Screening History and 7-Year Survival in 32,099 Colorectal Cancer Patients: A Population-Based Cohort Study [Response to Letter]

Dear editor

We thank Wardoyo and Anwar¹ for their valuable feedback and suggestions on our paper.² We agree that a thorough investigation of the relationship between screening history and colorectal cancer survival must encompass patient demographics, lifestyle factors, comorbidities, and treatment approaches.

In our paper,² we analyzed various factors including age at diagnosis, sex, urbanization and hospital levels, colorectal cancer stage and site, treatment, and other clinicopathological variables (Supplementary Table S8), such as grade, tumor size, lymph node ratio, circumferential resection margin, perineural invasion, obstruction, and perforation. Responding to Wardoyo and Anwar,¹ we further adjusted for body mass index, cigarette smoking, alcohol consumption, and family history of colorectal cancer in patients who had been screened. Despite these adjustments, we found that the association between screening history and colorectal cancer mortality remained largely consistent (Tables 1 and 2). It is important to note that while our adjustments were comprehensive, they were not exhaustive, due to the limitations imposed by the data available from the Taiwan Cancer Registry, the National Colorectal Cancer Screening Program, and the National Death Registry.

Table 1 Hazard Ratios for Death Due to Colorectal Cancer with Additional Adjustments for Body Mass Index, Cigarette Smoking, and Alcohol Drinking

Table 2 Hazard Ratios for Death Due to Colorectal Cancer with Additional Adjustment for Family History of Colorectal Cancer in Patients Who Had Been Screened