Colorectal cancer symptoms & staging treatment | Colorectal cancer screening guidelines

Colorectal cancer starts in the large intestine (colon) and rectum (end of the colon). This disease is adenocarcinomas, which develop from the lining of the large intestine and rectum (colorectal). Colorectal cancer usually begins as a button like swelling on the surface of the intestinal or rectal lining or on a polyp.

As the cancer grows, it begins to invade the wall of the intestine or rectum. Nearby lymph nodes also may be invaded. Because blood from the wall of the intestine and much of the rectum is carried to the liver, colorectal cancer usually spreads (metastasizes) to the liver soon after spreading to nearby lymph nodes.

This disease is mostly common in western countries. The incidence of colorectal cancer begins to rise at age 40 and peaks between the ages of 60 and 75. Each year, about 153,000 people in the United States develop colorectal cancer and about 52,000 die. Colon cancer is more common among women, and rectal cancer is more common among men.

Colorectal cancer Causes

Colorectal cancer is one of the leading causes of cancer-related deaths in the United States. All colon cancers begin as non-cancerous (benign) polyps, which slowly develop into cancer. One has a higher risk for colon cancer if he has:

• One Crohn's disease
• Family history of colon cancer
• Cancer elsewhere in the body
• Personal history of breast cancer
• Ulcerative colitis
• Colorectal polyps

Certain genetic syndromes also increase the risk of developing colon cancer. What one eats may play a role in his risk of colon cancer. Colon cancer may be associated with a high-fat, low-fiber diet and red meat. However, some studies found that the risk does not drop if you switch to a high-fiber diet, so the cause of the link is not yet clear.

Smoking cigarettes is another risk factor for colorectal cancer.

Colorectal cancer Symptoms:

Cancer of the colon and rectum can exhibit itself in several ways. If you have any of these symptoms, seek immediate medical help.

1.) You may notice bleeding from your rectum or blood mixed with your stool.

2.) It may be associated with fatigue and pale skin cancer of the colon and rectum can exhibit itself in several ways. If you have any of these symptoms, seek immediate medical help.

3.) People commonly attribute all rectal bleeding to hemorrhoids, thus preventing early diagnosis owing to lack of concern over bleeding hemorrhoids.

It usually, but not always, can be detected through a fecal occult (hidden) blood test, in which samples of stool are submitted to a lab for detection of blood.

Rectal bleeding may be hidden and chronic and may show up as an iron deficiency anemia.

If the tumor gets large enough, it may completely or partially block the colon. One can notice the following symptoms of bowel obstruction:

• Unexplained, persistent nausea or vomiting.
• Change in frequency or character of stool (bowel movements).
• Abdominal distension: Your belly sticks out more than it did before without weight gain.
• Small-caliber (narrow) or ribbon-like stools.
• Abdominal pain: This is rare in colon cancer. One cause is tearing (perforation) of the bowel. Leaking of bowel contents into the pelvis can cause inflammation (peritonitis) and infection.
• Unexplained weight loss.
• Rectal pain: Pain rarely occurs with colon cancer and usually indicates a bulky tumor in the rectum that may invade surrounding tissue.
• Sensation of incomplete evacuation after a bowel movement.

Studies suggest that the average duration of symptoms (from onset to diagnosis) is 14 weeks. There is no association between overall duration of symptoms and the stage of the tumor.

Colon Cancer Treatment by Stage:

With proper screening, Colon cancer can be detected before symptoms develop. Surgery for all stages of Colon Cancer, except stage 4, to remove the tumor is the initial treatment. Additional treatment, called adjuvant therapy, may be recommended for some cancer.

Stage 0

Stage 0 colon cancer is found only in the innermost lining of the colon. Treatment usually involves one of the following:

•  More extensive surgery (resection) to remove larger colon cancers. This may require a procedure called an anastomosis to remove the diseased part of the colon and reattach the healthy tissue to maintain bowel function, or
• Polypectomy or local excision to remove the tumor and a small amount of surrounding tissue.

Surgery to remove all of the cancer is considered curative.

Stage 1 (Dukes A)

Tumors in stage 1 have spread beyond the inner lining of the colon to the second and third layers and involves the inside wall of the colon. The cancer has not spread to the outer wall of the colon or outside the colon.

Standard treatment involves surgery to remove the cancer and a small amount of tissue around the tumor. Additional treatments are not usually needed.

Aggressive surgery to remove all of the cancer offers a great potential for cure. The five year survival rate for stage I colorectal cancer is 93% according to the American Cancer Society.

Stage 2 (Dukes B)

Stage II colon cancers are larger and extend through the muscular wall of the colon, but there is no cancer in the lymph nodes (small structures that are found throughout the body that produce and store cells that fight infection).

Standard treatment is surgical removal of the cancer and an area surrounding the cancer:

A person with Dukes B colon cancer may also be a candidate for a clinical trial looking at the use of adjuvant immunotherapy, radiation or chemotherapy.

The 5-year survival rate for Dukes B colon cancer is 78%.

Stage 3 (Dukes C)

Stage III colon cancers are spread outside the colon to one or more lymph nodes (small structures that are found throughout the body that produce and store cells that fight infection). Tumors within the colon wall are classified as Dukes Stage C1, while tumors that have grown through the colon wall and have spread, is called Dukes Stage C2 cancers.

Treatment involves:

• Radiation may be needed if the tumor is large and invading the tissue surrounding the colon.
• Surgery to remove the tumor and all involved lymph nodes if possible.
• After surgery, the patient will receive chemotherapy with 5-FU and leucovorin.

Occasionally, a Dukes C cancer may be unresectable for cure even if metastases are not present. That's because the cancer may have spread into the pancreas, small intestine, or other pelvic organs.

A person with Dukes C colon cancer may also be a candidate for a clinical trial looking at the use of adjuvant immunotherapy or other forms of chemotherapy.

The 5 year survival rate for Dukes C colon cancer is about 64%. Patients with one to four positive lymph nodes have a higher survival rate than people with more than five positive lymph nodes.

Colorectal cancer screening guidelines:

Regular screening, beginning at age 50, is the key to preventing colorectal cancer. The U.S. Preventive Services Task Force (USPSTF) recommends screening for colorectal cancer using high-sensitivity fecal occult blood testing, sigmoidoscopy, or colonoscopy beginning at age 50 years and continuing until age 75 years.

Recommended screening tests and intervals are:

• Flexible sigmoidoscopy, where physicians use a flexible, lighted tube (sigmoidoscope) to inspect visually the interior walls of the rectum and part of the colon should be administered every 5 years.
• High-sensitivity fecal occult blood test (FOBT), which checks for hidden blood in three consecutive stool samples, should be administered every year.
• Colonoscopy, where physicians use a flexible, lighted tube (colonoscope) to inspect visually the interior walls of the rectum and the entire colon, should be administered every 10 years. During this procedure, samples of tissue may be collected for closer examination, or polyps may be removed. Colonoscopies can be used as screening tests or as follow-up diagnostic tools when the results of another screening test are positive.

People at higher risk of developing colorectal cancer should begin screening at a younger age, and may need to be tested more frequently. The decision to be screened after age 75 should be made on an individual basis. If you are older than 75, ask your doctor if you should be screened. For more information, read the current colorectal cancer screening guidelines from the U.S. Preventive Services Task Force.

References

U.S. Preventive Services, Task Force. Screening for Colorectal Cancer: U.S. Preventive Services Task Force Recommendation Statement. AHRQ Publication 08-05124-EF-3, October 2008. Agency for Healthcare Research and Quality, Rockville, MD.

U.S. Preventive Services Task Force. Guide to Clinical Preventive Services, 2008: Recommendations of the U.S. Preventive Services Task Force. AHRQ Publication No. 08-05122, September 2008. Agency for Healthcare Research and Quality, Rockville, MD.

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