A vaccine to stop women developing breast cancer could be available within a decade after trials on mice gave ”overwhelmingly favourable results”. But experts are warning caution is needed over the findings, reports BBC. Human trials of the vaccine, which primes the immune system to kill off any problematic cells before cancer can take hold and attacks tumours that are already present, are expected to begin within two years.
‘We believe that this vaccine will someday be used to prevent breast cancer in adult women in the same way that vaccines have prevented many childhood diseases. If it works in humans the way it works in mice, this will be monumental. We could eliminate breast cancer,” the lead researcher, US immunologist Vincent Tuohy, from the Cleveland Clinic Lerner Research Institute, said.
In the study, genetically cancer-prone mice were vaccinated – half with a vaccine containing á-lactalbumin and half with a vaccine that did not contain the antigen. None of the mice vaccinated with á-lactalbumin developed breast cancer, while all of the other mice did. The US has approved two cancer-prevention vaccines, one against cervical cancer and one against liver cancer. However, these vaccines target viruses – the human papillomavirus (HPV) and the Hepatitis B virus (HBV) – not cancer formation itself.
In terms of developing a preventive vaccine, cancer presents problems not posed by viruses – while viruses are recognised as foreign invaders by the immune system, cancer is not. Cancer is an over-development of the body’s own cells. Trying to vaccinate against this cell over-growth would effectively be vaccinating against the recipient’s own body, destroying healthy tissue.
The strategy could be to vaccinate women over 40, when breast cancer risk begins to increase and pregnancy becomes less likely. If a woman would become pregnant after being vaccinated, she would experience breast soreness and would likely have to choose not to breast feed. For younger women with a heightened risk of breast cancer, the vaccine may be an option to consider instead of prophylactic radical mastectomy, researcher say.
“Most attempts at cancer vaccines have targeted viruses, or cancers that have already developed,” said Joseph Crowe, M.D., Director of the Breast Center at Cleveland Clinic. “Dr. Tuohy is not a breast cancer researcher, he’s an immunologist, so his approach is completely different – attacking the tumor before it can develop. It’s a simple concept, yet one that has not been explored until now.”
Because the approach is so new, many experts are cautious. “This is interesting, however extremely preliminary work,” says Dr. Freya Schnabel, a breast cancer expert at New York University Medical Center who worries that even if the vaccination eventually proved effective, finding the right stage in life to use the vaccine will be challenging.
“If malignant transformation is a process that takes years to complete, the 40s may actually be too late to vaccinate,” says Schnabel. Schnabel also points out that the study admits there is controversy over just how many breast cancers contain the treatment’s main target – a-lactalbumin.
Schnabel also points out that the study admits there is controversy over just how many breast cancers contain the treatment’s main target – a-lactalbumin. Still Tuohy is hopeful that the findings of this study might go beyond breast cancer, providing insight into the development of vaccines to prevent other types of cancer. [via BBC and CBS]