Colon cancer, or colorectal cancer as it is often referred to, is a cancer that originates in the large intestine (colon) or the rectum (end of the colon). When doctors refer to colorectal cancer they are talking about colon cancer that starts in the glands that are present in the lining of the colon and rectum.
There are other types of cancers that can also affect the colon. They include lymphoma, carcinoid tumors, melanoma and sarcomas. These other cancers are rare. When we use the term “colon cancer” we will be referring only to colon carcinoma.
The American Cancer Society states that colorectal cancer is one of the leading causes of death related to cancer. However, when it is diagnosed early, it most often leads to a complete cure. Almost all colon cancers begin as benign (non-cancerous) polyps, which if untreated, eventually and slowly will develop into cancer.
There is a higher risk for colon cancer with the following conditions:
- Older than 60
- Eating a diet that is high in red or processed meat
- African American or Eastern European descent
- Cancer is present elsewhere in the body
- Inflammatory bowel disease, Crohn’s disease or ulcerative colitis
- Colorectal polyps
- Family history of colon cancer
- Genetic syndromes, the most common of which are FAP (familial adenomatous polyposis) and HNPCC (hereditary nonpolyposis colorectal cancer) which is also known as Lynch syndrome
- Cigarette smoking
- Alcohol consumption
- Low fiber high fat diet
What is the colon?
The colon is also known as the large intestine or large bowel, and is located in the lower part of the digestive tract. It is a muscular tube about five feet long that travels around the borders of the abdominal cavity. This long tubular organ consists of the colon (large intestine) and the rectum, which is the last segment of the colon.
Once food is swallowed it starts to become digested in the stomach. Following that, it then empties into the small intestine, where the nutritional part of the food is absorbed. The remaining waste then travels through the colon into the rectum where it becomes expelled from the body. Both the colon and rectum absorb water, form stool, and hold the waste until it is ready to be expelled.
Muscles run across and around the colon. They will contract and relax rhythmically in order to propel the stool along. Water is absorbed along the way as the stool goes from a liquid to a solid. The route it travels is up the ascending (right) colon, across the transverse colon, and down the descending (left) colon to the curved and looped sigmoid colon. The stool is stored there until such time that it is conveniently passed outside. It will exit through the rectum, which is the last six inches of the colon. The blood and lymph vessels connected to the colon are referred to as the mesentery.
Many cases of colon cancer will not have any symptoms. When symptoms do occur they may present the following:
- Persistent abdominal pain and a tenderness that is present in the lower abdomen
- A change in bowel habit including diarrhea, constipation or a change in the consistency of the stool over a couple of weeks
- Rectal bleeding or bloody stool
- A feeling that your bowel doesn’t empty completely
- Weight loss without any known reason attached to it
- Narrow stools
- Weakness or fatigue
In most cases, the cause of colon cancer is not known. What we do know is that colon cancer occurs when healthy cells in the colon become altered. Under normal conditions, healthy cells will grow and divide in an orderly way to keep the body functioning normally. The growth of the cells can get out of control, they don’t die, and the cells will continue to divide even though new cells are not needed. This exaggerated growth can cause precancerous cells to form in the lining of the intestine. Over a period of years, these cells can become cancerous.
Potential causes for colon cancer include:
- Precancerous growths in the colon – Over a period of time, if not removed, these growths can become cancerous. The two types of growths are polyps (clumps of precancerous cells) on the inside lining of the colon and nonpolypoid lesions (flat or recessed precancerous growths recessed into the wall of the colon).
- Inherited gene mutations – Cancer is not inevitable when inherited gene mutations are present. However, they do significantly increase the risk for colon cancer. These inherited gene mutations have been linked to a small percentage of colon cancer.
Gene mutations include:
- Familial adenomatus polyposis (FAP) – FAP is a rare disorder causing thousands of polyps to develop in the lining of the colon and rectum. If left untreated, FAP can present an increased risk of developing colon cancer before age 40.
- Hereditary nonpolyposis colorectal cancer (HNPCC) – This is also known as Lynch syndrome and it increases the risk of colon cancer as well as other cancers. Those with HNPCC tend to develop colon cancer before age 50.
Genetic testing can detect both FAP and HNPCC. If there is a history of colon cancer in your family it is advisable to discuss the possibility of having genetic testing to screen for these disorders.
Colon cancer is most curable when it is detected before symptoms develop. Proper screening in most cases will detect cancer. The various methods of screening include:
PHYSICAL EXAM – This will rarely show any problems other than a lump (mass) which the doctor will feel when he presses on the belly area. A rectal exam could reveal changes in the rectal lining or a mass.
BLOOD TESTS – Small amounts of blood in the stool could possibly indicate the presence of colon cancer. A fecal occult blood test (FOBT) is performed to check for blood in the stool that can’t be seen by the naked eye. Hidden blood is often the sign of colon polyps or cancer. This test should also be performed with a colonoscopy or sigmoidoscopy. The carcinoembryonic antigen (CEA) test measures the amount of a protein that may appear in the blood of some people who have certain kinds of cancers, especially large intestine (colon and rectal) cancer.
COLONOSCOPY – The best screening test for colon cancer since it is the only one that provides an inside view of the entire colon and will discover colorectal polyps. This is an outpatient procedure performed under local anesthesia.
This test is performed in the hospital on an outpatient basis. The day before the test you have to do a bowel prep to clean out the bowel. Before the test, you are given medication to put you to sleep. A long, flexible lighted tube called a colonoscope is inserted into the rectum. It is slowly guided by the doctor so that the entire colon is visible.
Polyps located on the wall of the colon or rectum are removed during the colonoscopy through the colonoscope. They are sent to the lab for testing. If a polyp cannot be removed during the colonoscopy because of its size, shape or location, it will be removed at a later time with surgery. However, a biopsy (tissue sample) of the polyp may be taken during the colonoscopy and sent to a lab for testing. Biopsy of a polyp doesn’t always detect cancer. The most accurate method is to remove the entire polyp during surgery and then have it tested.
During a colonoscopy, a growth that is obviously cancer can be discovered and it will have to be removed with surgery.
The risks of a colonoscopy include:
- A tear or puncture in the colon
- The risks of anesthesia
SIGMOIDOSCOPY –This procedure examines the lower third section of the colon (rectum and sigmoid colon). A flexible lighted tube (sigmoidoscope) is inserted into the rectum and images of the rectum and sigmoid colon are shown on a video screen. This procedure can be performed in the physician’s office.
- BARIUM ENEMA – This test allows the physician to view the entire colon and rectum with the use of x-rays. A soft tube is placed in the rectum and it is used to fill the colon with liquid barium. This liquid makes the colon show up clearly on x-rays. A small amount of air may also be pumped into the colon to make the walls easier to view.
- CT SCAN – An x-ray machine that is linked to a computer will take a series of detailed photos of the colon and the other organs and blood vessels in the abdomen. There are several variations of CT scans. In addition to the abdominal scan there is also a CT angiogram where intravenous contrast is selectively infused through the artery to the colon. The results are displayed on a computer screen.
- PET SCAN – A Positron Emission Tomography (PET) scan is an imaging test that uses a radioactive substance called a tracer to look for disease in the body. A PET scan will show how organs and tissues are working. A small amount of radioactive material (tracer) is given through a vein (IV), usually on the inside of the elbow. This mildly radioactive substance helps detect cancer cells. The tracer travels through the blood and collects in organs and tissues. It allows the radiologist to see areas or diseases more clearly. The patient then has to wait an hour because of the time required for the tracer to be absorbed by the body. Once the tracer is absorbed, the patient then lies on a narrow table which slides into a large tunnel-shaped scanner. The PET scanner detects signals from the tracer which are then changed by a computer into 3-D photos. The pictures are then displayed on a monitor for the doctor to view.
- ENDOSCOPIC ULTRASOUND – A small ultrasound probe is placed into the rectum creating images of the rectum and anus.
- STAGING – This refers to testing that is performed if cancer is discovered. The staging is based on the size of the tumor and the degree to which it has penetrated. The tests are used to determine if cancer has spread, and if so to what degree. CT Scans, MRI and PET scans of the abdomen, chest, pelvic area or brain can be used to stage the cancer. The various stages are:
- Stage 0 – Very early cancer on the innermost layer of the intestine.
- Stage 1 – Cancer is found only in the colon or lining of the rectum.
- Stage 2 – Cancer has spread through the muscle wall of the colon to nearby tissue, but not to lymph nodes.
- Stage 3 – Cancer has spread to the lymph nodes but not other parts of the body.
- Stage 4 – Cancer has spread to other organs such as the lungs or liver.
The treatments performed are in part determined by the stage of cancer and the purpose is to stop the spread of the cancer and reduce the possibilities of it returning.
The treatments can include:
- Surgery – Stage 0 colon cancer can be treated by removing the cancer cells. This is often done during a colonoscopy. Stages 1, 2 and 3 require more extensive surgery to remove the part of the colon that is cancerous (colon resection).
- Chemotherapy – Medications are used to attack cancer cells. This is known as systemic therapy because it works throughout the body. It is most often performed in the doctor’s office or as an out patient in a hospital or clinic. The medication can be administered in pill form or through an IV line. Treatments are given in cycles so that the body has time to recover. Side effects can include nausea, hair loss, fatigue, mouth sores, neuropathy, diarrhea, sore throat and increased risk of infection. We will provide help in trying to control these side effects.There is currently some debate as to whether or not stage 2 patients should receive chemotherapy after surgery. Nearly all stage 3 patients will receive chemotherapy for 6 – 8 months.
Stage 4 patients are given chemotherapy to improve their condition and prolong their survival. Some will receive chemotherapy before and after surgery.
- Radiation – High energy x-rays are used to kill cancer cells. This is considered localized therapy because the specific area of the body that is affected by the cancer is targeted. It is performed as an outpatient in a hospital or radiation clinic. Treatments may occur every day for 5 – 7 days and each visit may last an hour even though radiation is only received for a few minutes. The side effects may include anal and bowel irritation, nausea, fatigue and swollen or irritated skin in the treatment area.This is usually used in combination with chemotherapy for patients with stage 3 rectal cancer. Patients with stage 4 where the cancer has spread to the liver can get various treatments specifically directed to the liver.
These Treatments include:
- Burning the liver (ablation)
- Radiation or chemotherapy delivered directly to the liver
- Freezing the cancer (cryotherapy)
Complication Following Treatments
Complications that can occur after the treatments include:
- Cancer returning to the colon
- Cancer spreading to other organs or tissues (metastasis)
- Blockage of the colon (obstruction)
- Development of a second primary colorectal cancer
When to call the doctor after treatments
Give us a call if any of the following occurs:
- Black, tar like stool
- Blood in a bowel movement
- A change in bowel habits
When caught early, colon cancer is a treatable disease. When treated early, many patients survive at least five years after the diagnosis. How well you will do after the diagnosis depends on many variables including the stage of the cancer. When the cancer does not return within five years, it is considered cured. Stages 1, 2 and 3 are considered curable. While Stage 4 Is not considered curable, the survival rate at five years is less than 1 percent.
Preparing for Surgery
- Depending on the patient’s age and medical condition blood work, medical evaluation, chest x-ray and an EKG will be required. Aspirin, blood thinners, anti-inflammatory medications (arthritis medications) and vitamin E will have to be avoided for several days to a week before surgery.
- The colon has to be cleansed the night prior to surgery. A preparation is used that includes a high powered laxative and which thoroughly cleans out the colon and reduces the risk of infection.
- The only thing that can be consumed after midnight is clear liquids so that the colon is kept free of stool.
- It is highly recommended that smokers stop smoking at least five days prior to surgery because a cough can put a strain on the incision.
- Diet medication and St. John’s Wort should not be used for two weeks prior to surgery.
Surgery (Colon Resection)
Colon surgery is performed to remove the affected section of the colon. The portion of the colon above the area that is resected is then reattached to the portion of the colon just below the resected area. This “re-attachment” is called an anastomosis and it is accomplished with the use of a suture and stapling device. This procedure can last for 2 – 4 hours,
or longer depending on the amount of colon that has to be removed, the location of the tumor, the amount of previous scarring, and the technique used.
Laparoscopic Colon Resection
Most laparoscopic colon resections are performed through 5 – 6 small incisions that are about a quarter inch each. A canula, a narrow tube-like instrument, is used to enter the abdomen. A laparoscope, a tiny telescope connected to a video camera, is inserted through the canula. This allows your surgeon to have a magnified view of the patient’s internal organs on a high definition television monitor. Several other canulas are inserted through the incisions to allow your surgeon to work inside the abdomen and remove part of the colon.
Advantages of Laparoscopic Colon Resection
- Less postoperative pain
- Shorter hospital stay
- Faster recovery time
- May experience a faster return to a solid food diet
- Colon function normalizes faster
- Faster return to normal activity
- Better cosmetic results (smaller scar)
Open Colon Surgery
The traditional “open” proc edure is highly invasive and patients often require a longer recovery time. Generally open colon surgeries require long incisions and that results in a hospital stay of 5 – 8 days and may require up to a six week recovery period. The factors that may cause the surgery to be performed with the open method include:
- Dense scar tissue caused by prior abdominal surgery
- The inability to see the organs
- Bleeding problems that may arise during the surgery
- Large tumors
There is a risk of a complication with this procedure as there is with any operation.
These complications include:
- A leak where the two sections of the colon were reconnected
- Injury to adjacent organs (small intestine, ureter, bladder)
- Blood clots to the lungs
- Anesthesia risks
After some surgeries the colon and rectum may have the need to be kept free of stool while they heal. In some surgeries the rectum has to be removed and therefore can’t be reconnected to the rest of the colon. In either of these scenarios, an ostomy will be needed. A new opening in the abdomen will be created which will enable waste to leave the body. This
may be a temporary procedure or a permanent one.
There are two different types of ostomies that can be performed:
- Colostomy – Part of the colon is connected to an opening (stoma) in the lower abdomen. Body wastes are eliminated directly through an opening of the colon onto the abdomen, where the stool is collected into a special appliance.
- Ileostomy – The small intestine is connected to an opening (stoma) in the abdomen. Body wastes are eliminated directly through an opening of the colon onto the abdomen, where the stool is collected into a special appliance.
Adjusting to a colostomy or ileostomy can be frightening and overwhelming. Prior to leaving the hospital, you will receive instructions on how the ostomy works, and how to care for it. You will continue to receive support after you return home. Caring for your ostomy will eventually become part of your daily routine if there is a need for it to be permanent. We are always available, if the need arises, to help with any problems and provide any advice you may want. It is a good suggestion that an appointment be set up with a specified ostomy nurse. They can help with ordering supplies, tips to help manage and adjust to living with an ostomy. Most hospitals have staff available to assist patients with this adjustment.
Day of Surgery
It is imperative that you arrive on time. You will be asked to change into a patient’s hospital gown, You will be given an IV to provide fluids and medication. Prior to the surgery you will meet with and talk to your anesthesiologist. Before surgery begins you are given a general anesthesia to put you into a deep sleep. A soft tube (catheter) may be placed into the
bladder to drain urine.
You will be sent to a recovery room after the surgery and transferred to a regular hospital room when your vital signs are stable. Your family will be permitted to visit with you when you are in the room. Pain medication will be made available.
If you were given a urinary catheter, it will probably be removed following surgery. The IV line will remain for a few days to provide fluids. You may find a thin plastic tube in your nose that will go down into your stomach to remove any air or fluid that could make you sick or uncomfortable. As soon as your bowels start working, usually 4 – 5 days after surgery, the tube will be removed. Once the tube is removed you will start on a liquid diet and eventually advance to regular food when you are capable of tolerating it. You will be assisted out of bed the morning after surgery and activities will gradually be introduced. It is important to do so in order to prevent complications like blood clots and pneumonia. Your abdomen might be slightly bruised and swollen. You may also have metal clips or staples on the surface’ depending on the type of procedure you had.
You will have to a make a follow up appointment to check your progress and address any issues you may have.
- Full recovery can take 4 – 6 weeks
- You may experience some bloating, loose stools and frequent bowel movements which are common after bowel surgery
- Walking and climbing stairs is encouraged. You will need to rest frequently because you will generally feel tired.
- You will be able to eat as you did prior to the operation, but many liquids and fiber will have to be included in your diet to avoid constipation
- Pain medication may be prescribed to take as directed
- You will be unable to lift anything weighing more than twenty pounds for about four weeks
- Showering is permitted as instructed with or without the dressings.
- Sexual activity can be resumed once you are comfortable.
- Driving and returning to work will depend on the recovery process and will be discussed at the follow-up appointment.
When to Call the Doctor
- When you have a fever of 101 degrees or higher
- Rectal bleeding
- Increased abdominal swelling
- If cramps develop or you become bloated and do not have a bowel movement for 2 -3 days
- The incision becomes red, swollen or drainage develops
- Persistent cough or shortness of breath
- Pain that is not relieved by medication
- Persistent vomiting or nausea
- Inability to eat or drink liquids
- Severe constipation or diarrhea
Due to increased awareness and screening (colonoscopy) the death rate for colon cancer has dropped approximately twenty percent during the last fifteen years.
Almost all men and women over age fifty should have a colonoscopy. Patients at risk may require earlier screening. Colon cancer can almost always be caught by a colonoscopy when it is in the earlier treatable stage. The colonoscopy can find polyps before they become cancerous and removing them may prevent the adevelopment of colon cancer.
Low fat and high fiber diets have been known to reduce the risk of colon cancer. Fresh fruits, vegetables, whole grains, fish and lean chicken are healthy foods for your diet.
It is recommended that you stay active since studies have shown that regular exercise can help reduce the risk of cancer.