结肠直肠癌

Cancer is when 细胞 grow out of control. 的细胞 form a clump of tissue called a 生长或肿瘤. Cancer 细胞 can invade nearby tissues. It can then spread to other 身体部位.

A tumor can be benign or malignant. A benign tumor is not 癌症 and will not spread to 身体的其他部位. In the colon (large 肠), most benign growths are called 息肉.

A malignant tumor is 癌症. Cancer 细胞 invade and damage tissue around them. 他们可以 also enter the lymph and blood streams, spreading to 身体的其他部位. 结直肠癌症 is the growth of malignant 细胞 in the colon.

癌细胞生长

Normal Anatomy and the Development of 结肠直肠癌

的 colon is the last part of the gastro肠道. 这片土地上有食物 taken in and digested for the body to use. 的 colon's main job is to absorb water and salt from solid waste before it is passed from the body as stool (poop). 的下一个是直肠. It stores stool until it is ready to be passed from the body through 肛管.

Cell growth and death are normal processes in the body to replace old or damaged 细胞. 的 walls of the colon have 细胞 that die and are replaced faster because of 消化过程. 的 colon may also be exposed to carcinogens, or things that 会导致癌症. 的se carcinogens may come from waste expelled from the body, food 分解，和肠道细菌. 的y can cause damage to 细胞 in the colon. 这可以 lead to a high level of cell turnover. Places where there are rapid changes like this are more at risk for 癌症 forming.

Polyps are another thing that can lead to 癌症 forming. 息肉是小的生长物 that can be found in the colon and rectum. 有几种类型. 大多数是良性的， but some can turn into 癌症. 的 highest risk of 癌症 development comes from 腺瘤息肉.

Cancer can happen anywhere in the colon, but it is most commonly found in the last section. 结肠直肠癌 may cause bleeding or make it hard for the colon to work 这是应该的.

If the 癌症 grows beyond the colon or rectum, it can spread into nearby places, such as the urinary tract, reproductive organs, or anus. 它可以使它很难 these organs to work as well and cause issues such as problems passing urine.

It can also spread to lymph nodes or blood vessels, which can carry 癌症细胞 to 身体的其他部位. 的 most common sites for colorectal 癌症 to spread to are lymph nodes in 身体的其他部位, the lungs, liver, or other organs in the 腹部和骨盆部位.

结直肠癌的种类

的 wall of the large 肠 is made of four layers. 从最里面到 outermost layer, they are named mucosa, submucosa, muscle, and serosa. 几乎所有的结直肠癌是 . That is, they start in the mucosa and spread outward through the serosa. 其他类型包括:

—these form from the hormone-producing 细胞 of the 肠道
—these form from special 细胞 in the colon wall, but can be found anywhere in the GI tract
—these are rare and form from the muscular tissue of the 肠

结肠癌

直肠癌

参考文献

本森,.P.维努克，A.B.等。. 结肠癌. 版本 2.2017 NCCN Clinical Practice Guidelines in Oncology. Journal of the National Comprehensive Cancer Network, 2017; 15 (3): 370-398.
结肠癌症 treatment option overview. 国家癌症学院网站. 可以在: http://www.癌症.gov/types/colorectal/patient/colon-treatment-pdq#section/%5F135.
结肠直肠癌. American Cancer Society website. 可在:http://www.癌症.org/acs/groups/cid/documents/webcontent/003096-pdf.pdf.
结肠直肠癌. EBSCO DynaMed网站. 可以在: http://www.力学.com/condition/colorectal-癌症.
Glynne-Jones R.Wyrwicz, L.等。. 直肠癌:ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. 肿瘤学年鉴， 2017; 28 (suppl%5F4): iv22-iv40.