did induce changes in several immune cell types. Specifically, they found increases in the number of “innate” (first responder) cells such as neutrophils and natural killer (NK) cells. NK cells help the body to fight infection and cancer. But the analysis found the increased NK cells in patients with chemotherapy-resistant disease lacked cytotoxic activity – the ‘killing instinct’. Researchers also found that immune-related genes associated with NK cells were those associated with cell inhibition or exhaustion, which meant NK cells were unable to fight cancer cells.

       Source: ANI