Objective: To investigate the survival rate and effect of clinicopathological characteristics on survival of rectal cancer in a Thai population.

Materials and Methods: A retrospective cohort study was performed. All data were collected from medical records of patients with rectal cancer at Roi Et Hospital during January 1, 2010 to
December 31, 2014. All cases were followed-up until death or to the end of the study (March 31, 2016).

Results: A total of 145 patients had rectal cancer and most of them were men (56.55%), with a mean age of 61.86+12.95 years. The total follow-up time was 6,284 person-months. The median survival
time was 55.7 months. Six-month and 1-, 2-, 3- and 5-year survival rates were 97.92%, 92.36%, 86.73%, 77.44%, and 36.67%, respectively. The factors affecting survival included cancer stage III
(adjusted HR = 1.45; 95% CI: 1.16 to 2.43), cancer stage IV (adjusted HR = 3.04; 95% CI: 1.25 to 7.41), radiotherapy (adjusted HR = 0.46; 95% CI: 0.23 to 0.95), and chemotherapy (adjusted
HR = 0.67; 95% CI: 0.17 to 0.87).

Conclusion: Rectal cancer stage III and IV affect the hazard of death. Patients who receive radiotherapy and chemotherapy have a lower risk of death and better survival rate than those who do
not.

Keywords: Rectal cancer; Survival rate, Chemotherapy