What is cancer? Cancer is a group of more than 100 different diseases. They affect the body's basic unit, the cell. Cancer occurs when cells become abnormal and divide without control or order. Like all other organs of the body, the colon and rectum are made up of many types of cells. Normally, cells divide to produce more cells only when the body needs them. This orderly process helps keep us healthy.
If cells keep dividing when new cells are not needed, a mass of tissue forms. This mass of extra tissue, called a growth or tumor, can be benign or malignant.
Benign tumors are not cancer. They can usually be removed and, in most cases, they do not come back. Most important, cells from benign tumors do not spread to other parts of the body. Benign tumors are rarely a threat to life.
Malignant tumors are cancer. Cancer cells can invade and damage tissues and organs near the tumor. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or lymphatic system. This is how cancer spreads from the original (primary) tumor to form new tumors in other parts of the body. The spread of cancer is called metastasis.
Colon Cancer At A Glance
Colorectal cancer is a malignant tumor arising from the inner wall of the large intestine.
Colorectal cancer is the third leading cause of cancer in males and fourth in females in the U.S.
Risk factors for colorectal cancer include heredity, colon polyps, and long-standing ulcerative colitis.
Most colorectal cancers develop from polyps. Removal of colon polyps can prevent colorectal cancer.
Colon polyps and early cancer can have no symptoms. Therefore regular screening is important.
Diagnosis of colorectal cancer can be made by barium enema or by colonoscopy with biopsy confirmation of cancer tissue.
Treatment of colorectal cancer depends on the location, size, and extent of cancer spread, as well as the age and health of the patient.
Surgery is the most common treatment for colorectal cancer.
What is cancer of the colon and rectum?
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. 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 Malignant tumors of the large intestine are called cancers metastasis of the colon cancer. Once metastasis has occurred in colorectal cancer, a complete cure of the cancer is unlikely.
Globally, cancer of the colon and rectum is the third leading cause of cancer in males and the fourth leading cause of cancer in females. The frequency of colorectal cancer varies around the world. It is common in the Western world and is rare in Asia and Africa. In countries where the people have adopted western diets, the incidence of colorectal cancer is increasing.
Causes of colon cancer?
Presence of polyps (as small , non-cancerous(benign) clumps of cells) in the colon.
A diet rich in fat and starch without fiber.
Sedentary life style.
Smoking and Alcohol consumption.
A family history of colon polyps.
A history of inflammatory bowel disease (Two diseases Ulcerative Colitis & Crohns disease)
Symptoms of colon cancer?
Symptoms of colon cancer are numerous and nonspecific. They include fatigue, weakness, shortness of breath, change in bowel habits, narrow stools, diarrhea or constipation, red or dark blood in stool, weight loss, abdominal pain, cramps, or bloating.
Tests done to detect colon cancer?
A blood test called “fecal occult” blood test which identifies hidden blood in stool.
Followed by visualization of colon through a procedure known as Colonoscopy.Colonoscopy is a procedure whereby a doctor inserts a long, flexible viewing tube into the rectum for the purpose of inspecting the inside of the entire colon. If colon polyps are found, they are usually removed through the colonoscope and sent to the pathologist.
The pathologist examines the polyps under the microscope to check for cancer. (biopsies) can be obtained and examined under the microscope to confirm the diagnosis. If colon cancer is confirmed by a biopsy, staging examinations are performed to determine whether the cancer has already spread to other organs.
Treatments and survival for colon cancer?
Surgery
Surgery is the most common treatment for colorectal cancer. During surgery, the tumor, a small margin of the surrounding healthy bowel, and adjacent lymph nodes are removed. The surgeon then reconnects the healthy sections of the bowel. In patients with rectal cancer, the rectum is permanently removed. The surgeon then creates an opening (colostomy) on the abdomen wall through which solid waste in the colon is excreted and most patients with colostomies return to a normal lifestyle. Chemotherapy
Chemotherapy is the use of medications to kill cancer cells. It is a systemic therapy, meaning that the medication travels throughout the body to destroy cancer cells. After colon cancer surgery, some patients may harbor microscopic metastasis. Chemotherapy is given shortly after surgery to destroy these microscopic cells. Chemotherapy is usually given in a doctor's office, in the hospital as a outpatient, or at home. Chemotherapy is usually given in cycles of treatment periods followed by recovery periods.
Modern chemotherapy agents are usually well tolerated, and side effects are manageable. Common side effects include loss of energy. hair loss, nausea, vomiting, and diarrhea. Radiation therapy
Radiation Therapy in colorectal cancer has been limited to treating cancer of the rectum. There is a decreased local recurrence of rectal cancer in patients receiving radiation either prior to or after surgery. Without radiation, the risk of rectal cancer recurrence is close to 50%. With radiation, the risk is lowered to approximately 7%.
Side effects of radiation treatment include fatigue, temporary or permanent pelvic hair loss, and skin irritation in the treated areas.
Follow-up care for colon cancer?
Follow-up exams are important after treatment for colon cancer. The cancer can recur near the original site or in a distant organ such as the liver or lung.