Human cytomegalovirus and Epstein-Barr virus infection impact on 18F-FDG PET/CT SUVmax, CT volumetric and KRAS-based parameters of patients with locally advanced rectal cancer treated with neoadjuvant therapy

Purpose It has long been debated whether human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are associated with rectal cancer. The gene products of HCMV and EBV contribute to cell-cycle progression, mutagenesis, angiogenesis and immune evasion. The aim of this prospective study was to analyse the association between infection of a tumour by HCMV and EBV and clinical, histological, metabolic ( 18 F-FDG uptake), volumetric (from CT) and molecular (KRAS status) features and long-term outcomes in a homogeneously treated group of patients with locally advanced rectal cancer. Methods HCMV and EBV were detected in pretreatment biopsies using polymerase chain reaction (PCR). The Cox proportional hazards regression model was used to explore associations between viral infection and disease-free survival (DFS) and overall survival (OS). Results We analysed 37 patients with a median follow-up of 74 months (range 5–173 months). Locoregional control, OS and DFS at 5 years were 93 %, 74 % and 71 %, respectively. Patients with HCMV/EBV coinfection had a significantly higher maximum standardized uptake value than patients without viral coinfection ( p = 0.02). Significant differences were also observed in staging and percentage relative reduction in tumour volume between patients with and without HCMV infection ( p