Can the Herpes Virus Kill Cancer?

Doctors recently modified the herpes simplex virus to fight skin cancer. Could the ability to kill cells by using viruses be the key to curing cancer for good?

There's a pretty good chance that you or someone you love has been affected by cancer in some way. It's the second leading cause of death after heart disease in the U.S. While there are a number of risk factors that can increase your chances of getting it, it can strike anyone at any time. It kills one in four Americans and is the leading cause of death for women aged 40 to 79 and men aged 60 to 79. While a number of treatments, like chemotherapy and radiation, can lower fatality rates, these treatments can bring some major side effects and health complications.

A promising new cancer treatment on the horizon uses a seemingly unlikely source: the herpes virus. The largest viruses are many times smaller than the smallest bacteria. They consists of nothing but genetic material wrapped in a protein coat, so they can't live without a host and reproduce by attaching themselves to other cells, which they reprogram to make new viruses. The host cell continues to reproduce the virus it's infected by until it explodes with new viruses. Certain viruses can turn normal cells into cancerous ones. Virotherapy, or using viruses to attack another virus is a known way to kill viruses. This potential first became clear more than a century ago when doctors noticed that cancer patients who caught measles, hepatitis, or other viral-based diseases seemed to temporarily go into remission. 

Recently, scientists at the Institute of Cancer Research in London have been conducting successful trials with a skin cancer drug called T-VEC, a genetically engineered version of the herpes simplex virus which only replicates in cancer cells while leaving healthy tissues intact. In the latest T-VEC trial, it was given to 436 patients suffering from inoperable melanoma. And though the drug is still not licensed, the results have been promising so far, and with any luck drugs like T-VEC will be able to fight other forms of cancer, too.