Survival Analysis and Prognostic Factors for Colorectal Cancer Patients in Malaysia

BACKGROUND: Cancer survival analysis is an essential indicator for effective early detection and improvements in cancer treatment. This study was undertaken to document colorectal cancer survival and associated prognostic factors in Malaysians.

MATERIALS AND METHODS: All data were retrieved from the National Cancer Patient Registry Colorectal Cancer. Only cases with confirmed diagnosis through histology between the year 2008 and 2009 were included. Retrieved data include sociodemographic information, pathological features and treatment received. Survival curves were plotted using the KaplanMeier method. Univariate analysis of all variables was then made using the Logrank test. All significant factors that influenced survival of patients were further analysed in a multivariate analysis using Cox' regression.

RESULTS: Total of 1,214 patients were included in the study. The overall 3 and 5year survival rates were 59.1% and 48.7%, respectively. Patients with localized tumours had better prognosis compared to those with advanced stage cancer. In univariate analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p=0.001) were found to be predictors of survival. None of the sociodemographic characteristics were found to exert any influence. In Cox regression analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p<0.001) were determined as independent prognostic factors of survival after adjusted for age, gender and ethnicity.

CONCLUSIONS: The overall survival rate for colorectal cancer patients in Malaysia is similar to those in other Asian countries, with staging at diagnosis, primary tumor size, involvement of lymph node and treatment modalities having significant effects. More efforts are needed to improve national survival rates in future.