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Colorectal cancer -- cancer of the colon and rectum -- is the second leading cause of cancer mortality in America. Colon cancer occurs in the large intestine. If the cancer is in the last 6 inches of the colon (the rectum), it is considered rectal cancer. The colon is the lower part of the digestive system, which processes food for energy and rids the body of solid waste. Together, these cancers are referred to as colorectal cancers. Most colorectal cancers begin as benign adenomas, or polyps that grow on the inner lining of the colon or rectum. These growths spread very slowly, taking from 10 - 20 years to become cancerous. Regular screening tests can identify and remove polyps before they become cancerous. Once colorectal cancer is diagnosed, the prognosis depends on how much the cancer has spread.
Most cases of colorectal cancer occur in people over 50. Although colorectal cancer is responsible for thousands of deaths every year, it is highly treatable if caught early.
Signs and Symptoms
Unfortunately, most people with colorectal cancer don't have any symptoms in the early stage of the disease. That's why screening tests, such as a colonoscopy, are so important.
In general, signs and symptoms of colorectal cancer can include the following:
These symptoms may be caused by colorectal cancer or by other conditions such as infections, hemorrhoids, and inflammatory bowel disease. It is important to tell your doctor about any of these symptoms.
More than half of all colorectal cancers occur without any known cause. Studies also suggest that genetics may play a role. Some people with colorectal cancer carry specific genetic mutations or have relatives with the condition. Those with a family history of specific genetic syndromes -- such as familial adenomatous polyposis, Lynch syndrome, juvenile polyposis, and Peutz-Jeghers syndrome -- are also at an increased risk of developing colorectal cancer. About 25% of patients have a familial component. Smoking and eating a high fat diet also raise the risk of developing cancer.
Risk factors for colorectal cancer include:
You doctor will take a complete medical history, perform a physical exam, and may order one or more tests to diagnose colorectal cancer including sigmoidoscopy, colonoscopy, and barium enema. During a sigmoidoscopy or a colonoscopy, your doctor removes a sample of tissue (called a biopsy) from the colon or rectum and examines it under a microscope to detect abnormal growths. If cancer is evident, your doctor will perform a series of tests (chest x-ray, abdominal CT scan, and blood tests to check liver function) to see if the cancer has spread and to help determine the stage (or extent) of the disease. Stages of colorectal cancer include:
Colorectal cancer is highly preventable, even curable, when detected early. Regular screening for colorectal cancer detects polyps before they become cancerous. Studies show that colonoscopies, in particular, prevent up to 19% of colorectal cancer deaths. Current guidelines recommend these screening options, starting at age 50 for people who have an average risk of colon cancer:
Those with a family history of colorectal cancer should have a colonoscopy every 3 - 5 years, starting at least 10 years before the age of the relative at the time of his or her diagnosis.
Diet and Exercise
Eating plenty of fruits and vegetables, as well as foods rich in omega-3 fatty acids (such as salmon and halibut), folate (such as whole grains and leafy green vegetables), and calcium (such as sea vegetables and kale), can help reduce the risk of colorectal cancer. Limiting alcohol consumption, quitting smoking, and reducing the intake of high fat and fried foods, particularly red meats, may also protect against developing colorectal cancer.
Maintaining a proper weight and exercising regularly also cut your risk of developing colorectal cancer. Even small amounts of exercise on a regular basis are protective. The American Cancer Society recommends at least 30 minutes of physical activity on most days.
Surgery to remove the part of the colon containing the tumor is the primary treatment. Depending on the stage of the cancer, surgery is followed with chemotherapy. If the tumor is particularly large, you may need radiation before or after surgery.
Some medications or supplements may help prevent the development of polyps or colorectal cancer. Making lifestyle changes, especially eating less red meat, losing weight, quitting smoking, and getting more exercise, may help prevent the disease -- even in people with a family history of the condition.
Even if you have no family history of colorectal cancer, an unhealthy lifestyle can increase your risk of developing the disease. Some experts believe making healthy lifestyle changes may lower the risk of developing colorectal cancer by as much as 70% for some people.
Many studies support the association between colorectal cancer and lack of exercise and obesity. Research continues to show that exercise and low-calorie diets may help prevent colorectal cancer.
A large, population-based study of men and women in Hawaii found that the following lifestyle factors were linked with colorectal cancer:
After surgery, chemotherapy (the use of anticancer drugs to destroy cancer cells) may be given to kill any cancerous cells that remain in the body. Chemotherapy controls the spread of the disease and improves survival rates over time. Doctors may use the following chemotherapeutic medications alone or in combination to treat colorectal cancer:
Researchers are investigating whether long-term use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) plays a role in the prevention and treatment of colorectal cancer. Preliminary studies are promising, however, these drugs have risks of their own, including an increased risk of stomach bleeding. NSAIDs may also increase risk of heart problems.
Surgery and Other Procedures
Surgery is the treatment of choice for colorectal cancer, and is best when the disease is found at an early stage. Polyps can be removed during a colonoscopy, before becoming cancerous. When colon cancer is present, a person may need a partial or total removal of the colon (colectomy) and rectum (rectal resection). It depends on how severe the cancer is, where it is located, and whether or where it has spread. During surgery, the surgeon also examines other organs for signs of cancer. If cancer has spread to the liver, a portion of the liver may be removed as well. After removing the tumor and nearby tissue, the surgeon reconnects the healthy portions of the colon or rectum. If the healthy parts of the colon or rectum cannot be reconnected, a temporary or permanent opening (stoma) is made through the wall of the abdomen to provide a path for waste material to leave the body. This procedure is called a colostomy. Radiation may also be used before or during surgery to shrink the tumor, and it may be recommended after surgery to reduce the risk of recurrence. After surgery, colonoscopies are performed every 3 - 6 months for 3 years.
Nutrition and Dietary Supplements
Colorectal cancer should never be treated with nutrition and dietary supplements alone. However, a comprehensive treatment plan for colorectal cancer may include a range of complementary and alternative (CAM) therapies. Some supplements and herbs may help reduce side effects from conventional medications. Others may help reduce the risk of developing colorectal cancer. Mind body therapies such as meditation, relaxation techniques, yoga, and qi gong may reduce the effects of stress and enhance your response to treatment. Ask your team of health care providers about the best ways to incorporate these therapies into your overall treatment plan.
Always tell your health care provider about the herbs and supplements you are using or considering using. Many supplements may interfere with conventional cancer treatments, including chemotherapy.
Follow these nutritional tips for overall health:
These supplements may also help reduce risk of developing colorectal cancer:
Herbs are a way to strengthen and tone the body's systems. However, herbs alone should never be used to treat colon cancer, and you should talk to your doctor before taking any herbs if you are being treated for colon cancer. Some herbs and supplements can interfere with chemotherapy and other treatments. As with any therapy, you should work with your health care provider to diagnose your problem before starting treatment. You may use herbs as dried extracts (capsules, powders, teas), glycerites (glycerine extracts), or tinctures (alcohol extracts). Unless otherwise indicated, make teas with 1 tsp. herb per cup of hot water. Steep covered 5 - 10 minutes for leaf or flowers, and 10 - 20 minutes for roots. Drink 2 - 4 cups per day. You may use tinctures alone or in combination as noted.
Acupuncture is not used as a treatment for cancer itself. But evidence suggests it can help reduce cancer-related symptoms (particularly the nausea and vomiting that often accompanies chemotherapy). Studies show that acupuncture may help reduce pain and shortness of breath. Acupressure (pressing on rather than needling acupuncture points) may also help in controlling breathlessness. People can learn this technique and use it to treat themselves.
Some acupuncturists prefer to work with a patient only after conventional medical cancer therapy. Others will provide acupuncture or herbal therapy during active chemotherapy or radiation. Make sure you discuss these treatments with your medical team before proceeding. Acupuncturists treat cancer patients based on an individualized assessment of the excesses and deficiencies of qi located in various meridians. In many cases of cancer-related symptoms, a qi deficiency is usually detected in the spleen or kidney meridians.
Mind Body Medicine
Relaxation techniques can help people undergoing surgery. One study found that patients who received standard care plus use of guided imagery audiotapes before, during, and after surgery experienced significantly better sleep and less pain following the surgery than patients who received only standard care.
Colorectal cancer may be hard to detect in pregnant women. That's because symptoms of the disease, such as rectal bleeding, nausea, and vomiting, resemble the symptoms of pregnancy. Pregnant women should avoid chemotherapy and radiation therapy. Surgery puts the fetus at risk. Usually folic acid and nutritional needs are maintained during pregnancy, and treatment is postponed until after the baby is delivered.
Prognosis and Complications
Follow up care after treatment for colorectal cancer is very important. If the cancer returns or if new cancer develops, it should be treated as soon as possible. Left untreated, colorectal cancer can spread to the liver or lungs, or a tumor may block the colon. People who have a colostomy may need counseling on how to care for the stoma, as well as how to deal with any emotional difficulties.
The prognosis depends on how deeply the tumor has grown into the tissue and whether the cancer has spread to lymph nodes in the abdominal region or to other areas of the body.
Abeloff: Abeloff's Clinical Oncology, 4th ed. Colon Cancer. Churchill Livingstone. 2008. Ch. 81.
Albanes D, Malila N, Taylor PR, et al. Effects of supplemental a-tocopherol and ß-carotene on colorectal cancer: results from a controlled trial (Finland). Cancer Causes Control. 2000;11:197-205.
Alimi D, Rubino C, Leandri EP, Brule SF. Analgesic effects of auricular acupuncture for cancer pain [letter]. J Pain Symptom Manage. 2000;19(2):81-82.
Anti M, Armelau F, Marra G, et al. Effects of different doses of fish oil on rectal cell proliferation in patients with sporadic colonic adenomas. Gastroenterology. 1994;107(6):1892-1894.
Baron JA, Beach M, Mandel JS, et al. Calcium supplements for the prevention of colorectal adenomas. N Eng J Med. 1999;340:101-107.
Bast A, Haenen GR. Lipoic acid: a multifunctional antioxidant. Biofactors. 2003;17(1-4):207-13.
Baur JA, Sinclair DA. Therapeutic potential of resveratrol: the in vivo evidence. Nat Rev Drug Discov. 2006;5(6):493-506.
Baxter NN, Warren JL, Barrett MJ, Stukel TA, Doria-Rose VP. Association between colonoscopy and colorectal cancer mortality in a US cohort according to site of cancer and colonoscopist specialty. J Clin Oncol. 2012; 30(21):2664-9.
Bonithon-Kopp C, Kronborg O, Giacosa A, Rath U, Faivre J. Calcium and fibre supplementation in prevention of colorectal adenoma recurrence: a randomised intervention trial. European Cancer Prevention Organisation Study Group. Lancet. 2000;356:1300-1306.
Burn J, Gerdes AM, Macrae F, et al. Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial. Lancet. 2012; 378(9809):2081-7.
Bushman JL. Green tea and cancer in humans: a review of the literature. Nutr Cancer. 1998;31(3):151-159.
Chang H, Mi M, Ling W, Zhu J, Zhang Q, Wei N, Zhou Y, Tang Y, Yuan J. Structurally related cytotoxic effects of flavonoids on human cancer cells in vitro. Arch Pharm Res. 2008 Sep;31(9):1137-44.
Cho E, Lee JE, Rimm EB, Fuchs CS, Giovannucci EL. Alcohol consumption and the risk of colon cancer by family history of colorectal cancer. Am J Clin Nutr. 2012; 95(2):413-9.
Cummings LC, Cooper GS. Colorectal cancer screening: update for 2011. Semin Oncol. 2011; 38(4):483-9.
Dahm CC, et al. Dietary fiber and colorectal cancer risk: a nested case-control study using food diaries. J Natl Cancer Instit. 2010;102(9):614-26.
Davies MJ, Bowey EA, Adlercreutz H, Rowland IR, Rumsby PC. Effects of soy or rye supplementation of high-fat diets on colon tumour development in azoxymethane treated rats. Carcinogenesis. 1999;20(6):927-931.
de Deckere EAM. Possible beneficial effect of fish and fish n-3 polyunsaturated fatty acids in breast and colorectal cancer. Euro J Cancer Prev. 1999;8:213-221.
Doron S, Gorbach SL. Probiotics: their role in the treatment and prevention of disease. Expert Rev Anti Infect Ther. 2006;4(2):261-75.
Douillard JY, Cunningham D, Roth AD, Navarro M, James RD, Karasek P, et al. Irinotecan combined with fluorouracil compared with fluorouracil alone as first-line treatment for metastatic colorectal cancer: a multicentre randomised trial. Lancet. 2000;355:1041-1047.
Ezzo J, Berman B, Hadhazy VA, Jadad AR, Lao L, Singh BB. Is acupuncture effective for the treatment of chronic pain? A systematic review. Pain. 2000;86:217-225.
Ferri. Ferri's Clinical Advisor 2013, 1st ed. St. Louis, MO: Mosby, An Imprint of Elsevier. 2012.
Filshie J, Penn K, Ashley S, Davis CL. Acupuncture for the relief of cancer-related breathlessness. Palliat Med. 1998;10:145-150.
Flood A, Schatzkin A. Colorectal cancer: does it matter if you eat your fruits and vegetables? J Natl Cancer Inst. 2000;92(21):1706-1707.
Giardiello FM, Offerhause GJ, DuBois RN. The role of nonsteroidal anti-inflammatory drugs in colorectal cancer prevention. Eur J Cancer. 1995;31A(7-8):1071-1076.
Giovannucci E, Colditsz GA, Stampfer MJ, Willett WC. Physical activity, obesity, and risk of colorectal adenoma in women (United States). Cancer Causes Control. 1996;7:253-263.
Greenberg ER, Baron JA, Tosteson TD, et al. A clinical trial of antioxidant vitamins to prevent colorectal adenoma. N Engl J Med. 1994;331:141-147.
Holt PR. Dairy foods and prevention of colon cancer: human studies. J Am Coll Nutr. 1999;18(suppl 5):379S-391S.
Jänne PA, Mayer RJ. Chemoprevention of colorectal cancer. N Engl J Med. 2000;342(26):1960-1968.
Jiminez B, Palekar N, Schneider A. Issues Related to Colorectal Cancer and Colorectal Cancer Screening Practices in Women. Gastroenterology Clinics. 2011; 40(2).
Kaur M, Mandair R, Agarwal R, Agarwal C. Grape seed extract induces cell cycle arrest and apoptosis in human colon carcinoma cells. Nutr Cancer. 2008;60 Suppl 1:2-11.
Kawamori T, Lubet R, Steele VE, et al. Chemopreventive effect of curcumin, a naturally occurring anti-inflammatory agent, during the promotion/progression stages of colon cancer. Cancer Res. 1999;59:597-601.
Kodama N, Komuta K, Nanba H. Effect of Maitake (Grifola frondosa) D-Fraction on the activation of NK cells in cancer patients. J Med Food. 2003;6(4):371-7.
LaValle JB, Krinsky DL, Hawkins EB, et al. Natural Therapeutics Pocket Guide. Hudson, OH:LexiComp; 2000: 452-454.
La Vecchia C, Braga C, Negri E, et al. Intake of selected micronutrients and risk of colorectal cancer. Int J Cancer. 1997;73:525-530.
Le Marchand L, Wilkens LR, Hankin JH, Kolonel LN, Lyu LC. Independent and joint effects of family history and lifestyle on colorectal cancer risk: Implications for prevention. Cancer Epidemiol Biomarkers Prevent.1999;8:45-51.
Le Marchand L, Hankin JH, Wilkens LR, Kolonel LN, Englyst HN, Lyu L. Dietary fiber and colorectal cancer risk. Epidemiology. 1997a;8:658-665.
Le Marchand L, Wilkens LR, Kolonel LN, Hankin JH, Lyu LC. Associations of sedentary lifestyle, obesity, smoking, alcohol use, and diabetes with the risk of colorectal cancer. Cancer Res.1997b;57:4787-4794.
Lee JE, Willett WC, Fuchs CS, et al. Folate intake and risk of colorectal cancer and adenoma: modification by time. Am J Clin Nutr. 2011; 93(4):817-25.
Littlejohn C, Hilton S, Macfarlane GJ, Phull P. Systemic review and meta-analysis of the evidence for flexible sigmoidoscopy as a screening method for the prevention of colorectal cancer. Br J Surg. 2012; 99(11):1488-500.
Maa SH, Gauthier D, Turner M. Acupressure as an adjunct to a pulmonary rehabilitation program. J Cardiopulm Rehabil. 1997;17(4):268-276.
Marshall J. Prevention of Colorectal Cancer: Diet, Chemoprevention, and Lifestyle. Gastroenterology Clinics. 2008;37(1).
Mayer RJ. Gastrointestinal tract cancer. In: Fauci AS, Braunwald E, Hauser SL, et al, eds. Harrison's Principles of Internal Medicine. 17th ed. New York, NY: McGraw-Hill; 2008:573-580.
Messina M, Bennink M. Soy foods, isoflavones and risk of colonic cancer: A review of the in vitro and in vivo data. Bailliéres Clin Endocrinol Metab. 1998:12(4):707-728.
Michels KB, Giovannucci E, Joshipura KJ, et al. Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers. J Natl Cancer Inst. 2000;92:1740-1752.
Milacic V, Banerjee S, Landis-Piwowar KR, Sarkar FH, Majumdar AP, Dou QP. Curcumin inhibits the proteasome activity in human colon cancer cells in vitro and in vivo. Cancer Res. 2008 Sep 15;68(18):7283-92.
Narisawa T, Fukaura Y, Hasebe M, et al. Prevention of N-methylnitrosourea-induced colon carcinogenesis in F344 rats by lycopene and tomato juice rich in lycopene. Jpn J Cancer Res. 1998;89:1003-1008.
Owen RW, Giacosa A, Hull WE, Haubner R, Spiegelhalder B, Bartsch H. The antioxidant/anticancer potential of phenolic compounds isolated from olive oil. Eur J Cancer. 2000a;36(10):1235-1247.
Pan CX, Morrison RS, Ness J, Fugh-Berman A, Leipzig RM. Complementary and alternative medicine in the management of pain, dyspnea, and nausea and vomiting near the end of life: a systematic review. J Pain Symptom Manage. 2000;20(5):374-387.
Piazza GA, Alberts DS, Hixson LJ, et al. Sulindac sulfone inhibits azoxymethane-induced colon carcinogenesis in rats without reducing prostaglandin levels. Cancer Res. 1997;57(14):2909-2915.
Potter JD. Nutrition and colorectal cancer. Cancer Causes Control. 1996;7:127-146.
Power D, Gloglowski E, Lipkin S. Clinical Genetics of Hereditary Colon Cancer. Hematology/Oncology Clinics of North America. 2010;24(5).
Qaseem A, Denberg TD, Hopkins RH, et al. Screening for colorectal cancer: a guidance statement from the American College of Physicians. Ann Intern Med. 2012: 156(5):378-86.
Quintero E, Castells A, Bujanda L. Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening. N Engl J Med. 2012; 366(8):697-706.
Renzi C, Peticca L, Pescatori M. The use of relaxation techniques in the perioperative management of proctological patients: preliminary results. Int J Colorectal Dis. 2000;15(5-6):313-316.
Schatzkin A, Lanza E, Corle D, et al. Lack of effect of a low-fat, high-fiber diet on the recurrence of colorectal adenomas. NEJM. 2000;342(16):1149-1155.
Shen J, Wenger N, Glaspy J, et al. Electroacupuncture for control of myeloablative chemotherapy-induced emesis. JAMA. 2000;284(21):2755-2761.
Shimizu M, Fukutomi Y, Ninomiya M, Nagura K, Kato T, Araki H, et al. Green tea extracts for the prevention of metachronous colorectal adenomas: a pilot study. Cancer Epidemiol Biomarkers Prev. 2008 Nov;17(11):3020-5.
Simopoulos AP. Essential fatty acids in health and chronic disease. Am J Clin Nutr. 1999;70(3 suppl):560S-569S.
Slattery ML, Benson J, Curtin K, Ma K-N, Schaeffer D, Potter JD. Carotenoids and colon cancer. Am J Clin Nutr. 2000;71:575-582.
Stock C, Knudsen AB, Lansdorp-Vogelaar I, Haug U, Brenner H. Colorectal cancer mortality prevented by use and attributable to nonuse of colonoscopy. Gastrointest Endosc. 2011; 73(3):435-443.
Sung MK, Lautens M, Thompson LU. Mammalian lignans inhibit the growth of estrogen-independent human colon tumor cells. Anticancer Res. 1998;18(3A):1405-1408.
Thiagarajan D, Bennink MR, Bourquin LD, Kavas FA. Prevention of precancerous colonic lesions in rats by soy flakes, soy flour, genistein, and calcium. Am J Clin Nutr. 1998;68(suppl):1394S-1399S.
Turowski GA, Rashid Z, Hong F, Madri J, Basson MD. Glutamine modulates phenotype and stimulates proliferation in human colon cancer cell lines. Cancer Res. 1994;54:5974-5980.
Vickers AJ. Can acupuncture have specific effects on health? A systematic review of acupuncture antiemesis trials. J R Soc Med. 1996;89:303-311.
Wang CZ, Yuan CS. Potential role of ginseng in the treatment of colorectal cancer. Am J Chin Med. 2008;36(6):1019-28.
Review Date: 2/14/2013
Reviewed By: Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.
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