Zhu Qiuwei, Zhu Chenyang, Zhang Xiaotao, Zhu Xiaodan, Chen Zhe, Gu Dejian, He Yuange, Jin Chunhui
Department of Gastrointestinal Surgery, Changzhou No. 2 People's Hospital Affiliated to Nanjing Medical University, Changzhou, China.
Department of Oncology, Wuxi Hospital Affiliated to Nanjing University of Chinese Medicine, Wuxi, China.
J Gastrointest Oncol. 2023 Jun 30;14(3):1307-1319. doi: 10.21037/jgo-23-120. Epub 2023 May 17.
Colorectal cancer (CRC) is a heterogeneous cancer. Its treatment depends on its anatomical site and molecular features. Carcinomas of the rectosigmoid junction are frequent; however, specific data on these tumors are sparse, as they are frequently assigned to either the colon or rectum. This study sought to identify the molecular features of rectosigmoid junction cancer to determine whether there should be any difference between the therapeutic management of rectosigmoid junction cancer and that of sigmoid colon or rectum cancer.
The data of 96 CRC patients with carcinomas in the sigmoid colon, rectosigmoid junction, and rectum were retrospectively summarized. The next-generation sequencing (NGS) data of the patients were analyzed to study the molecular characteristics of the carcinomas in different locations of the bowel.
In total, there was no difference in the clinicopathologic characteristics of the three groups. , , and genes were the top 3 alteration genes in sigmoid colon, rectosigmoid junction, and rectum cancer. The rates of the , , and increased as the location moved distally, while the rates of and decreased. Almost no significant molecular differences were found among the three groups. The prevalence of the , fms-related tyrosine kinase 1 (), and phosphoenolpyruvate carboxykinase 1 () mutation was lower in the rectosigmoid junction group than the sigmoid colon and rectum groups (P>0.05). The proportion of the transforming growth factor beta pathway was higher in the rectosigmoid junction and rectum groups than the sigmoid colon group (39.3% 34.3% 18.2%, respectively, P=0.121, P=0.067, P=0.682); a higher proportion of MYC pathway was also observed in the rectosigmoid junction than that in rectum and sigmoid colon (28.6% 15.2% 17.1%, P=0.278, P=0.202, P=0.171). Regardless of the clustering method employed, the patients were divided into two clusters, and the composition of clusters revealed no significant differences in terms of the different locations.
Rectosigmoid junction cancer has a distinctive molecular profile compared to the molecular profiles of the adjacent bowel segment cancers.
结直肠癌（CRC）是一种异质性癌症。其治疗取决于解剖部位和分子特征。直肠乙状结肠交界处的癌较为常见；然而，关于这些肿瘤的具体数据较少，因为它们常被归类为结肠癌或直肠癌。本研究旨在确定直肠乙状结肠交界处癌的分子特征，以确定直肠乙状结肠交界处癌与乙状结肠癌或直肠癌的治疗管理是否存在差异。
回顾性总结了96例乙状结肠、直肠乙状结肠交界处和直肠癌患者的资料。分析患者的二代测序（NGS）数据，以研究肠道不同部位癌的分子特征。
总体而言，三组的临床病理特征无差异。 、 和 基因是乙状结肠癌、直肠乙状结肠交界处癌和直肠癌中前三位的变异基因。随着部位向远端移动， 、 和 的发生率增加，而 和 的发生率降低。三组之间几乎未发现明显的分子差异。直肠乙状结肠交界处组中 、 与膜相关的酪氨酸激酶1（ ）和磷酸烯醇式丙酮酸羧激酶1（ ）突变的发生率低于乙状结肠组和直肠组（P>0.05）。转化生长因子β途径的比例在直肠乙状结肠交界处组和直肠组中高于乙状结肠组（分别为39.3%、34.3%、18.2%，P=0.121，P=0.067，P=0.682）；在直肠乙状结肠交界处也观察到比直肠和乙状结肠更高比例的MYC途径（28.6%、15.2%、17.1%，P=0.278，P=0.202，P=0.171）。无论采用何种聚类方法，患者均被分为两个聚类，聚类组成在不同部位方面未显示出显著差异。
与相邻肠段癌的分子特征相比，直肠乙状结肠交界处癌具有独特的分子特征。
