Colorectal Cancer

Colorectal cancer happens when abnormal growths (tumors) form on your colon or rectum. Your colon absorbs water and salt from digested food after it leaves the small intestine, and forms solid waste known as stool. After passing through your colon, stool is stored in the rectum until you eliminate it through a bowel movement.

Colon cancer and rectal cancer are actually two different conditions, but experts group them together because they have many similar traits.

Colorectal tumors can be passed on in families (inherited). If someone in your immediate family has experienced colorectal cancer, you may face a higher than normal risk of experiencing colorectal tumors in your lifetime. Inherited colorectal tumors can strike at an early age (young adulthood) and grow quickly.

Even if you are at risk of inherited colorectal tumors, there is still hope. Linda M. Farkas, M.D., our lead colorectal surgeon internationally recognized expert in inherited colorectal tumors.  Dr. Farkas' research and advocacy to improve access to cancer screening are helping more patients find and treat inherited colorectal tumors early when they are highly treatable.

If you are at risk, the first step is to know your family history. If you face a higher than normal risk, you may wish to undergo genetic testing to see if you carry the genes responsible for colorectal cancer. We also conduct screening tests on cancerous tissue we remove during a resection procedure.

Two of the most common inherited colorectal cancer syndromes are:

• Familial adenomatous polyposis (FAP), which can cause hundreds, and in some cases, thousands, of polyps to form in the colon
• Lynch syndrome or hereditary non-polyposis colorectal cancer (HNPCC), which causes polyps and colorectal cancer to appear earlier in life and also increases your risk other types of cancer. People with Lynch syndrome also face a higher than normal risk of other cancers, including uterine, ovarian, gastric and other cancers.

A colonoscopy is the first step in colorectal cancer diagnosis. This test works by inserting a thin flexible tube with a tiny camera at the tip (colonoscope) into the anus and gently advancing it up the entire length of the colon. Learn more about colonoscopy.

At UC Davis, we also offer alternatives to a traditional colonoscopy, including:

• Virtual colonoscopy: People who are not able to have a regular colonoscopy can still receive comprehensive colorectal cancer screening with a virtual colonoscopy. This test uses imaging technology instead of a colonoscope to examine your colon. Read more about colonoscopy.
• Double contrast barium X-ray: This imaging study is another alternative to colonoscopy. "Double contrast" refers to the two methods used to show the fine details of your colon:
• Inflating the colon with air makes the shape of the intestines appear dark
• Coating the intestines with a chemical (barium) makes the lining appear white
• Fecal occult blood test (FOBT): FOBT helps identify trace amounts of blood in the stool. The test works by placing a stool sample on chemically treated paper that shows the presence of iron, a component of blood. Blood in the stool can be a symptom of many gastrointestinal (GI) disorders. If your FOBT results are positive, we perform a colonoscopy to find the source of the blood.
• Flexible sigmoidoscopy: This test uses a thin flexible tube with a camera at the tip to examine the colon. Unlike a colonoscopy, sigmoidoscopy only examines the lower portion of the colon (sigmoid colon). You may need additional tests, such as a double contrast barium enema or virtual colonoscopy to thoroughly evaluate your colorectal cancer risk.

UC Davis has been recognized by the National Cancer Institute with its prestigious "comprehensive cancer center" designation. This designation means when you come to our center, you will receive the best available care. We offer the complete range of treatments, including radiation, chemotherapy and surgery.

If you have colorectal cancer, you will most likely need surgery to remove the tumor and prevent the cancer from spreading. We are able to access lower and early rectal tumors with the help of special instruments we insert through the anus (transanal minimally invasive surgery or TAMIS). TAMIS helps you avoid an incision in your abdomen. This lowers your risk of complications and helps you recover in as little as few days.

In fact, our surgeons offer a depth of experience in a wide range of minimally invasive techniques, including laparoscopic and robotic surgery as well as traditional open surgery. The best technique for you depends on the location, size and stage of the tumor as well as your medical history. Learn more about minimally invasive colorectal surgery.

The procedures we perform include:

• Transanal excision: During transanal excision, we access and remove early stage lower rectal tumors by inserting surgical instruments through the anal canal. We are often able to perform an excision during transanal minimally invasive surgery (TAMIS).
• Resection: During a resection, we remove part or all of the colon or rectum. You may need a resection if your colon is already compromised from another condition, such as inflammatory bowel disease (IBD). We make every effort to reconnect the remaining intestines, which can help you maintain normal bowel functioning. If this is not possible, you will need a stoma. You may be able to have a minimally invasive procedure, such as laparoscopy or robotic surgery, which can help you avoid a large incision.
• Ileal pouch anal anastomosis (IPAA): Even if you need to have your entire colon and rectum removed, IPAA can help you avoid an ileostomy. Also known as sphincter-sparing minimally invasive surgery, IPAA works by sewing the healthy end of your small intestines directly to the anus. We use colon tissue to create a pouch to collect stool until you eliminate it through a bowel movement. Learn more about sphincter-sparing colorectal surgery.
• Coloanal anastomosis: If we need to remove your entire rectum, coloanal anastomosis can help preserve normal bowel functioning by leaving your anus intact. Coloanal anastomosis works by connecting your colon directly to the anus.
• Transanal total mesorectal excision (TaTME): TaTME is similar to TAMIS in that we access the surgical area through the anus. Using minimally invasive techniques, such as laparoscopic and robotic surgery, we approach surgical areas from two angles instead of one. This approach allows us to quickly and completely remove polyps and tumors in difficult to reach areas.