To Örebro University

Background: Previous studies have shown that a high level of pre-treatment C-reactive protein to albumin ratio (CAR) is associated with poor outcomes in patients with diffuse large B cell lymphoma (DLBCL). However, these were single-centre studies with a relatively small number of patients. The aim of our study was to further investigate the prognostic value of CAR in a larger cohort and whether the addition of CAR to the International Prognostic Index (IPI) would result in a better discriminatory ability.

Methods: All adult patients treated 2000–2013 with R-CHOP/CHOP-like treatment for DLBCL in four counties of Sweden were included (n=414). The study population was divided into high respectively low CAR group using the Budczies et al.’s cut-off finder. The groups were compared in terms of differences in clinical characteristics, response to treatment and survival. The prognostic ability of IPI vs IPI plus CAR was compared by receiver-operating-characteristic curve (ROC), net reclassification improvement (NRI) and the integrated discrimination improvement index (IDI).

Results: The high CAR group was associated with higher IPI score, lower performance status, high LDH, bulky disease and more advanced Ann Arbour stage. The high CAR group had a higher proportion of patients with progressive disease (24.2% vs 6.4%, p<0.001) and a lower proportion of patients with complete remission (61.5% vs 85.7%, p<0.01). The high CAR group had poorer 5-year OS (49% vs 70%; p<0.001) and EFS (45% vs 68%; p<0.001). After adjustment for BMI, bulky disease and IPI, high CAR values independently predicted poor OS (HR: 1.58, 95% CI 1.18–2.11; p=0.002) and EFS (HR: 1.57, 95% CI 1.18–2.10; p=0.002). When assessed by NRI, the addition of CAR to IPI seems to better identify patients with better prognosis compared with IPI alone. However, the area under the ROC curve and IDI did not show any significant improvement in model performance.

Conclusions: CAR seems to be a useful prognostic biomarker in patients with DLBCL. Although the addition of CAR to IPI could identify some additional patients with better prognosis, the discriminatory ability of IPI was not improved. IPI remains the standard model for risk stratification in patients with DLBCL.