Medically Reviewed by Linda S. Lee, MD
Women's Health in Gastroenterology
Brigham and Women's Hospital
Instructor in Medicine
Harvard Medical School
- Overview & Diagnosis
- Treatment & Prevention
- Facts to Know & Questions to Ask
- Key Q&A
- Organizations and Support
What Is It?
Colon cancer is cancer of the large intestine or the rectum, and is often called colorectal cancer.
Colorectal cancer is one of the most common cancers in the United States. About one in 23 women (one in 21 men) will develop cancer of the colon or rectum in their lifetimes. It also is the second leading cause of cancer deaths when men and women are considered together and is the third leading cause of cancer death among women.
There are regional differences in colorectal cancer's incidence and mortality throughout the country, with the lowest rates occurring among those living in Western states, and survival rates lowest among African Americans.
The good news is that the disease is not only highly beatable and treatable, but also highly preventable. Regular screening and removal of polyps can reduce colorectal cancer risk by up to 90 percent. But unfortunately, fear, denial and embarrassment keep many people from being screened.
When colon cancer is caught and treated in stage I, there is a 92 percent chance of survival at five years. Once the cancer is larger and has spread to the lymph nodes, however, the five-year survival rate drops to between 53 and 89 percent, depending on the number of nodes involved. If the cancer has already spread to distant parts of the body such as the liver or lungs, the five-year survival rate goes down to 11 percent.
The large intestine is the last section of the digestive tract and consists of the colon and rectum. The colon is four to six feet long, and the last seven to nine inches of it is called the rectum. After food is digested in the stomach and nutrients are absorbed in the small intestine, waste from this process moves into the colon, where it solidifies and remains for one or two days until it passes out of the body.
Sometimes the body produces too much tissue, ultimately forming a tumor. These tumors can be benign (not cancerous) or malignant (cancerous). In the large intestine, these tumors are called polyps. Polyps are found in about 30 percent to 50 percent of adults. People with polyps in their colon tend to continue producing new polyps even after existing polyps are removed.
There are several types of polyps, the most common being hyperplastic polyps, adenomatous polyps, sessile serrated polyps and malignant polyps. Hyperplastic polyps are typically not precancerous. Adenomatous polyps (also called "adenomas") and sessile serrated polyps may undergo cancerous changes, becoming adenocarcinomas. Malignant polyps are already cancerous.
Colon cancers develop from precancerous polyps that grow larger and eventually transform into cancer. It is believed to take about 10 years for a small precancerous polyp to grow into cancer. Therefore, if appropriate colorectal cancer screening is performed, most of these polyps can be removed before they turn into cancer, effectively preventing the development of colon cancer.
Besides adenocarcinomas, there are other rare types of cancers of the large intestine, including carcinoid tumors typically found in the appendix and rectum; gastrointestinal stromal tumors found in the connective tissue of the colonic or rectal wall; and lymphomas, which are malignancies of immune cells that can involve the colon, rectum and lymph nodes.
The exact cause of colon cancer is unknown, but it appears to be influenced both by hereditary and environmental factors. People at an increased risk of colon cancer include those with either a personal or family history of colorectal cancer or polyps, individuals with a long-standing history of inflammatory bowel disease and people with familial colorectal cancer syndromes. Some of those at high risk may have a 100 percent chance of developing colorectal cancer.
Specific risk factors include:
- Personal History: A personal history of colorectal cancer, benign colorectal polyps which are adenomas or sessile serrated polyps, or chronic inflammatory bowel disease (e.g., ulcerative colitis and Crohn's disease) puts you at increased risk for colorectal cancer. In fact, people who have had colorectal cancer are more likely to develop new cancers in other areas of the colon and rectum, despite previous removal of cancer.
Heredity: If one of your parents, siblings or children has had colorectal cancer or a benign adenoma, you have a higher risk of developing colorectal cancer. If two or more close relatives have had the disease, you also have an increased risk; approximately 5 to 10 percent of all people with colorectal cancer fall into this category.
The most common genetic conditions that increase risk for colon cancer are familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC).
- Familial adenomatous polyposis (FAP). People who have inherited the FAP syndrome may develop hundreds to thousands of polyps in their colon and rectum at a young age, usually in their teens or early adulthood. These polyps are all adenomas. By age 40, almost all patients with FAP will develop colon cancer if they don't have preventive surgery. Most people who have this syndrome begin annual colon examinations while in elementary school, and many choose to have their colon and rectum removed before cancer develops. FAP is rare, accounting for about 1 percent of all cases of colorectal cancer.
Hereditary non-polyposis colon cancer (HNPCC). Also known as Lynch Syndrome, HNPCC is a more common form of inherited colon cancer, accounting for about 2 percent to 4 percent of all colorectal cancer cases. While it is not associated with thousands of polyps, polyps are present and grow more quickly into cancer than in patients without HNPCC. Colon cancer in people with HNPCC also develops at a younger age than sporadic colon cancer, although not as young as in those with FAP.
Cancers in patients with HNPCC tend to be fast growing and respond less to chemotherapy. The lifetime risk of colon cancer in people with HNPCC may be as high as 80 percent. People with HNPCC are also at an increased risk for other types of cancer, including cancer of the ovary, endometrium, stomach, pancreas, bile duct, brain, kidney, ureters, and bladder.
MUTYH-associated polyposis (MAP): People with this syndrome, which is caused by mutations in the gene MUTYH, develop colon polyps that are destined to become cancerous if they are not removed. Their colonoscopy findings may be similar to FAP with hundreds to thousands of polyps or not. People with MUTYH are also at increased risk of cancers of the small intestine, skin, ovary and bladder.
There are some additional rare genetic mutations associated with colon cancer. These include Turcot syndrome, an inherited condition in which people are at an increased risk of adenomatous polyps (and thus, colon cancer) and brain tumors, and Peutz-Jeghers syndrome, a condition that leads to freckles around the mouth and sometimes on the hands and feet, as well as large polyps in the digestive tract and an increased risk of colon and other cancers at a young age.
In addition, there are several gene mutations found in Jews of Eastern European descent (Ashkenazi Jews) that increase colon cancer risk. The most common mutation, which is called the I1307K APC mutation, is found in 6 percent of American Jews.
If you have a history of adenomas or colon cancer or suspect you have a family history of the disease, you should discuss this with your health care professional because you may need to begin screening for the disease at a relatively young age. In some cases, you may wish to undergo genetic testing.
- Age: The risk of colorectal cancer increases with age. Ninety percent of new cases of colorectal cancer in the United States are in people over 50. Clinical studies indicate that when screened for the disease, African Americans tend to be diagnosed with colorectal cancer at a younger age than Caucasians.
- Race: African Americans are more likely to get colorectal cancer than any other ethnic group. Compared to Caucasians, African Americans are about 10 percent more likely to develop colorectal cancer. Unfortunately, they also are more likely to be diagnosed in advanced stages. As a result, African Americans are more likely to die from colon cancer than Caucasians. In 2013, the rate of death from colon cancer among African Americans was about 32 percent greater than that among whites.
- Diet: Eating a diet high in processed meats (hot dogs and some lunch meats) and red meats (lamb, beef or liver) may increase your risk of developing the disease. Avoiding red meat and eating a low-fat diet rich in vegetables, fruit and fiber (e.g., broccoli, whole grains and beans) may reduce your risk of developing colorectal cancer. Some studies suggest that boosting calcium intake helps prevent colon cancer. Until further studies are done, men should keep their intake below 1,500 milligrams because of the increased risk of prostate cancer associated with high levels of calcium. Some research has also shown that vitamin D, which you can get from foods, sun exposure or a pill, can help lower colon cancer risk, but because of the increased risk of skin cancer with sun exposure, most health care professionals don't advocate getting more sun to reduce colorectal cancer at this time. Other studies suggest that taking a multivitamin that contains folic acid may lower colon cancer risk, but other studies have suggested folic acid may help existing tumors grow, so more study is needed in this area. There is some research suggesting that a diet high in magnesium may decrease colon cancer risk, especially in women. More research is necessary to find out if this link exists.
- Lifestyle: Regular exercise is a key weapon in the fight against colorectal cancer. Another significant risk factor in colorectal cancer is smoking. Get help quitting if you can't do it on your own. And keep your alcohol intake to one drink a day or less (two drinks a day or less for men).
- Obesity: Obesity is an epidemic in the United States and has been associated with many types of cancers, including colorectal cancer. There is a strong link between higher BMI (body mass index) and waist circumference and colon cancer risk in men and a weaker association seen in women. High levels of insulin and insulin-like growth factor may play a role in development of colon cancer in obese people. Weight loss has been shown to reduce the risk of colon cancer.
The United States Preventive Services Task Force (USPSTF) recommends all women and men between the ages of 50 and 75 who are at average risk of colorectal cancer get screened for colon cancer.
The USPSTF says that screening in adults between 76 and 85 years should be an individual decision based on the patient's overall health and screening history. People at increased risk for colon cancer due to a personal or family history of colorectal cancer, certain genetic conditions, previous growths in the colon or rectum, or a history of inflammatory bowel disease should talk to their doctors about getting screened before age 50.
Here are the screening options: Keep in mind these tests differ in their pros and cons. Talk to your doctor about the screening test that is right for you.
- A fecal occult blood test (FOBT) once a year. This test detects microscopic amounts of blood in the stool and only detects tumors that are bleeding. This must be performed on three separate bowel movements, and you should avoid nonsteroidal anti-inflammatory medications (NSAIDS) for seven days and vitamin C and red meat for three days before collecting the stool samples. Your health care professional provides the necessary materials to collect the stool specimens for simple testing at home or in the office. The stool should be collected before it is in the toilet water. A wooden stick is used to smear a small sample of stool onto the slots in the test card. You will get three test cards, which, when completed, you return to your health care professional. Your health care professional may recommend this test earlier than age 50 or more frequently if you are at high risk for colon cancer and/or polyps.
- A flexible sigmoidoscopy every five years. This examination allows the health care professional to inspect the rectum and lining of the left colon with a thin tube with a light and camera on the end. To prepare for the test, you may be asked to follow a special diet (such as drinking only clear liquids) for a day before the exam and to use enemas or laxatives to clean out your colon. The sigmoidoscope is inserted into the rectum while you lie on your left side. Sedative medication is not usually given for this procedure. This test is both diagnostic and therapeutic. However, it can only detect polyps or cancer accurately in the last two feet of the large intestine. Unfortunately, the sigmoidoscopy visualizes less than half the colon and misses about half of cancers and polyps that are close to becoming cancer in the first two to three feet of the colon.
- Fecal immunochemical test (FIT) every year. Similar to FOBT, FIT is a stool test that also detects hidden blood (occult) in the stool and must be performed every year. However, it tests for hidden blood in a different way than FOBT and has fewer false positive results. Some forms of FIT only require one stool specimen versus three for the FOBT, and neither vitamins nor foods will affect FIT results (these things can affect results of a FOBT); therefore, no dietary restrictions are necessary prior to collecting the stool samples. You perform the test in a similar manner as the FOBT. Similar to FOBT, the FIT test will not detect a tumor that is not bleeding, so a colonoscopy may be necessary for further screening or if cancer is suspected.
- Stool DNA test every one to three years. This test combines FIT with testing for abnormal DNA shed by tumor cells into the stool. It also screens for blood in the stool. The test requires an entire stool sample. You can take this noninvasive test in your doctor's office or at home (the FDA recently approved the first at-home stool DNA test called Cologuard). If the test is positive, a colonoscopy should follow. The DNA test is more likely to detect colorectal cancer than FIT alone, but it is also more likely to give false positives, requiring a follow-up colonoscopy, according to the USPSTF.
A colonoscopy every 10 years. Similar to the flexible sigmoidoscope, the colonoscope is a longer thin black tube that allows the health care professional to examine the entire large intestine. Preparation for the procedure requires drinking a laxative the day before the colonoscopy. Adequate preparation is critically important to enable the physician to visualize the entire lining of the colon. Leftover stool obscures the view of that portion of the colon and could lead to missing lesions. You typically receive a mild sedative during the procedure, so you should experience minimal discomfort. The procedure itself typically lasts 20 to 30 minutes.
This test is both diagnostic and therapeutic. It detects polyps and cancers found anywhere in the colon. Any polyps or other growths found during this examination are usually removed and sent to a laboratory for examination. Medicare now covers this procedure every 10 years for people over 50 who are considered average risk for developing colon cancer and every two years for people at high risk. Women and men over 50 should have a colonoscopy at least every 10 years. The American College of Gastroenterology recommends that African Americans, who tend to develop the disease at a younger age than other races, begin getting screening colonoscopies at age 45.
CT colonography (virtual colonoscopy) every five years. This is a relatively new technique that uses a CT scan to create a three-dimensional image to evaluate the colon. It does not allow for a biopsy (tissue sampling) or polyp removal if any abnormalities are found. You must take a laxative the day before this test, similar to a colonoscopy, and if any abnormalities are found, you must undergo a colonoscopy. Most insurance companies do not cover virtual colonography as screening for colorectal cancer.
Most women find sigmoidoscopies and colonoscopies much more tolerable than they expect. Worrying about the process and undergoing the necessary preparation beforehand are often more unpleasant than the exam itself. Of the above-mentioned tests, colonoscopy is the preferred screening/prevention test, and FIT is the preferred test for patients who decline invasive cancer prevention tests.
Other tests that your health care provider might perform include:
- Digital rectal examination (DRE). Your health care professional inserts a gloved finger into the rectum to feel for any abnormalities. This simple test, which may be uncomfortable but usually is not painful, can detect many rectal cancers. However, even the longest of fingers are far too short to examine the full length of the large intestine. For this reason, other tests and examinations, such as the FOBT, flexible sigmoidoscopy and colonoscopy must be used. The rectal exam is not sufficient to screen for colon cancer.
Genetic testing. The few hereditary cancer syndromes mentioned here are rare but are associated with mutations in specific genes. These mutations can be passed on to other family members. Thus, if your family is affected or may be affected by one of these syndromes, you may need to undergo genetic testing. If genetic testing and counseling are done properly, lives can be changed dramatically, both in terms of preventing colon cancer and lessening the psychological impact of knowing you are predisposed to the disease.
Genetic testing for colon cancer raises many scientific and ethical issues. Although tests are available to identify the mutations that may predispose you to colon cancer, they are not absolutely positive predictors. Additionally, some health care professionals are not yet fully educated about the tests and may misinterpret the results.
Thus, if you have a strong family history of colon cancer, you should be seen at a genetic screening center. Talk to your health care professional about the genetic screening process and how to locate such a center.
If there is a reason to suspect that you have colorectal cancer, your health care professional will take a complete medical history and perform a physical examination as part of an initial evaluation.
Symptoms of colorectal cancer include:
- Change in bowel habits (diarrhea, constipation or narrow stools for more than a few days)
- Urgency for a bowel movement or feeling like you need to move your bowels even if you just did
- Blood in the stool
- Stomach pain
- Weakness and/or fatigue
Contact your health care professional if you experience one or more of these symptoms. Keep in mind that colon cancer often causes no symptoms in the early stages, when it's most treatable. That's why it's important to get routine screenings.
Because the symptoms of colon cancer are vague and typically occur late in the development of the cancer, a variety of tests are used to both screen and diagnose the disease. Screening tests look for disease in those who look and feel healthy, ideally catching the disease as early as possible or, in the case of colon cancer, even before the precancerous lesion has turned into cancer. Diagnostic tests look for the cause and determine the extent of the disease in someone who has obvious symptoms.
A bowel preparation is often required before many of these tests, especially a colonoscopy. This involves cleaning out your bowel the night before the test with a laxative solution. It is important that the bowel be clean so the physician performing the colonoscopy gets the best look at your colon. Since some preparations can affect your blood level for certain electrolytes, your health care professional will tell you which preparation to use for your procedure.
Flexible sigmoidoscopy or colonoscopy. Sigmoidoscopy is a procedure that allows a physician to view the lining of the rectum and the lower part of the colon. This area accounts for less than one-half the total area of the rectum and colon. If a mass or any other types of abnormalities are seen through the flexible sigmoidoscope or colonoscope, a sample (biopsy) is taken for further examination by a pathologist to determine if it is cancerous or benign.
Complete blood count (CBC) and blood chemistry. The CBC determines whether you are anemic because many people with colorectal cancer become anemic due to prolonged bleeding from the tumor.
Computed tomography (CT). In this test, a rotating X-ray beam creates a series of pictures of the body from many angles, helping visualize any masses that may indicate that the colon cancer has spread to your liver or other organs.
Magnetic resonance imaging (MRI): Like CT, magnetic resonance imaging displays a cross-section of the body. However, MRI uses powerful magnetic fields and radio waves instead of radiation.
Chest x-ray. This familiar imaging test detects if colorectal cancer has spread to the lungs.
PET scanning: This test can determine if certain cells are using glucose more than other cells. Cancer cells, which are actively dividing, use more glucose so they light up on a PET scan. This test is used to follow cancer and can be combined with a CT scan to better localize a possible recurrence. It is important to remember that not all tumors will be responsive to PET/CT imaging.
Colorectal Cancer Stages
As with all cancers, there are various stages of colon cancer:
Stage 0: Abnormal (dysplastic) cells have been found in the innermost lining (mucosa) of the colon. This stage is also known as carcinoma in situ or intramucosal carcinoma, and there is a very small chance these cells have spread, so this stage is not considered to be invasive cancer.
Stage I: Cancer has spread to the inside lining of the colon but hasn't spread beyond the colon wall or rectum.
Stage II: Cancer has spread through the colon or rectum and may invade surrounding tissue, but no lymph nodes are involved.
Stage III: Cancer has spread to the lymph nodes, but not to distant sites.
Stage IV: Cancer has spread to other distant parts of the body, such as the liver or the lung.
Surgery is often required to treat colorectal cancer. The surgical procedure used depends on where the cancer is located. Most patients who undergo surgery for colon cancer have an open abdominal operation, where the surgeon makes an incision in the abdomen and removes the tumor and any affected lymph nodes. In some cases, however, a procedure called laparoscopic colon cancer resection may be used. Like open abdominal surgery, laparoscopic surgery is performed under general anesthesia, but multiple, much smaller incisions are made, which leads to a shorter recovery time. Studies have shown similar results when open abdominal and laparoscopic techniques are used to remove colon cancer. A surgeon experienced at laparoscopic surgery should perform these surgeries.
Occasionally, early cancerous changes may be limited to a portion of an otherwise noncancerous polyp. In these cases, it is sometimes possible to remove some very early colon cancers during a colonoscopy.
If part of the colon needs to be removed due to a larger cancerous tumor, the surgeon will remove the affected portion and leave as much of the healthy colon behind as possible. In rectal cancer, the rectum is removed.
In many cases, the surgeon will be able to reconnect the healthy portions of the colon and rectum, which allows waste to flow through the colon to the rectum. If this is not possible, you may need to have a colostomy. A colostomy (stoma) involves creating a hole in the wall of abdomen to which an end of your colon is attached so you can eliminate waste into a special bag. Depending on the situation, a colostomy may be temporary or permanent.
You may be referred to an enterostomal therapist (a health care professional, often a nurse, trained to help people with their colostomies) as part of your initial workup. The enterostomal therapist can address concerns about how a colostomy might affect your daily activities.
Even after colon cancer has been completely removed with surgery, cancer cells can remain in the body and cause relapse. To kill these cells and decrease the chances of a relapse, health care professionals use chemotherapy. Not all people need chemotherapy after surgery. Those most likely to receive chemotherapy are people at risk for recurrence, namely, those with stage III colon cancer or high risk stage II.
For some rectal cancers, chemotherapy is given along with radiation therapy in an attempt to shrink the tumor before surgery. This is called neoadjuvant chemotherapy.
Several chemotherapy drugs are used to treat colon cancer. In many cases, two or more of these drugs are combined for more effective treatment:
- 5-Fluorouracil (5-FU): 5-FU is often given together with another chemotherapy drug called leucovorin (folinic acid).
- Capecitabine (Xeloda): A chemotherapy drug in pill form, Xeloda changes to 5-FU once it reaches the tumor.
- Irinotecan (Camptosar)
- Oxaliplatin (Eloxatin)
- Trifluridine and tipiracil (Lonsurf): a combination drug in pill form.
Individuals with advanced colon cancer may receive targeted drugs that help stop cancerous tumors from growing. These drugs include bevacizumab (Avastin), cetuximab (Erbitux) and panitumumab (Vectibix). They may be given alone or together with chemotherapy.
Not all people benefit from targeted medications. Researchers are currently examining who are most likely to respond. Until then, health care professionals will continue to weigh the risks and benefits of targeted drugs before they prescribe them for people with advanced disease.
Radiation therapy may benefit some people with rectal cancer, but it is not usually used in the treatment of early stage colon cancer. Like chemotherapy, radiation may be helpful for patients who are at high risk of cancer recurrence, for instance if the cancer has spread to nearby organs. In general, the goal of radiation is to reduce chances of colon cancer recurrence rather than to improve survival.
For those whose colorectal cancer has metastasized to a few areas in the liver, lungs or elsewhere in the abdomen, surgically removing or destroying these metastases can increase survival.
If the cancer comes back in only one part of the body, you may need surgery again. If it has spread to several parts of the body, you may receive chemotherapy and/or radiation therapy.
The most important line of defense against colorectal cancer is screening for colorectal cancer. You should follow the established guidelines for screening procedures so that any precancerous polyps can be removed before they turn into cancer and, if cancer exists, it can be detected at the earliest possible stage. Talk to your health care provider about the best screening method for you, including your willingness to complete the screening and follow-up as recommended.
If you are at average risk of colorectal cancer, the American Cancer Society recommends that all women and men over the age of 50 undergo one of the following:
- annual fecal occult blood test
- flexible sigmoidoscopy every five years
- double contrast barium enema every five years
- colonoscopy every 10 years unless you are African American, in which case your screening can begin at age 45
- virtual colonoscopy (CT colonography) every five years
- stool DNA test every one to three years
Any positive screening test should be followed by an appropriate and complete diagnostic evaluation of the colon including a colonoscopy with biopsies, if necessary.
If you are at an increased risk of colorectal cancer or adenomas because of a family history of cancer or polyps, you should follow the above recommendations and also:
Begin colorectal screening at age 40, or 10 years before the youngest case of colon cancer in the immediate family.
Discuss genetic counseling and/or testing with your health care professional.
If you are at an increased risk for colorectal cancer for a reason other than family history, such as a personal history of inflammatory bowel disease, you may also need to begin screening before age 50. Screening recommendations vary based on your particular risk factors; discuss your individual screening schedule with your health care professional.
Modifying your diet and exercise may help decrease your risk of forming colon polyps and/or colon cancer. A diet rich in vegetables, fruit and fiber and low in fat may reduce the risk of developing colon cancer. Some suggest that increasing intakes of calcium and vitamin D can help prevent colon cancer. (Men should keep their intake below 1,500 milligrams because of the increased risk of prostate cancer associated with high levels of calcium.) Calcium can be found in dairy products, calcium-fortified products such as orange juice, soy and dark green vegetables. Other research has shown that taking a multivitamin containing folic acid (a B complex vitamin) decreases the risk of colon cancer, but other studies show folic acid may help existing tumors to grow, so more study is needed. There is some research suggesting that a diet high in magnesium may decrease colon cancer risk, especially in women. More research is necessary to find out if this link exists.
Regular exercise is important in preventing colon cancer. Experts say that vigorous exercise is not necessary. Instead, just incorporate more activity into your daily routine, such as taking the steps instead of the elevator or parking your car farther from the building you are entering. Overall, the American Cancer Society recommends 150 minutes of moderate physical activity or 75 minutes of vigorous physical activity per week.
It is also advisable to drink alcohol only in moderation (no more than one alcoholic beverage per day for women, for a total of less than seven drinks per week, and no more than two alcoholic beverages for men, for a total of less than 14 drinks per week) and abstain from tobacco use.
Results from multiple studies show that people who regularly take aspirin and other non-steroidal anti-inflammatory medications (NSAIDS) have a lower risk of colorectal cancer and adenomatous polyps. However, the risk of stomach ulcers and other side effects associated with aspirin and NSAIDS may outweigh the benefits. Therefore, experts do not recommend people at average risk of colorectal cancer take NSAIDS as a prevention strategy. There may be some value of NSAIDS in people at increased risk of colorectal cancer, which is being studied. The drug celecoxib (Celebrex) has been approved by the United States Food and Drug Administration (FDA) for reducing polyps in people with FAP. Celebrex may cause less bleeding in the stomach than other NSAIDs, but it may increase risk for heart attack and stroke.
Discuss the potential risks and benefits of taking NSAIDS with your health care professional.
Facts to Know
The American Cancer Society estimates that about 95,270 new cases of colon cancer and 39,220 new cases of rectal cancer will be diagnosed in 2016. Combined, these cancers are predicted to cause about 49,190 deaths during 2016.
While colorectal cancer is the second leading cause of cancer deaths when men and women are considered together and is the third leading cause of cancer death among women, incidence in the United States has been decreasing, perhaps due to improved screening methods.
The risk of developing colorectal cancer is highest among those with a family history of colorectal cancer or adenomatous polyps and those who have inflammatory bowel disease.
Except for those with hereditary conditions that may predispose them to developing colorectal cancer relatively early in life, 90 percent of all cases occur after the age of 50.
Tumors that grow in the large intestine are called polyps. A biopsy determines if the polyp is benign (not cancerous) or malignant. Benign polyps can be precancerous (adenomatous and sessile serrated) or not precancerous (hyperplastic). Thirty percent to 50 percent of the population has polyps. Over the course of about 10 years, adenomatous polyps can become cancerous if they are not removed.
Undergoing appropriate screening for colorectal cancer can decrease death rates from this cancer by up to 90 percent. Colorectal cancer screening is designed to detect and remove precancerous polyps (adenomas and sessile serrated polyps) before they turn into cancer and to diagnose cancer at the earliest stages.
About one-third of eligible adults in the United States have never been screened for colorectal cancer. There are now more choices in colorectal cancer screening methods, which may encourage more people to get screened.
If you or a close relative were diagnosed with colon cancer at age 45, then other members of your family should begin screening around age 35. If you have a close relative with colorectal cancer, you should begin screening at the age of 40 or 10 years before the age at which the youngest relative was diagnosed with cancer.
Cancer specialists are using more aggressive strategies to make sure cancer does not return after surgery. You may receive both chemotherapy and radiation therapy to increase your chances of a complete cure. These treatments destroy microscopic accumulations of cancer cells that cannot be seen or removed during surgery.
When colon cancer is caught and treated in stage I, there is a 92 percent chance of survival at five years. Once the cancer is larger and has spread to lymph nodes, the five-year survival rate drops to 53 to 89 percent depending on the number of nodes involved If the cancer has already spread to distant parts of the body such as the liver or lungs, the five-year survival rate goes down to 11 percent.
You may be able to reduce your risk for colorectal cancer by eating a diet high in fiber and low in fat, getting plenty of exercise, limiting your alcohol intake to one drink or less a day, losing weight if you are obese, taking calcium and having regular colorectal cancer screenings.
Questions to Ask
Review the following Questions to Ask about colon cancer so you're prepared to discuss this important health issue with your health care professional.
What causes colorectal cancer?
How can I reduce my risk for colorectal cancer?
What are the signs and symptoms of colorectal cancer?
What exams or tests will you do during my regular physical to screen for colorectal cancer?
Which colon cancer screening option is best for me? Would you consider non-invasive testing options for me?
What is the "stage" of my cancer? What does that mean? What does it tell me about how severe my cancer is?
Will treatment be needed before I have surgery?
How long will I be in the hospital?
If I'm in pain, what medication will you give me to make me feel better?
Will I need more treatment after surgery?
If I need chemotherapy after surgery, how soon after my surgery would I start?
What kind of chemotherapy is used for colon cancer?
When is radiation therapy used for colon cancer?
My health care professional told me I have polyps. What are these and how will they be treated?
Colorectal polyps are excess growths of tissue in the lining of your colon or rectum. They can be noncancerous (hyperplastic), precancerous (adenomas or sessile serrated polyps) or malignant (cancerous). All colorectal cancers develop from precancerous polyps. Therefore, if these precancerous polyps are removed during colonoscopy or sigmoidoscopy, they will no longer be able to grow into cancer. Most colorectal polyps are easily removed during colonoscopy without the need for surgery. Once you have polyps, you are at increased risk for developing more polyps in the future and need repeated screening to detect and remove them.
My father and grandmother both had colon cancer. What are my risks and what should I do?
First, realize the disease is highly curable when diagnosed early. When the cancer spreads to other distant places like the lung or liver, however, the survival rate is less than 10 percent. A family history of colon cancer or adenomatous polyps significantly increases your chances of developing the disease, and the more family members you have with colon cancer, the higher your risk. Make an appointment with your health care professional now to discuss your personal and family health history and to determine the next steps you should take. You will need to have colorectal cancer screening starting at the age of 40 or 10 years before the age at which the youngest relative was diagnosed with cancer. You will probably have regular surveillance of your colon by colonoscopy.
Is there any way to reduce my risks for colon cancer?
Most important is to ask your health care professional about colorectal cancer screening beginning at age 50 (45 for African Americans) if you are at average risk or earlier if you have family members (such as your father, mother, sister or brother) who had colorectal polyps or cancer. If you undergo appropriate screening for colorectal cancer, you may decrease your risk of death from colorectal cancer by 90 percent. This is because physicians can detect and remove precancerous polyps before they turn into cancer, most effectively by colonoscopy. Talk to your health care provider about choosing the screening option that is best for you. Research increasingly suggests that a diet high in fiber, fruits and vegetables and low in fat may help reduce your risk for colon cancer. Losing weight if you are obese may decrease your risk of colorectal cancer. Taking calcium and vitamin D may prevent formation of precancerous polyps and colon cancer. And getting regular exercise may help, too.
Which method of screening for colon cancer is best for me?
There are many factors that can influence this choice, and you and your health care provider will want to make the decision together. The U.S. Preventive Services Task Force (USPSTF) recommends screening for everyone age 50 years through 75 years. From age 76 to 85, screening is an individual decision, factoring in your overall health and screening history. Studies have shown that no screening method is decidedly more effective than others—they all have strengths and limitations. The USPSTF encourages health care providers to talk with their patients about what screening strategy they are most likely to complete. This can depend on your personal preferences, as well as access to the various methods. For example, colonoscopy requires a significant commitment over a short time to complete the preparation, procedure and recovery, but the time between screenings is greater than with stool-based screening. Stool-based screening is quick, noninvasive and can be done at home, but it requires you to handle your feces to send them to the lab. Flexible sigmoidoscopy combined with annual fecal immunochemical test may appeal if you want the reassurance from endoscopic screening but want to avoid colonoscopy as much as possible. The best method for you is the one you and your health care provider select.
My health care professional told me my cancer had metastasized and that I had a "met" in another place besides the colon. What does that mean?
"Met" is short for metastasis, which means the cancer has spread to other parts of the body. Any time your health care professional uses a word you don't understand, stop him or her right there and ask what that word means.
What are my chances of a cure?
No one really knows if cancer is totally cured. But it is sometimes pushed back so far it never grows again, which is called achieving remission or long-term survival. Your chances of surviving for a long time largely depend on the stage of your cancer at the time of diagnosis and the success of treatments you receive. The earlier the cancer is detected, the higher your chances for long-term survival.
My cancer is pretty advanced. How long have I got?
Any number that a health care professional gives you is based on estimates derived from experiences with other patients. No one can tell you what your specific chances are. Survival averages are just that: averages.
What can I do about this ongoing pain?
One of the worst things that cancer patients do is to suffer pain when they do not have to! Discuss your pain with your health care professional so that you can get the relief you need. It might be necessary to see a pain specialist. Most health care professionals can refer you to someone who specifically handles chronic pain problems. If you have severe pain, narcotics may be the best type of medicine.
What caused this? Was it something I did? How long did it take to grow?
No one is really sure what causes colorectal cancer. It's very unlikely that it was something you did. The tendency to get the disease may be hereditary, that is, it may run in families. A polyp in your colon can take as many as 10 years to become cancerous. Colorectal cancer is difficult to find without regular screening and often does not cause symptoms until it's already well developed. So don't beat yourself up that you didn't "catch" it a few months ago.
Organizations and Support
American Cancer Society (ACS)
Address: 250 Williams Street
Atlanta, GA 30303
Hotline: 1-800-ACS-2345 (1-800-227-2345)
American College of Gastroenterology
Address: P.O. Box 342260
Bethesda, MD 20827
Association of Cancer Online Resources, Inc.
Address: 173 Duane Street, Suite 3A
New York, NY 10013-3334
Cancer Information and Counseling Line (CICL)
Address: AMC Cancer Research Center
1600 Pierce Street
Denver, CO 80214
Email: [email protected]
Corporate Angel Network
Address: Westchester County Airport
One Loop Road
White Plains, NY 10604-1215
Email: [email protected]
Mautner Project - The National Lesbian Health Organization
Address: 1875 Connecticut Ave., NW Suite 710
Washington, DC 20009
Hotline: 1-866-MAUTNER (1-866-628-8637)
Email: [email protected]
National Cancer Institute (NCI)
Address: NCI Public Inquiries Office
6116 Executive Boulevard, Room 3036A
Bethesda, MD 20892
Hotline: 1-800-4-CANCER (1-800-422-6237)
Phone: TTY: 1-800-332-8615
National Coalition for Cancer Survivorship (NCCS)
Address: 1010 Wayne Ave., Suite 770
Silver Spring, MD 20910
Hotline: 1-877-NCCS-YES (1-877-622-7937)
Email: [email protected]
National Comprehensive Cancer Network
Address: 275 Commerce Dr, Suite 300
Fort Washington, PA 19034
Prevent Cancer Foundation
Address: 1600 Duke Street, Suite 500
Alexandria, VA 22314
The Colon Cancer Survivors' Guide, Second Edition: Living Stronger, Longer
by Curtis Pesmen
Understanding Colon Cancer
by A. Richard M.D. F.A.C.P. Adrouny
Living With Colon Cancer: Beating the Odds
by Eliza Wood Livingston, David, M.D. Spiegel
Intimacy After Cancer: A Woman's Guide
by Dr. Sally Kydd, Dana Rowett
What to Do If You Get Colon Cancer: A Colon Cancer Specialist Helps You Take Charge and Make Informed Choices
by Paul Miskovitz, Marian Betancourt
National Cancer Institute
Emails: [email protected]
Medline Plus: Colon Cancer
Address: Customer Service
US National Library of Medicine
8600 Rockville Pike
Bethesda, MD 20894
Email: [email protected]