Two men diagnosed with skin cancer and given months to live have been cured using genetically-modified immune cells from their own bodies.
Findings in a study published online by the journal Science yesterday herald a new direction in the fight against cancer, where the focus is on boosting the body's immune system instead of relying on toxic chemotherapy and radiation treatments.
Dr Steven Rosenberg and his team at the National Cancer Institute in Bethesda, Maryland, US, developed the technique and said it could be adapted to treat breast, lung, prostate and other common cancers.
Dr Rosenberg's team harvested immune cells, called T cells, from 17 cancer patients. They armed the T cells with a "receptor" protein that recognises the melanoma tumour and attacks it.
A virus was used to transport the genetically modified T cells into the patient's bloodstream. Once in the body, the T cells lock onto the tumour and release hormones that destroy it.
One patient, Mark Origer (53) from Wisconsin, had tried a myriad treatments before enrolling in the trial. He is now cancer free and was able to attend his daughter's wedding last year.
The other man, aged 39, cleared the cancer that had spread to his liver, lymph nodes and lung.
Dr Rosenberg cautions that there is still more failure than success with this type of treatment. Fifteen of the study participants still have cancer.
Nevertheless, experts say the results are extremely exciting and proof that this new therapy can work.
The Irish Cancer Society said yesterday at present, once cancer has spread from the original site, it is almost impossible to cure.
"Therefore it is exciting to see that progress has been made with this gene therapy," according to Dr Patrick Corley, Cancer Research Officer for the society.
"These are early results and this is a technically challenging treatment to develop. However, the body's immune system must be respected, as it has the power to cure disease."
The society said that more than 5,000 new cases of non-melanoma skin cancer and 400 new cases of malignant melanoma are diagnosed in Ireland every year.
Approximately 64 people in Ireland die from melanoma annually.
• If you are concerned or have been affected by skin cancer, freefone the National Cancer Helpline on 1800 200700 (weekdays 9am to 5pm; Tuesdays until 9pm).