What is Colon Cancer?
Colorectal cancer, also known as colon cancer, is the development of cancer in the colon or rectum. This cancer can occur in any part of your lower digestive tract—the large intestine. The last several inches of the large intestine is referred to as the rectum. Cancer that occurs in the upper portion of the large intestine is called colon cancer, and the lower portion of the intestine, the rectum, is called colorectal cancer. Cancer is due to the abnormal growth of cells that have the ability to invade or spread to other parts of the body. In the colon, these growths start as noncancerous polyps. Over time, these polyps can become colon cancer. It usually takes up to 10 years or more for this change to occur.
Currently, colorectal cancer, also known as colon cancer, is the second-leading cause of cancer-related deaths in both men and women and the third most frequently diagnosed cancer in America. Last year, the American Cancer Society estimated that 136,830 people would be diagnosed with colorectal cancer and 50,310 people would succumb to the disease. Yet, one of the most remarkable things about colon cancer is that it’s one of, if not the most preventable, treatable, and beatable cancers in the world. Get screened!
There are two types of risk factors: modifiable and non-modifiable. Modifiable risk factors are changeable characteristics. These are behaviors or traits that you can change. Common modifiable risk factors include:
- alcohol consumption.
Non-modifiable risk factors are characteristics you have no control over. Common non-modifiable risk factors include:
- personal or family history.
The following risk factors are most commonly associated with colorectal cancer diagnosis:
- Older than 50 years of age
- African American race
- Previous colorectal cancer diagnosis
- Inflammatory intestinal conditions, such as Crohn’s Disease and/or ulcerative colitis
- Genetic predisposition to colon cancer
- Diets low in fiber and high in fat
- Physical Inactivity
The following are signs and symptoms associated with colorectal cancer. Please note that at early stages of the disease most people do not exhibit any signs or symptoms. For this reason, screening is extremely important.
- Unexplained weight loss
- Bleeding from your rectum or blood in your stool
- Nagging abdominal discomfort
- Changes in your bowel habits, including constipation and/or diarrhea
- Dark colored or black stool
Most people are diagnosed with colon cancer after undergoing screening measures and testing. There are several tests that can be done to examine the intestines for colon cancer. The test most recommended and most effective is the colonoscopy. During this exam, a flexible, long scope with a small camera attached on the end of it is passed through the intestine. The doctor is able to view the entire colon and rectum with the camera. If the doctor comes across any polyps that look cancerous, they can be removed at that time and sent for testing. That is the reason why this test is most beneficial—it can catch the pre-cancerous polyp before it starts to grow and cause problems. Also, under the new Affordable Care Act, most insurance companies have to cover the costs of this exam as it falls under the umbrella of preventative screening care. Once a colorectal cancer diagnosis is made, the doctor will need to determine the stage of the cancer. There are four stages:
- Stage 1 is localized and the easiest to treat.
- Stage 2 has spread through layers of the colon wall but not yet to the lymph nodes.
- Stage 3 has reached the lymph nodes.
- Stage 4 has spread to other organs. Stage 4 is the hardest to treat.
The cancer is progressively worse as the Stage increases. When the cancer is diagnosed early, most treatments are mildly invasive. For example, small polyps can be removed during the colonoscopy, or a minimally invasive laparoscopy (small incisions in the abdomen where the doctor can insert tools to remove larger polyps). If the cancer is more advanced and has grown through the wall of the colon, segments of the colon may need to be removed. This removal can lead to a temporary or permanent colostomy (a portion of the intestine is pulled to the surface of the skin on the abdomen and a bag is placed over the opening to collect waste). Another type of treatment is chemotherapy. This form of treatment uses medications that destroy the cancer cells, and it is often initiated after surgery or when cancer spreads to lymph nodes. Radiation therapy uses highly powerful energy sources to kill cancerous cells. However, it is often not used in early-stage cancer. Lastly, there are a host of facilities around the world that are developing research and experiments to treat cancer. Some people may enter clinical trials for alternative forms of treatment.
The American Cancer Society estimated that, in 2017, there was an estimated 95,520 new cases of
colon cancer and 39,910 cases of rectal cancer diagnosed in the US.
The Healthy People 2020 Initiative has set a goal to reduce colorectal cancer deaths by 10 percent. Although that still represents 161.4 deaths per 100,000 population, it is an improvement over the 2007 baseline when there were 179.3 cancer deaths per 100,000 population (age adjusted to the year 2000 standard population).
Colorectal Cancer Incidence Rates* by State, 2011†
Light Green (32.5 to 37.6)
Arizona, Colorado, Delaware, Maryland, Massachusetts, New Mexico, Oregon, Rhode Island, South Carolina, Utah, Virginia, Washington, and Wyoming
Medium Green (37.7 to 40.0)
California, Connecticut, Florida, Idaho, Kansas, Maine, Michigan, Montana, North Carolina, Texas, Vermont, and Wisconsin
Medium Blue (40.1 to 42.6)
Alabama, Alaska, Arkansas, Georgia, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Oklahoma, and Tennessee
Dark Blue (42.7 to 48.9)
District of Columbia, Hawaii, Illinois, Indiana, Iowa, Kentucky, Louisiana, Mississippi, Nebraska, North Dakota, Pennsylvania, South Dakota, and West Virginia
Light Gray (Data not available‡)
*Rates are per 100,000 and are age-adjusted to the 2000 U.S. standard population.
‡Rates are not shown if the state did not meet USCS publication criteria or if the state did not submit data to CDC.
†Source: U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999–2011 Incidence and Mortality Web-based Report. Atlanta (GA): Department of Health and Human Services, Centers for Disease Control and Prevention, and National Cancer Institute; 2014. Available at: www.cdc.gov/uscs.