Tumor tissue from 125 patients with glioblastoma or other glial cancers did not have cytomegalovirus (CMV) infection, indicating no association between CMV infection and the development of aggressive brain cancer. These results contradict previous research that reported a connection between the infection and cancer.1
The investigators emphasized that additional research is needed to confirm these results; however, they suggest that these results weaken the evidence supporting a role for cytomegalovirus in the development of brain cancers.
Previous research, including results in 2002, reported CMV infection in glioblastomas and gliomas. These earlier results indicated potential antiviral therapeutic approaches and interventions.
Nonetheless, not all laboratories discovered an association between CMV infection and aggressive brain cancers.
In this study, tumor samples from 99 men and 26 children with glioblastoma and high-grade glioma were examined. Tumor samples were stored as fresh frozen tissue, in paraffin wax blocks on standard pathology slides, or in a tissue microarray.
All samples were examined with at least one of the following techniques: real-time PCR, a technique to amplify copies of cytomegalovirus DNA; chromogenic in situ hybridization, which interrogates the presence of cytomegalovirus DNA; and immunohistochemistry, to examine potential proteins from cytomegalovirus in paraffin-embedded and microarray samples.
Next, the investigators obtained blood samples from 18 patients with recently diagnosed glioblastoma or aggressive glioma prior to radiotherapy and occasionally after radiotherapy.
Plasma tests of cytomegalovirus antibodies revealed approximately half of the patients had latent cytomegalovirus, yet none of these patients had any signs of CMV infection in their tumors.
The researchers suggest further studies with large numbers of tumor samples from around the world examined by independent, unbiased laboratories are needed to determine whether cytomegalovirus plays any role in the development of high-grade gliomas.
1. Holdhoff M, Guner G, Rodriguez FJ, et al. Absence of cytomegalovirus in glioblastoma and other high-grade gliomas by real-time PCR, immunohistochemistry and in situ hybridization. Clin Cancer Res. 2016 Dec 29. doi: 10.1158/1078-0432.CCR-16-1490 [Epub ahead of print].