Multistage logistic regression model for analyzing survival from colorectal cancer

Abstract

Colorectal cancer, which is also known as bowel cancer, colon cancer, or rectal cancer, is the third most common cancer worldwide, and the second most common in Malaysia. In most situations, the tumor/cancer may return even after the tumor removal. The impact of the type of surgery performed for tumor removal on the occurrence of a new tumor and the impact of a patient's state at previous follow-up on the occurrence of a new tumor in the next follow-up are of interest. Thus, the probability of surviving with no tumor recurrence, the probability of surviving but with tumor recurrence, and the probability of not surviving can be obtained. A multistage logistic regression, which was designed for longitudinal data, was used. Data from 161 colorectal cancer patients who experienced tumor removal through surgery and were followed-up for two years were used in this study. The results showed that in the first year after tumor removal surgery, regardless of whether the patients had undergone elective or emergency surgery, the chance of patient survival with no tumor was approximately five times higher than the chance of dying; meanwhile, the chance of dying was approximately three times higher than the chance of developing a new tumor. Similar results have also been obtained for a period of 2 years after the tumor removal surgery.