Colon cancer is a type of cancer that initially manifests as noncancerous polyps in the large intestine. Polyps are cell clumps that can turn cancerous in some cases. Colon cancer is usually studied along with rectal cancer due to the proximity of the organs and the common features of the diseases. Colorectal cancer accounts for the third-highest number of cancer cases among people in the country.
Causes of colon cancer
While the cause of colorectal cancer is yet unknown, research has found quite a few genetic risk factors:
- Familial Adenomatous Polyposis (FAP)
People with FAP develop hundreds of polyps in their colon, and the number of polyps increases with age. On average, cancer develops around the age of 39. In the case of attenuated FAP, polyps develop later in life, and cancer develops around 55. Mutations in the APC gene cause both types of FAP. - Lynch syndrome
This is an inherited condition that increases the risk of colon, endometrial, and several other cancers. Three percent of all colon cancer cases result from Lynch syndrome. A mutation in a dominant gene causes this syndrome, so one has a 50% chance of developing it if a parent has it. - MYH-associated polyposis
MYH-associated polyposis causes polyps in the colon and rectum and is a milder form of FAP. It is a recessive mutation of the MYH gene, and research suggests that it significantly increases the risk of colorectal cancer. - Hyperplastic polyposis
This is a type of hereditary colon cancer that causes benign hyperplastic polyps, but they can also increase the risk of cancer. Research is in the early stage, so no gene has been associated with the development of this syndrome yet.
Symptoms of colon or colorectal cancer
Colorectal cancer typically presents the following symptoms:
- Changes in bowel habits
This can include frequent diarrhea and constipation for unknown reasons, incomplete emptying of the bowel, and bowel incontinence. These symptoms could last over a month without receding in the case of colon cancer. - Bleeding
Rectal bleeding indicates anal fissures, Crohn’s disease, or hemorrhoids. Also, the consumption of certain foods like beetroot might result in red or dark-colored stools, but chronic blood loss in stools can be because of colon cancer. - Anemia
Chronic bleeding can result in anemia and iron deficiency, and a drastic reduction in red blood cells in the body can cause exhaustion. No amount of rest can improve the sluggish feeling, and patients could also experience shortness of breath in such cases. - Changes in bowel shape and size
The size and shape of stools also change due to the presence of malignant tumors blocking the colon. Narrow, ribbon-like stools are a typical symptom of colon cancer. - Chronic abdominal pain
Although not very common, abdominal pain can be a symptom of colon cancer. A perforated bowel or a leak of bowel into the pelvis can cause pain. When left untreated, the tumors grow and block the bowels, causing discomfort, cramps, pain, and bloating.
