A single gene in skin cancer tumors seems to predict whose cancer will spread and whose will not, researchers said on Friday.

They said they hoped to develop a test that will tell a doctor who needs extra screening after having a melanoma removed.

Patients whose tumors "express" the melastatin gene, meaning the gene is active in the tumor cells, are most likely to survive their melanoma, the joint team of researchers, at Millennium Pharmaceuticals Inc. and Massachusetts General Hospital in Boston, said.

"The activity of the melastatin gene in cutaneous melanoma tumors accurately predicts which patients are at most risk of having their skin cancer metastasize (spread), and those most likely to remain disease-free, based on findings in the study," Millennium, whose findings are published in Friday's issue of the Journal of Clinical Oncology, said in a statement.

They tested 150 patients whose melanoma had not yet spread.

Patients with stage I melanoma, the earliest stage, all lived for eight years without a recurrence of their cancer. Thirty-three, or just over half, of the patients fit into this group. The 25 stage I patients whose tumors did not express the melastatin gene had a 77 percent rate of eight-year disease-free survival.

In the stage II patients, whose cancer was more advanced but had not yet spread, 90 percent of those with the melastatin gene lived for eight years without a relapse and 51 percent of those without it survived that long.

A TUMOR'S THICKNESS

Doctors currently look at a tumor's thickness to predict a patient's chances of surviving without their cancer coming back.

Dr. Michael Kauffman, a vice president of medicine at Millennium who worked on the study, said the melastatin gene might be a substitute for or an addition to this method.

"With the publication of this study, we have proof-of-principle that molecular targets can be used for diagnostic tests in skin cancer," he said.

This might tell doctors which patients need to have further tests, such as a "sentinel node" biopsy -- a test of the nearest lymph node to see if the cancer has spread, said Dr. Lyn Duncan, the Massachusetts General researcher who led the study.

Melanoma accounts for about 4 percent of skin cancer cases, but causes about 79 percent of skin cancer deaths. About 44,000 people are diagnosed with melanoma every year in the United States.

"Currently, there is no cure for patients who present with melanoma metastatic to distant sites and the median survival of these patients is only about six months," the researchers wrote in their paper.

But they noted that work is underway on melanoma vaccines and said patients lacking the melastatin gene might be first in line to test such vaccines.

(From ChinaDaily)