What to know about colon cancer stages

Despite the fact that colorectal cancer cases have been declining in the United States since the mid-1980s, it is still the third most common cancer diagnosed each year excluding skin cancer. Often shortened to colon cancer, colorectal cancer occurs when cells in the colon and/or the rectum begin to grow uncontrollably and eventually spread to other parts of the body.

One important tool when understanding a colon cancer diagnosis is learning about the stages. The staging system is used to determine the severity of cancer and how much it has spread, which is an important factor in each individual’s prognosis and treatment plan.

Below, we will be sharing information about colon cancer stages, in addition to common risk factors and treatment plans to consider. Read on to learn more.

How colon cancer stages are determined

When determining the stages of colon cancer, doctors typically use the American Joint Committee on Cancer TNM system. This is based on the following factors:

  • The size and depth of the tumor (T)
  • The spread to nearby lymph nodes (N)
  • The spread/metastasis to distant sites (M)

By assessing these factors, doctors are able to understand more about the cancer diagnosis and provide a stage accordingly.

The stages of colon cancer

The stages of colon cancer range from 0 to 5 depending on the results from the TNM assessment. Some stages also have additional categories to provide more insight into the status of the cancer’s growth.

  • Stage 0: Cancer cells have only been found in the mucosa (inner lining) of the colon or rectum
  • Stage I: The cancer has grown through the mucosa layer into the muscular layer but has not spread into nearby tissues or lymph nodes
  • Stage IIA: Cancer has grown through the muscular layer, but has not invaded other nearby tissues or lymph nodes
  • Stage IIB: The cancer has grown through the muscular layer into the lining of the abdomen, but has not spread to any other areas or lymph nodes
  • Stage IIC: The cancer has spread through the wall of the colon or rectum, growing into nearby structures but no other areas or lymph nodes
  • Stage IIIA: After growing through the muscle layers of the intestine, the cancer has also spread to between one and three lymph nodes or has caused a nodule of tumor cells around the colon or rectum
  • Stage IIIB: Cancer has fully grown through the organ walls or to surrounding organs, and has spread to between one and three lymph nodes or to a nodule of tumor in tissues around the colon or rectum
  • Stage IIIC: The cancer cells have spread to four or more lymph nodes, but not to other parts of the body
  • Stage IVA: The cancer has spread to a single other location in the body (such as the liver or lungs)
  • Stage IVB: The cancer has spread to more than one part of the body
  • Stage IVC: The cancer has spread to the peritoneum (the lining of the abdomen cavity), and may have also spread to other sites or organs

Common colon cancer risk factors

When assessing a person’s risk factors for colon cancer, doctors consider several factors. The foremost is age, as the likelihood of developing colon cancer increases throughout a person’s life. Most cases of colon cancer occur in people over the age of 50, but the rate of younger adults getting colon cancer diagnoses has risen in recent years. A person’s racial and ethnic background can also play a role, as African Americans and Ashkenazi Jews have the highest incidence of colon cancer. Additionally, if a family member (especially an immediate relative such as a parent, sibling, or child) has a history of colon cancer, a person’s risk is elevated.

In addition to these unchangeable factors, other lifestyle habits may influence colon cancer risk as well. Living a sedentary lifestyle, being overweight, using alcohol heavily, and smoking are all linked to increased colon cancer rates.

Colon cancer treatment plans

Typically, treatment for colon cancer will involve several methods, but the options depend heavily on the cancer’s stage and location. Early-stage colon cancer is often treated first with surgery, and may also involve chemotherapy and radiation treatments. More advanced instances may require partial colectomies and lymph node removal, in addition to chemotherapy and radiation. Treating colon cancer is very specific to each instance, but early diagnosis is one of the best ways to ensure therapies are effective.

Though early detection is one of the best ways to improve the prognosis of a colon cancer diagnosis, there are still many things that researchers do not understand about the disease. Clinical trials are vital for new medical breakthroughs, and many are enrolling now — click the link below to learn more.