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Prepared by: Ghalia kayal 412 chs - Level 8 - May 2009 Dr. Ebtisam Fetoohy ( Health Education ). Colon cancer. Definition of Colon Cancer:. Colon cancer is cancer of the large intestine (colon), the lower part of your digestive system.
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Prepared by: Ghaliakayal 412 chs - Level 8 - May 2009 Dr. EbtisamFetoohy (Health Education) Colon cancer
Definition of Colon Cancer: Colon cancer is cancer of the large intestine (colon), the lower part of your digestive system. With 655,000 deaths worldwide per year,it is the third most common form of cancer and the second leading cause of cancer-related death in the Western world.
Introduction: Many colorectal cancers are thought to arise from adenomatouspolyps in the colon. These mushroom-like growths are usually benign, but some may develop into cancer over time. Polyps may be small and produce few, if any, symptoms. Regular screening tests can help prevent colon cancer by identifying polyps before they become cancerous.
Your best chance for surviving colorectal cancer is detecting it early. When found early, there is nearly a 90 percent chance for cure.
Symptoms: There often are no symptoms of colorectal cancer in its early stages. Most colorectal cancers begin as a polyp. As polyps grow, they can bleed or obstruct the intestine. When the disease spreads, it is still called colorectal cancer
Symptoms: • rectal bleeding • blood in the stool or toilet after a bowel movement • prolonged diarrhea or constipation • a change in the size or shape of your stool • A change in bowel movement pattern that continues over time • General discomfort in the abdomen (frequent gas pains, cramping pain, feeling of bloating or fullness) • Vomiting • Constant fatigue • Chronic constipation
Risk Factors: • Age: Colorectal cancer is most common in people over 50. • Family history: Your risk is higher with a family history (especially parent, sibling) of colorectal cancer, or adenomatous polyps. • Personal history: Your risk is higher with a personal history of inflammatory bowel disease (Crohn’s disease or colitis), colon cancer, or adenomatous polyps. • Weight: Lack of physical activity and obesity are risk factors.
Diet: A high-fat diet, particularly animal fats, may Increase your risk. Diets high in fruits and Vegetables are thought to decrease your risk. diets high in red and processed meat, as well as those low in fiber, are associated with an increased risk of colorectal cancer. Individuals who frequently eat fish showed a decreased risk • Cigarette smoking and alcohol: Your risk may be higher if you smoke or drink • Physical inactivity: People who are physically active are at lower risk of developing colorectal cancer.
Familial Adenomatous Polyposis (FAP) • Familial adenomatous polyposis (FAP) is a genetic condition where affected individuals will develop hundreds to thousands of polyps • If a parent has FAP, each child has a 50% (or, 1 in 2) chance of inheriting FAP. Each child also has a 50% chance of not inheriting FAP. FAP does not skip generations. Both males and females are equally likely to be affected. Therefore, if you have FAP, your children each have a 1 in 2 chance of having FAP.
DIAGNOSIS: Colorectal cancer screening rates remain low. Therefore, screening for the disease is recommended in individuals who are at increased risk. There are several different tests available for this purpose.
Continue • Digital rectal exam (DRE): The doctor inserts a lubricated, gloved finger into the rectum to feel for abnormal areas. It only detects tumors large enough to be felt in the distal part of the rectum but is useful as an initial screening test. • Fecal occult blood test (FOBT): a test for blood in the stool. Two types of tests can be used for detecting occult blood in stools i.e. guaiac based (chemical test) and immunochemical. The sensitivity of immunochemical testing is superior to that of chemical testing without an unacceptable reduction in specifity.
Endoscope: • Sigmoidoscopy: A lighted probe (sigmoidoscope) is inserted into the rectum and lower colon to check for polyps and other abnormalities. • Colonoscopy: A lighted probe called a colonoscope is inserted into the rectum and the entire colon to look for polyps and other abnormalities that may be caused by cancer. A colonoscopy has the advantage that if polyps are found during the procedure they can be immediately removed. Tissue can also be taken for biopsy.
Pathology: The pathology of the tumor is usually reported from the analysis of tissue taken from a biopsy or surgery. A pathology report will usually contain a description of cell type and grade. The most common colon cancer cell type is adenocarcinoma which accounts for 95% of cases. Other, rarer types include lymphoma and squamous cell carcinoma.
Cancers on the right side (ascending colon and cecum) tend to be exophytic, that is, the tumour grows outwards from one location in the bowel wall. This very rarely causes obstruction of feces, and presents with symptoms such as anemia. Left-sided tumours tend to be circumferential, and can obstruct the bowel much like a napkin ring.
Colectomy with Ileorectostomy (IleorectalAnastomasis) In this procedure, the colon is removed, but all or most of the rectum is left in place. The small intestine is attached to the upper portion of the rectum. Most patients maintain very good bowel function, though anti-diarrhea medications are sometimes needed. This procedure is typically recommended when there are very few polyps in the rectum. . 1-Surgery and treatment: .
Restorative Proctocolectomy (Ileal Pouch Anal Anastomosis) • This operation involves removing the entire colon and most of the rectum. A new rectum, or reservoir for stool, called a pouch, is made out of the lower end of the small intestine (ileum). • The pouch is joined to the anus so bowel movements can flow in the normal way. A temporary ileostomy, or a stoma where the waste empties into a bag through the abdominal wall, is usually needed to help heal this delicate connection.
This operation involves removing the entire colon and rectum. The end of the small bowel (ileum) is brought to the surface of the abdomen, where it is permanently stitched into place. This is called an end ileostomy. Total Proctocolectomy With Ileostomy
Chemotherapy Chemotherapy is used to reduce the likelihood of metastasis developing, shrink tumor size, or slow tumor growth. Chemotherapy is often applied after surgery (adjuvant), before surgery (neo-adjuvant), or as the primary therapy (palliative). The treatments is to improve survival and/or reduce mortality rate, In colon cancer, chemotherapy after surgery is usually only given if the cancer has spread to the lymph nodes (Stage III)
Life Style and Nutrition • The comparison of colorectal cancer incidence in various countries strongly suggests that sedentarily, overeating (i.e., high caloric intake), and perhaps a diet high in meat (red or processed) could increase the risk of colorectal cancer • In contrast, a healthy body weight, physical fitness, and good nutrition decreases cancer risk in general.
. Accordingly, lifestyle changes could decrease the risk of colorectal cancer as much as 60-80%. • A high intake of dietary fiber (from eating fruits, vegetables, cereals, and other high fiber food products) has, until recently, been thought to reduce the risk of colorectal cancer • Calcium or folic acid (a B vitamin), aspirin are able to decrease carcinogenesis in pre-clinical development models: Some studies show full inhibition of carcinogen-induced tumors in the colon of rats.