Preventing Deaths from Colon and Rectal Cancer

I am sure that during your association with the Ostomy Society, you have known individuals with colon cancer, or more likely rectal cancer, who underwent surgery, then the misery of chemotherapy and radiation, but still developed recurrent cancer and ultimately succumbed. I would like to talk about preventing deaths from colon and rectal cancer. It will take an effort, but 80-90% of the deaths from colon and rectal cancer can be prevented. Not only can the deaths be prevented, but the radiation treatment and chemotherapy can be prevented, if not the disease itself and the need for surgery.

How big a problem is colon and rectal cancer? How many people get it? How many people die of it? This year, 2003, The American Cancer Society estimates that 157,000 Americans will be diagnosed with colon or rectal cancer and 47,000 will die of the disease. In one year more Americans will die of colon and rectal cancer than died during the Viet Nam War. Colon and rectal cancer will kill more people in the United States than breast cancer kills women and prostate cancer kills men - and it is the cancer that no one has to have.

Several news shows today covered SARS - Severe Acute Respiratory Syndrome. Thus far, about 4800 cases have been reported worldwide and just over 300 people have died. During the time that we have known about SARS, over 5000 Americans have died of colorectal cancer. SARS is getting a lot of publicity at this time, and rightly so, but colorectal cancer is the disease that no one wants to talk about.

What do we know about the cause of colon and rectal cancer? Most cases are sporadic occurrences. Today, it is thought that a genetic mutation occurs and the result is an adenomatous polyp. A polyp is a benign growth occurring in the colon. There are several types, but the one of concern is the adenomatous polyp. These polyps are not uncommon and sometimes a second genetic mutation occurs, resulting in the appearance of cancer cells in the adenomatous polyp.

Some cases of colon and rectal cancer occur in patients with chronic ulcerative colitis and in patients with Crohn’s colitis. Patients with these two conditions should be counseled about the possibility of colorectal cancer and should receive regular colorectal cancer screening.

About 6% of cases of colorectal cancer are due to genetic disease. This means that the risk of colorectal cancer may be passed from one generation to another. There are two such inherited conditions. One is called Familial Adenomatous Polyposis and the other Hereditary Non-polyposis Colorectal Cancer. The key to diagnosing these two diseases is the family history.

At one time it was thought that a diet high in fat or a diet low in fiber contributed to the development of colorectal cancer. The basis for this was the fact that countries such as the United States or the Western European countries tended to consume too much fat and too little fiber and had a high incidence of colorectal cancer. In comparison, countries in Africa with a mostly low fat, high fiber diet had very little colorectal cancer. Though this is interesting and a high fiber, low fat diet is associated with a healthy lifestyle, today dietary factors are not thought to play a major role in the development of colorectal cancer.

No specific carcinogen has been identified that causes colorectal cancer. Several have been suggested such as food additives and ionizing radiation, but none have been linked to colorectal cancer - certainly not like tobacco is linked to lung cancer.

Most cases of colon and rectal cancer are diagnosed after a patient seeks medical attention because of symptoms - rectal bleeding, a change in bowel habit, abdominal or rectal pain, weight loss, or symptoms of anemia. An occasional patient will present because of a bowel obstruction. After an appropriate workup, testing will reveal the presence of colon or rectal cancer and the patient will most likely undergo an attempt at surgical removal of the malignancy. If the tumor is located in the colon, we will remove the tumor, the section of colon that the tumor is in, and what is known as the mesentery to the colon. The mesentery contains the veins draining the site of the tumor as well as the draining lymph channels and lymph nodes. If the tumor is attached to another structure, that structure can be removed with the tumor. These structures may include a portion of the abdominal wall, a segment of small bowel, the uterus or an ovary in women, the spleen, the tail of the pancreas, or part of the bladder. An “en-bloc” removal of the bladder and prostate is possible at the time of resection of a rectal cancer.

If cancer involves the rectum, we perform one of two operations - the anterior resection with anastomosis or the abdominal perineal resection. (Illustration) Surgery for cancer of the rectum is associated with special risks - impotence in men and voiding difficulties in men and women. The risk of local recurrence - recurrent cancer in the pelvis - is higher after surgery for rectal cancer than the risk of local recurrence after surgery for colon cancer. This is because the pelvis, especially in men and in obese individuals, makes it more difficult to do a wide resection of the cancer.

What is the cure rate of a patient who undergoes surgery for colon and rectal cancer? About 55%. What determines the cure rate for colon and rectal cancer? The most important factor that determines cure is the stage of the disease. After we remove a section of the colon because of cancer, we send it to the pathologist, who determines the depth of invasion of the wall of the colon by the tumor and if there has been spread of the tumor to the lymph nodes in the mesentery. If the tumor is confined to the wall of the colon, the cancer is considered to be in stage I. If the tumor is found to have penetrated the wall of the colon, but has not spread to the lymph nodes, it is considered stage II. If the lymph nodes are involved, but there is no distant spread of the tumor, it is considered stage III. Distant spread, most commonly to the liver, is considered stage IV. The cure rate for stage I is 80% or better; stage II, 50-60%; stage III, 25-35%; and stage IV, <2%.

As a surgeon, I am disappointed to say that we have not significantly improved the cure rate by our surgical techniques. Significant changes have occurred in surgery during my 33 years as a surgeon - these changes include better anesthesia, better surgical technique, improved methods of preparing (cleaning) the bowel for surgery, better antibiotics, better postoperative care, and improvement in the treatment of associated medical problems. The changes have decreased the surgical mortality, but sadly have not changed the 5-year survival after surgery for colon and rectal cancer.

There has been a slight increase in the cure rate of Stage III cancer by giving chemotherapy as soon as the patient has recovered from the surgery - even though there is no obvious cancer remaining after surgery. This is called adjuvant therapy. Surgery plus chemotherapy in patients with Stage III colon and rectal cancer results in a better cure rate than surgery alone.

Also, it has been shown that the mortality rate after surgery for rectal cancer goes down and the 5-year survival rate goes up when the surgery is done by surgeons who do over 20 of these cases per year or have special training in colon and rectal surgery. It has been shown, in other surgical procedures such as pancreatic resections and esophageal resections, that surgeons who do more than a certain number of procedures obtain better results than those who do only a few of the procedures. (When a person is selecting a surgeon for cancer surgery, or any other surgery for that matter, he should, at least, ask if the surgeon is board certified, if the surgeon is a member of the American College of Surgeons, and how many times the surgeon has performed the procedure.)

I have alluded to the fact that surgery for rectal cancer is more difficult than surgery for cancer elsewhere in the large bowel. This is because the surgery is done in the pelvis. In men, who by the Creator’s design have a smaller pelvis than women, and in the obese patient it is harder to perform a wide resection of the cancer. This may result in recurrence of the cancer in the pelvis. This recurrence is usually unresectable and may result in severe pain. Therefore, rectal cancer is frequently treated by a combination of surgery, radiation and chemotherapy in an effort to improve the survival and decrease the incidence of local recurrence. Surgery, especially the abdominal perineal resection, may result in voiding difficulties, impotence in men, and painful intercourse in women. Chemotherapy can be very unpleasant during its administration and there are significant and irreversible side effects of radiation therapy.

Colon and rectal cancer is the second leading cause of cancer deaths in the United States. 47,000 people will die this year. Lung cancer is number one; breast cancer is a close number three; prostate cancer is number four. The deaths from lung cancer would drop precipitously if no one smoked tobacco products. Ninety-nine percent of women can tell you what examinations are required to make an early diagnosis of breast cancer. Most men now know that yearly prostate examinations and the PSA blood test will improve the survival rate from prostate cancer.

How can we prevent 80 to 90% of the deaths from colon and rectal cancer? Screening is the answer. Screening means that average risk people over age 50 should have an examination for polyps and cancer when they are without symptoms. Individuals at increased risk for colon and rectal cancer should have screening at an earlier age.

Any type of screening will reduce the incidence and death rate of colon and rectal cancer. Examinations that have been used for screening include (1) the hemoccult test (2) flexible sigmoidoscopy (3) barium enema and (4) colonoscopy . Colonoscopy is the best form of screening. In 95% of cases the entire colon can be successfully visualized. Polyps, when found, can be removed and biopsies can be taken of lesions suspicious for malignancy. The disadvantages of colonoscopy include a very slight risk. The incidence of perforation of the colon during a diagnostic study is about 1 in 2000. Another drawback to colonoscopy is that the costs are not covered by all insurance carriers when the procedure is done strictly for screening.

Colorectal cancer, in almost all cases, develops in adenomatous polyps. If these polyps are removed during a screening colonoscopy, the risk of developing colorectal cancer is decreased. If an existing cancer is found during a screening colonoscopy in a patient who has no symptoms, cures of 80 to 90% can result. When a patient is found to have colon or rectal cancer and when he or she is asymptomatic, the cancer is much more likely to be in Stage I or Stage II which has a better cure rate than Stage III or Stage IV. Conversely, patients who are discovered to have colorectal cancer because of symptoms are more likely to have advanced stage disease and a poorer cure rate. This is how screening reduces the death rate from colon or rectal cancer - by the removal of adenomatous polyps and by the detection of cancer in an early stage.

Screening (colonoscopy) will reduce the number of deaths from colon and rectal cancer. Screening will reduce the need for surgery, for chemotherapy, and for radiation therapy and screening will reduce the complications of these forms of therapy. Despite the advantages of screening, only about 20 to 30 % of Americans have undergone any type of screening. One reason frequently quoted is the fear of discomfort from the procedure. Colonoscopy is done under intravenous sedation, usually versed, and I can tell you from experience that there is no discomfort involved.

A second possible reason for not having colonoscopy is the cost. Eventually there will be enough demand for colonoscopy as a screening procedure and it will be covered by all insurance carriers. Also, studies indicate that it is cost effective. Screening programs are cheaper than the cost of surgery, prolonged hospitalizations, chemotherapy, radiation therapy and death due to incurable or recurrent cancer.

People with no symptoms of colorectal cancer and with no risk factors should begin screening at age 50. In the past screening has meant hemoccult testing (testing the stool for blood) yearly and flexible sigmoidoscopy (examination of the rectum and lower colon) every five years. In the future colonoscopy will most likely become the screening procedure of choice and should be done every 10 years, if the initial exam is negative.

People at increased risk include those with (1) a family history of colon cancer or adenomatous polyps, (2) a personal history of colon cancer or adenomatous polyps, (3) chronic ulcerative colitis or Crohn’s colitis, (4) a family history of Familial Adenomatous Polyposis or Hereditary Non-polyposis Colorectal Cancer, and (5)a history of abdominal radiation. Women with a personal history of breast, uterine or ovarian cancer have a one in six lifetime risk of colon or rectal cancer. People at increase risk usually start screening at an earlier age and undergo screening more often.

Thank you. I will be glad to answer any questions.

Robert L. Baird