Rub-on treatment for melanoma closer

New Zealand researchers hope their work could ultimately see skin cancer treated with a cream or tablet rather than surgery.

The research by Hutt Hospital trainee surgeon Dr Sydney Ch'ng and plastic surgeon Dr Swee Tan, on the role of a particular type of cell in skin cancer, is controversial because it differs from overseas findings.

Overseas studies have found that people who developed skin cancers such as melanoma had more mast cells - a part of the immune system, and present in high numbers in the skin's upper layers.

The studies suggested mast cells promoted the development of skin cancers. A United States research team, confident of replicating similar findings, has patented the idea of adding a substance to sunscreens that inhibits the actions of mast cells.

But Dr Ch'ng's laboratory work found the opposite effect - mast cells inhibited the growth of both melanoma and squamous cell carcinoma, the two most lethal types of skin cancer when cultured together.

"All we really know for sure is that they're not innocent bystanders," Dr Ch'ng told the Royal Australasian College of Surgeons' annual scientific meeting in Hamilton.

"They have an important role, which we're well on the way to understanding and using, hopefully to prevent the development of skin cancers.

"This shows us that probably we could try and enhance the body's immune system to fight cancers. Hopefully, one day we won't have to go down the path of surgery."

Dr Ch'ng, who was awarded the Louis Barnett prize for her research, said the work was preliminary, but researchers hoped to identify the substances produced by the mast cells so that a synthetic therapeutic treatment could be developed.

"What we are looking for is a novel biological treatment. If we can give someone a tablet, an injection or a cream, that is definitely the way to go," she said.

Dr Tan - Dr Ch'ng's supervisor - said advances in biological research could greatly reduce the need for invasive surgery for skin cancer.

New Zealand has one of the highest rates of skin cancer in the world. Nearly 300 people die and more than 50,000 cases are diagnosed here each year.

The cost to the health system is believed to be more than $33 million annually.