Surgery: Surgery is the treatment of choice for colorectal cancer. Treatment depends on the stage of the disease and the overall health of the patient. Chemotherapy and radiation therapy may be used as adjuvant treatments (in addition to surgery).
Radical bowel resection, also called partial colectomy and hemicolectomy, is used to treat 80-90% of colorectal cancer patients. This procedure may be performed through a large incision in the abdomen (open surgery) or through several small incisions (laparoscopic surgery). If the cancer has spread, the lymph nodes will be removed. Removal of the lymph nodes is called lymphadenectomy.
Recovery from surgery varies depending on the patient's age, overall health, and the extent of the surgery. After surgery, patients may experience pain, weakness, fatigue, and loss of appetite. Dietary modifications may be necessary until the digestive tract heals. Complications that may occur include allergic reaction to anesthesia, formation of a blockage of the intestine, formation of blood clots or bleeding, wound infection, and leakage at the reconnection site.
If the colon cannot be reconnected, a temporary or permanent colostomy is performed, which allows feces from the colon to pass into a collection vessel outside the body. Approximately 15% of patients require a permanent colostomy.
Chemotherapy: Chemotherapy is used to reduce the likelihood of metastasis (spreading), shrink tumor size, or slow tumor growth. Chemotherapy is often used after surgery (adjuvant), before surgery (neo-adjuvant), or as the primary therapy if surgery is not indicated (palliative). It may be combined with biological therapy (also called immunotherapy) and radiation therapy.
Adjuvant (after surgery) chemotherapy: The most commonly used intravenous regimen is called FOLFOX, and includes 5-fluorouracil (5-FU) or capecitabine (Xeloda®), leucovorin (folinic acid), and oxaliplatin (Eloxatin®).
Chemotherapy for metastatic disease: Commonly used first line chemotherapy regimens involve the combination of 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) with bevacizumab (Avastin®), or 5-fluorouracil, leucovorin, and irinotecan (Camptosar®) (called FOLFIRI) with cetuximab (Erbitux®).
Other chemotherapy combinations and agents: Chemotherapy combinations used to prevent recurrence following surgery or used to shrink the tumors prior to surgery include FOLFOX (5-FU, leucovorin, and oxaliplatin) and FOLFIRI (5-FU, leucovorin, and irinotecan). Colorectal cancer with liver metastasis also may be treated using floxuridine (FUDR®) administered through an artery. Other agents for metastatic colorectal cancer include bortezomib (Velcade®), panitumumab (Vectibix®), oblimersen (Genasense®, G3139), gefitinib and erlotinib (Tarceva®), topotecan (Hycamtin®), Bacillus Calmette-Guérin (BCG), and levamisole (Ergamisol®).
Chemotherapy side effects: Side effects of chemotherapy include nausea, vomiting, inflammation of the intestine (enteritis), diarrhea, mouth irritation (mucositis), low white blood cell count (neutropenia), and hair loss (alopecia). Biological therapy may cause flu-like side effects such as chills, diarrhea, fever, loss of appetite, muscle aches, peripheral neurophathy (nerve pain), weakness, and nausea/vomiting.
Radiation therapy: Radiation therapy uses X-rays to kill any cancer cells that might remain after surgery, to shrink large tumors before operations so that they can be removed easily, or to relieve symptoms of colorectal cancer and rectal cancer. The goal of therapy is to damage the tumor without harming the surrounding tissue. If the cancer has spread through the wall of the rectum, radiation treatments in combination with chemotherapy after surgery may be used. This may help prevent cancer from reappearing in the same place. Side effects of radiation therapy may include diarrhea, rectal bleeding, fatigue, reddened and swollen skin, loss of appetite, and nausea /vomiting.
Vaccine: A new vaccine, called TroVax®, works by using the patient's own immune system to fight the disease. TroVax® is in clinical trials and has reported positive results for colorectal cancer therapy.
Follow-up treatment: Follow-up care is recommended for colorectal cancer patients to ensure that recurrent or metastatic disease is detected as soon as possible. Patients will generally undergo regular physical examinations, fecal occult blood tests, colonoscopies, CT scans, and chest X-rays.
Prognosis: Prognosis depends on the stage of the disease and the overall health of the patient. Overall, colorectal cancer patients have a five-year survival rate of about 61%. The five-year survival rate is about 92% when the disease is treated before it has spread (metastasized); 64% when the cancer has spread to nearby organs or lymph nodes; and 7% when it has spread to other parts of the body (e.g. liver, lungs).
Good scientific evidence
Probiotics: Probiotics are beneficial bacteria (sometimes referred to as "friendly germs") that help maintain the health of the intestinal tract and aid in digestion. They also help keep potentially harmful organisms in the gut (harmful bacteria and yeasts) under control. Most probiotics come from food sources, especially cultured milk products. There is recent evidence that supplementation with Lactobacillus casei may help reduce the recurrence of colorectal tumors in patients who have previously undergone surgery for colorectal cancer. Long-term consumption of probiotics is considered safe and well tolerated. Diarrhea may be a sign of too many probiotics.
Psychotherapy: Psychotherapy is an interactive process between a person and a qualified mental health professional (psychiatrist, psychologist, clinical social worker, licensed counselor, or other trained practitioner). There is strong evidence that psychotherapy can enhance cancer patients' quality of life by reducing emotional distress and aiding in coping with the stresses and challenges of cancer. Therapy may be supportive-expressive therapy, cognitive therapy, or group therapy. Studies conflict on whether therapy improves self-esteem, death anxiety, self-satisfaction, etc. While some patients seek psychotherapy in hopes of extending survival, there is no conclusive evidence regarding its effects on medical prognosis.
Unclear or conflicting scientific evidence
Acupuncture: Acupuncture, or the use of needles to manipulate the "chi" or body energy, originated in China over 5,000 years ago. There has been limited research on acupuncture for cancer pain, and the research that was done was shown to have mixed results. More studies are needed to determine potential benefits. Evidence from several small studies supports the use of acupuncture at a specific point on the wrist (P6), which helps reduce the nausea and vomiting associated with chemotherapy. Electroacupuncture has been studied to treat vasomotor symptoms in breast cancer patients, but more studies are needed to determine its role.
Aloe: Transparent gel from the pulp of the meaty leaves of Aloe vera has been used topically for thousands of years to treat wounds, skin infections, burns, and numerous other dermatologic conditions. Preliminary research suggests that aloe may help prevent or aid in the regression of cancerous tumors. Additional research is needed in this area. Caution is advised when taking aloe supplements due to the large number of adverse effects that may occur including its laxative effect, cramping, dehydration, and possible drug interactions. Aloe should not be used if the patient is pregnant or breastfeeding, unless otherwise directed by a doctor.
American pawpaw: Evidence supporting the use of the American pawpaw (Asimina triloba) tree for the treatment of cancer in humans is largely anecdotal and subjective. However, use in humans has reported minimal side effects, and evidence from animal and in vitro studies suggests that American pawpaw extract does have some anticancer activity. Pawpaw standardized extract has been used for 18 months in patients with various forms of cancer, but well-designed studies on the long-term effects of pawpaw extracts have not been conducted.
Antineoplastons: Antineoplastons are a group of naturally occurring peptide fractions, which were observed by Dr. Stanislaw Burzynski in the late 1970s and found to be absent in the urine of cancer patients. There is inconclusive scientific evidence regarding the effectiveness of antineoplastons in the treatment of cancer. Several preliminary human studies have examined antineoplaston types A2, A5, A10, AS2-1, and AS2-5 for a variety of cancer types. It remains unclear if antineoplastons are effective, or what doses may be safe. Until better research is available, no clear conclusions can be drawn.
Arabinoxylan: Arabinoxylan is made by altering the outer shell of rice bran using enzymes from Hyphomycetes mycelia mushroom extract. Arabinoxylan has been found to improve immune reactions in diabetes and cancer patients. Arabinoxylan products may contain high calcium and phosphorus levels, which may be harmful for patients with compromised renal (kidney) function.
Arginine: Arginine, or L-arginine, is an amino acid used by the body for health. Several studies have found that supplementation with an oral combination of arginine and omega-3 fatty acids may reduce length of hospital stay and infections after surgery in gastrointestinal cancer patients. There is conflicting evidence as to when to give the combination (either before or after surgery). Both strategies have been reported as superior to conventional treatment (no artificial nutrition) at reducing infections after surgery and reducing hospital stay.
Aromatherapy: Healing with fragrant oils has been used for thousands of years. Aromatherapy is often used in people with chronic illnesses (frequently in combination with massage) with the intention to improve quality of life or well-being. There is not enough scientific evidence in this area to form a firm conclusion about the effectiveness of aromatherapy. Essential oils should not be used internally.
Art therapy: Art therapy involves the application of a variety of art modalities including drawing, painting, clay, and sculpture. Art therapy enables the expression of inner thoughts or feelings when verbalization is difficult or not possible. Limited evidence suggests that family caregivers of cancer patients may benefit from art therapy to help them cope with the stress of care giving. Possible benefits include reduced stress, lowered anxiety, increased positive emotions, and increased positive communication with cancer patients and healthcare professionals. Art therapy may also reduce pain and other symptoms in cancer patients. More studies are needed to determine how best to use this form of intervention with this population.
Astragalus: Astragalus (Astragalus membranaceus) has been used in Chinese medicine for centuries for its immune enhancing properties. Although early laboratory and animal studies reported increased immune cell function and reduced cancer cell growth associated with the use of astragalus, there is no reliable human evidence in these areas. A recent study reports that astragalus-based Chinese herbal medicine may increase effectiveness of platinum-based chemotherapy when combined with chemotherapy. Astragalus is also sometimes used with the intention to reduce side effects of cancer treatments, such as fatigue and weight loss. Due to a lack of well-designed research, a firm conclusion cannot be drawn. Caution is advised when taking astragalus supplements because numerous adverse effects, including drug interactions, are possible.
Bee pollen: Bee pollen is considered a highly nutritious food because it contains a balance of vitamins, minerals, proteins, carbohydrates, fats, enzymes, and essential amino acids. Research has found that bee pollen may reduce some adverse effects associated with cancer treatment. Additional studies are needed before a firm recommendation can be made. Caution is advised when taking bee pollen supplements as allergic reactions may occur in sensitive individuals. Bee pollen should not be used if the patient is pregnant or breastfeeding, unless otherwise directed by a doctor.
Bitter melon: Bitter melon (Momordica charantia) is used in the traditional Ayurvedic form of medicine from India to lower blood sugar levels. Research has also found that bitter melon extracts may be beneficial in cancer therapies. MAP30, a protein isolated from bitter melon extract, is reported to possess anti-cancer effects in laboratory studies; however, potential anti-cancer effects have not been studied appropriately in humans. Caution is advised when taking bitter melon supplements, as numerous adverse effects, including blood sugar lowering and drug interactions, are possible. Bitter melon should not be used if the patient is pregnant or breastfeeding unless otherwise directed by a doctor.
Black tea: Black tea (Camellia sinensis) is from the same plant as green tea, but is processed very differently. Black tea usually contains more caffeine than green tea. Several studies have explored a possible association between regular consumption of black tea and rates of cancer in populations. This research has yielded conflicting results, with some studies suggesting benefits, and others reporting no effects. Laboratory and animal studies report that components of tea, such as polyphenols, have antioxidant properties and certain effects against tumors. However, effects in humans remain unclear, and these components may be more common in green tea than in black tea. Some animal and laboratory research suggests that components of black tea may actually be carcinogenic, or cancer causing, although effects in humans are not clear. Overall, the relationship of black tea consumption and human cancer remains undetermined.
Bromelain: Bromelain is a sulfur-containing proteolytic digestive enzyme that is extracted from the stem and the fruit of the pineapple plant (Ananas comosus). There is not enough information recommending its use for or against the treatment of cancer, whether bromelain is used alone or in addition to other therapies. One small study found that a bromelain supplement decreased tumor size in 12 breast cancer patients. Patients took the supplements for a number of months to years. Caution is advised when taking bromelain supplements due to their adverse effects, which include blood thinning and a number of drug interactions.
Calcium: Most large prospective studies have found increased calcium intake to be weakly associated with a decreased risk of colorectal cancer. Further studies are needed to verify these results.
Cat's claw: Originally found in Peru, the use of cat's claw (Uncaria tomentosa) has dated back to the Inca civilization, possibly as far back as 2,000 years. Cat's claw has anti-inflammatory properties, and several low-quality studies suggest that cat's claw may slow tumor growth. However, this research is early and has not identified specific types of cancer. A few studies suggest that cat's claw may also boost the immune system. Caution is advised when taking cat's claw supplements, due to a number of adverse effects such as blood thinning and possible drug interactions.
Chaparral: Chaparral was used by the Native Americans for various health conditions. The chaparral component nordihydroguaiaretic acid (NDGA) has been evaluated as a treatment for cancer, but due to the risk of toxicity it is considered unsafe and not recommended for use. Chaparral and NDGA have been associated with cases of kidney and liver failure, liver cirrhosis, kidney cysts, and kidney cancer in humans. In response to these reports, the U.S. Food and Drug Administration (FDA) removed chaparral from its "Generally Recognized as Safe" (GRAS) list in 1970. Chaparral and NDGA are generally considered unsafe and are not recommended for use.
Copper: Copper is a mineral that occurs naturally in many foods including vegetables, legumes, nuts, grains and fruits, as well as shellfish, avocado, and beef (organs such as liver). Preliminary research reports that lowering copper levels theoretically may arrest the progression of cancer by inhibiting blood vessel growth (angiogenesis). Copper is potentially unsafe when used orally in higher doses than the recommended dietary allowance (RDA). Copper supplements should not be used if pregnant or breastfeeding, unless otherwise directed by a doctor.
Cranberry: Several laboratory studies have reported positive effects of proanthocyanidins, flavonoid components of cranberry (Vaccinium macrocarpon) and other fruits such as blueberries, grape seed, and pomegranate, on health. Based on a small amount of laboratory research, cranberry has been proposed for cancer prevention. Study is needed in humans before a recommendation can be made.
Echinacea: The evidence from a small number of randomized trials evaluating efficacy of Echinacea in the treatment of radiation-induced leukopenia (decrease in white blood cells) is equivocal. Studies have used the combination product Esberitox®, which includes extracts of Echinacea (Echinacea purpurea and pallida) root, white cedar (Thuja occidentalis) leaf, and wild indigo (Baptisia tinctoria)root.
Essiac®: Essiac® contains a combination of herbs, including burdock root (Arctium lappa), sheep sorrel (Rumex acetosella), slippery elm inner bark (Ulmus fulva), and Turkish rhubarb (Rheum palmatum). The original formula was developed by the Canadian nurse Rene Caisse (1888-1978) and is thought to be effective in cancer therapies, although currently there is no evidence for or against its use for any type of cancer. Different brands may contain variable ingredients, and the comparative effectiveness of these formulas is not known. None of the individual herbs used in Essiac® have been tested in rigorous human cancer trials, although some components have shown anti-tumor activity in laboratory studies. Caution is advised when taking Essiac® supplements, as numerous adverse effects including drug interactions are possible. Essiac® should not be used if pregnant or breastfeeding, unless otherwise directed by a doctor.
Focusing: Focusing (experiential therapy) is a method of psychotherapy that involves being aware of one's feelings surrounding a particular issue and understanding the meaning behind words or images conveyed by those feelings. Early evidence suggests focusing may improve mood and body attitude in cancer patients. Firm recommendations cannot be made until well-designed clinical trials are available.
Garlic: Preliminary human studies suggest that regular consumption of garlic (Allium sativum, particularly aged garlic) may reduce the risk of developing several types of cancer. Some studies use multi-ingredient products so it is difficult to determine if garlic alone may play a beneficial role. Further well-designed human clinical trials are needed to conclude whether eating garlic or taking garlic supplements may prevent or treat cancer. Garlic may cause an increase in bleeding in sensitive individuals, such as those taking blood thinning medications such as warfarin (Coumadin®).
Ginseng: Several human studies suggest that Asian ginseng (Panax ginseng) may reduce the risk and progression of various organ cancers, especially if ginseng powder or extract is used. Results may have been affected by other lifestyle choices in people who use ginseng, such as exercise or dietary habits. Asian ginseng is also reported to help protect against radiation damage, increase immunity and well-being, and decrease fatigue. Additional trials are necessary before a clear conclusion can be reached. Caution is advised when taking ginseng supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Ginseng should not be used if pregnant or breastfeeding, unless otherwise directed by a doctor.
Green tea: Green tea is made from the dried leaves of Camellia sinensis, a perennial evergreen shrub. Green tea has a long history of use in health and longevity, dating back to China approximately 5,000 years ago. Although used for centuries to help prevent diseases, the relationship of green tea consumption and human cancer remains inconclusive. Evidence from well-designed clinical trials is needed before a firm recommendation can be made in this area. Caution is advised when taking green tea supplements, as numerous adverse effects, including an increased risk of drug interactions, are possible. Green tea should not be used if pregnant or breastfeeding, unless otherwise directed by a doctor. Caffeine-free supplements are available.
Healing touch (HT): Preliminary data suggests that healing touch may be of benefit in cancer patients for inducing relaxation and improving quality of life. However, due to weaknesses in design and the small number of studies, data is insufficient to make definitive recommendations.
Hoxsey formula: "Hoxsey formula" is a misleading name, because it is not a single formula, but rather a therapeutic regimen consisting of an oral tonic and topical (applied to the skin) preparations. The tonic is individualized for cancer patients based on general condition, location of cancer, and previous history of treatment. An ingredient that usually remains constant for every patient is potassium iodide. Other ingredients are then added and may include licorice, red clover, burdock, stillingia root, berberis root, pokeroot, cascara, Aromatic USP 14, prickly ash bark, and buckthorn bark. A red paste may be used, which tends to be caustic (irritating), and contains antimony trisulfide, zinc chloride, and bloodroot. A topical yellow powder may be used, and contains arsenic sulfide, talc, sulfur, and a "yellow precipitate." A clear solution may also be administered and contains trichloroacetic acid. There are no well-designed human studies available evaluating the safety or effectiveness of Hoxsey formula. Caution is advised when taking the Hoxsey formula supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Hoxsey formula should not be used if pregnant or breastfeeding, unless otherwise directed by a doctor.
Hydrazine sulfate: Hydrazine is an industrial chemical marketed as having the potential to repress weight loss and cachexia (muscle wasting) associated with cancer, and to improve general appetite status. However, in large randomized controlled trials, hydrazine has not been proven effective for improving appetite, reducing weight loss, or improving survival in adults. The National Cancer Institute (NCI) sponsored studies of hydrazine sulfate that claimed efficacy in improving survival for some patients with advanced cancer. Trial results found that hydrazine sulfate did not prolong survival for cancer patients. The U.S. Food and Drug Administration (FDA) has received requests from individual physicians for approval to use hydrazine sulfate on a case-by-case "compassionate use" basis on the chance that patients with no other available effective therapy might benefit. The overall controversy in the use of hydrazine sulfate is ongoing, and relevance to clinical practice is unknown. The use of hydrazine sulfate needs to be evaluated further before any recommendations can be made. Side effects have been reported, including nausea, vomiting, and diarrhea.
Iodine: Iodine is an element (atomic number 53), which is required by humans for the synthesis of thyroid hormones (triiodothyronine/T3 and thyroxine/T4). The potential role of non-radioactive iodine in cancer care remains unknown. Antioxidant and anti-tumor effects have been proposed based on laboratory research. In contrast, some scientists have asserted that tumors may uptake more iodine than normal tissues. Povidone-iodine solutions have been used as a part of alternative cancer regimens, such as the Hoxsey formula. Preliminary study has also indicated povidone-iodone solution as a potential rectal washout for rectal cancer. Overall, no clear conclusion can be drawn based on the currently available evidence. Iodine should not be used if pregnant or breastfeeding, unless otherwise directed by a doctor.
Lycopene: High levels of lycopene are found in tomatoes and in tomato-based products. Tomatoes are also sources of other nutrients such as vitamin C, folate, and potassium. Several laboratory and human studies examining tomato-based products and blood lycopene levels suggest that lycopene may be associated with a lower risk of developing cancer and may help stimulate the immune system.
Maitake mushroom: Maitake is the Japanese name for the edible fungus Grifola frondosa. Maitake has been used traditionally both as a food and for medicinal purposes. Early studies in the laboratory as well as in humans suggest that beta-glucan extracts from maitake may increase the body's ability to fight cancer. However, these studies have not been well designed, and better research is needed before the use of maitake for cancer can be recommended.
Melatonin: There are several early-phase and controlled human trials of melatonin in patients with various advanced stage malignancies, including brain, breast, colorectal, gastric, liver, lung, pancreatic, and testicular cancer, as well as lymphoma, melanoma, renal cell carcinoma, and soft-tissue sarcoma. Currently, no clear conclusion can be drawn in this area. There is not enough definitive scientific evidence to discern if melatonin is beneficial against any type of cancer, whether it increases (or decreases) the effectiveness of other cancer therapies, or if it safely reduces chemotherapy side effects. Melatonin is not to be used for extended periods of time. Caution is advised when taking melatonin supplements, as numerous adverse effects including drug interactions are possible. Melatonin is not recommended during pregnancy or breastfeeding, unless otherwise advised by a doctor.
Mistletoe: Mistletoe is one of the most widely used unconventional cancer treatments in Europe. Extracts have been studied for a variety of human cancers including bladder, breast, cervical, CNS, colorectal, head and neck, liver, lung, lymphatic, ovarian, and renal (kidney) cancers as well as melanoma and leukemia. However, efficacy has not been conclusively proven for any one condition. In fact some studies have shown lack of efficacy of certain preparations for a variety of cancers. Larger, well-designed clinical trials are needed. Caution is advised when taking mistletoe supplements, as numerous adverse effects including nausea, vomiting, and drug interactions are possible.
Moxibustion: Moxibustion is a healing technique employed across the diverse traditions of acupuncture and oriental medicine for over 2,000 years. Moxibustion uses the principle of heat to stimulate circulation and break up congestion or stagnation of blood and chi. Moxibustion is more closely related to acupuncture as it is applied to specific acupuncture points. More studies are needed to determine its exact role.
Omega: Omega-3 fatty acids are essential fatty acids found in some plants and fish. There should be a balance of omega-6 and omega-3 fatty acids for health. Several population (epidemiologic) studies report that dietary omega-3 fatty acids or fish oil may reduce the risk of developing breast, colon, or prostate cancer. Although preliminary studies report that growth of colorectal cancer cells may be reduced by taking fish oil, effects on survival or remission have not been measured adequately. Caution is advised when taking omega-3 supplements, as numerous adverse effects including an increase in bleeding and drug interactions are possible. Omega-3 supplements should not be used if pregnant or breastfeeding, unless otherwise by a doctor.
PSK: Protein-bound polysaccharide (PSK) has been used in traditional Chinese medicine (TCM) since the Ming Dynasty of China. PSK is obtained from cultured mycelia of the Coriolus versicolor, a mushroom thought to have antimicrobial, antiviral, antitumor, and immune stimulating properties. PSK, in addition to chemotherapy and surgery, has been associated with increased disease-free survival rate for patients with colorectal cancer in various clinical trials as opposed to pharmaceutical drugs alone. Well-designed clinical trials are needed to confirm these results along with optimal dosing regimens and optimal pharmaceutical combinations. PSK does not seem to affect the cure rate of colorectal cancer. Caution is advised when taking PSK supplements, as numerous adverse effects including drug interactions are possible. PSK supplements should not be used if pregnant or breastfeeding, unless otherwise directed by a doctor.
Psyllium: Psyllium, also referred to as ispaghula, is derived from the husks of the seeds of Plantago ovata. Psyllium contains a high level of soluble dietary fiber, and is the chief ingredient in many commonly used bulk laxatives. Results from animal studies indicate that diets, including psyllium, could be an effective means of reducing colorectal cancer risk. One preliminary human study reports the effects of psyllium in colorectal cancer. Healthcare professionals recommend not taking medications and dietary supplements (including herbs and vitamins) within one hour before taking psyllium and two hours after. Psyllium may interfere with the absorption of medications and dietary supplements.
Reishi mushroom: Reishi (Ganoderma lucidum) has been shown to have antineoplastic and immunomodulatory effects in animal studies. One clinical trial and two case reports exist on advanced cancer patients using Ganopoly®, a Ganoderma lucidum polysaccharide extract. Results show improved quality of life and enhanced immune responses, which are typically reduced or damaged in cancer patients receiving chemotherapy and/or radiation therapy. Well-designed long-term studies are needed to confirm these results and potential side effects.
Seaweed: Bladderwrack (Fucus vesiculosus) is a brown seaweed that grows on the northern coasts of the Atlantic and Pacific oceans and the North and Baltic seas. Bladderwrack appears to suppress the growth of various cancer cells in animal and laboratory studies. However, currently there are no reliable human studies available to support a recommendation for its use in cancer. Caution is advised when taking bladderwrack supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Bladderwrack should not be used if the individual has thyroid disorders (such as hyperthyroidism) or is pregnant or breastfeeding, unless otherwise directed by a doctor.
Selenium: Selenium is a trace mineral found in soil, water, and some foods. It is an essential element in several metabolic pathways. Several studies suggest that low levels of selenium (measured in the blood or in tissues such as toenail clippings), may be a risk factor for developing cancer, particularly prostate cancer. Population studies suggest that people with cancer are more likely to have low selenium levels than healthy matched individuals, but in most cases it is not clear if the low selenium levels are a cause or merely a consequence of disease. It remains unclear if selenium is beneficial in the treatment of any type of cancer.
Shark cartilage: For several decades, shark cartilage has been proposed as a cancer treatment. Studies have shown shark cartilage or the shark cartilage product AE-941 (Neovastat®) to block the growth of new blood vessels, a process called "anti-angiogenesis," which is believed to play a role in controlling the growth of some tumors. There have also been several reports of successful treatments of end-stage cancer patients with shark cartilage, but these have not been well-designed nor did they include reliable comparisons to accepted treatments.
Many studies have been supported by shark cartilage product manufacturers, which may have influenced the results. In the United States, shark cartilage products cannot claim to cure cancer, and the U.S. Food and Drug Administration (FDA) sent warnings to companies ensuring they would not promote the products this way. Without further evidence from well-designed human trials, it remains unclear if shark cartilage is of any benefit in cancer, and patients are advised to check with their doctor and pharmacist before taking shark cartilage.
Shiitake mushroom: Shiitake (Lentinus edodes) has been taken orally to boost the immune system, decrease cholesterol levels, and for anti-aging purposes. Lentinan, derived from shiitake, has been injected as an adjunct treatment for cancer and HIV infections. Laboratory, animal, and human studies of lentinan have shown positive results in cancer patients when used in addition to chemotherapy drugs. Further well-designed clinical trials on all types of cancer are required to confirm these results.
Soy: Soy (Glycine max) contains compounds that have reported efficacy against tumors. Genistein, an isoflavone found in soy, has been found in laboratory and animal studies to possess anti-cancer effects, such as blocking new blood vessel growth (anti-angiogenesis), acting as a tyrosine kinase inhibitor (a mechanism of many new cancer treatments), or causing cancer cell death (apoptosis). In contrast, genistein has also been reported to increase the growth of pancreas tumor cells in laboratory research. There is not enough scientific evidence to determine if dietary intake of soy affects the risk of developing colorectal cancer. Study results are mixed and more research is needed before a recommendation can be made.
Thiamin (Vitamin B1): Thiamin deficiency has been observed in some cancer patients, possibly due to increased metabolic needs, but it is not clear if these low levels are beneficial. Currently, it remains unclear if thiamin supplementation plays a role in the management of any cancers.
Traditional Chinese Medicine (TCM): The ancient Chinese philosophy of Taoism provided the basis for the development of Chinese medical theory. TCM uses over 120 different herbs for cancer depending on which type is being treated and its cause. Studies have reported significant benefits such as reducing tumors, reducing treatment side effects, and improved response to treatment. More studies of stronger design are needed before TCM can be recommended with confidence as an adjunct to cancer treatment; however, centuries of traditional use in cancer cannot be discounted.
Transcutaneous electrical nerve stimulation (TENS): Transcutaneous electrical nerve stimulation (TENS) is a non-invasive technique in which a low-voltage electrical current is delivered through wires from a small power unit to electrodes located on the skin. Although TENS has been used with some success in pain associated with cancer, there is not enough reliable evidence to draw a firm conclusion in this area.
Turmeric: Turmeric (Curcuma longa) is commonly used for its anti-inflammatory properties. Several early animal and laboratory studies report anti-cancer (colon, skin, breast) properties of curcumin. Many mechanisms have been considered, including antioxidant activity, anti-angiogenesis (prevention of new blood vessel growth), and any direct effects on cancer cells. Currently, it remains unclear if turmeric or curcumin has a role in preventing or treating human cancers. There are several ongoing studies in this area. Turmeric may cause an increase in bleeding in sensitive individuals, such as those taking blood thinning medications such as warfarin (Coumadin®).
Vitamin C (ascorbic acid): Dietary intake of fruits and vegetables high in vitamin C has been associated with a reduced risk of various types of cancer in population studies (particularly cancers of the mouth, esophagus, stomach, colon, or lung). However, it is not clear that it is specifically the vitamin C in these foods that is beneficial, and vitamin C supplements have not been found to be associated with this protective effect. Experts have recommended increasing dietary consumption of fruits and vegetables high in vitamin C, such as apples, asparagus, berries, broccoli, cabbage, melon (cantaloupe, honeydew, watermelon), cauliflower, citrus fruits (lemons, oranges), fortified breads/grains/cereal, kale, kiwi, potatoes, spinach, and tomatoes. Vitamin C has a long history of adjunctive use in cancer therapy, and although there have not been any definitive studies using intravenous (or oral) vitamin C, there is evidence that it has benefit in some cases. Better-designed studies are needed. When used in large doses (greater than two grams), vitamin C may cause diarrhea and/or gastrointestinal upset.
Vitamin E: There is no reliable scientific evidence that vitamin E is an effective treatment for any specific type of cancer. There is not sufficient scientific evidence to determine if vitamin E prevents colorectal cancer. In patients with previous colorectal cancer, a combination of vitamins A, C, and E has been reported to reduce the risk of developing recurrent colorectal cancer. Preventive benefits have also been suggested in those with no prior colorectal cancer when vitamin E is used in multivitamin preparations but not alone. Recent results of the Women's Health Study report no overall reduction in cancer risk with daily use of vitamin E, although this study was not large enough to look at colorectal cancer specifically. Additional research is necessary in this area before a firm conclusion can be reached. Caution is merited in people undergoing treatment with chemotherapy or radiation, because it has been proposed that the use of high-dose antioxidants may actually reduce the anti-cancer effects of these therapies. This remains an area of controversy and studies have produced variable results. Patients interested in using high-dose antioxidants such as vitamin E during chemotherapy or radiation should discuss this decision with their medical oncologist or radiation oncologist. Caution is advised when taking vitamin E supplements, as numerous adverse effects, including an increased risk of bleeding and drug interactions, are possible.
Yoga: Yoga is an ancient system of relaxation, exercise, and healing with origins in Indian philosophy. Several studies in cancer patients report enhanced quality of life, lower sleep disturbance, decreased stress symptoms, and changes in cancer-related immune cells after patients received relaxation, meditation, and gentle yoga therapy. Yoga is not recommended as a sole treatment for cancer but may be helpful as an adjunct therapy.
Fair negative scientific evidence
Apricot: Apricot generally refers to the fruit of the Prunus armeniaca tree. Although a few studies have used extracts from apricot for cancer therapy, there is currently a lack of available scientific evidence to use apricot in colorectal cancer. Apricot pits are not well tolerated and are toxic at low to moderate dosing levels.
Beta-carotene: Beta-carotene is a member of the carotenoids, which are highly pigmented (red, orange, yellow), fat-soluble compounds naturally present in many fruits, grains, oils, and vegetables (green plants, carrots, sweet potatoes, squash, spinach, apricots, and green peppers). Alpha, beta, and gamma carotene are considered provitamins because they can be converted to active vitamin A.
While diets high in fruits and vegetables rich in beta-carotene have been shown to potentially reduce the incidence of certain cancers, results from randomized controlled trials with oral supplements do not support this claim.
There is some concern that beta-carotene metabolites with pharmacological activity can accumulate and potentially have cancer causing (carcinogenic) effects. A higher, statistically significant incidence of lung cancer in male smokers who took beta-carotene supplements has been discovered. Beta-carotene/vitamin A supplements may have an adverse effect on the incidence of lung cancer and on the risk of death in smokers and asbestos exposed people or in those who ingest significant amounts of alcohol. In addition, high-dose antioxidants theoretically may interfere with the activity of some chemotherapy drugs or radiation therapy. Therefore, individuals undergoing cancer treatment should speak with their oncologist if they are taking or considering the use of high dose antioxidants. Beta-carotene in the amounts normally found in food does not appear to have this adverse effect.
Hypnotherapy: Hypnotherapy did not reduce anxiety or improve the quality of life in cancer patients undergoing curative radiotherapy in one study.
Iridology: There is currently limited available data supporting iridology as a diagnostic tool in cancer. Additional study is needed.
Selenium: Selenium is a trace mineral found in soil, water, and some foods. It is an essential element in several metabolic pathways. Evidence from the Nutritional Prevention of Cancer (NPC) trial suggests that selenium supplementation does not significantly reduce the risk of developing colorectal cancer. This randomized study was conducted in 1,312 Americans over a 13-year period, and compared the effects of daily selenium versus placebo. Although initial (interim) analysis suggested possible benefits, a later analysis found a lack of statistical significance.
Traditional or theoretical uses lacking sufficient evidence
Integrative therapies with historical or theoretical uses in cancer but which lack sufficient clinical evidence include: acerola (Malpighia glabra, Malpighia punicifolia), aconite (Aconitum napellus), African wild potato (Hypoxis hemerocallidea), alfalfa (Medicago sativa), Andrographis (Andrographis paniculata Nees, Kan Jang®, SHA-10), L-arginine, ashwagandha (Withania somnifera), asparagus (Asparagus officinalis), barley (Hordeum vulgare), bilberry (Vaccinium myrtillus), boron, bupleurum (Bupleurum falcatum), chicory (Cichorium intybus), DHEA, feverfew (Tanacetum parthenium), garcinia (Garcinia cambogia), Hydroxycitric acid, holy basil (Ocimum sanctum), kava kava (Piper methysticum), licorice (Glycyrrhiza glabra), neem (Azadirachta indica), ozone therapy, PC-SPES, podophyllum (Podophyllum peltatum), pycnogenol (Pinus pinaster), rehmannia (Rehmannia glutinosa), spiritual healing, sweet almond (Prunus amygdulus dulcis), thymus extract, watercress (Nasturtium officinale), and yew (Taxus sp.).
Fruits, vegetables, and whole grains: Fruits, vegetables, and whole grains contain vitamins, minerals, fiber, and antioxidants, which may help protect against cancer. Eating five or more servings of fresh fruits and vegetables every day is important for health. A variety of produce should be included in the patient's diet such as kale, chard, spinach, dark green lettuce, peppers, and squash.
Fat intake reduction: Individuals who eat high-fat diets may have a higher rate of colorectal cancer. It is important to limit saturated fats from animal sources such as red meat. Other foods that contain saturated fat include milk, cheese, ice cream, coconut, and palm oils. It is best to restrict the total fat intake to about 30% of the daily calories, with no more than 10% coming from saturated fats.
Vitamins and minerals: Calcium, magnesium, pyridoxine (vitamin B6), and folic acid may help reduce the risk of colorectal cancer. Good food sources of calcium include skim or low-fat milk and other dairy products, shrimp, and soy products such as tofu and soy milk. Magnesium is found in leafy greens, nuts, peas and beans. Food sources of vitamin B6 include grains, legumes, peas, spinach, carrots, potatoes, dairy foods, and meat. Folic acid is found in dark leafy greens such as spinach and lettuce, and in legumes, melons, bananas, broccoli, and orange juice.
Alcohol consumption avoidance: Consuming moderate to heavy amounts of alcohol, such as more than one drink a day for women and two for men, may increase the risk of developing colorectal cancer. This is particularly true if the individual has a close relative, such as a parent, child, or sibling with cancer.
Smoking cessation: Smoking can increase the risk of colorectal and other cancers.
Exercise and weight control: Controlling weight and exercising regularly can reduce the risk of developing colorectal cancer. Exercise, including light walking, stimulates movement through the bowel and reduces the time the colon is exposed to harmful substances (carcinogens) that may cause cancer. The American Cancer Society recommends at least 30 minutes of physical activity five or more days a week if the individual can tolerate it.
Screening tests: It is best to follow the early detection screening guidelines to help find colon or rectal cancer. When these cancers are found and treated early, they can often be cured. Screening can also find polyps, and their removal helps prevent some cancers.
Anti-inflammatory drugs: Aspirin and other anti-inflammatory drugs, such as ibuprofen and celecoxib (Celebrex®), appear to help prevent the growth of polyps. They may also help reduce polyps for some people whose family members tend to develop polyps.
Statin drugs: Statin drugs are commonly used to lower blood cholesterol levels. The regular use of these drugs has recently been found to decrease the risk of developing colorectal cancer. However, another study found no benefit between taking statins and colon cancer prevention, but the use of statins did seem to reduce the risk of stage IV cancer.