Analysis of the Characteristics of Coexisting Lesions in Colorectal Cancer Patients in an International Study: A Subgroup Analysis of the ATLAS Trial

<b><i>Introduction:</i></b> 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. <b><i>Methods:</i></b> We retrospectively reviewed 3,050 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 2,958 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 [SSLs], and SSLs with dysplasia [SSLD]). Additional analyses of coexisting lesion types were performed according to sex and location of CRC (right- or left-sided). <b><i>Results:</i></b> A multivariate analysis showed that HGA (odds ratio [95% confidence interval] 4.29 [2.16–8.18]; <i>p</i> &lt; 0.01), LGAV (3.02 [1.16–7.83], <i>p</i> = 0.02), and age (1.04 [1.01–1.06], <i>p</i> = 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], <i>p</i> &lt; 0.01) and HGA (4.46 [1.95–10.20], <i>p</i> &lt; 0.01) in males and HGA (4.82 [1.47–15.80], <i>p</i> &lt; 0.01) in females. Regarding the location of CRC, SSLD (21.9 [1.31–365.0], <i>p</i> = 0.03) was significant for right-sided CRC, and HGA (5.22 [2.39–11.4], <i>p</i> &lt; 0.01) and LGAV (3.46 [1.13–10.6], <i>p</i> = 0.02) were significant for left-sided CRC. <b><i>Conclusions:</i></b> The significant coexisting lesions in CRC differed according to sex and location. These findings may contribute to comprehending the pathogenesis of CRC.