Predictive factors of human cytomegalovirus reactivation in newly diagnosed glioblastoma patients treated with chemoradiotherapy

The human cytomegalovirus (HCMV) is a ubiquitous herpes virus which infects 40 to 99% of the population. HCMV reactivation may occur in the context of immunosuppression and can induce significant morbidities. Several cases of HCMV infections or HCMV reactivation have thus been reported in glioblastoma (GBM) patients treated with radio(chemo)therapy. With the aim to identify the main risk factors associated with HCMV reactivation, we reviewed all patients treated for a newly diagnosed GBM in our institution from October 2013 to December 2015. Age, sex, Karnofsky performance status (KPS), absolute lymphocyte count (ALC), serological HCMV status, and steroid doses were recorded at the start and 1 month after the end of radiotherapy (RT). Within the 103 patients analyzed, 34 patients (33%) had an initial negative serology for HCMV, and none of them developed a seroconversion after treatment. Among patients with positive HCMV IgG (n = 69), 16 patients (23%) developed a viremia at one point during treatment. Age (> 60 years), steroid intake, and ALC (< 1500/mm³) before RT were correlated with HCMV reactivation. HCMV viremia was associated with neurological decline 1 month after chemoradiotherapy but progression-free survival was not impacted. A shorter overall survival was seen in these patients when compared with the others, but this could be biased by the older age in this subgroup. HCMV reactivation needs to be sought in case of a neurological decline during RT especially in older patients treated with steroids and low lymphocytes counts.