Supplementary Material for: Analysis of the characteristics of coexisting lesions in colorectal cancer patients in an international study: A subgroup analysis of the ATLAS trial

Introduction: We investigated coexisting lesion types in patients with invasive colorectal cancer (CRC) in a multinational study for comprehending the adenoma-carcinoma and serrated pathway about the development of CRC. Methods: We retrospectively reviewed 3050 patients enrolled in the international randomized controlled trial (ATLAS study) to evaluate the colorectal polyp detection performance of image-enhanced endoscopy in 11 institutions in four Asian countries/regions. In the current study, as a subgroup analysis of the ATLAS study, 92 CRC patients were extracted and compared to 2958 patients without CRC to examine the effects of age, sex, and coexisting lesion types (high-grade adenoma [HGA], low-grade adenoma with villous component [LGAV], 10 adenomas, adenoma ≥10 mm, sessile serrated lesions [SSL], and SSL with dysplasia [SSLD]). Additional analyses of coexisting lesion types were performed according to sex and location of CRC (right- or left-sided). Results: A multivariate analysis showed that HGA (odds ratio [95%confidence interval] 4.29 [2.16-8.18]; p<0.01), LGAV (3.02 [1.16-7.83], p=0.02) and age (1.04 [1.01-1.06], p=0.01) were independently associated with CRC. According to sex, the coexisting lesion types significantly associated with CRC were LGAV (5.58 [1.94-16.0], p<0.01) and HGA (4.46 [1.95-10.20], p<0.01) in males and HGA (4.82 [1.47-15.80], p<0.01) in females. Regarding the location of CRC, SSLD (21.9 [1.31-365.0], p=0.03) was significant for right-sided CRC, and HGA (5.22 [2.39-11.4], p<0.01) and LGAV (3.46 [1.13-10.6], p=0.02) were significant for left-sided CRC. Conclusions: The significant coexisting lesions in CRC differed according to sex and location. These findings may contribute to comprehending the pathogenesis of CRC