The immune system of one patient has been tweaked to eliminate breast cancer cells, offering a potential treatment approach for metastatic breast cancers for which conventional therapies have failed, according to a new paper published online this week in Nature Medicine.
Immunotherapy is an exciting area of research which in recent years has resulted in effective new treatments being made available for melanoma and kidney cancers. Up until now, immunotherapy research in breast cancer has mainly focused on developing treatments for triple negative breast cancer, as they tend to have more genetic mutations which can help to activate the immune system.
Today, we have seen exciting results from scientists at the National Cancer Institute in Maryland, USA, suggesting that immunotherapy has the potential to treat hormone-positive breast cancers too, opening up the possibility that immune-based therapies could be developed to benefit a much greater proportion of women with breast cancer.
The therapy involved isolating the immune cells found in a patient’s tumour, and selecting those with the greatest potential to attack the patient’s cancer cells. The scientists then introduced these cells back into the patient, along with a drug called a ‘checkpoint inhibitor’, which blocks the molecular signals which stop the immune system from carrying out its attack.
The findings are based on treating just one patient, however, meaning that the approach needs to be tested in many more patients to determine its effectiveness.
Dr Simon Vincent, Director of Research at Breast Cancer Now, said:
This is a remarkable and extremely promising result, but we need to see this effect repeated in other patients before giving hope of a new immunotherapy for incurable metastatic breast cancer.
This is a hugely exciting first in the treatment of advanced breast cancer. But it has only been shown to work in a single patient and we now need larger trials to investigate how the T-cell therapy and ‘checkpoint inhibitors’ have worked together to attack the secondary tumours.
It’s also highly significant that this outcome suggests reprogramming patients’ immune cells as part of a two-pronged attack could be a viable way to treat ER-positive tumours – which could open this approach up to benefit many patients with metastatic breast cancer.
Metastatic breast cancer remains incurable, and if we are to finally stop women dying we urgently need to find new ways to target and stop the spread of the disease. We are thrilled by this early finding, but we must remember that this type of immunotherapy remains an experimental approach that has a long way to go before it might be routinely available to patients.
While T-cell immunotherapy has mostly been used in other cancers to date, world-class research is now beginning to uncover its potential to also target breast tumours. With the disease still taking lives on a heart-breaking scale, we very much hope approaches that target the immune system in this way can be developed to help give patients with metastatic breast cancer more time to live. We eagerly look forward to following the progress of this innovative and extremely encouraging immunotherapy.”