Impact of the addition of bevacizumab, oxaliplatin, or irinotecan to fluoropyrimidin in the first-line treatment of metastatic colorectal cancer in elderly patients

Introduction: The clinical benefit of double-front-line therapy (including oxaliplatin or irinotecan or bevacizumab plus 5-fluorouracil (5FU) or capecitabine) compared to monotherapy (5FU or capecitabine) in elderly (> 70 years) patients with metastatic colorectal cancer (MCRC) is controversial. We performed a meta-analysis of published randomized studies.

Materials and methods: The selection of the studies was carried out using PubMed with the following keywords: "metastatic colorectal cancer," "elderly," "oxaliplatin," "irinotecan," "bevacizumab," "survival." The efficacy endpoints were overall survival (OS) and progression-free survival (PFS). Hazard ratios (HRs) with their 95% confidence intervals (CIs) were collected from the studies and pooled. By convention, an HR < 1 was a result in favor of biotherapy.

Results: This meta-analysis (MA) included ten studies: three assessing irinotecan (FFCD 2001-02, CAIRO, and an already published MA by Folprecht), three assessing oxaliplatin (FOCUS2, FFCD 2000-05, and a published study by De Gramont), and four assessing bevacizumab (PRODIGE-20, AVEX, AGITG-MAX, and "AVF2192g" by Kabbinavar). Our MA included 1652 patients (62% of men). Concerning age, we chose a cut-off of 70 years or a cut-off of 75 years, corresponding to the available data for each study. The performance index (PS) was 0-1 for about 90% of patients, with the exception of FFCD 2001-02 and FOCUS2 which included 30% of patients with PS2. Overall, the addition of bevacizumab to fluoropyrimidin statistically improves both OS and PFS (HR = 0.78; CI 0.63-0.96 and HR = 0.55; CI 0.44-0.67, respectively). The addition of oxaliplatin did not statistically improve OS (= 0.99; CI 0.85-1.17) but improves PFS (HR = 0.81; CI 0.67-0.97) as well as the addition of irinotecan (HR = 1.01; CI 0.84-1.22 and HR = 0.82; CI 0.68-1.00, respectively).

Conclusion: In previously untreated elderly patients with MCRC, the addition of bevacizumab to fluoropyrimidin appears more effective in terms of OS or PFS than the addition of oxaliplatin or irinotecan.