Scientists from the University of Georgia and the Mayo Clinic in US have developed a vaccine that could deal a serious blow to seven in ten lethal cancers.
In tests, the vaccine it shrunk breast tumours by 80%, and researchers believe it could also tackle prostate, pancreatic, bowel and ovarian cancers.
Even tumours that resist treatment with the best medicines on the market, including the “wonder drug” Herceptin, may be susceptible to the vaccine.
The experiments done so far have been on mice, but researchers hope to pilot the drug on people within two years.
If all goes well, the vaccine – one of the first to combat cancer – could be on the market by 2020.
Rather than attacking cancer cells, like many drugs, the new treatment harnesses the power of the immune system to fight tumours.
The search for cancer vaccines has until now been hampered by fears that healthy tissue would be destroyed with tumours.
To get round this, researchers, who led the study, were focused on a protein called MUC1 that is made in bigger amounts in cancerous cells than in healthy ones.
Not only is there more of it, but a sugar that it is “decorated” with has a distinctive shape.
The vaccine “trains” the immune system to recognize the rogue sugar and turn its arsenal against the cancer.
Researcher Professor Sandra Gendler said: “Cancer cells have a special way of thwarting the immune system by putting sugars on the surface of tumour cells so they can travel around the body without being detected.
“To enable the immune system to recognize the sugar, it took a special vaccine that had three parts to it.
“That turned out to be a winning combination.”
The co-author, Professor Geert-Jan Boons said: “This vaccine elicits a very strong immune response.
“It activates all three components of the immune system to reduce tumour size by an average of 80 per cent.”
The misshaped MUC1 sugar is found in 90% of breast and pancreatic cancers and around 60% of prostate cancers, as well as many other tumours.
The researchers believe more than 70% of all cancers that kill may be susceptible to the vaccine.
Despite their excitement, the work is still only at an early stage.
After the “dramatic” results of the tests on mice with breast tumours, the researchers now plan to try the drug on human cancer cells in a dish.
Years of large-scale human trials would need to follow before the drug was judged safe and effective for widespread use in hospitals.
It could then be used with existing drugs to boost treatment and given to prevent tumours from coming back after surgery.
Men and women known to be at high risk of cancer because of their genes could also be vaccinated in an attempt to stop tumours from appearing.
Prof. Geert-Jan Boons, who has founded a biotech company to commercialize the vaccine, said: “We are beginning to have therapies that can teach our immune system to fight what is uniquely found in cancer cells.
“When combined with early diagnosis, the hope is that one day cancer will become a manageable disease.”
The vaccine is one of several treatments in the pipeline that work by triggering the immune system to attack and kill cancer cells.