Colon cancer is a type of cancer that originates in the colon, also known as the large intestine, which acts as the final segment of the digestive tract. It commonly begins as benign polyps that form on the interior of the colon, which can later develop into cancer. Over time, the cancerous cells grow and spread, destroying healthy tissue along the way. Left untreated, these abnormal cells can spread and metastasize in other areas of the body where the disease will continue to erode away at healthy cells and organs.
Types of colorectal cancers include:
- Adenocarcinomas – Accounts for 96% of all colorectal cancers, which start in the mucus-secreting cells that lubricate the colon and rectum.
- Carcinoid tumors – A rare form of cancer that begins in hormone-making cells within the intestine.
- Gastrointestinal stromal tumors (GISTs) – Another rare form of cancer that starts in the interstitial cells of Cajal.
- Lymphomas – Immune system cell cancers that typically start in lymph nodes but can originate in the colon or rectum.
- Sarcomas – Atypical cancers that can form in connective tissue, muscle layers, or blood vessels in the walls of the colon and rectum.
According to the American Cancer Society, colorectal cancer is the third most common cancer in both men and women and is also the third leading cause of cancer-related deaths. In 2019 there will be:
- 101,420 new cases of colon cancer
- 44,180 new cases of rectal cancer
- 51,020 deaths caused by either.
The lifetime risk of developing it is 4.49% of men and 4.15% of women. The vast majority of those diagnosed with it are at least 55 years or older.
Causes and Risk Factors of Colorectal Cancer
As with the vast majority of all cancers, doctors remain uncertain as to the specific causes of colorectal cancer besides the fact that the cell’s DNA is somehow damaged and mutated. That said, there are significant risk factors that can impact your likelihood of developing it. These include:
- Alcohol and cigarette use – Both heavy smoking and alcohol use dramatically increase risk.
- Chronic inflammatory diseases – If you’ve had chronic diseases that cause inflammation in the colon such as Crohn’s or ulcerative colitis.
- Diabetes – Those with diabetes or who have insulin resistance are more likely to develop colon cancer.
- Family history of colorectal cancer – If more than one family member has had it, you’re more likely to develop it.
- Genetic inheritance – Some gene mutations can be shared through generations that can increase risk.
- Obesity – People who live an inactive, sedentary lifestyle, have higher rates.
- Older age – The vast majority of all cases of colorectal cancer involve patients over the age of 50.
- Race – Blacks have an increased risk of colon cancer when compared to other races.
Early Detection, Diagnosis, and Staging
Because early detection is difficult, and few symptoms of the disease manifest, doctors recommend that an average-risk person begins semi-frequent colorectal screening at the age of 45. In the later stages, signs and symptoms include:
- A constant change in bowel habits and patterns
- Changing stool consistency
- Rectal bleeding
- Blood in stool
- Abdominal pain
- Feeling like your bowels aren’t empty
- Inexplicable weight loss
The most common screening method is a colonoscopy, wherein a tube with a video camera goes up the rectum to observe the entire colon and rectum. If suspicious polyps are found, a small, minimally invasive biopsy will be done to remove tissue samples for testing. If necessary, surgery may be needed to remove any remaining tissue.
Stages of Colorectal Cancer
Staging determines what kind of treatment or therapy may be necessary to combat the disease, or if the patient will need surgery. Minimally invasive approaches can also be taken based on the severity of the disease. Staging depends on the specific factors of your case, but can be seen in a general view such as:
- Stage I – The cancer has developed into the outermost layers of the colon or rectum but has not gone through them.
- Stage II – The cancer has developed through the wall of the colon or rectum but is not in local tissues or organs.
- Stage III – The cancer has developed through the wall of the colon or rectum and can be found in 4 to 6 local lymph nodes.
- Stage IV – The cancer has spread to lymph nodes, local organs, and distant organs.
If you believe that you or a loved one may have colon cancer, the time to start acting is now. We offer targeted therapy treatment options for a variety of infectious diseases, cancers, autoimmune diseases, and more. For more information on planning your visit, check out our website or call our team of experienced doctors today.
American Cancer Society. Key Statistics for Colorectal Cancer. https://www.cancer.org/cancer/colon-rectal-cancer/about/key-statistics.html
Dimou, A. NCBI. Disparities in colorectal cancer in African-Americans vs Whites: Before and after diagnosis. 2009. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2726450/
Cho, S. NCBI. Alcohol Drinking, Cigarette Smoking and Risk of Colorectal Cancer in the Korean Multi-center Cancer Cohort. (2015). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4492359/