Understanding Colorectal Cancer
Understanding colorectal cancer can help you make informed choices about your health. Whether you want to know more about colorectal cancer screening or you’ve recently received a colorectal cancer diagnosis, we’re here to provide the answers you need.
What is colorectal cancer?
Colorectal cancer is a gastrointestinal cancer, meaning it starts in your digestive tract. Colorectal cancer can develop in the colon or rectum, located in the lower part of your digestive tract. Cancer can also develop in your anus, the last part of your digestive tract. Doctors who treat colon and rectal cancer also treat anal cancer since the organs are so close together.
Your colon (also called your large intestine or large bowel) is a tube-like organ in your lower abdomen. It absorbs water and helps break down food after the food leaves your small intestine. The lowest part of your large intestine is your rectum. Waste from your colon stays in your rectum until it leaves your body through your anus.
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How does colorectal cancer start?
Nearly all colorectal cancers start as abnormal growths called polyps. Doctors try to find colorectal polyps as early as possible with colonoscopies and other colorectal cancer screening tests. Some polyps are flat, but most are either dome-shaped or have a head and stalk.
If a polyp contains cancer, the disease can grow into the colon or rectal wall as a malignant tumor. Most colorectal polyps aren’t cancerous. Large polyps or clusters of several polyps are more likely to turn into cancer
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What happens if I have a colorectal polyp?
If we find a polyp during a colonoscopy, we can often remove the growth during that procedure. We take a sample of cells from the polyp, and a pathologist examines the sample under a microscope.
The polyp may be noncancerous (harmless), precancerous (could turn into cancer) or cancerous. Your doctor might recommend a repeat colonoscopy or other tests to confirm a colorectal cancer diagnosis. Cancerous polyps require more treatment. Your doctor will discuss the next steps with you.
Treatment is different depending on where the cancer is in your colon, rectum or anus. That’s why it’s so important to get an accurate diagnosis from an experienced colorectal team.
What are the symptoms of colorectal cancer?
Talk to your doctor if you notice any of these symptoms:
- Abdominal pain or cramps
- Blood in your stool
- Changes in bowel habits, such as diarrhea or constipation
- Fatigue
- Persistent nausea or vomiting
- Unexplained weight loss
What causes colorectal cancer?
Cancer is the result of changes to the DNA inside our cells. These changes affect how cells behave. Some DNA changes cause cells to grow and divide uncontrollably, forming tumors.
Many factors can increase your risk of developing colorectal cancer. Risk factors you can control include:
- Being overweight or obese
- Drinking alcohol
- Eating a diet high in red meat or processed meats
- Not exercising
- Smoking
Risk factors you can’t control include:
- Age (being over 50)
- Family history of colorectal polyps or cancer
- Having certain genetic conditions
- Having inflammatory bowel disease (IBD)
Mouth Bacteria Linked to Colorectal Cancer
Recent studies has linked colorectal cancer to bacteria associated with gingivitis in the mouth
Is colorectal cancer genetic?
Most risk factors for colorectal cancer are not genetic. But some genetic conditions do increase the chance of developing the disease or colorectal polyps. These conditions are tied to genetic changes inherited from your parents.
Henry Ford Health’s Cancer Genetics Program offers testing and counseling for conditions such as:
- Lynch syndrome, also called hereditary nonpolyposis colorectal cancer (HNPCC)
- Familial adenomatous polyposis (FAP)
- Peutz-Jeghers syndrome (PJS)
- MYH-associated polyposis (MAP)
How is colorectal cancer treated?
Colorectal cancer treatment often includes a combination of surgery, chemotherapy and radiation therapy. Treatment depends on whether you have colon cancer, rectal cancer or anal cancer. Other treatments, such as targeted therapy and immunotherapies, may help people with advanced colorectal cancer.
What is the colorectal cancer survival rate?
Colorectal cancer is highly treatable if caught and treated early. Doctors measure the success of treatment with the five-year survival rate — the number of people alive five years after diagnosis. As of 2018, about 90 percent of people whose cancer did not spread beyond the colon or rectum were still alive. About 70 percent of people whose cancer had spread only to nearby lymph nodes were still alive.