Cancer of the colon and/or rectum is commonly referred to as colorectal cancer, the fourth most common cancer in the United States. More than 145,000 new cases of the disease are diagnosed each year. Only lung cancer accounts for more cancer deaths than colorectal cancer. Incidences of colorectal cancer have declined dramatically in recent decades. In 1995, 53 new cases of colorectal cancer were diagnosed for every 100,000 Americans. In 2015, that number dropped to 36. Colon cancer and rectal cancer are grouped together because they share many characteristics, symptoms and treatments. Two-thirds of colorectal cancers are colon cancers.What causes colorectal cancer?
Together, the colon and rectum make up the large intestine. The colon, which is about four feet long, helps digest food and remove nutrients and water before sending the waste to the rectum, the final few inches of the intestine. Colorectal cancer may develop when:
Other risk factors for colorectal cancer include:
Learn more about risk factors for colorectal cancerWho gets colorectal cancer?
The risk of colorectal cancer increases with age. According to the National Cancer Institute:
Get answers to top questions about colorectal cancerColorectal cancer types
More than 95 percent of all colorectal cancers are adenocarcinomas of the colon or rectum. Colorectal adenocarcinomas form in glands that secrete fluids to lubricate the colon and rectum. Adenocarcinomas are found in most common cancers, including breast, prostate and pancreatic. Other types of colorectal cancer include:
Recurrent colorectal cancer is cancer that returns to the same part of the colon or rectum where it was originally diagnosed.
Colorectal cancer that has spread to other parts of the body is called metastatic colorectal cancer. When it spreads, colorectal cancer is most often found in the liver, but may also spread to the lungs, bone and/or brain.
Learn more about colorectal cancer typesColorectal cancer symptoms
Symptoms of colorectal cancer include:
Learn more about colorectal cancer symptomsColorectal cancer diagnostics and screening
Colorectal cancer may be detected and treated early with a proper screening regimen.
Facts about colorectal cancer screening:
During a colonoscopy, a doctor may be able spot cancer in its early stages, perform a biopsy and remove polyps that may develop into cancer. For some patients who choose not to get a colonoscopy, less invasive stool tests may be an option.
Learn more about diagnostic procedures for colorectal cancerTreating colorectal cancer
Surgery is most often the first-line treatment for colorectal cancer. Other treatments include:
Learn more about treatment options for colorectal cancer
Next topic: What are the risk factors for colorectal cancer?