New findings suggest that the cytomegalovirus (CMV), which has infected and is being carried in a latent form by 70 per cent of the population, is active in many forms of cancer, including malignant glioblastoma. Patients with this form of brain tumour have always had a very dismal prognosis regardless of treatment regimen, with an expected mean survival of 12 to 14 months and an expected two-year survival rate of 15 to 26 per cent. However, by treating the CMV virus, the researchers have now managed to give these patients more hope for the future.
“Our results are beyond all our expectations,” says lead investigator Cecilia Söderberg-Nauclér, Professor at Karolinska Institutet. Our treatment data show that CMV is actively and crucially involved in glioblastoma, and that targeting CMV can be a new avenue of attack against these tumours.
CMV treatment was given to 50 patients with glioblastoma, after which their expected mean survival was found to increase from 13.5 to 56.4 months. The two-year survival rate increased from 18 to 70 per cent in patients who had received at least six months of treatment, and to 90 per cent if they continued to be treated for CMV as a supplement to their regular oncological treatment.
“Valcyte is a well-tolerated, safe form of treatment to give glioblastoma patients in combination with chemotherapy and radiotherapy,” says Giuseppe Stragliotto, Consultant at Karolinska University Hospital’s neurology clinic, and the doctor responsible for the treatment of the patients. “Patients treated with antiviral medicine have hardly experienced any distressing or painful side-effects at all, which is important if they need prolonged treatment.”
Since treatment with antiviral drugs delayed the relapse of the disease much longer than expected, the researchers believe that some patients could even avoid chemotherapy, at least temporarily.
“Looking at it from the perspective of the patients and their relatives, the possibility of having a longer period of sustained life quality is very important,” says Dr Stragliotto. “The analysis of the viral infection in the tumour can also help us doctors give a more nuanced prognosis to each individual patient.”
The researchers hope that the results of the study now published will have a significant bearing on a number of other forms of cancer that have a strong demonstrated link to CMV. Several studies have shown that over 90 per cent of breast, colon and prostate cancers and the childhood tumours medulla blastoma and neuroblastoma are CMV-positive.
The present study was financed by grants from the pharmaceutical company Roche, the Torsten Söderberg Foundation, the Ragnar Söderberg Foundation, BILTEMA, the Stichting af Jochnick Foundation and the IngaBritt and Arne Lundberg Foundation.
Survival in Patients with Glioblastoma Receiving Valganciclovir
NEJM September 5, 2013 issue