As with all cancers, a new diagnosis of colon cancer can be a terrifying experience. In addition to coming to terms with your illness and possibly mortality, you will likely have to address the fears and concerns of your family members, friends, and other loved ones.
Perhaps the most important tool for navigating a colon cancer diagnosis is also the simplest: information. Equipping yourself with information about your diagnosis, its prognosis, and any possible treatments can help you to make informed decisions about your care.
Let’s review the stages of colon cancer and the rate of survival for each stage, as well as typical prognosis.
Stages of Colon Cancer
Essentially, colon cancer has five stages. These stages are numbered zero through five. For example, you might hear a person say they have “stage 2 colon cancer.”
As with other cancers, colon cancer is staged based on the extent of its penetration into the affected colon, as well as the degree to which it has spread throughout the body and affected other organs or systems.
Cancer stages with a higher number affect more of the colon and other body systems and are associated with a poorer prognosis and lower rates of survival.
Each stage of colon cancer also has several sub-stages within that particular stage.
Determining Stages and Survival Rates
Determining the stage of colon cancer can be difficult without surgical intervention. This is because without removing and dissecting the lymph nodes, it is hard for doctors to know if the cancer has spread to adjacent lymph nodes or to other parts of the body.
Of course, a lower stage of cancer when diagnosed is associated with a more optimistic prognosis and higher overall rates of survival. However, since staging is nearly impossible without surgery and surgery is not often done until later stages of the disease, it may be difficult for your doctor to tell you definitively what stage of cancer you have or what your anticipated prognosis will be.
Similarly, younger age is associated with a better overall prognosis, while prognoses are more guarded with advanced age.
Stage 0 Colon Cancer
Stage 0 colon cancer is the first stage of colon cancer, from which all further stages develop. It is sometimes referred to as colon cancer in situ. Some people count stage 0 cancer among the stages of cancer, and others do not.
In stage 0 colon cancer, there are cancerous cells within the innermost lining of the colon. A thin layer called the epithelium. Only cells of the epithelium are affected, and the cancer has not affected cells beyond this layer of the colon.
This stage of colon cancer is associated with the most favorable prognosis and the highest rate of survival.
Stage 1 Colon Cancer
In stage 1 colon cancer, the cancerous growth extends beyond the epithelium of the mucosa, or lining of the colon.
The growth of cancer cells in stage 1 colon cancer extends into the muscles of the intestine that are responsible for pushing food through the colon to be digested. However, the wall of the colon remains intact and has not been completely penetrated by the growth.
The 5-year survival rate for people with stage 1 colon cancer is 92%.This means that five years following their initial diagnosis with Stage 1 colon cancer, 92 people out of 100 are still living.
Stage 2 Colon Cancer
In stage 2 colon cancer, the cancerous growth has entirely penetrated the wall of the colon. There are two sub-stages within this stage, IIa,and IIb.
Stage IIa colon cancer means the growth has gone through the entire wall of the bowel but has not penetrated peritoneum, which is the layer of tissue that attaches the bowels to the wall of the abdomen. It is associated with a 5-year survival rate of 87%.
Stage IIb colon cancer is similar to stage IIa, but in this sub-stage, the peritoneum is also affected. This is associated with a lower five-year survival rate, of 63% in five years.
Stage 3 Colon Cancer
In stage 3 colon cancer, the cancer has spread to one or more lymph nodes as well as affecting the colon. It may also affect adjacent organs within the abdomen.
There are three sub-stages of stage 3 colon cancer. How the sub-stage is classified will depend on whether adjacent organs have been affected, as well as the number of lymph nodes to which the cancer has spread.
The survival rates for these stages range from 89% to 53%.
Stage 4 Colon Cancer
In stage 4 cancer, the cancer has spread to distant parts of the body, such as the bones, liver, or brain. It is stage IVa if it has spread to a single distant part of the body, or stage IVb if it has spread to more than one bodily part.
The survival rate associated with cancers that have spread to other parts of the body are much lower, usually around 10-15% after five years.
It is important to keep in mind these numbers make sense only in context, are affected by many factors, and may or may not apply to individual cases. It is essential you speak with your physician about your specific circumstances and diagnosis to understand your prognosis.
If you are concerned about your family member or loved one’s risk of colon cancer, share this article with them. It is never too early to be concerned with your colon health.
