What is Colorectal Cancer?
Medikoe Health Expert
Koramangala, bengaluru, karnataka, india, Bengaluru Feb 12, 2017
The colon or large intestine is where the body extracts water and salt from solid wastes. The waste then moves through the rectum and exits the body through the anus. The colon is about 6 feet long.
Colon cancer is also known as colorectal cancer starts when the process of the normal replacement of colon lining cells goes away. Cells begin to divide independently and growth of cells is altered completely. As these abnormal cells grow and divide, they can lead to growths within the colon polyps.
Once colorectal cancer forms, it begins to grow in two ways. First, cancer can grow locally and extend through the wall of the intestine and invade adjacent structures, making the mass more of a problem and harder to remove.
Second, as cancer grows it begins the process of metastasis, shedding thousands of cells a day into the blood and lymphatic system that can cause cancers to form in distant locations. Colorectal cancers most commonly spread first to local lymph nodes before traveling to distant organs after that it spread to the liver, the abdominal cavity, and the lung are the next most common destinations of metastatic spread.
Colorectal cancer is the third most common cause of cancer in the U.S. in both men and women. It affects almost 135,000 people annually, representing 8% of all cancers.
Colorectal cancer is not contagious but factors that increase a person’s risk of colorectal cancer include increasing age, African-American race, high fat intake, a family history of colorectal cancer and polyps, and the presence of polyps in the large intestine, and inflammatory bowel diseases, primary chronic ulcerative colitis.
Symptoms of colorectal cancer are numerous and nonspecific. They include fatigue, weakness, shortness of breath, change in bowel habits, narrow stools, diarrhea red or dark blood in stool, weight loss, abdominal pain, cramps or bloating, colitis, Crohn’s disease, diverticulosis, and peptic ulcer disease.
The right colon is wider and more flexible. Cancers of the right colon can grow to large sizes before they cause any abdominal symptoms. Due to the slow loss of blood over a long period of time right-sided colon cancer cause iron deficiency anemia. Iron deficiency anemia causes fatigue, weakness, and shortness of breath. The left colon is narrower than the right colon.
A physician will ask about personal and family medical histories and will carry out a complete physical exam.
To inspect the inside of the colon a long, flexible tube with a camera on one end is inserted into the rectum.
Used to examine a smaller portion of the colorectal area.
Double-contrast barium enema
This x-ray procedure uses a liquid called barium to provide clearer imaging results than a standard x-ray can give. Before a barium enema, the patient must fast for several hours.
- If a biopsy suggests colon cancer, the doctor may order a chest x-ray, ultrasound, or CT scan of the lungs, liver, and abdomen to assess the spread of cancer.
- There may also be a blood test for a substance produced by some cancer cells called carcinoembryonic antigen (CEA).
- Following a diagnosis, the doctor will determine the stage of cancer based on the size and extent of the tumor.
Treatment will depend on the type and stage of cancer, and the age, health status, and other characteristics of the patient.
There is no single treatment for any cancer, but the most common options for colon cancer are surgery, chemotherapy, and radiation therapy.
Surgery to remove part or all of the colon is called a colectomy. The surgeon removes the part of the colon containing cancer and the surrounding area.
Some small, localized cancers can be removed using endoscopy.
Laparoscopic surgery, using several small incisions in the abdomen, may be an option to remove larger polyps.
Palliative surgery may relieve symptoms in cases of untreatable or advanced cancers.
Chemotherapy administers chemicals that interfere with the cell division process by damaging proteins or DNA in order to damage and kill cancer cells.
Chemotherapy is generally used to treat cancer that has spread because the medicines travel through the whole body. Treatment occurs in cycles, so the body has time to heal between doses.
Common side effects include hair loss, nausea, fatigue, and vomiting.
Radiation treatment damages and kills cancer cells by focusing high-energy gamma-rays on them.
Side effects may include, mild skin changes resembling sunburn, nausea, vomiting, diarrhea, fatigue, appetite and weight loss.
Most side effects resolve a few weeks after completing treatment.
“For prevention of colon cancer, annual screening is recommended for men and women aged 50 to 75 years, especially since symptoms may not appear until cancer has progressed.”