Each year, cancer of the large bowel (colon, rectum, and anus) affects 135,000 people and causes 57,000 deaths in this country. It is the second leading cause of cancer death in the U.S.  Over the five-year period 1999-2003, about 2,500 Minnesotans were diagnosed with cancer of the colon and rectum each year, and 900 Minnesotans died each year of the disease.

Colorectal cancer can be cured.  Even more importantly, it can be prevented. Most colon cancers start as polyps — precancerous overgrowths of colon tissue. If polyps can be detected by screening tests, they can be removed using a colonoscope usually in the outpatient clinic.  Subsequent cancer development is thus prevented. Early stage colorectal cancers can generally be treated by surgery and are unlikely to recur.  More advanced tumors may require surgery coupled with chemotherapy or chemotherapy plus radiation. 

On this page:

• Risk Factors
• Types of Large Bowel Malignancies
• Screening and Diagnosis
• Treatment
• Clinical Trials
• Care Team
• Support Groups
• Resources and Web Links

Risk Factors

• Age — the older one is, the greater the risk
• Personal history of prior colorectal cancer or polyps
• Personal history of ovarian, uterine, or breast cancer
• Family history of colorectal cancer or polyps. For more information, see the Familial Cancer Clinic section.
• Specific genetic mutations linked to familial adenomatous polyposis and other hereditary disorders including hereditary nonpolyposis colon cancer syndrome. For more information, see the Familial Cancer Clinic section.
• Inflammatory bowel disease, especially ulcerative colitis, or Crohn's colitis, of more than 7 to 10 years duration
• High-fat or low-fiber diet
• Sedentary lifestyle and obesity
• Smoking

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Types of Large Bowel Malignancies

• Adenocarcinoma (vast majority of colorectal cancers). Several variants include:
  • Mucinous (colloid) adenocarcinoma 
• Signet ring adenocarcinoma 
• Adenocarcinoma with neuroendocrine features 
• Carcinoid tumors
• Sarcoma
• Lymphoma
• Anal margin cancers: 
  • Subtypes include: 
    • Paget's disease 
    • Bowen's disease 
    • Basal cell carcinoma 
    • Squamous cell carcinoma 
• Anal canal cancers: 
  • Subtypes include:
    • Squamous cell carcinoma (basaloid, cloacogenic, epidermoid) 
    • Adenocarcinoma 
    • Malignant melanoma 
    • Sarcoma 
    • Small cell carcinoma

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Screening and Diagnosis

Screening

For asymptomatic men and women with no special risk factors, the American Cancer Society recommends one of five screening regimens beginning at age 50 years: 

• Fecal occult blood testing yearly
• Flexible sigmoidoscopy and digital rectal examination every 5 years
• Fecal occult blood testing yearly plus flexible sigmoidoscopy and digital rectal examination every 5 years (the combination is preferred to using either test alone). 
• A double-contrast barium enema every 5 to 10 years
• A colonoscopy every 10 years (increasingly being used for screening even average risk Americans 50 years of age and older).

New screening methods including virtual colonoscopy (CT colonography) and gene testing of stool for abnormalities are being developed and tested. While promising, their development should not delay being tested with currently available screening methods.

Individuals with the following risk factors should begin checkups earlier, have them more often, and generally undergo a more thorough test such as colonoscopy which assesses the entire colon and rectum: 

• A personal history of colorectal cancer or adenomatous polyps
• A first degree relative with colorectal cancer or polyps
• A personal history of chronic inflammatory bowel disease of more than 7 to 10 years duration
• Families with hereditary colorectal cancer syndromes. See the Minnesota Colorectal Cancer Initiative Web site for more detailed information about hereditary colorectal cancer.

Diagnosis

The diagnosis of colorectal cancer is generally made by doctors with digital rectal examination, protosigmoidoscopy, colonoscopy, or barium enema xrays. A biopsy is often taken to confirm the diagnosis of cancer, and other tests such as chest xray, CT or MRI scans, and endorectal ultrasonograghy are done to stage the cancer. 

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Treatment

Treatment depends on a number of factors, including the general health of the patient and the size, location, type, and extent of the tumor. Doctors classify the cancer into different stages based on the information and choose different treatments for them. These can be surgery, radiation, chemotherapy, and immunotherapy. Surgery is the main form of treatment in most patients with colorectal cancer. Doctors often combine two or more methods to treat more advanced stage cancers. Patients may also take part in clinical trials which are used to assess new treatments for cancer. Patients are generally treated by a team of specialists, which may include a radiologist, gastroenterologist, a colorectal surgeon or surgical oncologist, a medical oncologist, and a radiation oncologist. 

Localized colorectal carcinoma

Surgery is the primary therapy for early-stage disease. For more advanced disease, radiation, chemotherapy, and/or immunotherapy may be used in addition to surgery. These added therapies can improve the cure rate, and may be given before or after the surgery.  

Metastatic colorectal carcinoma

Colorectal cancer most commonly metastasizes to the liver and/or lungs. When these metastases are limited to only one of these organs, surgical resection or ablation (cryotherapy or radiofrequency ablation) may be considered. Resection of liver metastasis can result in 25%-40% 5-year survival in appropriately selected patients. Ablation is often reserved for the treatment of technically unresectable disease. 

Cytoreductive surgery plus hyperthermic (heated) chemotherapy improves the survival and quality of life for patients with peritoneal metastases (tumors involving the lining of the abdomen). Physicians at the Masonic Cancer Center have nationally recognized expertise in this innovative treatment.

Recurrent cancer may also develop at the original site of the colorectal cancer. Treatment varies depending on the area involved. 

For widespread disease that cannot be surgically resected, the primary treatment is often chemotherapy. Chemotherapy can improve the quality of life and may increase survival.

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Clinical Trials

Clinical trials are studies that evaluate the effectiveness of new interventions for patients. There are different types of cancer clinical trials, such as prevention trials, early detection trials, and treatment trials. 

If you take part in a clinical trial, you may benefit from a new drug, procedure, or symptom-control method while helping scientists evaluate its effectiveness. 

The Colorectal Cancer Interdisciplinary Team is actively engaged in both national and regional clinical trials for colorectal cancer.

• Gastrointestinal cancer clinical trials available through the Masonic Cancer Center
• All clinical trials available through the Masonic Cancer Center

For more information about gastrointestinal cancer clinical trials, contact the Masonic Cancer Center's Cancer Information Line.

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Care Team

The links below go to physician profiles on the University of Minnesota Physicians Web site. To return to this site, either bookmark this page or use your browser's back button.

Digestive Tract Interdisciplinary Clinical Team

Surgery: Colon and Rectal

David A. Rothenberger, M.D.

Robert Madoff, M.D.

Surgery: Hepatobiliary

Todd Tuttle, M.D.

Eric Jensen, M.D.

Surgery: Pancreatic

Todd Tuttle, M.D.

Eric Jensen, M.D.

Selwyn Vickers, M.D.

Medical Oncology

Edward Greeno, M.D.

Arkadiusz Dudek, M.D.

Gastroenterology: Hepatology and Nutrition

Martin Freeman, M.D.

Jack Lake, M.D.

Shawn Mallery, M.D.

Rebecca Lai, M.D.

Therapeutic Radiology: Radiation Oncology

Chung K. Lee, M.D.

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Support Groups

Contact the Cancer Center's Cancer Information Line if you need help finding a support group.

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Resources and Web Links

Colorectal Cancer: Prevention Is Worth a Pound of Cure (Academic Health Center)
In this Health Talk & You feature, colon and rectal surgeon David Rothenberger, M.D., explains why he believes colonoscopy is the most effective screening method for colorectal cancer. Rothenberger is a professor and deputy chair of the University of Minnesota's Department of Surgery. He is also associate director of clinical affairs at the Masonic Cancer.

Rothenberger is one of the editors of the American Cancer Society's Complete Guide to Colorectal Cancer. He wrote the chapters on surgery and follow-up, and contributed to the chapter on diagnosis and staging. Cancer Center member Ed Greeno, M.D., wrote the chapter on understanding your prognosis, and Rocco Ricciardi, M.D., contributed to the chapter on diagnosis and staging. Visit the American Cancer Society Web site for more information about Complete Guide to Colorectal Cancer.

• Tribal leaders, health professionals unite to examine the unequal burden of colorectal cancer among American Indians
• Colorectal Cancer Awareness Month Resources
• University of Minnesota Physicians: Practices that Serve Colon Cancer
• Division of Colon and Rectal Surgery, Department of Surgery, University of Minnesota
• Colon and Rectal Surgery Associates
• Familial Cancer Clinic
• Health Talk & You: Colorectal Cancer: Prevention Is Worth a Pound of Cure
• U of M study shows radiation therapy for pelvic cancers increases risk for fractures in older women
• U of M Cancer Center study shows radiation therapy for prostate cancer nearly doubles the risk for rectal cancer
• U of M study finds lymph node evaluations of colorectal cancer patients in U.S. not meeting recommended standards
• U of M research shows calcium may protect women from colorectal cancer
• Minnesota Colorectal Cancer Initiative
• American Society of Colon and Rectal Surgery
• Colon Cancer PDQ® (National Cancer Institute)
• Rectal Cancer PDQ® (National Cancer Institute)
• Cancer Risk: Understanding the Puzzle — Colorectal Cancer (National Cancer Institute)
• American Gastroenterological Association
• Minnesota Cancer Facts and Figures 2006 (PDF), Colorectal Cancer, page 20

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