Colon Cancer

Colorectal cancer is preventable. Nearly all cases of colorectal cancer develop from polyps, benign growths on the inner lining of the colon or rectum. Detection and removal of polyps through colonoscopy reduces the risk of rectal cancer. Colorectal cancer screening recommendations are based on medical and family history. Screening typically starts at age 50 in patients with average risk. Those at higher risk are advised to receive their first screening at a younger age.

While it is not definitive, there is some evidence that diet may play a significant role in preventing colorectal cancer. A diet high in fiber (whole grains, fruits, vegetables and nuts) and low in fat may help prevent colorectal cancer.

Colorectal cancer symptoms include:

Colorectal cancer often causes no symptoms and is detected during routine screenings. It is important to note that other common health problems can cause some of the same symptoms. For example, hemorrhoids are a common cause of rectal bleeding but do not cause colorectal cancer. Colorectal cancer symptoms include:

• A change in bowel habits (e.g., constipation or diarrhea)
• Narrow shaped stools
• Bright red or very dark blood in the stool
• Ongoing pelvic or lower abdominal pain (e.g., gas, bloating or pain)
• Unexplained weight loss
• Nausea or vomiting
• Feeling tired all the time

Abdominal pain and weight loss are typically late symptoms, indicating possible extensive disease. Anyone who experiences any of the above symptoms should see a physician as soon as possible.

Most colorectal polyps do not cause any symptoms, which is why screening for colorectal polyps and cancer is so important. The presence of polyps can cause blood in the stool in some patients. Excess mucus production, changes in bowel frequency, and abdominal pain are less common symptoms associated with the presence of colorectal polyps.

The following are used to offer a diagnosis and treatment plan:

• Medical history
• Physical exam
• Blood tests
• Digital rectal exam (DRE) Insertion of a gloved, lubricated finger into the rectum to check for abnormalities
• Proctoscopy Examination of the anal cavity and rectum using a narrow instrument called a proctoscope
• Colonoscopy Examination of the entire colon with a long, flexible instrument called a colonoscope
• Biopsy Taking samples of tissues to view under a microscope for signs of cancer

Colorectal Cancer Staging Tests

Your physician will use a combination of the following tests to provide information about the staging or extent of cancer:

• Computed Tomography (CT) scan A highly sensitive X-ray test that allows physicians to see "inside" the body and look at all of the organs. This test can help detect the presence of cancer that has spread outside the colon or rectum.
• Positron emission tomography (PET) scan An imaging test that uses a special dye that has radioactive tracers. This allows physicians to identify areas where cancer may have spread outside the colon or rectum.
• CEA assay Carcinoembryonic antigen is a substance in the blood that may be elevated if cancer is present. Although not completely conclusive on its own, this test is used to help monitor patients after their cancer has been treated.
• Magnetic Resonance Imaging (MRI) An imaging test that uses a magnetic field and pulses of radio wave energy to create pictures of organs and structures inside the body. This helps determine if the tumor has spread through the wall of the colon or rectum and invaded nearby structures.
• Abdominal ultrasound A procedure in which a transducer is moved along the skin over the abdomen. This test looks for tumors that may have spread to the liver, gallbladder, pancreas or elsewhere in the abdomen.

The extent of cancer (clinical stage) is linked to treatment decision making and post-treatment patient outcome. Staging is based on whether the tumor has invaded nearby tissues or lymph nodes, and/or cancer has spread to other parts of the body. The exact stage is often not determined until after surgery.

Surgical Treatment

Surgery to remove the colorectal cancer is almost always required for a complete cure. The tumor and lymph nodes are removed, along with a small portion of normal colon on either side of the tumor. Minimally invasive surgical techniques may be used by trained surgeons based on the individual case. Your surgeon will discuss this with you prior to surgery and decide on the best approach.

Ostomy

An ostomy may be necessary in some surgeries to treat colorectal cancer. An ostomy, or stoma, is a surgically created opening between the intestines and the abdominal wall. The most common types of ostomies connect either the small intestines (ileostomy or jejunostomy) or the large intestine (colostomy) to the abdominal wall. After an ostomy is created, bowel movements pass through the opening in the abdominal wall or stoma and into the ostomy appliance. Ostomies can be temporary or permanent.  Your surgeon can advise you about this possibility and how to prepare for it.

Medical Treatment

Chemotherapy or radiation therapy may be offered either before or after surgery, depending on the stage of the cancer.

Outcomes

Early detection through screening methods (like colonoscopy) is crucial. Patient outcome is strongly associated with the rectal cancer stage at the time of diagnosis, including:

• Cancer stage (how advanced the cancer is)
• Cancer location in the colon or rectum
• Whether the bowel is blocked or has a hole in it
• Whether all of the tumor can be removed surgically
• Patient's general health and ability to tolerate different treatments
• Whether the cancer is newly diagnosed or has recurred (come back)

Post-Treatment Follow-up

Follow-up care after treatment for colorectal cancer is important. Even when the cancer appears to have been completely removed or destroyed, the disease may recur.