Colon cancer, is also known as colorectal cancer. Cancer is a disease in which cells in the body grow out of control. When cancer starts in the colon or rectum, it is called colorectal cancer.
According to the American Cancer Society, colorectal cancer is the third most common cancer diagnosed in both men and women in the United States (excluding skin cancers). Estimates for the number of colorectal cancer cases in the United States for 2021 are:
- 104,270 new cases of colon cancer
- 45,230 new cases of rectal cancer
Risk factors for colon cancer
According to the Centers for Disease Control and Prevention, some of the risk factors for colorectal cancer include:
- Getting older: Colorectal cancer can occur in young adults and teenagers, but the majority of colorectal cancers occur in people older than 50.
- Race: Black people have the highest rates of sporadic, or non-hereditary, colorectal cancer in the United States. Colorectal cancer is also a leading cause of cancer-related death among Black people.
- Gender: Men have a slightly higher risk of developing colorectal cancer than women.
- Family history: Colorectal cancer may run in the family if first-degree relatives (parents, brothers, sisters, children) or many other family members (grandparents, aunts, uncles, nieces, nephews, grandchildren, cousins) have had colorectal cancer.
- Other health conditions: Families that have uncommon inherited condition have a higher chance of living with colorectal cancer. Some of these conditions include Lynch syndrome, familial adenomatous polyposis, attenuated familial adenomatous polyposis, juvenille polyposis syndrome, Gardner syndrome,
- Members of families with certain uncommon inherited conditions have a higher risk of colorectal cancer, as well as other types of cancer. Find a list here.
- Inflammatory bowel disease (IBD): People with IBD, such as ulcerative colitis or Crohn’s disease, may develop chronic inflammation of the large intestine. This increases the risk of colorectal cancer.
- Adenomatous polyps (adenomas): Polyps are not cancer, but some types of polyps called adenomas can develop into colorectal cancer over time. Polyps can often be completely removed using a tool during a colonoscopy, a test in which a doctor looks into the colon using a lighted tube after the patient has been sedated.
- Personal history of certain types of cancer: People with a personal history of colorectal cancer previously, or a diagnosis of ovarian cancer or uterine cancer are more likely to develop colorectal cancer.
- Physical inactivity and obesity: A sedentary lifestyle increases the risk of developing colorectal cancer.
- Food/diet: Current research consistently links eating more red meat and processed meat to a higher risk of the disease.
- Smoking: Smokers are more likely to die from colorectal cancer than nonsmokers. Learn more about quitting tobacco.
Colon cancer stages
Colon cancer stages are the way doctors categorise how much cancer is in the body as well as how far it has spread. Colon cancer stages help doctors to determine how serious the cancer is as well as how best it can be managed and treated. Colon cancer stages are also used to best understand survival statistics.
Colon cancer stages are as follows:
- Stage 0
- State 1
- Stage 2
- Stage 3
- Stage 4
Stage 0 is the earliest stage of colorectal cancer. As the stage numbers increase, the risk becomes higher and means that the cancer has spread further. The lower the number, the lower the risk of spreading. Prevention is the best cure when it comes to treating colorectal cancer.
Let’s go through the colon cancer stages in more depth.
Stage 0: This is the early stage and means that the cancer is located in one place. It has not yet spread.The cancer cells are only in the mucosa, or the inner lining, of the colon or rectum.
Stage I: The cancer has begin to replicate and spread, during stage 1, the cancer begins to invade muscular layers of the colon and/or rectum.
Stage IIA: The cancer has grown through the wall of the colon or rectum but has not spread to nearby tissue or to the nearby lymph nodes.
Stage IIB: The cancer has grown through the layers of the muscle to the lining of the abdomen. It has not spread to the nearby lymph nodes or elsewhere.
Stage IIC: The tumor has spread through the wall of the colon or rectum and has grown into nearby structures. It has not spread to the nearby lymph nodes.
Stage IIIA: The cancer has grown through the inner lining or into the muscle layers of the intestine. It has spread to 1 to 3 lymph nodes or to a nodule of tumor cells in tissues around the colon or rectum that do not appear to be lymph nodes but has not spread to other parts of the body.
Stage IIIB: The cancer has grown through the bowel wall or to surrounding organs and into 1 to 3 lymph nodes or to a nodule of tumor in tissues around the colon or rectum that do not appear to be lymph nodes. It has not spread to other parts of the body.
Stage IIIC: The cancer of the colon, regardless of how deep it has grown, has spread to 4 or more lymph nodes but not to other distant parts of the body.
Stage IVA: The cancer has spread to a single distant part of the body, such as the liver or lungs.
Stage IVB: The cancer has spread to more than 1 part of the body.
Stage IVC: The cancer has spread to the peritoneum. It may also have spread to other sites or organs.
Symptoms of colon cancer
According to Mayo Clinic, the leading symptoms of colon cancer include:
- A persistent change in your bowel habits, including diarrhea or constipation or a change in the consistency of your stool
- Rectal bleeding or blood in your stool
- Persistent abdominal discomfort, such as cramps, gas or pain
- A feeling that your bowel doesn’t empty completely
- Weakness or fatigue
- Unexplained weight loss
Who should get tested for colorectal cancer?
According to LetsGetChecked, you should get tested for colorectal cancer if:
- You are experiencing symptoms associated with colorectal cancer
- You have a family history of cancer
- You have a history of adenomas (benign tumors)
- You have inflammatory bowel disease (IBD)
- You have ulcerative colitis
- You have Crohn’s disease
- You have type 2 diabetes
- You have undergone radiation therapy
- You have Lynch syndrome
- You have Peutz-Jeghers Syndrome
- Colorectal (Colon) Cancer - cdc.gov
- Key Statistics for Colorectal Cancer - cancer.org
- United States Cancer Statistics - cdc.gov
- Colorectal Cancer Stages - cancer.org
- Colon cancer - mayoclinic.org
- Colon cancer screening test - letsgetchecked.com