| Screening, diagnosis, and treatment of precancerous lesions and early colorectal cancer (CRC) are essential to lower the mortality of CRC, and colonoscopy plays an important role. Population-based CRC screening using a fecal immunochemical test followed by colonoscopy has been implemented since 1992 in Japan; however, CRC remains a leading cause of cancer-related deaths. Considering the potential effectiveness and cost-effectiveness of screening colonoscopy, discussions about more efficient use of colonoscopy in CRC screening are warranted (Sekiguchi M, et al. Jpn J Clin Oncol. 2016;46:116-125). Risk-stratification of the screening population and the possibility of using computer-aided detection systems for screening colonoscopy also warrant discussion (Sekiguchi M, et al. J Gastroenterol. 2018;53:1109-1119/ Sekiguchi M, et al. Dig Endosc. 2023;10.1111 [published online ahead of print]). Regarding the treatment of early CRC, endoscopic submucosal dissection (ESD) has become the standard treatment method for large cTis and T1a cancers. Compared to piecemeal endoscopic mucosal resection, ESD is more acceptable for large lesions in terms of effectiveness and cost-effectiveness (Sekiguchi M, et al. Dig Endosc. 2022;34:553-568). Despite the remarkable development of endoscopic diagnosis, pT1b cancers occasionally occur after endoscopic resection. The current standard management method for pT1b cancer is colectomy with lymphadenectomy; however, whether surgical treatment should be performed in patients at risk for operative complications, such as elderly patients, is difficult to determine. The optimal management of such patients requires discussion among a multidisciplinary team (MDT). Data for prediction of the risk of lymph node metastasis from T1 CRC is useful for this decision (Kajiwara Y, et al. Gastrointest Endosc. 2023;97:1119-1128). A single-arm confirmatory trial of adjuvant chemoradiation for patients with high-risk rectal submucosal invasive cancer (JCOG1612) is ongoing to establish less invasive management. A new clinical trial for pT1b colon cancer is also warranted. A single-arm phase III confirmatory trial on indications of ESD for elderly patients with early gastric cancer (JCOG1902) is being conducted, and it may also be meaningful to examine the potential for expanding the indications of colorectal ESD for elderly patients (Sekiguchi M, et al. Jpn J Clin Oncol. 2022;52:425-432). The difficulty of managing rectal neuroendocrine tumors following endoscopic resection is another hot topic, and an MDT approach and further investigations are key to solve this issue (Sekiguchi M, et al. J Gastroenterol. 2022;57:547-558). |
