About 156,000 new cases of colorectal cancer (cancer of the colon and rectum) are diagnosed in the United States each year. Over 90% of these patients are over 50 years old. Men are slightly more likely than women to develop the diseased.

Colorectal cancer accounts for approximately 58,300 deaths each year. Only lung cancer exceeds colorectal cancer in the number of deaths each year. Despite the high mortality rate, the potential for saving lives through early detection of colorectal cancer is great.

The colon and rectum make up the final portion of the digestive tract. Also known as the large bowel or large intestine, this portion absorbs water from food already digested by the stomach and small intestine, forms the solids into waste matter, and holds the waste matter until it can be eliminated from the body.

Some tumors may interfere with body functions and require surgical removal, but they do not spread to other parts of the body. These are known as benign tumors. Malignant - or cancerous - tumors not only invade and destroy normal tissue; by a process known as metastasis, cells break away from the original tumor and move to other parts of the body. There they may form additional malignant tumors.

Cancer of the colon is about three times more common than cancer of the rectum. If not detected early, cancers of the colon and rectum can spread to the lymph nodes, bladder, liver, bone and brain.

Many polyps are believed to be precursors - or forerunners - of colorectal cancer. Polyps are masses of tissue that grow inward from the wall of the bowel. Generally, larger polyps are more likely than others to become malignant. Colorectal cancer rates may be greatly reduced if polyps are found and removed before they become cancerous.

Familial polyposis syndrome encompasses a group of hereditary diseases that can produce many polyps, often when an individual is still in adolescence. Persons with close relatives who have or have had familiar polyposis or colorectal cancer are at increased risk of developing these diseases themselves.

A history of inflammatory bowel disease also increases the risk of developing colorectal cancer. Such diseases include ulcerative colitis, particularly when the disease has lasted more than 10 years, and Crohn’s disease, an inflammation of the small intestine.

Population studies increasingly implicate diet - particularly a diet high in fat and low in fiber, with insufficient grains and fresh fruits. Such a diet is typical of many Americans and of those in other highly developed societies that have high colorectal cancer rates.

Colorectal cancer sometimes causes enough bleeding to induce iron-deficiency anemia. Any older person with this condition should be examined for colon cancer. Rectal tumors can cause bloody diarrhea or a sensation that the bowel never completely empties.

People often ignore rectal bleeding, thinking it is only a sign of hemorrhoids. This is unwise because individuals with hemorrhoids may also have colorectal cancer. Only a medical examination and tests can rule out cancer.

Digital rectal examination: The physician inserts a gloved, lubricated finger into the rectum to feel for any irregular or abnormally firm areas that may be malignant.

Stool blood test: This simple test can reveal hidden blood in the stool. Thin smears from three consecutive bowel movements are applied to chemically coated slides that are then sealed and returned to the physician or laboratory. It is important to remember that a positive stool blood test indicates only that there is blood in the stool, not what is causing the bleeding. It could be colorectal cancer, but it could also be a variety of other, less serious conditions. A negative test does not rule out colorectal cancer or polyps since bleeding can be intermittent.

Proctosigmoidoscopy: The physician visually inspects the wall of the colon with a hollow, lighted tube. Newer instruments are longer, but more flexible for greater patient comfort. If a growth is discovered, a small tissue sample is removed for microscopic examination (biopsy).

The two procedures most commonly used to diagnose cancer and locate the tumor are colonoscopy and barium enema. Because the two techniques have different advantages, they are often used together.

Colonoscopy: A flexible, lighted instrument allows the physician to examine the entire length of the colon. Samples of suspicious growths can be removed for biopsy as can entire polyps.

Barium enema with air contrast examination: Barium sulfate, a chalky substance that shows up clearly on x-rays, is given in enema form. By careful x-raying of the colon, small or large growths that may have been overlooked by other procedures may be detected. The barium is then removed for the final x-ray, known as the air contrast study. While this examination is better than colonoscopy in finding cancers in the upper colon, it is not as good in detecting those in the rectum.

Surgery is the mainstay of colorectal cancer treatment. Alone it can cure 50% of colon cancers and 45% of rectal cancers. The surgeon removes the section of the bowel containing the tumor and a border of tissue surrounding the tissue. These border cells are later examined to check that cancer cells have not spread there. The lymph nodes draining the area may also be removed because the lymph system is one of the main routes for carrying cancer cells to other parts of the body.

Important advances in surgery have resulted in less extensive operations for colorectal cancer. In most cases, the two sections of the bowel can be rejoined by a stapling technique at the time the tumor is removed. If it’s possible to use it, this technique can eliminate the need for a colostomy, a surgical procedure to create an opening, the stoma, in the abdominal wall for the removal of wastes. If the two bowel sections cannot be rejoined when the tumor is removed, a colostomy will be necessary. This is usually a temporary condition; once some healing has occurred, the colostomy can be reversed and the two sections attached. In some cases, particularly cancers of the lower rectum, the colostomy will be permanent. The current rate of colorectal cancer patients needing a permanent colostomy is not less than 15% and continues to decline. After adjusting to some initial problems, these patients can and do lead normal, fully active lives.

The aim of radiation therapy is to destroy cancer cells by injuring their ability to divide, while minimizing the damage to surrounding tissue. Radiation is proving effective in helping to prevent tumors from recurring in the bowel and spreading elsewhere, and in relieving pain. It may be used before surgery to reduce the size of the tumor and so increase the chances of surgical removal, and afterwards to destroy remaining malignant cells. Side effects can include skin irritations, nausea, vomiting, and a feeling of tiredness.

The use of chemotherapy to treat colorectal cancer has been extensively studied. Previously, chemotherapy was used mainly to help relieve pain among patients with advanced disease. New studies have shown that chemotherapy can also help increase survival times among patients with early stage rectal cancer. These are patients whose cancer can be completely removed by surgery and has not yet spread, but who are at risk for having the cancer recur. Among these patients who, following surgery, receive a combination of anti-cancer drugs like 5-fluorouracil or 5-FU and methyl-CCNU, there may be an increase in survival. The effect of chemotherapy on early stage colon cancer is less clear-cut, but recent data show that 5-FU and levamisole are useful as adjuvant treatment for certain early stage colon cancer patients.

5-FU continues to be used to shrink tumors and relieve pain among patients with advanced cancers of the colon and rectum. It has been estimated that 5-FU can provide relief in 20% to 25% of patients with advanced disease. Cancers that have spread to the liver can sometimes be reduced by implanting a small pump that delivers anti-cancer drugs directly into the liver. The use of these pumps is, however, still considered experimental.

The drugs used in chemotherapy produce more extensive damage to cancer cells than to normal cells, and the physician must maintain a delicate balance of dose and frequency - giving enough chemotherapy to kill cancer cells but not so much as to destroy healthy cells. Dividing cells, both normal and cancerous, are most vulnerable to anti-cancer drugs.

Most chemotherapy can be given in a doctor’s office or outpatient department of a hospital. Sometimes, however, patients may be hospitalized to constantly monitor treatment and ensure that the delicate balance between too much and too little treatment is maintained. Patients may receive chemotherapy as part of clinical trials - experimental programs designed to test the effectiveness of newly developed drugs or new combinations of drugs. Because of the promising results produced by these trials in recent years, it is important that physicians and patients be kept informed about their availability.

Common side effects of chemotherapy include nausea and vomiting, hair loss, and change in the blood counts. Most of these side effects disappear once treatment is stopped. Any unexpected side effects should be discussed with a physician.

Some people delay following up on a symptom of colorectal cancer or having colorectal exams at the recommended intervals because they fear that the detection of colorectal cancer would necessarily mean extensive surgery and a colostomy. Early detection, however, reduces the likelihood of major surgery.

These recommendations must be based on the individual patient, extent of disease, and type of treatment. They may include repeating some of the tests originally used to diagnose the cancer. Another test that has shown to be useful in follow-up is the carcinoembryonic antigen (CEA) test. CEA is often elevated in blood of patients with large bowel tumors, and its presence can provide an early warning of a recurrence. Since other factors, such as smoking, may also influence test results, it is not totally reliable.

The process begins in the hospital. The stoma appears as a small reddish opening about the size of a quarter. Methods of keeping it clean and avoiding irritation are explained to the patient by the physician, nurse, and often an enterostomal therapist, or ET. An ET has a nursing or similar medical background and additional intensive training in every phase of stomal care. Ets sometimes confer with surgeons prior to the operation on the best location for the opening and afterwards teach the patient methods of daily care.

Following surgery, the stoma will be covered by a small plastic bag known as a colostomy pouch. Nowadays many patients prefer to "irrigate" their colostomies, usually once a day. This takes the place of a bowel movement and frees the patient from worries about spillage into the bag. The patient can then wear a small waterproof patch between irrigations to protect clothing from stains. Generally, patients can wear their normal clothes, although tight fitting or binding garments may prove uncomfortable.

The patient may also receive assistance on a one-to-one basis from American Cancer Society and United Ostomy Association volunteers. These are fellow colorectal cancer patients who have adjusted well to their colostomies and are interested in helping others to do so. With the approval of the attending physician, these carefully selected and specially trained volunteers provide invaluable help, proving that having a colostomy does not preclude a career, marriage, sexual relations, or engaging in most sports. Patoents are usually greatly relieved to be able to discuss their fears and concerns with someone who is successfully living with a colostomy.