OBJECTIVETo assess the efficacy and safety of bevacizumab plus irinotecan-based regimen for the first line treatment in metastatic colorectal cancer (mCRC) patients, and to investigate the correlation between serum tumor markers including CEA and CA19-9 and response as well as prognosis.

METHODSFrom May 2007 to July 2008, 67 previously untreated mCRC patients received treatment of IFL (n = 25), IFL plus Bevacizumab (n = 20) or FOLFIRI (n = 22). The treatment continued until disease progression or unacceptable toxicity. The data were retrospectively analyzed.

RESULTSAll patients were evaluable for response, survival and toxicity analysis. The objective response rate of IFL, IFL plus Bevacizumab or FOLFIRI regimen groups was 16.0% (4/25), 35.0% (7/20) and 18.2% (4/22), respectively (χ(2) = 6.026, P = 0.049). The median progression-free survival (PFS) of IFL plus bevacizumab group was 7.5 months, significantly improved as compared with 3.7 months in the IFL group and 4 months in FOLFIRI group (χ(2) = 11.97, P = 0.003). Of all 67 cases, the one-year survival rate was 47.0%, two-year survival rate was 27.0%, and the median overall survival (OS) was 13.0 months, with no significant difference among the three treatment groups (χ(2) = 3.42, P = 0.18). The serum CEA and CA19-9 levels were decreased after treatment, but with no significant difference among the three groups (P > 0.05). The common toxicity profiles of IFL and FOLFIRI regimens were diarrhea and neutropenia, while the toxicity related to bevacizumab was consistent with that documented in previous literature, such as hypertension, hemorrhage, cardiac toxicity and delayed wound healing.

CONCLUSIONThe addition of bevacizumab to irinotecan-based regimen significantly improves the response rate and PFS in first-line treatment for patients with mCRC and its toxicity is well tolerated.