Colorectal Cancer


Colorectal cancer is among the most common types of cancer with more than 94,000 new diagnoses each year.  An additional 37,000 are diagnosed annually with cancer of the rectum.  The colon and rectum are part of the digestive system. They have two major jobs or functions. The colon absorbs water and minerals from food and transports them
into the bloodstream. The rectum stores fecal matter until it's eliminated from the body. Together, they form a long muscular tube known as the large intestine or bowel. The upper 5-6
feet of the large intestine is the colon, and the lower 5-6 inches is the rectum.  Cancer occurs when cells of the colon or rectum become abnormal and grow uncontrollably interfering with the function of these organs and sometimes surrounding tissue and organs.  When detected early, both colon and rectal cancer have high cure rates. 

Diagnostic Tests

 Colorectal cancer deaths could be reduced by at least 50% if more people age 50 and older were screened for the disease, according to a recent report by the National Colorectal Cancer Roundtable.

"We seriously think the number could be higher than 50%, but we are being cautious,” says Dr. Bernard Levin, NCCRT chair and vice president for cancer prevention and professor of medicine at the M. D. Anderson Cancer Center.

The report, published in the American Cancer Society’s international Cancer journal, states that an estimated 150,000 people will be diagnosed with colorectal cancer by the end of 2003. Of that total, 57,000 people are expected to die from the disease.

Despite these statistics – and the fact that colorectal cancer is 90% curable when caught early – the majority of Americans are not screened, the NCCRT report says. Colorectal cancer is the second-most common cancer in both men and women in the U.S. According to one study, however, only 21-34% of those surveyed had undergone colorectal cancer screenings in the previous five years.
 
Risk Factors:
  • Age 50 and over
  • A diet low in fruits and vegetables
  • Obesity and/or sedentary lifestyle
  • Tobacco use
  • Alcohol consumption
  • A diet high in animal fat
  • Inflammatory bowel disease
  • Family or personal history of colorectal polyps or cancer

Cancer Symptoms 

Early warning signs include:

  • Bright red blood in the stool
  • Diarrhea that is not the result of cold or flu
  • A long period of constipation
  • Crampy pain in the abdominal region
  • Persistent decrease in size or caliber of stool
  • Frequent feeling of distention or bloating in the abdominal or bowel region
  • Weight loss
  • Unusual and continuing lack of energy
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Current Treatments    

Colon Cancer - When colon cancer is detected in an early stage, it is most commonly treated with a surgical procedure called a colectomy.  The surgeon removes the part of the colon that contains the cancer as well as a small portion of surrounding normal tissue.  In all but the rarest cases, the surgeon is able to reconnect the healthy sections of the colon and rectum, and bowel function soon returns to normal.  If the cancer is completely removed during surgery and pathologists determine that it was an early
stage cancer, no further treatment may be needed.

If surrounding tissue is found to contain any cancer cells, the doctors will likely recommend chemotherapy as well. The drugs are given intravenously and/or orally and travel through the bloodstream to destroy tumor cells that may have broken away from original tumor and could begin to grow again elsewhere in the body.  Sometimes chemotherapy is given prior to surgery to shrink a tumor and reduce the extent of surgery.  This is called neo-adjuvant therapy.  Chemotherapy is also given when the cancer has spread beyond the scope of surgery.

Rectal Cancer - Surgeons at Johns Hopkins have refined surgical techniques for rectal cancer that often allow nerves and sphincter muscles to remain intact, preserving continence and sexual function, and many times eliminating the need for external waste collection pouches known as ostomies.  These innovative procedures have not only
saved lives but greatly enhanced the quality of life for rectal cancer patients.

 

New Approaches
The collaborative efforts of the clinicians and researchers have
led to many advances in the early detection and treatment of colon and rectal cancer.  These endeavors promise to translate into better treatment outcomes for all patients.

Oncology researchers were the first to isolate a series of mistakes in human DNA, called genetic mutations , that lead to the development and progression of colon and rectum cancer.  These findings have already been used to develop screening blood tests for people with a family history of certain types of hereditary colon and rectum cancers.  Several new anticancer agents are being studied for their ability to interfere with the genetic alterations and stop the initiation of cancer.  As genetic causes continue to be uncovered, researchers expect that a
broad-based screening test to detect colon and rectum cancer in its earliest and most treatable stage will become available.

Virtual Colonoscopy  

A new method called virtual colonoscopy is under study to examine the colon by taking
a series of x-rays (called a CT scan) and then using a high-powered computer to reconstruct 2-D and 3-D pictures of the interior surfaces of the colon from these x-rays. The pictures can be saved, manipulated to better viewing angles and reviewed after the procedure, even years later - Also called computed tomography colography.


A Final Thought

Given the aging of our population and the serious nature of this disease, the words of
the experts warrant repeating: "Colorectal cancer deaths could be reduced by at least 50% if more people age 50 and older were screened for the disease."

 
Sources:   Back to Top
1. Johns Hopkins Medicine    
2. MD Anderson Cancer Center    
3. National Cancer Institute