US doctors have for the first time successfully treated a skin cancer patient with cells cloned from his own immune system, a study released Wednesday showed.

The ground-breaking treatment for advanced melanoma, or skin cancer, led to a long remission for the patient and used his own cloned infection-fighting T-cells, said doctor Cassian Yee, the lead author of the study in the New England Journal of Medicine.

Yee and his associates from the Clinical Research Division at Fred Hutchinson Cancer Research Center in Seattle removed CD4+ T-cells, a type of white blood cell, from a 52-year-old man whose melanoma had spread to a groin lymph node and to one of his lungs.

The melanoma was already well advanced and in stage four.

The T-cells which specifically fight melanoma were modified and expanded in the laboratory and some five billion cells were then infused into the patient, who received no other kind of treatment.

Two months later no tumors were found during scans of the patient’s organs. And he has been cancer free for two years, Yee said.

"We were surprised by the anti-tumor effect of these CD4 T cells and its duration of response," Yee said. "For this patient we were successful, but we would need to confirm the effectiveness of therapy in a larger study."

It was the first ever case to show that cloned cells from a patient’s own immune system can successful combat skin cancer. If further tests confirm the efficiency of the method, it could be used in some 25 percent of patients with late-stage skin cancer, the study said.