Prognostic factors in 1,138 Iranian colorectal cancer patients

The incidence of colorectal cancer is increased in Iran in recent years and colorectal cancer is the fourth most common cancer in both sexes. The aim of this study is to define the prognostic factors in Iranian colorectal cancer patients using univariate and multivariate methods.

All patients with colorectal cancer diagnosis according to the pathology report that registered in our cancer registry center in the period between Jan 2002 until Jan 2007 were eligible for this study. These patients were followed up by telephone contact. The probability curves for survival were calculated according to the Kaplan-Meier method and compared by the Log-rank test. Multivariate analysis was carried out using the Cox proportional hazard model.

Of 1,138 cases, a survival information was available on 1,127 patients, 690 males (61.2%) and 437 females (38.8%). Mean survival time was 105.1 (CI: 95.1-115.1) months. The Kaplan-Meier method indicated that the 1, 3, 5, 7, 10, and 15 years of survival rates are 91.1%, 73.1%, 61.0%, 54.9%, 47.9%, and 25.9%, respectively. According to the univariate analysis, the factors influencing overall survival rate were the following: type of first treatment, body mass index, marital status, tumor grade, extent of wall penetration, distant metastasis, regional lymph nodes metastasis, and pathologic stage of tumor. The following five variables were independent prognostic factors for survival as determined by multivariate analysis: tumor size, metastasis of tumor, body mass index, marital status, and grade of tumor.

Our results showed that stage of tumor, distant metastasis, grade of tumor, and tumor size should be considered as the most important prognostic factors in colorectal cancer patients.