News of a prototype breast cancer “vaccine” caused something of a stir in the media recently, with flurries of reports on how researchers at the Cleveland Clinic have come up with a jab that could prime the body to recognise and destroy breast cancer cells. The approach centres on a naturally occurring protein called alpha- lactalbumin, which crops up in many breast cancers.
At the moment, it seems to work well in a pre-clinical model: if a mouse that is susceptible to developing tumours gets a single dose of this vaccine, its risk of developing breast cancer is cut.
We could eliminate breast cancer,” said researcher Dr Vincent Tuohy in a release from the clinic. Vaccines that have already been approved for liver and cervical cancer recruit the immune system to fight off viruses associated with the diseases, but the breast cancer vaccine targets the cancer cells themselves.
It’s a promising step, and more generally it highlights how scientists are working out the links between cancer and the immune response. Several drug companies are now developing and testing potential immune-based therapies to help manage and treat cancer. ‘By the time a tumour presents, you are guaranteed to have millions of cancer cells circulating in the bloodstream, and where the immune system is fighting the tumour those patients have a good life expectancy,” he says.
Cancerous growths can engineer a local “radar blackout”, so the immune system won’t pick them up, explains Soden. “The tumour stimulates a certain type of cell that suppresses the local response, so it becomes a no-go zone for the immune system.”
Researchers at the University College Cork centre are also looking at another, more specific way of getting a patient’s immune system to weigh in on campaigns against cancer cells. Just as the Cleveland Clinic scientists came up with a way of flagging breast cancer cells to the immune system, the Cork researchers have developed a DNA-vaccine that targets prostate-specific antigen (PSA), a biochemical found in prostate cells.
If a patient has had his prostate removed because of a tumour, getting this vaccine would prime his immune system to recognise and kill off any prostate cancer cells remaining in the body. “By the time a tumour presents, you are guaranteed to have millions of cancer cells circulating in the bloodstream, and where the immune system is fighting the tumour, those patients have a good life expectancy.
