What Causes Colon Cancer?
In the U.S., colorectal cancer is the third leading cause of cancer in both men and women. Colorectal cancer is a type of cancer that originates in the large intestine or rectum. While colon cancer usually affects older individuals, it can occur at any age. It typically begins with small, benign polyps that develop in the colon; these polyps can become cancerous over time. But, it begs the questions, what causes colon cancer? Let's find out.
Causes of Colon Cancer
Colorectal cancer develops when the cells of the colon or rectum undergo mutations, allowing cells to grow out of control, and overtime these cells form a tumor in the colon or rectum.
While the exact cause of colorectal cancer remains unknown, there are various risk factors that have been identified that increase your risk of developing colon cancer, including:
- Heavy alcohol consumption
- Diet high in red and processed meats
- Sedentary lifestyle
- Increasing age
- History of inflammatory bowel disease (IBD)
- History of colorectal polyps
- Type 2 diabetes
- Family history of colorectal cancer
- Inherited syndrome [familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC)]
- Racial and ethnic background (African Americans and Ashkenazi Jews have an increased risk)
Symptoms of Colon Cancer
Signs and symptoms of colon cancer vary among individuals due to colon cancer stages, and may include:
- A change in your bowel habits
- Blood in your stool (may be bright red, or black)
- Narrow stools
- Constipation or diarrhea
- A feeling that your bowels have not completely emptied
- Frequent bloating, cramps, or fullness
- Frequent gas pains
- Unintentional weight loss
It’s important to keep in mind that these symptoms may be caused by colorectal cancer or other medical conditions. It’s therefore important to consult with your doctor if you begin experiencing any of the above-mentioned symptoms to determine what is causing them.
Treatment for Colon Cancer
Colon cancer treatment depends on a variety of factors including your age, general health, tumor location and stage. Typically, treatment will involve surgery to remove the tumor and may also include other therapies such as chemotherapy and radiation therapy.
If you have a small tumor, your doctor may recommend one of the following types of minimally invasive surgery:
- Polypectomy. This is removing small cancers that are localized within a polyp during a colonoscopy.
- Endoscopic mucosal resection. This is when special tools may be used to remove larger polyps and a small portion of the inner lining of the colon during a colonoscopy.
- Laparoscopic surgery. This is when several incisions are made in the abdominal wall so that instruments with attached cameras can be inserted to allow for removal of cancers that cannot be removed during a colonoscopy.
Tumors that have grown into or through your colon wall are more complicated and therefore your doctor may recommend one of the following surgeries.
This surgery is usually performed via laparoscope and involves removing the area of your colon that contains the cancer as well as a margin of normal tissue on either side of the cancerous mass. The healthy portions of the colon or rectum are then reconnected.
If reconnection of the healthy parts of the colon or rectum cannot be completed, an opening in the wall of your abdomen from the remaining bowel is created to allow for stool elimination into a bag that fits over the abdominal opening. In some cases, the ostomy is temporary while your colon or rectum heals, but in some cases, it is permanent.
During surgery, nearby lymph nodes are usually removed and tested for cancer.
If you are in poor health or if your cancer is very advanced, your doctor may recommend removing a colon blockage via surgery to improve symptoms. It is important to keep in mind that this surgery does not cure your cancer, but rather relieves symptoms of the cancer, such as bleeding or discomfort.
In cases where your cancer is advanced, but has spread to only certain areas, and you are healthy, your doctor may recommend other localized treatment options to remove the cancer followed by chemotherapy.
Your doctor may also recommend the following treatment options:
This treatment uses medications to kill cancer cells. It’s often given after surgery if your cancer has spread to the lymph nodes to kill any remaining cancer cells and reduce the risk of recurrence. Also, it may be used prior to surgery to help shrink a tumor for easier removal. This therapy is sometimes used in combination with radiation therapy.
This treatment uses beams of energy to destroy cancer cells. It’s commonly used prior to surgery to shrink a tumor for easier removal. When surgery is not ideal, radiation therapy may be used to provide symptom relief. This therapy is sometimes used in combination with chemotherapy.
This therapy trains your body’s immune system to identify and attack cancer cells. This therapy is typically used for advanced colorectal cancer.
Targeted Drug Therapy
This therapy focuses on specific abnormalities within the cancer cells to target and block them, causing cell death. This treatment is often used for advanced colorectal cancer and in combination with chemotherapy
When colorectal cancer is advanced and treatment is not warranted, palliative care will be offered. Palliative care focuses on providing symptom relief to improve your quality of life.
How to Prevent Colon Cancer
While there are factors such as your age and family history that you cannot control, there are a number of preventative steps that you can take to minimize your risk of developing colon cancer.
Make sure to go for a colorectal cancer screening. A screening is the most effective way of finding abnormal growths (polyps) before they develop into cancer. Finding colorectal cancer early leads to more successful treatment. These screening tests look for abnormalities before signs and symptoms begin. These tests include the fecal immunochemical test, flexible sigmoidoscopy and colonoscopy. The American Cancer Society recommends screening to begin at the age of 45 for people who have an average risk of colon cancer and earlier for those at a heightened risk.
Make sure to consume lots of whole grains, fruits and veggies; consuming a healthy diet with lots of whole grain, fruits and veggies has been associated with a decreased risk of developing colorectal cancer. Avoid or reduce the amount of red meat and processed meat that you consume as these foods have been linked with an increased risk of colorectal cancer. This goes in hand with exercising regularly. Inactivity has been linked to an increased risk of developing colorectal cancer. Regularly exercising may help to decrease your risk. Maintaining a healthy weight by eating well and regularly exercising can help to decrease your risk.
If you smoke, quit it. Smoking is linked to an increased risk of developing, and dying from, colorectal cancer. Quitting smoking can help to lower your risk. Also be sure to drink alcohol in moderation. Drinking alcohol is linked to an increased risk of developing colorectal cancer. The American Cancer Society recommends maximum of two drinks per day for men and a maximum of one drink per day for women. A single drink is equivalent to 12 ounces of beer, 1.5 ounces of hard liquor, or 5 ounces of wine.
If you notice any unusual and persistent symptoms that concern you, consult with your doctor to determine when you should begin colon cancer screening. General guidelines suggest beginning screening around the age of 45, but your doctor may recommend earlier, or more frequent screening depending on your symptoms and risk factors. Just like most cancer, finding colorectal cancer early allows for the best treatment outcomes.