LEWISTOWN - A cancer research team in Australia recently discovered that breast cancer cells are destroying a gene linked to the immune system, allowing cancer to become metastatic, or spread throughout other parts of the body, reported a press release from the Peter MacCallum Cancer Centre.
The gene, called IRF7, controls the production of interferon, an immune protein that fights tumor cells, bacteria and viruses. Usually, when breast cancer cells spread to the bloodstream and into bone marrow, the release of interferons will cause the immune system to recognize the cancer cells and eliminate them. However, the study found that this immune signal was switched off in some cases, enabling cancer cells to hide from the immune system and spread, states the press release.
"By identifying this genetic pathway in models, we have discovered a 'mask' that breast cancer cells put on, allowing them to hide and spread to bone, thriving undetected," said Dr. Belinda Parker, study leader and research fellow at the Peter MacCallum Cancer Centre. "In fact, measurement of this immune signal in a patient's cancer may predict the risk of spreading to the bone, which is currently extremely difficult."
According to an article published on Reuters Health, at www.reuters.com, Parker and her team tried two different ways to revive the immune response through various mice experiments, both appearing to be successful.
The research team put the IRF7 gene back into the cancer cells so it can't be switched off, allowing the immune pathway to be stimulated and the cancer remaining in the breast, Parker said in the Reuters article. The second way treated the animals with interferon, which is available for treating other diseases. That also prevented the spread of cancer to the bone, she added.
Studies, like the one from Australia, on stopping the spread of breast cancer to other parts of the body are incredibly important, said Dr. Victor Vogel, an oncologist with Geisinger Health System. No one dies from a tumor in the breast, the issues arise when the cancer spreads to the brain, lungs or bone, he said.
According to the American Cancer Society, 98 percent of patients with localized breast cancer live five years or more, while only 23 percent of patients whose cancer has spread survive five years, translating to one death from metastatic breast cancer every 14 minutes.
Although the information learned in the Australian study is exciting, it's still in the very early stages, Vogel said. The hypothesis still needs a great deal of testing and it could be a number of years before any type of resulting treatment reaches the U.S., he said.
"Often times, information we learn in the lab is helpful, but it can be extremely difficult to translate into clinical treatment," Vogel said. "Interferon was tested a number of years ago in cancer research, when it was first used to treat hepatitis, multiple sclerosis and metastatic melanoma, but interferons never showed any real potential for breast cancer treatment at the time."
However, U.S. breast cancer clinics have been using immune system approaches in cancer treatment for a number of years, Vogel said. Currently, breast cancer treatment includes the use of Herceptin and Perjeta, which are medicinal antibodies, used by the immune system to fight breast cancer cells and keep them localized, he said.
"These antibodies attach to the proteins on breast cancer cells and then recruit other immune system cells to destroy the cancer," Vogel said. "The antibodies also stop the cancer cells from emitting growth signals. The treatment has been very effective."
Other treatment for metastasis breast cancer includes hormonal therapy, chemotherapy, radiation and surgical options. Treatment is determined based on tested characteristics of found breast cancer cells and the potential of continued spreading, Vogel said.