Colon cancer Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum (parts of the large intestine). Signs and symptoms may include blood in the stool, a change in bowel ...

staging is an estimate of the amount of penetration of a particular cancer. It is performed for diagnostic and research purposes, and to determine the best method of treatment. The systems for staging colorectal cancers depend on the extent of local invasion, the degree of lymph node involvement and whether there is distant

metastasis Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...

. Definitive staging can only be done after surgery and histopathology of colorectal carcinoma. An exception to this principle would be after a colonoscopic polypectomy of a malignant pedunculated polyp with minimal invasion. Preoperative staging of rectal cancers may be done with

endoscopic ultrasound Endoscopic ultrasound (EUS) or echo-endoscopy is a medical procedure in which endoscopy (insertion of a probe into a hollow organ) is combined with ultrasound to obtain images of the internal organs in the chest, abdomen and colon. It can be used t ...

. Adjunct staging of metastasis include

abdominal ultrasound Abdominal ultrasonography (also called abdominal ultrasound imaging or abdominal sonography) is a form of medical ultrasonography (medical application of ultrasound technology) to visualise abdominal anatomical structures. It uses transmission ...

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio w ...

, CT, PET scanning, and other imaging studies.

TNM staging system

The most common staging system is the TNM (for tumors/nodes/metastases) system, from the

American Joint Committee on Cancer {{Short description, Organization standardising cancer staging The American Joint Committee on Cancer (AJCC) is an organization best known for defining and popularizing cancer staging standards, officially the AJCC staging system. The American Joi ...

. This system assigns a number based on three categories. "T" denotes the degree of invasion of the intestinal wall, "N" the degree of

lymphatic Lymph (from Latin, , meaning "water") is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues t ...

node involvement, and "M" the degree of

. Possibly, the overall Joint Committee stage is a shorter format of the TNM stage, and is usually quoted as a number I, II, III, IV derived from the TNM value grouped by prognosis; a higher number indicates a more advanced cancer and likely a worse outcome. Following is the eighth edition from 2017:

Tumor (T)

Diagram showing T stages of bowel cancer CRUK 276

Numbers 0 to 4, with subgroups, are used to describe deepest tumor depth: Approved by the Cancer.Net Editorial Board, 11/2018. In turn citing:
*TX: The primary tumor cannot be evaluated. *T0: No evidence of cancer in the colon or rectum. *Tis: Carcinoma ''in situ''; Cancer cells are found only in the epithelium or lamina propria *T1: Growth into the

submucosa The submucosa (or tela submucosa) is a thin layer of tissue in various organs of the gastrointestinal, respiratory, and genitourinary tracts. It is the layer of dense irregular connective tissue that supports the mucosa (mucous membrane) and ...

*T2: Growth into the

muscularis propria The muscular layer (muscular coat, muscular fibers, muscularis propria, muscularis externa) is a region of muscle in many organs in the vertebrate body, adjacent to the submucosa. It is responsible for gut movement such as peristalsis. The Latin, ...

*T3: Growth through the muscularis propria and into the subserosa, or into tissues surrounding the colon or rectum (but not the visceral peritoneum or surrounding organs). *T4a: Growth into the surface of the visceral

peritoneum The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesot ...

. *T4b: The tumor has grown into or has attached to other organs or structures.

Node (N)

Numbers 0 to 2, and subgroups, are used to describe lymph node involvement: *NX: The regional lymph nodes cannot be evaluated. *N0: No evidence of spread to regional lymph nodes. *N1a: Tumor cells found in 1 regional lymph node. *N1b: Tumor cells found in 2 or 3 regional lymph nodes. *N1c: There are cancerous nodules near the colon that do not appear to be lymph nodes. *N2a: Tumor cells found in 4 to 6 regional lymph nodes. *N2b: Tumor cells found in 7 or more regional lymph nodes.

Metastasis (M)

Numbers 0 and 1, with subgroups, describe the

status: *M0: No evidence of distant metastasis *M1a: Spread to 1 other part of the body beyond the colon, rectum or regional lymph nodes. *M1b: Spread to more than 1 part of the body other than the colon, rectum or regional lymph nodes. *M1c: Spread to the peritoneal surface.

Overall AJCC stage

Dukes classification

In 1932 the British

pathologist Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in t ...

Cuthbert Dukes Cuthbert Esquire Dukes OBE (24 July 1890 – 3 February 1977) was an English physician, pathologist and author, for whom the Dukes classification for colorectal cancer is named. Career Dukes was educated at Caterham School. He graduated with ...

(1890–1977) devised a

classification Classification is a process related to categorization, the process in which ideas and objects are recognized, differentiated and understood. Classification is the grouping of related facts into classes. It may also refer to: Business, organizat ...

system for colorectal cancer. Several different forms of the Dukes classification were developed. However, this system has largely been replaced by the more detailed

TNM staging The TNM Classification of Malignant Tumors (TNM) is a globally recognised standard for classifying the extent of spread of cancer. It is a classification system of the anatomical extent of tumor cancers. It has gained wide international acceptance ...

system and is no longer recommended for use in clinical practice. * Dukes A: Invasion into but not through the bowel wall * Dukes B: Invasion through the bowel wall penetrating the muscle layer but not involving

lymph nodes A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that incl ...

* Dukes C: Involvement of lymph nodes * Dukes D: Widespread

metastases Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, the ...

Astler-Coller classification

An adaptation by the Americans Astler and Coller in 1954 further divided stages B and C * Stage A: Limited to

mucosa A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

* Stage B1: Extending into

but not penetrating through it; nodes not involved * Stage B2: Penetrating through muscularis propria; nodes not involved * Stage B3: Invading into adjacent organs/structures; nodes not involved * Stage C1: Extending into muscularis propria but not penetrating through it. Nodes involved * Stage C2: Penetrating through muscularis propria. Nodes involved * Stage D: Distant metastatic spread The stage gives valuable information for the

prognosis Prognosis (Greek: πρόγνωσις "fore-knowing, foreseeing") is a medical term for predicting the likely or expected development of a disease, including whether the signs and symptoms will improve or worsen (and how quickly) or remain stabl ...

and management of the particular

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...

Full Dukes classification

Another modification of the original Dukes classification was made in 1935 by Gabriel, Dukes and Bussey. This subdivided stage C. This staging system was noted to be prognostically relevant to rectal and colonic adenocarcinoma. Stage D was added by Turnbull to denote the presence of liver and other distant metastasesTurnbull RB Jr, Kyle K, Watson FR, et al: Cancer of the colon: the influence of the no touch isolation technique on survival rates. Ann Surg 166:420-7, 1967 * Stage A: Limited to

; nodes not involved * Stage B: Extending beyond

; nodes not involved * Stage C: Nodes involved but highest (apical) node spared * Stage D: Distant metastatic spread File:Diagram showing Dukes A bowel cancer CRUK 116.svg, Dukes stage A bowel cancer; the cancer is only in the inner lining of the bowel. File:Diagram showing Dukes' B bowel cancer CRUK 117.svg, Dukes stage B bowel cancer; the cancer has invaded the muscle. File:Diagram showing Dukes' C bowel cancer CRUK 118.svg, Dukes stage C bowel cancer; the cancer has invaded the nearby lymph nodes. File:Diagram showing Dukes' D bowel cancer CRUK 119.svg, Dukes stage D bowel cancer; the cancer has metastasized.

References

{{reflist Cancer staging zh:大腸癌#分期