The exact causes of colorectal cancer are not known,
however, there are certain risk factors associated with the disease.
A risk factor is something that affects a person's
chance of getting a disease. Having one or more risk factor doesn’t necessarily
mean one will get the disease; likewise, someone with no risk factors could
still get it.
Risk factors for colorectal cancer include: age,
more than nine out of 10 people with colorectal cancer are older than 50;
having had polyps or colorectal cancer before; having a history of bowel
disease such as ulcerative colitis and Crohn's disease; a family history of
colorectal cancer, specifically close relatives (parents, brothers/sisters, or
children) who have had this cancer, especially if diagnosed before age 60.
Other risk factors includes one’s race or ethnic
background - some racial and ethnic groups such as African Americans and Jews
of Eastern European descent (Ashkenazi Jews) have a higher colorectal cancer
risk.
Diets that are high in red meats (beef, lamb, or
liver) and processed meats such as hot dogs, bologna, and lunch meat and cooking
meats at very high heat (frying, broiling, or grilling) which can create chemicals
that might increase risk as well.
A lack of exercise, being overweight, smoking, and
the heavy use of alcohol have been linked to colorectal cancer. People with
type 2 diabetes also have an increased chance of getting colorectal cancer and
tend to have a worse outlook (prognosis).
Early colorectal cancer is usually symptomless.
Symptoms are usually seen with more advanced
disease. These include a change in bowel habits such as diarrhea, constipation,
or narrow stool that lasts for more than a few days; a feeling that you need to
have a bowel movement that doesn't go away after doing so; rectal bleeding,
dark stools, or blood in the stool (often, though, the stool will look normal);
cramping or stomach pain; weakness, tiredness and extreme fatigue; frequently
having gas pains or cramps, or feeling full or bloated; losing weight with no
known reason; and having nausea or vomiting.
Although most of these symptoms are more likely
caused by something other than colorectal cancer, it is still important to see
a doctor right away if any of these problems are present so the cause can be
found and treated, if needed.
The cause of colorectal cancer is unknown; however,
prevention is possible through regular screening.
Screening tests are used to look for disease in
people who do not have any symptoms. In many cases, these tests can find
colorectal cancers at an early stage and greatly improve the chances of
successful treatment.
From the time it forms, a polyp (tissue growth) can
take around five to 15 years to develop into colorectal cancer. Screening tests
can help by allowing doctors to find and remove these polyps before they potentially
become cancer.
Next
week: Screening Guidelines