A Saki Malehi, E Hajizadeh, R Fatemi,
Volume 8, Issue 2 (9-2012)
Abstract
Background
& Objectives: Identifying
the important influential factors is a great challenge in oncology studies.
Decision tree is one of methods that could be used to evaluate the prognostic
factors and classifying the patients' homogeneously. This method identifies the
main prognostic factors and then determines the subgroups of patients based on
those prognostic factors. The aim of this study was to assess the prognostic
factors and homogeneous subgroups of colorectal patient through survival tree.
Methods: Data collected from an observational
of 739 colorectal patients registered in the cancer registry affiliated to the
center of Research Center of Gastroenterology and Liver Disease (RCGLD), Shahid
Beheshti Medical University, Tehran, Iran. Death was the interested event and
the survival time was calculated from date of diagnosis until occurrence of
event (or censoring) in months. Finally we used decision tree based method for
classifying and analyzing the data.
Results: Based on our result, decision tree
identified four covariates as important prognostic factors in 0.05 significant
levels: general stage of cancer, age of diagnosis, histology of tumor and
morphology type of tumor. Also patients based on these prognostic factors
divided into five homogeneous subgroups. The greater values of measure of
separation (SEP) criterion support the appropriateness of this model for such
the data.
Conclusion:
Decision tree is powerful and intuitive method. It has a key feature that is in
addition to evaluate the prognostic factors, provides the homogeneous subgroups
for future analysis.
