A Bayesian Approach to Model the Underlying Predictors of Early Recurrence and Postoperative Death in Patients with Colorectal Cancer

Abstract

Objective: This study, aimed at using a Bayesian approach semi-competing risks technique to model the underlying predictors of early recurrence and postoperative death in patients with colorectal cancer (CRC).Methods: This study was a retrospective cohort of 284 patients with colorectal cancer who underwent surgery referred to Imam Khomeini clinic in Hamadan from 2001 to 2017. The primary outcomes were the probability of recurrence, the probability of death without recurrence, and the probability of death after recurrence. The patients 'recurrence status was determined from patients' records. The Bayesian survival modeling was carried out by semi-competing risks illness-death models in R 4.1 softwareResults: The results showed that gender(TR = 0.764 , 95% CI: 0.456 - 0.855), age at diagnosis (TR =0.764 , 95 % CI: 0.538 - 0.935 ), T 3 stage (TR = 0601 , 95 % CI : 0.530 - 0.713) , N2 stage ( TR = 0.714 , 95 % CI : 0.577 - 0.935 ) , tumor size (TR = 0.709 , 95 % CI : 0.610 - 0.929), Grade (differentiation level) (TR = 0.856 , 95 % CI: 0.733 - 0.988 for poor level , TR = 0.648 , 95 % CI : 0.503 - 0.955 for moderate level) and number of chemotherapy (TR =1.583 , 95 % CI: 1.367 - 1.863) was significantly related with recurrence . Also, age at diagnosis (TR= 0.396 , 95% CI : 0.313 - 0.532) , metastasis to other sites (TR = 0.566 , 95% CI : 0.490 - 0.835) , T3 stage (TR = 0.363 , 95 % CI : 0.592 - 0.301), T4 stage (TR = 0.434 , 95 % CI : 0.347 - 0.545) , Grade (differentiation level) at moderate level (TR = 0.527 , 0.95 %CI : 0.387 - 0.674), tumor size (TR = 0.595 95 % CI : 0.500 - 0.679) and number of chemotherapy (TR= 1.541 , 95% CI : 1.332 - 2.243) was the significantly predicted the death. Also, age at diagnosis (TR= 0.659, 95% CI: 0.559 - 0.803) and number of chemotherapy (TR= 2.029, 95% CI: 1.792 - 2.191) was significantly related to death after recurrence.Conclusion: According to the specific results obtained for terminal and nonterminal events, appropriate screening strategies and the earlier detection of CRC leads to substantial improvements in the survival of patients.