Published March 2010 / Reviewed March 2011
Colorectal cancer (CRC) is the third most common type of cancer, accounting for 11% of cancers diagnosed in women and men in the US. Approximately 140,000 new cases of CRC are diagnosed each year, about 100,000 in the colon, the remainder in the rectum. The lifetime probability of an average person to develop CRC is 6% (1 in 20). CRC remains the second leading cause of cancer mortality; nearly 60,000 people die of CRC each year. This is a high figure, emphasizing the need for proper screening. After all, CRC is preventable, treatable and beatable if diagnosed at an early stage.
Who is at Risk?
Although CRC may occur at any age, more than 90% of CRC occur in people over the age of 40. Most people are diagnosed in their 50s or later. People with a personal or family history of breast, uterine or ovarian cancer, inflammatory bowel disease (ulcerative or Crohn's colitis) and a family history of polyps or colorectal cancer are at higher risk to develop CRC.
How does CRC develop?
Most CRC develops from precancerous polyps (abnormal growths). As polyps increase in size, they may become cancer with the potential to invade through the bowel wall and spread to other sites in the body. The change of a benign polyp into a cancer appears to be associated with changes (mutations) in the genes that control each cell. This may be inherited or may occur spontaneously.
What are the Symptoms?
Common symptoms are bleeding with bowel movements, changes in bowel habits, such as new constipation or persistent diarrhea. Pain and unexplained weight loss may be symptoms of larger and more advanced cancers.
How Can You Prevent Colorectal Cancer?
Simple screening methods can detect many polyps early. Finding and removing colorectal polyps with sigmoidoscopy/ colonoscopy clearly reduces the risk of their developing into cancers. A diet high in fiber and low in animal fats will likely reduce your overall risks of developing cancer.
When should you be Checked for Colon and Rectal Polyps?
If you have any of the symptoms noted above, you should see a colorectal surgeon. Routine screening, even if no symptoms are present, with a colonoscopy should be carried out every 10 years, starting at age 50. Occult blood stool testing should be carried out every year, starting at age 40. Flexible sigmoidoscopy should be performed every 5 years. In addition "virtual colonoscopy" and Barium enemas can be used for screening purposes. Both are x-ray tests. However, a non x-ray colonoscopy exam with the ability to take biopsies and remove pre-cancerous polyps before they can turn into cancer has remained the gold standard screening tool. If one parent has familial polyp syndrome (polyposis), screening should start at age 12-14. Screening in individuals with other risks such as inflammatory bowel disease (Crohn's disease or ulcerative colitis), should be discussed with your doctor.
People who have a family history of colorectal cancer or polyps or a personal history of colorectal cancer or polyps should have a colonoscopy. Women with a personal history of breast, ovarian or uterine cancer should also have a colonoscopy every three to five years beginning at age 40.
How Does Colorectal Cancer Spread?
CRC can spread by direct growth of the tumor into adjacent organs and by distant spread of cancerous cells clumps, called metastases. Metastases spread to other parts of the body through the blood or lymph stream.
How are Cancers of the Colon and Rectum Treated?
CRC is removed surgically. An operation is usually performed through an abdominal incision. The section of bowel containing the cancer along with the associated blood vessels and lymph nodes are removed. In most cases, the bowel is reconnected so that normal bowel function is restored
Cancers of the rectum develop in the lower six inches of the large bowel above the anus. There are more options for treating these tumors. Most are also removed surgically. Larger, non-cancerous polyps and some early cancers may be removed through the anus. Most of the larger cancers are removed surgically through the abdomen.
Minimally invasive surgery, laparoscopy and robotic surgery, are rather new techniques that cause small incisions, make healing faster and less painful.
If a cancer is located close to the anal opening, a colostomy is created. This is a surgically created opening which allows the excretion of stool into a bag-like appliance. Rarely, a temporary colostomy may be required. Using modern surgical techniques and instruments, less than 5% of all CRC patients require a permanent colostomy.
Additional treatment for CRC includes radiation therapy and/or chemotherapy. One or both of these treatments may be given before or after surgery.
What is "Staging" and Why is it Important?
A staging system evaluates the tumor based on: spread into the bowel wall; spread into nearby lymph nodes; spread to distant organs or tissues. Staging helps predict the chances of survival and guides additional treatments. If CRC recurs it will usually do so within five years. The best chance for a cure is associated with a low cancer stage. Patients with an early cancer that has not penetrated the bowel and spread to other organs have a 90% survival chance.
The appearance (differentiation) of the tumor cells under the microscope is also significant in determining treatment. Tumors are classified as well, moderately, or poorly differentiated. Patients with well differentiated tumors have a better outcome than those with poorly differentiated tumors. Staging and tumor differentiation help deciding whether radiation and/or chemo-therapy in addition to surgery is required.
What is the Long-Term Outcome After Treatment?
Long-term cure depends on the CRC stage. Patients with early cancers, which have not grown through the bowel wall and have not spread to the lymph nodes or elsewhere, have an excellent outlook. When the cancer has spread to other areas, the chance for cure may be improved by additional surgery and/or chemotherapy or radiation therapy.
The key to preventing or curing colorectal cancer is to detect it early by undergoing appropriate screening and, when found, removing polyps. Early detection of cancers with prompt treatment will result in a high cure rate. You may wish to discuss this important topic further with your physician colorectal surgeon.
What is a Colorectal Surgeon? Colon and rectal surgeons are experts in the surgical and non-surgical treatment of colon and rectal problems. They have completed advanced training in the treatment of colon and rectal problems in addition to full training in general surgery. Colon and rectal surgeons treat benign and malignant conditions, perform routine screening examinations and surgically treat problems when necessary.
Claudia Hriesik, MD
Dr. Hriesik was born and raised in Germany where she attended medical School. She completed her Surgical Residency at the Drexel University of Medicine in Philadelphia. She graduated from two fellowships; the first in Surgical Oncology at the University of Pittsburgh and then in Colon and Rectal Surgery at the Cleveland Clinic in Ohio. Dr. Hriesik joined Rochester Colon-Rectal Surgeons in 2008.
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