"This is likely to have implications beyond breast cancer," said Dr. Michael Reiss, another of the paper's authors and director of the breast cancer research program at the Cancer Institute of New Jersey. "Very often these processes are not unique to one cancer type."
Kang said his research shows the gene also might play a role in 20 percent of prostate cancer patients.
Most of the talk about breast cancer and genes has focused on the BRCA1 and BRCA2 genes, mutations of which increase the likelihood that their carriers will develop breast or ovarian cancer.
The new gene is different. This wouldn't aid doctors in preventing cancer from developing. It would predict whether the patient's breast cancer is likely to spread and kill.
Among the next steps for researchers are larger trials to see whether the MTDH gene and its apparent role in the spread of breast cancer hold true. At the same time, Kang and Reiss hope that drug companies will fund research into therapies that could turn off the gene in these cancer patients.
Park said he would be surprised if further research showed that so many cases of deadly cancer could be traced back to one gene. He has seen a lot of studies in the past claiming to "be the biggest thing since sliced bread" that, in the end, don't "pan out."
"To say you can actually prognosticate someone's breast cancer recurrence by a single gene is a little bit of a hard sell in this business," he said. "Biology tends to be more complicated [in the body] than it is in the laboratory."
