Ahmed Monjur
132 South 10th Street, Main Building, Suite 468, Philadelphia, PA 19107, USA. Email:
Gastroenterology Res. 2020 Feb;13(1):1-10. doi: 10.14740/gr1239. Epub 2020 Feb 1.
Colon cancer is a common preventable cancer. With the adoption of widespread colon cancer screening in the developed countries, the incidence and mortality of colon cancer have decreased in the targeted population. But unfortunately, the incidence and mortality of colorectal cancer (CRC) have been increasing over the last 25 years in the young adults below the age of 50. There is disparity in benefit, i.e. reduction in risk of death between right-sided and left-sided colon cancer by screening colonoscopy. The reason could be multifactorial and various measures have been taken to decrease this disparity. Although most of the screened populations are average risk individuals, a minority of the population have various risk factors for developing colon cancer and need to follow specific colon cancer screening guidelines. Gene mutations (adenomatous polyposis coli (APC), deleted in colon cancer (DCC), K-ras, p53, B-Raf proto-oncogene serine/threonine kinase (BRAF), mismatch repair genes) and microsatellite instability lead to the development of colon cancer. Although various non-invasive methods of colon cancer screening are now available, colonoscopy remains the gold standard of colon cancer screening and adenoma detection rate is now being used as the quality metrics in screening colonoscopy. Although Multi-Society Task Force (MSTF) and American College of Physicians (ACP) recommend initiating screening colonoscopy at age 50 years in all individuals except African Americans who should begin screening colonoscopy at age 45 years, the American Cancer Society (ACS) recommends initiating screening colonoscopy at age 45 years in all individuals irrespective of race and ethnicity. Low-volume split-dose prep has been found to be as effective as high-volume split-dose prep and more tolerable to patients with increased compliance. Boston bowel preparation scale is recommended to measure the quality of colon cleansing. CRC is curative if it is diagnosed at an early stage but various palliative treatment options (endoscopic, oncologic and surgical) are available in advanced stages of this cancer. Adequate number of lymph node assessment during surgery is essential in accurate staging of CRC. Checkpoint inhibitors have been found to have dramatic response and durable clinical benefit in dMMR/MSI-H metastatic CRC. Different genetic and immune-oncologic research trials are ongoing for early detection and better management of CRC.
结肠癌是一种常见的可预防癌症。随着发达国家广泛采用结肠癌筛查，目标人群中结肠癌的发病率和死亡率有所下降。但不幸的是，在过去25年里，50岁以下年轻人的结直肠癌（CRC）发病率和死亡率一直在上升。结肠镜筛查在降低右侧和左侧结肠癌死亡风险方面存在获益差异。原因可能是多方面的，并且已经采取了各种措施来减少这种差异。虽然大多数接受筛查的人群是平均风险个体，但少数人群有患结肠癌的各种风险因素，需要遵循特定的结肠癌筛查指南。基因突变（腺瘤性息肉病 coli（APC）、结肠癌缺失（DCC）、K-ras、p53、B-Raf原癌基因丝氨酸/苏氨酸激酶（BRAF）、错配修复基因）和微卫星不稳定性会导致结肠癌的发生。虽然现在有各种非侵入性的结肠癌筛查方法，但结肠镜检查仍然是结肠癌筛查的金标准，腺瘤检出率现在被用作结肠镜筛查的质量指标。尽管多学会特别工作组（MSTF）和美国医师协会（ACP）建议除非洲裔美国人应在45岁开始结肠镜筛查外，所有个体在50岁开始结肠镜筛查，但美国癌症协会（ACS）建议所有个体无论种族和民族均在45岁开始结肠镜筛查。已发现小剂量分剂量肠道准备与大剂量分剂量肠道准备一样有效，并且对依从性提高的患者更易耐受。建议使用波士顿肠道准备量表来衡量结肠清洁的质量。如果CRC在早期被诊断出来是可以治愈的，但在这种癌症的晚期有各种姑息治疗选择（内镜、肿瘤学和手术）。手术期间足够数量的淋巴结评估对于CRC的准确分期至关重要。已发现检查点抑制剂在错配修复缺陷/微卫星高度不稳定（dMMR/MSI-H）转移性CRC中具有显著反应和持久的临床获益。正在进行不同的基因和免疫肿瘤学研究试验，以早期检测和更好地管理CRC。
