BACKGROUND Different genetic characteristics according to tumor location result in variations in survival rates and treatment responses in advanced colorectal cancer (CRC). However, the effects of tumor location during early CRC are still unclear. METHODS Patients with T1 CRC treated between 2003 and 2019 were enrolled from a prospectively collected database. Patients were once divided into four groups, then combined into two groups (right- and left-sided CRC) according to the tumor location, and clinical features and oncologic behaviors were compared. RESULTS In total, 458 patients were analyzed. Right-sided CRC had a lower incidence of polypoid type tumor than left-sided CRC (36/126 (28.6%) vs 186/332 (56.0%), p < 0.001). There were no differences in tumor size, pathological grade, pT1 substage and lymphovascular invasion between right- and left-sided CRC. Overall, lymph nodal involvement was observed in 42/458 (9.1%) patients. Right-sided CRC had a lower rate of patients with lymph nodal involvement than left-sided CRC (6/126 (4.8%) vs 36/332 (10.8%), p = 0.04). CONCLUSION The present study revealed that there were significant differences in the macroscopic type and the incidence of lymph node involvement between right- and left-sided CRC. The clinical features and oncologic behaviors of T1 CRC are possible to vary according to tumor location.

中文翻译：

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T1期结直肠癌的临床特征和肿瘤学行为因肿瘤部位而异。

背景技术根据肿瘤位置的不同遗传特征导致晚期结直肠癌(CRC)的存活率和治疗反应的变化。然而，肿瘤位置对早期 CRC 的影响仍不清楚。方法 从前瞻性收集的数据库中招募 2003 年至 2019 年间接受治疗的 T1 CRC 患者。先将患者分为四组，然后根据肿瘤部位合并为两组（右侧和左侧结直肠癌），并比较临床特征和肿瘤学行为。结果 总共分析了 458 名患者。右侧 CRC 的息肉样肿瘤发生率低于左侧 CRC（36/126 (28.6%) vs 186/332 (56.0%)，p < 0.001）。肿瘤大小、病理分级、pT1 亚期和右侧和左侧 CRC 之间的淋巴血管侵犯。总体而言，在 42/458 (9.1%) 名患者中观察到淋巴结受累。右侧 CRC 的淋巴结受累率低于左侧 CRC (6/126 (4.8%) vs 36/332 (10.8%), p = 0.04)。结论 本研究表明，右侧和左侧结直肠癌的宏观类型和淋巴结受累发生率存在显着差异。T1 CRC 的临床特征和肿瘤学行为可能因肿瘤位置而异。结论 本研究表明，右侧和左侧结直肠癌的宏观类型和淋巴结受累发生率存在显着差异。T1 CRC 的临床特征和肿瘤学行为可能因肿瘤位置而异。结论 本研究表明，右侧和左侧结直肠癌的宏观类型和淋巴结受累发生率存在显着差异。T1 CRC 的临床特征和肿瘤学行为可能因肿瘤位置而异。