Cells from cancer-resistant people could soon be used to help cancer patients fight their disease, says a U.S. researcher.

Wake Forest University of Medicine researchers in Winston-Salem, N.C., have received the go-ahead from the U.S. Food and Drug Administration to conduct the trials, during which they will obtain cancer-fighting cells from people resistant to the disease, and inject them into patients with matching blood types.

The trials, planned for summer 2008, are described in an article in Saturday's issue of New Scientist.

In recent studies, Zheng Cui, an associate professor of pathology, took blood samples from over 100 people and mixed their immune cells with cervical cancer cells. While the immune cells from one individual killed around 97 per cent of cancer cells within 24 hours, those from another healthy individual only killed around two per cent of such cells.

Cui's research has uncovered that people over 50, those with cancer and those people who are stressed have lowered cancer-fighting ability and fewer immune cells. And the summer is better for fighting cancer than the winter.

"Nobody seems to have any cancer-killing ability during the winter months from November to April," says Cui.

Preliminary evidence suggests it may be possible to transfer the ability to fight off cancer between people.

Immune cells are already taken from donors and given to some patients whose immune systems have been depleted by chemotherapy, for example, though not to treat cancer directly.

Last year, Cui successfully treated a range of different cancers in mice by injecting them with immune cells from a strain of mice that are completely resistant to cancer.