|
Carcinoma colon Colon carcinoma is a disease in which malignant (cancer) cells form in the tissues of the colon. The colon is part of the body's digestive system. The digestive system removes and processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and water) from foods and helps pass waste material out of the body. The digestive system is made up of the esophagus, stomach, and the small and large intestines. The first 6 feet of the large intestine are called the large bowel or colon. The last 6 inches are the rectum and the anal canal. The anal canal ends at the anus (the opening of the large intestine to the outside of the body). Types of carcinoma colon Aden carcinoma is the most common type of colon cancer but there are many other forms as well. Examples include leiomyosarcoma, lymphoma, melanoma, and neuroendocrine tumors. Aden carcinomas: Adenocarcinoma is a cancer of epithelia originating in glandular tissue. Epithelial tissue includes, but is not limited to, skin, glands and a variety of other tissue that lines the cavities and organs of the body. Epithelium is derived embryologically from ectoderm, endoderm and mesoderm. To be classified as adenocarcinoma, the cells do not necessarily need to be part of a gland, as long as they have secretory properties. Leiomyosarcomas : This type of colon cancer occurs in the smooth muscle of the colon. Leiomyosarcomas account for less than two percent of colorectal cancers and have a fairly high chance of metastasizing. Lymphomas: Colorectal lymphomas are rare and are more likely to start in the rectum than in the colon. However, lymphomas that start somewhere else in the body are more likely to spread to the colon than to the rectum. Non-Hodgkins lymphoma accounts for about 0.5 percent of all colorectal cancers and has many forms. Melanomas: This type of colon cancer is rare. Usually, it results from a melanoma that started somewhere else and then spread to the colon or rectum. Melanomas account for less than two percent of colorectal cancers Symptoms 1 .Pallor, easy fatigability, weakness, dizziness, dyspnoea on exertion may be the only symptoms. 2. Anorexia, indigestion and weight loss are often the presenting complaints. 3. Anemia of varying degree is very common in case of carcinoma in this region 4. Abdominal pain and tenderness in the lower abdomen 5. Intestinal obstruction Causes and Prevention Causes There is no single cause for colon cancer. Nearly all colon cancers begin as noncancerous (benign) polyps, which slowly develop into cancer. Higher risk for colon cancer if a person 1. Have cancer elsewhere in the body. 2 Have colorectal polyps. 3. Have inflammatory bowel disease (Crohn's disease or ulcerative colitis) 4. Have a family history of colon cancer 5. Have a personal history of breast cancer Prevention: With proper screening, colon cancer can be detected before symptoms develop, when it is most curable. A fecal occult blood test (FOBT) may detect small amounts of blood in the stool, which could suggest colon cancer. However, this test is often negative in patients with colon cancer. For this reason, a FOBT must be done along with colonoscopy or sigmoidoscopy. It is also important to note that a positive FOBT doesn't necessarily mean you have cancer. Imaging tests to diagnose colon cancer Colonoscopy: Colonoscopy is the endoscopic examination of the colon and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It may provide a visual diagnosis (e.g. ulceration, polyps) and grants the opportunity for biopsy or removal of suspected lesions. Sigmoidoscopy: Sigmoidoscopy is the minimally invasive medical examination of the large intestine from the rectum through the last part of the colon. There are two types of sigmoidoscopy, flexible sigmoidoscopy, which uses a flexible endoscope, and rigid sigmoidoscopy, which uses a rigid device. Flexible sigmoidoscopy is generally the preferred procedure. A sigmoidoscopy is similar but not the same as a colonoscopy. A Sigmoidoscopy only examines up to the sigmoid, the most distal part of the colon, while colonoscopy examines the whole large bowel. Treatments Treatment depends partly on the stage of the cancer.Treatments may include 1. Chemotherapy: Usually used for stage 1-4 disease. They are given in combinations. One of the most common treatments is cyclophosphamide plus doxorubicin (Adriamycin), known as AC; these drugs damage DNA in the cancer, but also in fast-growing normal cells where they cause serious side effects. Damage to the heart muscle is the most dangerous complication of doxorubicin. 2. Radiation: Radiotherapy is given after surgery to the region of the tumor bed, to destroy microscopic tumors that may have escaped surgery. It may also have a beneficial effect on tumour microenvironment. Radiation therapy can be delivered as external beam radiotherapy or as brachytherapy (internal radiotherapy). Conventionally radiotherapy is given after the operation for breast cancer. Radiation can also be given, arguably more efficiently, at the time of operation on the breast cancer- intraoperatively 3. Surgery (most often a colectomy) to remove cancer cells
|
