A 52-year-old man with advanced melanoma, the lethal form of skin cancer, has been successfully treated using just his own blood.
The development has been hailed by British experts as an "exciting advance" in the use of cancer immunotherapy, which harnesses the body's immune system to fight the disease.
Researchers in the US who were treating the patient extracted white blood cells, the key component of the immune system, and grew one type – the infection-fighting CD4+ T cells – in the laboratory. The cloned T cells, which had been vastly expanded, were then reinfused to the patient to fight the cancer.
The man was diagnosed with stage four melanoma, when death normally occurs within months. The cancer, triggered by sunburn, started in a mole on the skin and had spread to a lymph node in his groin and to his lungs. But, two months after the T-cell treatment, scans revealed no tumour. Two years later, when he was last checked, the man remained free of the disease. He had previously had surgery and drug treatment without any response.
Melanoma is the deadliest form of skin cancer, causing 1,800 deaths a year in the UK. It is the fastest rising cancer, with cases up 40 per cent in the past decade. The cancer is caused by intermittent, intense exposure to the sun. The typical victim is the office worker who spends two weeks broiling on a beach each summer. Adults with fair skin who suffered severe sunburn before the age of 15 are at highest risk.
Cassian Yee, who carried out the experimental treatment with colleagues at the Fred Hutchinson Cancer Research Centre in Seattle, said that one in four late-stage melanoma patients had the same type of immune system and tumour antigen as the patient, for whom the therapy could be effective. But he warned that they had only proved its success in one patient. "We were surprised by the anti-tumour effect of these CD4+ T cells and its duration of response. For this patient we were successful, but we would need to confirm the effectiveness of the therapy in a larger study."
The findings are published in The New England Journal of Medicine, which describes them in a commentary as a "novel strategy" which points to a "feasible new direction" for treatment.
Louis Weiner, the author of the commentary and director of the Lombardi Comprehensive Cancer Centre in Washington, said that although it was too early to be sure of the significance of this one case, the indications were that it will give a substantial boost to the technique of cancer immunotherapy. "I suspect that if the destination is not yet at hand, it is in sight. The endgame has begun," he said.
Cancer immunotherapy is a growing area of research which has proved successful in some other cancers, including kidney cancer. The aim is to developless toxic treatments which are at least as effective as chemotherapy and radiation.
Ed Yong, a health information manager at Cancer Research UK, said: "While it's always good news when anyone with cancer gets the all-clear, this treatment will need to be tested in large clinical trials to work out how widely it could be used."
Professor Peter Johnson, Cancer Research UK's chief clinician and a consultant in Southampton, said: "Although the technique is complex and difficult to use for all but a few patients, the principle that someone's own immune cells can be made to work in this way is very encouraging."
How immunotherapy works
* Cancer immunotherapy is the technique of harnessing the body's immune system to attack the cancer.
* The immune system normally responds to threats to the body by distinguishing between itself and foreign invaders.
* In the case of cancer, this is difficult because most tumours consist of the body's own cells growing out of control.
* However, many cancer cells display unusual antigens or receptors on their surface that allows them to be identified.
* Antibodies and cancer vaccines to stimulate the immune system are being developed to attack these tumour cells.
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