The colon is the part of the digestive system where the waste material is stored. The rectum is the end of the colon adjacent to the anus. Together, they form a long, muscular tube called the large intestine (also known as the large bowel). Tumors of the colon and rectum are growths arising from the inner wall of the large intestine. Benign tumors of the large intestine are called polyps. Malignant tumors of the large intestine are called cancers. Benign polyps do not invade nearby tissue or spread to other parts of the body. Benign polyps can be easily removed during colonoscopy and are not life-threatening. If benign polyps are not removed from the large intestine, they can become malignant (cancerous) over time. Most of the cancers of the large intestine are believed to have developed from polyps. Cancer of the colon and rectum (also referred to as colorectal cancer) can invade and damage adjacent tissues and organs. Cancer cells can also break away and spread to other parts of the body (such as liver and lung) where new tumors form. The spread of colon cancer to distant organs is called metastasis of the colon cancer.
Causes of colon cancer
Age is the number one risk factor for colon cancer. Does that mean that age causes colon cancer? Not directly. It's just that by age age 50, one in four people has polyps. You'll learn more about polyps and their role in #14.
2.AlkoholResearch has indicated that alcohol increases colorectal cancer risk. Research has also shown that it lowers it, or that it has no effect at all. So which is right? All of it may be. The key appears to be what kind of alcohol you're drinking.
3. DiabeticA study published in the journal Gastroenterology found that insulin dependency contributes to colon cancer development. In general, diabetics are up to 40% more likely to develop colon cancer than people who don't have diabetes.
4. GeneticResearchers estimate that about 25% of colon cancer cases have some sort of genetic link. Examples of the most common genetic causes of colon cancer include mutations leading to FAP (familial adenomatous polyposis) and HNPCC (hereditary non-polyposis colorectal cancer).
5. Imflammatory bowel disesesInflammatory bowel disease, often characterized by conditions such as ulcerative colitis and Chron's disease, increases the risk of developing colorectal cancer. In general, the longer a person has had inflammatory bowel disease, the greater his or her chance of developing colorectal cancer.
6. Lack of ExerciseThere's no denying that exercise is good for you. The couch potato in me would like to see a study every once in a while declaring otherwise, but that just doesn't happen. Research has shown that a sedentary lifestyle contributes to colon cancer development.
7. ObesityNobody likes to have the word obese thrown at them. But, obesity is a medical term that indicates someone exceeds their recommended weight, one step beyond simply being overweight. And the answer to the question is yes, obesity does increase colon cancer risk.
yes, obesity does increase colon cancer risk.
8. Personal Medical HistoryYour personal medical history can significantly impact your chances of developing colorectal cancer. A medical history that includes polyps, bowel inflammation, or certain cancers is particularly relevant.
9. PolypsVirtually all colon cancer develops from adenomatous polyps in the colon, generally referred to simply as colon polyps. A personal or family history of polyps puts you at higher risk for colon cancer.
10. SmokingLong-term cigarette smoking causes colon cancer for two main reasons. First, inhaled or swallowed tobacco smoke transports carcinogens to the colon. Second, tobacco use appears to increase polyp size.
Sign and symptoms
It is common to have colon or rectal cancer without symptoms. Many patients are free of symptoms until their tumors are quite advanced.
Symptoms associated with colorectal cancer include may also be caused by other conditions. These symptoms include:
- Changes in bowel movements, such as diarrhea or constipation, or change in consistency of stools
- Feeling that the bowel has not emptied completely after a bowel movement
- Abdominal discomfort such as gas, bloating, and cramps
- Rectal bleeding or blood in stool
- Unexplained weight loss
- Abdominal pain and tenderness in the lower abdomen
- Blood in the stool
- Diarrhea ,constipation,or other change in bowel habits
- Unexplained iron-deficiency anemia (low red blood cell count)
- Weakness and fatigue
Exams and tests
if your doctor thinks you may have colorectal cancer, he or she will ask you questions about your medical history and give you a physical exam. Other tests may include:
- A colonoscopy test in which your doctor uses a lighted scope to view the inside of your entire colon. A colonoscopy may be done to look into symptoms such as unexplained bleeding from the rectum, constant diarrhea or constipation, blood in the stool, or pain in the lower abdomen. A colonoscopy is recommended when another screening test shows you may have colorectal cancer.
- A Sigmoidoscopy a test in which your doctor uses a lighted scope to view the lower part of your intestine. A sigmoidoscopy may be done to look into symptoms such as unexplained bleeding from the rectum, constant diarrhea or constipation, blood in the stool, or pain in the lower abdomen. Doctors can also remove polyps during this test.
- A barium enema, in which a whitish liquid with barium is inserted through your rectum into your intestine. The barium outlines the inside of the colon so that it can be seen on an X-ray.
- A biopsy, in which a sample of tissue is taken from the inside of your intestine and examined under a microscope. A doctor called a pathology can look at the tissue sample and see if it contains cancer.
- A complete blood account(cbc) which is a blood test. It is used to look into symptoms such as fatigue, weakness, anemia, bruising, or weight loss.
Treatment for ca colon
- Surgery is the most common treatment for all stages of colon cancer. Depending on the stage and size of your tumor, your doctor will remove your cancer with one of the following methoLocal excision — This surgical approach is used for very early stage cancers. It involves inserting a tube through the rectum into the colon and removing the cancer, rather than making a cut in the abdominal wall. If the cancer is found in a polyp, the procedure is called a polypectomy.
- Resection — This approach is used for larger and more advanced cancers and includes a partial colectomy, which involves removing the cancer, a small amount of surrounding healthy tissue and in many cases, nearby lymph nodes to examine for cancer. Afterwards, the doctor will sew the healthy parts of the colon together, during a procedure called an anastomosis.
- Resection and colostomy — This approach is used when the ends of the colon cannot be sewn back together. In these cases, a colostomy is performed, in which an opening outside of the body for waste to pass through is created, called a stoma. A bag is then placed around the stoma to collect the waste. The colostomy may be temporary, although if the entire lower colon is removed, it is permanent. Our specially trained nurses will help you learn how to manage your colostomy and incorporate it into your lifestyle.
- Laparoscopic surgery — Also called "keyhole surgery," this innovative approach is being used for some patients with colon cancer. During the procedure, a lighted tube, called a laparoscope, and special instruments are placed inside the body through a few small incisions in the abdomen, rather than one large one. The surgeon is then guided by the laparoscope, which transmits a picture of the intestinal organs on a video monitor and then removes diseased areas of the intestines.
Laparoscopic surgery for colon cancer offers an alternative and many advantages to standard surgery, including less pain and a shorter recovery period.
Radiation therapy is the use of X-rays or other high-energy rays to kill cancer cells and shrink tumors.
Chemotherapy is the use of drugs to kill cancer cells. It may be taken by pill, or injected into a vein.
Biological treatment, also called immunotherapy, tries to make your body fight against cancer. It uses materials made by the body or made in a laboratory to boost, direct or restore your natural defenses against disease.
This innovative approach involves using a special probe with tiny electrodes to kill cancer cells. The probe is inserted through an incision in the abdominal wall or directly into the skin, using local anesthesia.
After we know about ca cancer ,we can do the best things to keep healthy for our future and to avoid ca colon,with health life style,and finally do our best for our health.