Research into the development of a unique vaccine shows early promise for an effective treatment against high-risk breast cancer.
Breast cancer is one of the most common forms of the disease. Around one in nine Kiwi women are affected by breast cancer in their lifetime, according to the Breast Cancer Foundation, and while the survival rate is high thanks to early detection measures such as screening, more than 650 women in New Zealand die from breast cancer every year.
New Zealand researchers have now tested a unique vaccine design that according to preclinical results, may slow tumour growth and block the spread of breast cancer throughout the body, as per a study led by the Malaghan Institute of Medical Research in Wellington, New Zealand and published in the academic journal, Clinical & Translational Immunology, this week.
In collaboration with the Ferrier Research Institute in Lower Hutt, the Malaghan Institute has been working on developing stimulatory molecules that act as 'vaccine adjuvants'. An adjuvant works alongside a vaccine targeting specific breast cancer antigens to boost the immune system's natural response to the cancer, helping it kill affected cells - not only at the main tumour site, but elsewhere throughout the body, possibly preventing further spread.
In collaboration with the Ferrier Research Institute in Lower Hutt, the Malaghan Institute has been working on developing stimulatory molecules that act as 'vaccine adjuvants'. An adjuvant works alongside a vaccine targeting specific breast cancer antigens to boost the immune system's natural response to the cancer, helping it kill affected cells - not only at the main tumour site, but elsewhere throughout the body. This may possibly prevent further spread, or metastasis, of breast cancer in the body, which is the primary cause of death in patients.
In a statement on Tuesday, the authors said their research offers optimism for the future development of an effective, therapeutic vaccine against high-risk breast cancer.
"We investigated our vaccines in models of both HER2-positive breast cancer and triple negative breast cancer," said Malaghan Institute Postdoctoral Fellow, Dr Olivia Burn.
"We're particularly interested in triple-negative breast cancer because it can present as a more aggressive kind of breast cancer and currently has very limited treatment options.
"First, we combined segments of the HER2 protein with our immune-stimulatory compound – a glycolipid which activates a particular immune cell population – to enhance the immune response against HER2. A single dose of this treatment delayed tumour growth and prevented its growth in the lung.
"Then, in a model of triple-negative breast cancer, we used a different vaccine that targeted parts of the protein NY-ESO-1, which is often overexpressed in these cancers, particularly when it has spread to other organs and found similarly encouraging anti-tumour results."
Although breast cancer is typically very treatable, the principal cause of death is not the initial tumour itself, but its spread to other parts of the body. Preventing this spread, or metastasis, is key to reducing the number of people who die from this disease, Dr Burn said.
"Metastatic cancers typically originate from a single source, with the resulting tumours often being copies of the 'parent' tumour and displaying the same physical markers on their surface. Because of this similarity, there is good potential for developing a breast cancer vaccine that prevents the tumour from spreading to other parts of the body."
The research indicates that this unique glycolipid-vaccine platform can be used to generate strong immune responses against clinically relevant breast cancer markers, Dr Burn added.
"Future steps could include progressing this vaccine design, possibly using RNA technology, where the whole protein for HER2 and NY-ESO-1 could be used as a vaccine target, which would provide greater population coverage. RNA technology could also make it easier to investigate other relevant breast cancer markers and help us assess if metastasis to other organs, such as the liver, can be prevented."
According to the Breast Cancer Foundation New Zealand, breast cancer occurs when abnormal breast cells grow in an uncontrolled way, usually forming a tumour. It is the most common cancer for Kiwi women and the third most common cancer overall.
About 70 to 75 percent of women who are diagnosed with breast cancer, and about 80 percent of women who die from it, are aged 50 years or older. Some women are at a greater risk of developing breast cancer if there is a history of family members having the disease: however, most women who develop breast cancer have no relatives with the illness.
While it is less common, young women can get breast cancer too. Six percent of breast cancer in New Zealand occurs under the age of 40. Although it is uncommon, men also get breast cancer - about 25 men are diagnosed in New Zealand each year.
In the early stages of breast cancer, when a tumour is small, there is usually no pain or obvious signs and symptoms. It may not be easy to feel a lump, so screening mammography is the best method of detection. However, as the cancer grows, obvious changes in the breast may appear, and these need to be checked by your doctor.
The Foundation urges women to be alert for new lumps or thickened tissue; changes in nipple, breast shape or size; and unusual pain that doesn't go away.
