Researchers in Sweden demonstrated for the first time it is possible to inhibit growth of brain tumors by treating a common virus that affect tumors. Cecilia Soderberg-Naucler of the Karolinska Institutet in Sweden said the common Cytomegalovirus, a virus found in a wide range of tumor types, offers a possible route toward controlling tumor growth and reducing the size of the tumor as a complement to conventional therapies. Soderberg-Naucler said the virus is found in 70 percent to 75 percent of the adult population. Normally, it is dormant and goes unnoticed, but when a cancer develops in the body, the virus seems to control many of the mechanisms in the cancer cells. Brain tumors, breast cancer, colon cancer and prostate cancer are some of the cancer forms in which the virus may play a central role, Soderberg-Naucler said. By studying medullablastomas -- the most common form of childhood brain tumor -- the researchers showed the presence of the virus in these tumors and that treatment for Cytomegalovirus can reduce tumor growth. \"We show in this study that Cytomegalovirusis found in 92 percent of tumors from medullablastoma patients,\" Soderberg-Naucler said in a statement. \"We also show in experimental systems that we can inhibit the growth of these tumors with anti-viral drugs, which opens up a new potential therapeutic approach to certain tumors in the future.\" The findings are published in the Journal of Clinical Investigation.