Scientists unveil new 'vaccine' for cancer

Scientists have created genetically engineered "vaccines" that have been used for the first time to treat prostate cancer in humans.

Scientists have created genetically engineered "vaccines" that have been used for the first time to treat prostate cancer in humans.

The "personalised vaccines" were made using cancer cells from individual patients and were found to boost their immune systems, enabling them to fight the disease. Cancer specialists believe the breakthrough could lead to gene therapy being used alongside surgery, chemotherapy and radiation therapies.

"We were astounded to find that every part of the immune system was alerted and turned on," said Dr Jonathan Simons, an associate professor of oncology and urology at Johns Hopkins University in Baltimore, who led the study.

"Using gene therapy, we re-educated the immune system to recognise prostate cancer cells as a potential infection and attack."

In Britain, prostate cancer is the second biggest cancer killer for men after lung cancer. Each year nearly 16,000 men are diagnosed with the disease and only 43 per cent survive for more than five years. About 10,000 men a year die from it.

The scientists, who published their work in the latest issue of the journal Cancer Research, found that although vaccines did not cure any of their patients, it activated the immune system to fight the cancer. The initial phase of the research was done two years ago on 11 patients, none of whom have died.

The medical team took cancer from the patients' own prostate tumours and grew them in a laboratory dish. They inserted the gene, which produces a protein that activates the immune system to recognise tumours, into the cancer cells. They used a retrovirus to carry the gene into the cells but said their technique was safe because the virus does not normally infect people, and because the work was done outside the patients' bodies.

Then they zapped the cells with X-rays to make sure the cells did not themselves cause more cancer and injected them into the patients. Within four weeks, the researchers found immune cells known as B-cells circulating and producing antibodies against prostate cancer cells. Another kind of immune cell, T-cells, were directly attacking the tumour.

Dr William Nelson, part of the medical team, said: "The gene we used to turn on the immune system is so good that it activates everything. Such a complete and thorough activation of the immune system against prostate cancer has never before been seen."

Dr Nelson said they were unclear about why the first vaccine had not cured any patients. "If we give more vaccine will we be better off? Or perhaps a booster will help."

Surgery or radiation therapy can cure many cases of cancer. But sometimes cancer cells are missed, which can start secondary tumours elsewhere in the body.

Now the researchers are testing another gene therapy vaccine using a nonpersonalised approach. If it works, it could be used in conjunction with chemotherapy and radiotherapy.