Abstract
OBJECTIVES: MYC gene rearrangements in diffuse large B cell lymphomas (DLBCLs) result in high proliferation rates and are associated with a poor prognosis. Strong proliferation is associated with high metabolic demand and tumour necrosis. The aim of this study was to investigate differences in the presence of necrosis and semiquantitative (18)F-FDG PET metrics between DLBCL cases with or without a MYC rearrangement. The prognostic impact of necrosis and semiquantitative (18)F-FDG PET parameters was investigated in an explorative survival analysis. METHODS: Fluorescence in situ hybridisation analysis for MYC rearrangements, visual assesment, semiquantitative analysis of (18)F-FDG PET scans and patient survival analysis were performed in 61 DLBCL patients, treated at a single referral hospital between 2008 and 2015. RESULTS: Of 61 tumours, 21 (34%) had a MYC rearrangement (MYC(+)). MYC status was neither associated with the presence of necrosis on (18)F-FDG PET scans (necrosis(PET); p = 1.0) nor associated with the investigated semiquantitative parameters maximum standard uptake value (SUV(max); p = 0.43), single highest SUV(max) (p = 0.49), metabolic active tumour volume (MATV; p = 0.68) or total lesion glycolysis (TLG; p = 0.62). A multivariate patient survival analysis of the entire cohort showed necrosis(PET) as an independent prognostic marker for disease-specific survival (DSS) (HR = 13.9; 95% CI 3.0-65; p = 0.001). CONCLUSIONS: MYC rearrangements in DLBCL have no influence on the visual parameter necrosis(PET) or the semi-quantiative parameters SUV(max), MATV and TLG. Irrespective of MYC rearrangements, necrosis(PET) is an independent, adverse prognostic factor for DSS. KEY POINTS: • Retrospective analysis indicates that MYC rearrangement is not associated with necrosis on (18) F-FDG PET (necrosis (PET) ) scans or semiquantitative (18) F-FDG PET parameters. • Necrosis (PET) is a potential independent adverse prognostic factor for disease-specific survival in patients with DLBCL and is not influenced by the presence of MYC rearrangements.