A genetically engineered version of the virus that  causes herpes  shows promise as a treatment for a particularly aggressive type of breast  cancer, according to a new study in animals.

The virus targeted and killed triple-negative  breast cancer cells in mice. Triple-negative breast cancer is a form of  breast cancer that cannot be treated with hormone therapies, such as tamoxifen  and Herceptin.

The results are preliminary, and it’s not clear  whether the therapy will have the same effect on tumors growing in people. Much  more research is needed to determine this. If a treatment is developed, it will  likely be used in conjunction with other cancer therapies, including  chemotherapy and radiation, the researchers said.

Read more: http://www.foxnews.com/health/2011/10/26/herpes-virus-could-kill-aggressive-breast-cancer/#ixzz1cMcR62t7

The study was presented at the meeting of the  American College of Surgeons in San Francisco.

Herpes therapy

Triple-negative breast cancer accounts for about 20  percent of all breast cancer cases. It disproportionally effects young,  African-American women and is usually treated with chemotherapy.  (Triple-negative breast cancers are not fueled by the hormone estrogen, so they  do no respond to treatments designed to block the hormone.)

Study researcher Dr. Sepideh Gholami, a research  fellow in the at Memorial Sloan-Kettering Cancer Center in New York City. and  colleagues infected breast cancer cells in a dish with a herpes  virus called NV1066. Within a week, the virus killed up to 90 percent of the  tumor cells.

The researchers then injected breast cancer cells  into mice. After treating the mice with the virus for 20 days, they saw the  tumors had largely disappeared, Gholami said.

The dramatic response may be due to the fact that  triple-negative breast cancer cells have high levels of a protein called p-MAPK.  The herpes virus specifically targets cells with high levels of this protein,  the researchers said.

The therapy is just one of many in recent years to  explore the use of viruses  as a means to target and destroy cancer cells. The herpes virus has been  tested in people as a treatment for head and neck cancer, but not for breast  cancer, the researchers said.

More research

The study is an “extremely exciting step” in the  pursuit of a cancer therapy that uses the herpes virus, said Dr. Stefan Gluck, a  medical oncologist at the University of Miami’s Sylvester Comprehensive Cancer  Center.

However, the researchers still need to show that  this herpes virus is safe to use in patients. After all, the herpes virus is  known to cause infection in humans, including infections in the brain. Proving the therapy’s safety will likely  be a lengthy process, and will involve testing it on other animals first, such  as dogs and primates, Gluck said.

The researchers plan to figure out exactly how the  virus works to kill the breast cancer cells, and try to bolster its effect.

Pass it on: The herpes virus  can infect and kill breast cancer cells in a dish and in mice.

Read more: http://www.foxnews.com/health/2011/10/26/herpes-virus-could-kill-aggressive-breast-cancer/#ixzz1cMcsUCCO