[Efficacy of cetuximab combined with chemotherapy for patients with advanced colorectal cancer and unclear K-ras status].

OBJECTIVE: To study the efficacy and safety of cetuximab combined with chemotherapy for patients with advanced colorectal cancer (ACRC) and unclear K-ras status.

METHODS: Clinical data of 102 ACRC patients, treated by cetuximab combined with chemotherapy in Sun Yat-sen Cancer Center from March 2005 to December 2008, were collected. The cumulative survival rate, objective response rate (ORR), disease control rate (DCR), progression free survival (PFS) of the cases were calculated. The difference in ORR, DCR, PFS and oval survival (OS) between the regimens used as first-line and non-first-line treatment, and between the regimens including oxaliplatin and irinotecan were compared.

RESULTS: The overall ORR of cetuximab plus chemotherapy was 43.1%, DCR 73.5%, median PFS 4.0 months, OS 28.5 months, and the 1-year, 3-year, and 5-year survival rate was 89.2%, 50.9% and 27.5%, respectively. The differences in ORR (50.0% vs. 40.0%, P = 0.344), DCR (78.1% vs. 72.9%, P = 0.571) and OS (51.0 months vs. 35.0 months, P = 0.396) between the regimens as first line and as non-first line treatment were not statistically significant. However, the PFS of the regimen as first-line was longer than that as non-first-line treatment (PFS 5.5 months vs. 3.0 months, P = 0.001). The differences in ORR (54.2% vs. 40.0%, P = 0.223), DCR (79.2% vs. 74.7%, P = 0.654), PFS (5.0 months vs. 3.0 months, P = 0.726) and OS (36.0 months vs. 40.0 months, P = 0.759) between cetuximab plus oxliplatin and irinotecan were not statistically significant. The most common side effects of cetuximab plus chemotherapy were acneiform eruption (80.4%, grade 3-4 in 9.8%), neutropenia (66.7%, grade 3-4 in 18.6%), and diarrhea (19.6%, grade 3-4 in 5.9%). No treatment-related death was recorded.

CONCLUSION: Patients with advanced colorectal cancer and unclear K-ras treated by cetuximab combined with chemotherapy have good ORR and OS, and the regimen is safe with less adverse events for them. There is no significant difference between the efficacies of regimens as first line and as non-first line treatment, and between cetuximab plus oxliplatin and cetuximab plus irinotecan regimens.