Comparison of the Effect of Standard Chemotherapy and its Combination with Cetuximab on the Survival of Patients with Progressive Colon Cancer

Recent advances in molecular and cellular biology and the importance of Epidermal growth factor receptor(EGFR) in the development and progression of many solid malignancies such as Colorectal Cancer (CRC) and non- small cell lung cancer have allowed rapid advances in rational drug design and targeted therapies for malignancies.Cetuximab or Erbitux, an IgG1 monoclonal antibody that targets the EGFR,is one of the most recent treatments for advanced colorectal cancer. The aim of this study is the comparison of "standard chemotherapy" with "combination of standard chemotherapy and Cetuximab" in the survival of advanced colon cancer patients.At the time of this trial, the K –ras mutation wasn’t defined as a cause of response to monoclonal antibody. Patients and Ninty-one patients with relapsed advanced CRC were enrolled in this semi -experimental trial.The age of patients was between 20 to 80 years. We randomly selected 47 patients to receive standard chemotherapy and 44 patients to receive chemotherapy and Cetuximab(combined therapy). Duration of treatment was based on the factors such as serious drug reactions to, death or reaching therapy allotted time of the treatment. Thus survival was measured in the two groups. After gathering the information, they were presented in the form of statistic and numeral tables. We used Kaplan Meier table to evaluate the survival analysis and Logmar and Breslow tests for the comparison between the survival time of two groups. We also evaluated the number of deaths with Chi square and Fisher's exact tests.The p-value was defined as 5% and all the analyses were done with SPSS V.15. Since June 2004 to November 2007, 91 patients aged 20-76 years and kf>60% with refractory advanced CRC were evaluated. Forty –four patients (48%) received combination therapy and 47 (52%)cases received combined monotherapy with chemotherapy regimen. Among the 47 patients on standard therapy, 18 (38.3%) and among 44 patients on combination therapy 13 (29.5%) expired. Median survival in standard therapy was 236 + 20 days and in combination therapy was 301 + 27 days(p=0.2011). Although Cetuximab improves the response rate and disease progression as compared to standard chemotherapy,combination therapy (cetuximab and standard chemotherapy) does not have any significant difference in regard to survival of patients with advanced CRC.