many people do not know about colon cancer (also know as colorectal cancer), and in this post, i will talk bout the causes of colon cancer and symptoms as well as prevention.
colorectal/colon cancer is not contagious (a person cannot catch the disease from a cancer patient). Some people are more likely to develop colorectal cancer than others.
Factors that increase a person’s risk of colorectal cancer include increasing age, race, high fat intake, a family history of colorectal cancer and polyps, the presence of polyps in the large intestine, and inflammatory bowel diseases, primarily chronic ulcerative colitis.
Increasing age is the main risk factor for colorectal cancer. Around 90% of colorectal cancers are diagnosed after age 50.
Africans have a higher incidence of colorectal cancer than people of other races.
Diet and colorectal cancer
Diets high in fat have been shown in numerous research studies to predispose people to colorectal cancer. In countries with high colorectal cancer rates, the fat intake by the population is much higher than in countries with low cancer rates.
It is believed that the digestion of fat that occurs in the small intestine and the colon leads to the formation of cancer-causing chemicals (carcinogens). Likewise, research studies also reveal that diets high in vegetables and high-fiber foods such as whole-grain breads and cereals contain less fat that produces these carcinogens and may counter the effects of the carcinogens. Both effects would help reduce the risk of cancer.
What are the signs and symptoms of colon cancer?
Symptoms of colorectal 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. Other conditions such as irritable bowel syndrome (spastic colon), ulcerative colitis, Crohn’s disease, diverticulosis, and peptic ulcer disease can have symptoms that mimic colorectal cancer.
Some symptoms and signs of colon cancer can also include:
rectal bleeding or blood in the stool,
change in bowel habits,
change in stool consistency,
Colorectal cancer can be present for several years before symptoms develop. Symptoms vary according to where in the large intestine the tumor is located.
The right colon is wider and more flexible. It can even be called relatively spacious as compared to the rest of the colon. Cancers of the right colon can grow to large sizes before they cause any abdominal symptoms. Typically, right-sided cancers cause iron deficiency anemia due to the slow loss of blood over a long period of time. Iron deficiency anemia causes fatigue, weakness, and shortness of breath.
The left colon is narrower than the right colon. Therefore, cancers of the left colon are more likely to cause partial or complete bowel obstruction. Cancers causing partial bowel obstruction can cause symptoms of constipation, narrowed stool, diarrhea, abdominal pains, cramps, and bloating.
Bright red blood in the stool may also indicate a growth near the end of the left colon or rectum.
What tests can be done to detect and diagnose colon cancer?
When colon cancer is suspected, a colonoscopy is typically performed to confirm the diagnosis and locate the tumor.
Colonoscopy is a procedure whereby a health care professional inserts a long, flexible viewing tube into the rectum for the purpose of inspecting the inside of the entire colon.
Colonoscopy is generally considered more accurate than barium enema X-rays, especially in detecting small polyps. If colon polyps are found, they usually are removed through the colonoscope and sent to the pathologist. The pathologist examines the polyps under the microscope to check for cancer.
Colonoscopy is the best procedure to use when cancer of the colon is suspected. While the majority of the polyps removed through colonoscopes are benign, many are precancerous. Removal of precancerous polyps prevents the future development of colon cancer from these polyps.
If cancerous growths are found during colonoscopy, small tissue samples (biopsies) can be obtained and examined under the microscope to determine if the polyp is cancerous. If colon cancer is confirmed by a biopsy, staging examinations are performed to determine whether the cancer has already spread to other organs.
Since colorectal cancer tends to spread to the lungs and the liver, staging tests usually include CT scans of the lungs, liver, and abdomen. Positron emission tomography (PET) scans, a newer test which looks for the increased metabolic activity that is common in cancerous tissue, also are employed frequently to look for the spread of colon cancer to lymph nodes or other organs.
What are the treatments for colon cancer?
Surgery is the most common initial medical treatment for colorectal cancer. During surgery, the tumor, a small margin of the surrounding healthy intestine, and adjacent lymph nodes are removed. The surgeon then reconnects the healthy sections of the bowel. In patients with rectal cancer, the rectum sometimes is permanently removed if the cancer arises too low in the rectum.
The surgeon then creates an opening (colostomy) on the abdominal wall through which solid waste from the colon is excreted. Specially trained nurses (enterostomal therapists) can help patients adjust to colostomies, and most patients with colostomies return to a normal lifestyle.
For early colon cancers, the recommended treatment is surgical removal. For most people with early stage colon cancer (stage I and most stage II), surgery alone is the only treatment required.
Chemotherapy may be offered to some people with stage II cancers who have factors suggesting that their tumor may be at higher risk of recurrence. However, once a colon cancer has spread to local lymph nodes (stage III), the risk of the cancer returning remains high even if all visible evidence of the cancer has been removed by the surgeon. This is due to an increased likelihood that tiny cancer cells may have escaped prior to surgery and are too small to detect at that time by blood tests, scans or even direct examination.
Their presence is deduced from higher risk of recurrence of the colon cancer at a later date (relapse). Medical cancer doctors (medical oncologists) recommend additional treatments with chemotherapy in this setting to lower the risk of the cancer’s return.
Drugs used for chemotherapy enter the bloodstream and attack any colon cancer cells that were shed into the blood or lymphatic systems prior to the operation, attempting to kill them before they set up shop in other organs.
This strategy, called adjuvant chemotherapy, has been proven to lower the risk of cancer recurrence and is recommended for all patients with stage III colon cancer who are healthy enough to undergo it, as well as for some higher risk stage II patients whose tumor may have been found to have obstructed or perforated the bowel wall prior to surgery.
In general, anticancer medications destroy cells that are rapidly growing and dividing. Therefore, normal red blood cells, platelets, and white blood cells that also are growing rapidly can be affected by chemotherapy. As a result, common side effects include anemia, loss of energy, and a low resistance to infections. Cells in the hair roots and intestines also divide rapidly.
Therefore, chemotherapy can cause hair loss, mouth sores, nausea, vomiting, and diarrhea, but these effects are transient.