Researches in the US have identified a new way to fight cancer.

Using gene therapy, plastic surgeons delivered cancer-fighting proteins through skin flaps (a mass of healthy tissue) placed on cancerous tumours on rats and found a 79 percent reduction in tumour volume.

While this new delivery technique, which is yet to be tested in humans, did not cause toxicity in the body of rats, administering the same anti-tumour agent intravenously in humans has previously been shown to cause liver damage.

"This new technique may allow us to reprogram skin flaps, using gene therapy, to provide a blueprint for anti-tumour agents like Interleukin-12 to be produced in the tumour to kill cancer, while avoiding adverse side effects," said Geoffrey Gurtner, MD, American Society of Plastic Surgeons (ASPS) Member and study senior author.

"In this study we took skin flaps in animal models and delivered IL-12 directly to the tumour area with tremendous success. Since skin flaps are used thousands of times each year in cancer patients, this may potentially open up an entirely new area in plastic surgery and bring the specialty, once again, to the centre of medicine," he added.

Gene therapy has been heralded as a new tool to restrain or prevent tumour growth and recurrence in humans.

However, its use has been limited because of serious side effects and the difficulty in concentrating anti-tumour agents at the site of the cancer.

In the new study, skin flaps taken from rats were injected with the gene for IL-12 into the flaps' blood supply. The flaps were then placed onto cancerous tumours on the rats.

Researchers found a 79 percent reduction in tumour volume for animals treated with IL-12 as compared to control animals.

According to the study, the treatment allowed individual cells within the flap to become encoded with IL-12 and function as 'miniature factories' producing the IL-12 protein at very high levels in the tumour site.

Besides this, the serious side effects previously documented with systemic use of IL-12 were not found in the treated rats. The liver, lung and spleen remained normal throughout the study.

Researchers also found that the delivery technique through free flaps did not cause liver toxicity, whereas using IL-12 intravenously in humans has been shown to cause liver damage.

"This could be a major advance for the delivery of a therapeutic agent to diseased parts of the body. I can see this therapy being used for breast cancer, head and neck cancers, central nervous system malignancies, and somewhere down the line hemophilia, diabetes and infections," said Dr. Gurtner.

The study is published in the May issue of Plastic and Reconstructive Surgery, the official medical journal of ASPS.