["In the light of an emerging role for early-mid treatment 18 F-deoxyfluoroglucose positron emission tomography (FDG-PET) as an important prognostic indicator in aggressive non-Hodgkin's lymphoma (NHL) , we attempted to determine whether a simple parameter, such as the early-mid treatment CRP (C-reactive protein) level, could also be utilized as a significant prognostic factor in aggressive NHL.", 'Serum CRP levels were monitored in 55 patients with aggressive NHL. The lowest value of the early mid-term CRP levels recorded was compared with the interim PET-CT results, as well as with the clinical course and eventual outcome.', 'During chemotherapy, the lowest value of early-mid treatment CRP levels significantly predicted the results of the interim FDG-PET (P = 0.04 with an odds ratio of 1.13). Patients who did not achieve an early-mid treatment CRP level of <5 mg/L, had a shorter time to disease progression or relapse (P = 0.001) as well as a reduced overall survival (OS) (P = 0.016).'] Is early-mid treatment C-reactive protein level a prognostic factor in aggressive non-Hodgkin 's lymphoma?