Colorectal cancer is a cancer that starts in your colon or rectum. Depending on where the tumor begins, it may also be called colon cancer or rectal cancer. Colorectal cancer occurs when cells in the colon or rectum change and grow abnormally.
Colorectal cancer begins as a growth (polyp) on the lining of the colon or rectum. These growths can spread through different layers of the colon or rectum and into the blood vessels, eventually traveling to distant parts of your body.
Staging is used to help doctors determine the best treatment and predict survival rates. How much the cancer has spread determines the stage of the cancer.
Colorectal cancer is usually staged using the TNM staging system developed by the American Joint Committee on Cancer.
Staging is based on the following information:
- Primary tumor (T). The size of the original tumor and how far it’s grown into the colon wall or spread to nearby areas.
- Regional lymph nodes (N). The cancer has spread to nearby lymph nodes.
- Distant metastases (M). The cancer has spread to distant lymph nodes or organs, such as the lungs or liver.
The stages of colorectal cancer range from stage 0 to stage 4. Each stage can be further sub-divided into levels of severity. These levels are indicated by the letters A, B, or C.
The cancer is in its earliest stage and hasn’t spread beyond the mucosa, which is the inner lining of the colon or rectum. This stage is also known as carcinoma in situ.
The cancer has grown through the lining of the colon or rectum but hasn’t spread beyond the colon wall or rectum.
The cancer has grown through the wall of the colon or rectum but hasn’t spread to regional lymph nodes. Stage 2 can be divided into stages 2A, 2B, and 2C depending on how deep into the wall it has spread and whether or not it has spread to nearby organs, such as the bladder or prostate.
The cancer has spread to regional lymph nodes. Stage 3 can be divided into stages 3A, 3B, and 3C depending on where the cancer has grown and the number of lymph nodes involved.
The cancer has spread to distant sites. This is the most advanced stage. Stage 4 can be divided into stages 4A and 4B. Stage 4A indicates the cancer has spread to one distant site. Stage 4B indicates the cancer has spread to two or more distant sites.
Colorectal cancer survival rates are used as a tool to help understand your prognosis. It provides the percentage of people with the same type and stage of cancer that are still alive after a specific amount of time — usually five years after diagnosis. Many people live longer than five years, and often much longer.
Survival rates are only general estimates and can’t predict how long you will live. There are a number of individual factors that can affect survival that these numbers don’t take into account:
- a person’s age and other health issues
- how a person responds to treatment
- specific tumor markers
- type of treatment received
- whether or not the cancer came back
Colorectal cancer survival rates by stage
According to the National Cancer Institute, the current estimated relative five-year survival rate for colorectal cancer is 64.5 percent. This is the estimated number of people in the United States with colorectal cancer who are still alive five years after being diagnosed. The number is based on the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program data collected from 2008 to 2014.
Based on this data, here is the breakdown by stage:
- Localized. Early stage colorectal cancer that hasn’t spread outside the primary site — usually stage 0 or stage 1 — has a five-year survival rate of 89.8 percent.
- Regional. The five-year survival rate for cancer that has spread to nearby lymph nodes is 71.1 percent.
- Distant. The five-year survival rate for cancer that has spread to a distant site, such as the liver, brain, or lungs, is 13.8 percent.
- Unknown. In some instances, cancer may not be staged. There are a number of possible reasons for this, such as a personal choice by a patient. The five-year survival rate for cancer that is not staged is 35 percent.
Gender appears to impact survival in people with colorectal cancer. More men are diagnosed with colorectal cancer than women, according to the most recent statistics. Multiple studies have found that women also have better survival rates.
A 2017 meta‐analysis that studied the influence of gender on overall survival and cancer-specific survival in people with colorectal cancer found that gender was the most significant predictor of relative advantage for survival.
Earlier studies have also found women to have higher colorectal cancer survival rates than men. One large study found this to be the case for young and middle-aged women with localized cancer, as well as older women who had taken hormone replacement therapy after menopause. Another study that looked at gender’s effect on survival estimates in metastatic colorectal cancer also found younger women with metastatic colorectal cancer lived longer than men.
Researchers believe that sex hormones may be linked to the lower risk of colorectal cancer and higher survival rates in women.
In its early stages, colorectal cancer may not cause any symptoms. Signs and symptoms appear after the tumor grows into surrounding tissues.
colorectal cancer SYMPTOMS
- change in bowel habits lasting more than four weeks
- narrow stools
- blood in your stool or rectal bleeding
- feeling that your bowel doesn’t fully empty
- persistent abdominal pain, such as bloating, pain, or gas
- rectal pain
- unexplained weight loss
- swollen lymph nodes, difficulty breathing, or jaundice (associated with cancer that has spread)
Having a strong support network can make dealing with your diagnosis, treatment, and recovery easier. Family and friends can help you with emotional as well as practical challenges of colorectal cancer. Some people also find comfort in speaking with clergy or a spiritual advisor.
Outside supportive care is also available for you and your loved ones through the American Cancer Society. They offer access to free support programs and services in your area, as well as online communities and support groups where you can connect with experts and other people with colorectal cancer.
Colorectal cancer survival rates are only estimates and cannot predict individual outcomes. Your outlook is specific to your individual circumstances. Your doctor can help put the statistics into context for you based on your situation. Speak to your doctor if you have questions about colorectal survival statistics and how they apply to you.