Colorectal cancer is the third most common cancer in men and women. An estimated 131,000 Americans are diagnosed with this disease each year and some 55,000 die as a result of it. Certain genetic factors play a role in the development of this cancer. The specific cause of Colorectal cancer is unknown, however, environmental, genetic, familial factors and preexisting Ulcerative Colitis have been linked to the development of this cancer. It is more common among African-Americans.
Risk Factors
Age: Average age at the time of diagnosis is between 60-65, and the older we get the higher our risk of colorectal cancer.
Family History of colorectal cancer increases the risk of developing this illness in first- degree relatives. Certain familial conditions, like Familial Polyposis, is associated with a much higher risk.
Genetic factors clearly play a role in the development of colorectal cancers. Several genetic and inherited illnesses carry a very high risk of colorectal cancer: Familial Polyposis, Turcot syndrome, Gardner syndrome, Peutz-Jeghers syndrome, Juvenile Polyposis, Cowden's disease, Neurofibromatosis.
Ulcerative colitis , High Dietary Fat and Low Dietary Fiber can each increase the risk of this cancer.
Signs and Symptoms
This cancer may exhibit no signs in its early stages. Gradually, as the disease progresses, any of the following may be seen;
* Blood in the stool
* Diarrhea
* Constipation
* Bowel obstruction, causing nausea, vomiting and abdominal distention
* Abdominal pain
* Pelvic pain
* Anemia due to blood Loss
* Weight loss
* Loss of appetite
* Fatigue
Screening and Diagnosis
This cancer may be detected in its very early stages by any of the following screening tests:
Stool Occult Blood Test. Annual screening for colorectal cancer with a stool occult blood test for adults over age 50 is a must. Incidence of this cancer rises with age. This test is a rather simple test. Small amounts of stool are placed on a paper card and delivered to the physician's office for testing. A positive test mandates a complete work-up, including a Colonoscopy.
Flexible Sigmoidoscopy is a simple test that has a higher accuracy in detecting lower colon and rectal cancer. A tube is inserted inside the rectum and advanced into lower part of the large bowel. The performing physician can look for any abnormalities and take a biopsy from the abnormal area. Almost 50% of colorectal cancers are detected with this procedure.
Digital Rectal Examination is very simple to perform and can detect lesions in rectum and prostate. It should be done in a routine physical exam for adults. The physician examines the area by inserting his finger inside the rectum and feeling for abnormalities.
When colon cancer is suspected, a careful workup should be done to establish the diagnosis or to rule it out. It is empirical to visualize the entire colon and rectum. This is achieved by:
* Barium Enema - A radiological study wherein patients are given a barium enema followed by a series of x-rays of the abdomen.
* Colonoscopy -This is by far the best method for evaluating the colorectal area. Biopsies can be taken of any abnormal areas at the same time. A diagnosis is established by laboratory examination of the cancer tissue.
Staging:
What is the extent of cancer? How advanced is the cancer? What areas of the body are involved? Has the cancer spread to lymph glands, bones, liver, etc.? This step is referred to as staging. These important questions must be answered prior to treatment. The answers to these questions should be obtained by utilizing a minimal number of tests and least invasive methods.
Once the diagnosis is established, the next step is to determine the extent of the disease and to implement an appropriate treatment plan. A cancer specialist should be involved for proper planning of testing and studies. A chest x-ray is always a routine aspect of this workup. Further testing will rely on the findings of the physician and his intuition. Other x-rays, CT scans, Bone scan, MRI study , etc., will determine the extent of the cancer. CEA is a blood test which indicates the presence of the cancer.
Prognosis and treatment plans for colorectal cancer depend on the extent and pattern of spread of the cancer at the time of diagnosis. Staging workup is incomplete until the removed cancer is studied by a pathologist.
* Stage 1 or Duke A: When the cancer is limited to the inside of bowel
* Stage 2 or Duke B: When the cancer is larger and penetrates through the wall of the bowel to the outside layers
* Stage 3 or Duke C: When cancer has spread to the lymph glands in the abdomen
* Stage 4 or Duke D: When the cancer has spread to other organs -- liver, lungs, etc.
-References From Wikipedia-