May 2010 and an apparent remarkable breakthrough in breast cancer prevention comes not, as one would expect, from a cancer researcher – but from an immuologist.
Vincent Tuohy, an immunologist at the Cleveland Clinic in Ohio, took a radically different approach to the problem of preventing breast cancer. Though not primarily a breast cancer researcher, Tuohy applied some effective lateral thinking to the problem and came up with the novel idea of vaccinating women against breast cancer. (See Nature Medicine – link below.) The goal was to identify a protein essential to the initial development and growth of breast tumours and block its action with a vaccine.
Dr Joseph Crowe, who is the Director of the Breast Centre at the Cleveland Clinic, said:
“Dr Tuohy is not a breast cancer researcher, he’s an immunologist, so his approach is completely different – attacking the tumour before it can develop. It’s a simple concept, yet one that has not been explored until now.”
The protein present in breast tumours which can be blocked by Dr Tuohy’s vaccine is alpha-lactalbumin. Dr Tuohy explains:
“Tumours are like drunks in a bar, saying and doing things they shouldn’t. One of these things is expressing (or making) alpha-lactalbumin – and we are taking advantage of that.”
The vaccine triggers the immune system to attack alpha-lactalbumin, preventing tumour growth. After 100% effective trials on mice, Dr Tuohy will test his vaccine on women during 2011. One trial will study the vaccine’s effect on breast tumours already present in women with advanced breast cancer. Another will study its effect in young women whose family history gives them a high risk of developing the disease. Other young women would not generally be vaccinated as alpha-lactalbumin plays a role in breast-feeding.
Tuohy’s team has already tested the vaccine on mice specially bred to be prone to breast cancer. Such mice generally develop breast tumours during the first year of their lives. After vaccination with a vaccine made from alpha-lactalbumin and an ‘adjuvant’, all the mice stayed clear of breast cancer in their first year. The mice which didn’t receive the vaccine, however, all developed large breast tumours.
“Over the duration of the study, [the vaccine] was completely effective” Tuohy said. “If it works in humans the way it works in mice, this will be monumental. Breast cancer affects everyone. We all have wives, mothers, sisters and daughters, so we are all affected by it.”
After initial trials, longer studies on larger numbers of women will be needed which means it could be 2020 before the vaccine is widely available. Dr Tuohy believes it should then be offered to all women over 40, since breast cancer risk starts to rise in midlife. It would also be offered to younger women with a higher than normal genetic risk of the disease.
Tuohy was so encouraged by the apparently unequivocal science underlying the vaccine’s development, and laboratory test results already seen, that he added: “Our view is that breast cancer is a completely preventable disease.”
Since breast cancer rates have risen steeply in the last two decades this is a hugely important claim if it can be substantiated in the human trials.
Breast cancer is attributed variously to hormonal changes, genetic factors, smoking, drinking alcohol, obesity and hormone replacement therapy (HRT) but the causes are not precisely understood. If Tuohy’s vaccine works however, it will eliminate the need for further research into breast cancer development.
Now that the possibility of vaccinating against a protein’s activity is being tested, the technique offers hope for vaccines against other cancers too. Identifying similar proteins in other cancerous tumours could open the way for more vaccines.
“When you are an adult” Tuohy says “you could be vaccinated against adult diseases like breast cancer, ovarian cancer, prostate cancer, and so forth. Maybe even Alzheimer’s.”