March is Colorectal Cancer Awareness month. Cancer of the colon and rectum affects one in 20 persons in the western world, and over 156,000 new cases are diagnosed in the U.S. each year. Recent data show a decrease in the incidence of colon cancer, attributable to a higher immigration from eastern Mediterranean, African and Asian nations, which have a much lower incidence of the disease as compared to earlier immigrants from Germany, Ireland and Eastern Europe, where colon cancer is prevalent.
Nebraska and its neighboring states have a high incidence of colorectal cancer because of the relatively large population of ethnic East Europeans and Germans and high consumption of red meat.
Seventh Day Adventists and Mormons have a very low mortality rate for bowel cancer when compared with other religious groups in the same region. This is attributable to vegetarian diet and abstinence from alcohol and tobacco. Japanese immigrants to this country, who have adopted the American diet, have a 2.5 times greater rate of colon cancer than their compatriots living in Japan. The typical American diet—high in fat and cholesterol and low in fiber—appears to increase the risk of colon cancer. A high-fiber diet is assumed to have a protective effect against cancer.
Patients with inflammatory bowel disease have a thirtyfold increased risk of colon cancer, as well as those with dysplasia, polyps and pelvic radiation. Genetic research has identified a subgroup of patients who are at high risk of colon cancer, caused by inherited genes such as familial multiple polyposis and Lynch syndrome.
Colorectal cancer is the second-leading cause of cancer deaths in the U.S., with 56,000 expected to die from this disease each year. Ironically, colorectal cancer is one of the most curable cancers but only if detected early and treated correctly. Cancer of the colon and rectum has been dubbed the “silent killer,” because there are usually no symptoms in the early stages when it can only be found by regular screenings.
The possibility of curing patients after symptoms develop is only about 50 percent, but if colorectal cancer is found and treated at an early stage before symptoms develop, a five-year survival and cure rate of 90 percent is attainable.
The American Cancer Society and the American Society of Colon & Rectal Surgeons recommend the following colorectal screening guidelines:
*For people at average risk of getting colorectal cancer, a digital rectal examination and fecal occult blood test (FOBT), which screens for hidden blood in the stool, are recommended annually beginning at age 40 for both men and women and should be included in every complete physical exam. A colonoscopy is recommended at age 50 and every five to 10 years thereafter. Flexible sigmoidoscopy with barium enema (preferably double contrast) every five to 10 years is an acceptable alternative if colonoscopy is not available.
*People at increased risk of colorectal cancer include those with a personal or family history of colorectal polyps or cancer; those with a personal or family history of breast, uterine or ovarian cancer; and those with inflammatory bowel disease (ulcerative colitis or Crohn’s disease), or multiple familial polyposis syndromes or Lynch syndrome. They should be screened at an earlier age and have more frequent examinations. These patients should see their health care provider for specific recommendations.
Fecal occult blood test (FOBT) is only significant if it is positive, because it will prompt the patient to undergo further testing to rule out colonic lesions (tumors, polyps, etc.). FOBT has a false negative incidence of about 20 percent, meaning that in about one out of five patients with lesions there will be no indication of blood in the stool, giving the patient a false sense of relief and probably foregoing further testing. Therefore, negative FOBT is meaningless and should never be relied upon for definitive results, especially in the presence of other symptoms.
Colonoscopy is the gold standard examination for the detection of colonic lesions. It is a skill-intensive procedure and should only be performed by an experienced practitioner to minimize the risk of bowel injury or missed lesions. Studies have shown that the highest margin of safety and the least number of missed lesions is achieved only by a well-trained physician who has done a minimum of 3,000 such procedures and does at least 250 colonoscopies a year to maintain proficiency. Medicare and most major health insurance companies reimburse the cost of screening, diagnostic or therapeutic colonoscopy.
“Virtual colonoscopy” is a 3-D CT scan of the colon and is still considered as experimental. It is presently not reimbursed by Medicare and other insurers. The out-of-pocket cost to the patient averages $1,600. At this stage, it is not as reliable as an expertly done colonoscopy. A major disadvantage of the virtual procedure is if a polyp is found, a colonoscopy will be necessary to remove the polyp.
In addition to getting screened, people can lower their risk of developing colorectal cancer by
*Avoiding foods that are high in fat.
*Eating plenty of vegetables, fruits and other fibers and consuming cruciferous vegetables regularly.
*Supplementing their diet with vitamin A, C, D and E.
*Exercising regularly and maintaining a normal body weight.
*Abstaining from smoking and consuming alcohol in moderation or not at all.
If patients develop signs of colorectal cancer—including rectal bleeding, abdominal bloating, cramping or distention, recent change in bowel habits, constipation or diarrhea that lasts longer than two weeks, or unexplained anemia, loss of energy, loss of weight or loss of appetite—they should immediately seek a consultation with a primary care physician or other health care provider, who will schedule the needed tests and/or make the appropriate referral to a specialist.
Primary treatment for potentially curable colorectal cancer is surgical excision. The extent of colon resection is determined by the local tumor growth and invasion, as well as its metastasis to lymph nodes and/or other organs. Overall cure rates and length of survival depend on the stage of the cancer and the complexity of the treatment. It varies from over 90 percent in the early stage to a dismal 35 percent or less in advanced stages. Along with surgical excision, chemotherapy is necessary for the treatment of late-stage cancers that have positive lymph nodes or metastasis to other organs. Radiation therapy is frequently used for rectal cancers.
Major studies in Europe and the United States have shown that patients with colon cancer, treated by a team of specialists that included board certified surgeons who were experienced in colon surgery, oncologists and radiotherapists, fared much better than patients managed by less specialized practitioners. Over 1,100 new cases of colon and rectal cancer will be diagnosed and 400 patients will die of this disease this year alone in Nebraska. It is imperative that people at risk should seek appropriate screening, diagnosis and early treatment if at all possible.