How to improve RCHOP as frontline therapy for diffuse large B-cell lymphoma: a systematic review and meta-analysis of 21 randomized controlled trials

RCHOP is the standard of care for patients with diffuse large b-cell lymphoma (DLBCL) but failures occur in approximately 40% of them. We performed a meta-analysis of 21 randomized controlled trials (RCTs) comparing experimental regimens with RCHOP. We searched the database of PubMed with proper criteria, and data of efficacy (Progression Free Survival-PFS) in the ITT population were extracted and analyzed. Cross comparisons of RCTs were performed by using the CINEMA software. Odds ratio (OR) and 95% confidence intervals (95%, CI) are reported. The literature search yielded 21 RCTs including 5785 patients in the RCHOP arm and 5648 patients in the experimental arm. Odds ratio (OR) for PFS in the total cohort was OR (95%, CI): 0.87 (0.76-0.99), p=0.02. Among different strategies to improve RCHOP, addition of a novel agent on RCHOP improved PFS. In total 1740 patients in the RCHOP arm were compared with 1755 in the RCHOP plus a novel agent arm, and the OR (95% CI) for PFS was 0.84 (0.71-0.97), p=0.02. Indirect comparisons of nine studies adding a novel agent on RCHOP does not give prominence to any agent. Subgroup analysis according to cell of origin was performed for non-GC DLBCL patients. In this subgroup, 1546 patients treated with RCHOP were compared with 1538 patients treated with experimental regimens. The OR (95% CI) for PFS was 0.86 (0.73-1.02), p=0.34. Overall survival data extracted from 18 studies showed no superiority of experimental regimens over RCHOP. Efficacy of RCHOP backbone is marginally improved when adding a novel anti-lymphoma agent.