Determination of Cut Point in the Age of Colorectal Cancer Diagnosis Using a Survival Cure Model

Abstract

Background and Objectives: Colorectal Cancer (CRC) is the fourth cancer-related cause of death worldwide.<br />CRC is a multi-stage cancer, which is curable during the early stages of the disease. Therefore, determining the time of<br />cut-point existence could improve treatment planning and help directly allocate resources. This study aims to determine<br />the cut point in the age of CRC diagnosis. Methods: This study, covering the course 1985 to 2012, consisted of 345<br />colorectal cancer patients registered in Taleghani Hospital, Tehran, Iran and followed up to 2013. The cut-point in the<br />age of CRC diagnosis was obtained using a mixture cure model. The data were analyzed using SPSS and R, V. 20 and<br />2.15.0, respectively. Results: The results showed that the cut point in the age of CRC diagnosis was 50 years. Based<br />on our estimation, 65% of the patients diagnosed with CRC at or younger than 50 were cured, while 31% of them<br />diagnosed older than 50 were cured, and the younger group had a better survival over the older group. Conclusion:<br />Since access to a cut-point and analysis of created prognostic groups are important in screening and treatment planning,<br />our results suggested that it is better to estimate the cut-point in the age of curable cancers in early stages via survival<br />cure models, and the cure rate would increase by CRC timely screening.