Information on Colorectal Cancers
This section of the Prostate Cancer Guide gives a brief overview of colon cancer. Here you will find information about the causes, symptoms and the treatment of the condition. Additionally the guide carries a colon cancer blog that aims to give the latest information on research into the condition and stories about how people cope with the condition.
What are colorectal cancers?
Colorectal cancers are the third most common type of cancer, it affects both men and women, and in the United States alone more then 110,000 new cases are expected every year.
Cancers that affect the colon and rectum are known as colorectal cancers. Typically these cancers develop very slowly over many years. Usually before a cancer develops in either the colon or the rectum a polyp will first develop; many of these growths, such as hyperplastic polyps and inflammatory polyps are non-cancerous. The types of polyp known as adenomatous or adenomas are the ones that normally become cancerous.
More than 95% of colorectal cancers are of the adenocarcinomas class. The remaining classes mainly consist of lymphomas, gastrointestinal stromal tumors and carcinoid tumors. Other types of colorectal cancers also exist.
Colorectal cancers are the third most common type of cancer, it affects both men and women, and in the United States alone more then 110,000 new cases are expected every year.
Surviving colon cancer
The death rate from colon cancer has been falling year after year; this is mainly as a result of improved colorectal screening techniques, which are able to recognize polyps at an early stage. It is estimated that 90 percent of people who are diagnosed with the condition at an early stage will survive for at least five years. However due to the nature of the disease the death rate increases dramatically when colon cancer is first found at a later stage.
It is hoped that the colon cancer guide will provide you with lots of useful information, but it is paramount that you visit your doctor on a regular basis for preventative screening and that if you are diagnosed with the condition you listen to the doctor’s advice. Don't be afraid to ask them any questions so that they clear up anything that you do not understand.
Colon Cancer Tests and Screening
Secondary prevention of colon cancer describes the way that doctors identify non-cancerous polyps and early stages of cancer (compare this to primary prevention, such as a good diet that are in the hands of the sufferer). There are two main methods of secondary prevention of colorectal cancer: these are screening and early prevention. By using these strategies the likelihood of developing a fatal cancer can be greatly lowered. Screening is generally recommended to a degree for all people and not just those who are thought to be at risk from cancer. Using these screening methods is very effective as colorectal cancers generally develop very slowly so early detection allows pre-cancerous abnormal tissue to be removed.
The main methods of colon cancer screening and early detection techniques include the following: digital rectal exam (similar to that performed for prostate cancer); Flexible sigmoidoscopy; Colonoscopy; x-ray (double contrast barium enema) and fecal occult blood tests (FOBT).
Recommendations for screening
The American cancer society recommends that people are screened for colorectal cancer from the age of fifty onwards: these screens should include a yearly fecal occult blood test; five to ten yearly double contrast barium enema; and a colonoscopy every ten years.
Digital rectal examination
Although annual digital rectal examination screening is recommended for everybody over 50 as a preventative measure against colon cancer, it is best that men have the exam from the age of 40 as the method is also able to detect prostate cancers. In this procedure the doctor will insert his finger up the rectum and detect any abnormal growths or polyps by touch. Due to the size of the colorectal system additional methods to the digital rectal examination are required to detect cancers that do not first develop in the rectum.
Fecal occult blood tests
As polyps and cancerous tumors may lead to bleeding in the intestine, a telltale sign of their presence may be the presence of blood in stools. Often the amount of blood may be small and not easy to detect, therefore a procedure known as fecal occult blood test is performed in order to detect the presence of blood. Following a digital rectal examination a doctor will often perform a fecal occult blood test using faeces present on the examination glove. A piece of diagnostic test paper is smeared and the presence of blood ascertained.
Flexible sigmoidoscopy is an invasive method of colon cancer screening. A viewing instrument is inserted into the anus allowing the doctor to take a detailed look colon tissue. It is estimated that if people were to undergo a sigmoidoscopy screening every five years the incidence of colon cancer could be reduced by as much forty percent.
Symptoms of Colon Cancer
It is not always the case that symptoms will be seen by people suffering from colon cancer. When colon cancer symptoms do occur they are typically related to changes in the bowels. This generally manifests itself as constipation or diarrhea. Things to be in particularly on the look out for include narrow stools, bloody stools, cramps and pain in the abdomen. Itching and pain in the anal region are often associated symptoms of anal cancer. Other signs of colorectal cancer include fatigue, loss of appetite and weight loss. Many of the symptoms given above may also be associated with other conditions such as hemorrhoids for example.
Early symptoms of colon cancer
Polyps that grow in the intestinal regions may develop into cancer without any recognizable symptoms until the tumor has reached an advanced stage.
It is therefore highly recommended that regular screening for the cancer is taken. Screenings include the digital rectal examination, colonoscopy, x-ray barium enema, and faecal occult blood tests. More details of these tests can be found in the screening section of the colon cancer guide website.
Later Symptoms of colon cancer
The symptoms mentioned above such as changes in bowel movements and bleeding in the stools are typically noticeable when the colorectal cancer has advanced. As people vary tremendously in their bowel habits, you should be looking out for a change in the rate of your bowel patterns. Of course dietary patterns also play a big role in bowel fluctuations, if you have started a diet rich in dietary fiber, or the opposite, similar changes in patterns of bowel movements may also occur.
Blood in the stools is a common symptom of colon cancer, if you observe blood in the toilet bowl or as streaks in your faeces you should consult your doctor; he/she may also perform an occult blood test on the stool to detect hidden blood.
Symptoms may enable the location of the colorectal cancer to be ascertained.
As different symptoms are associated with different areas of the colon, it may be possible to locate the cancer. If cancer occurs on the descending colon it often grows around the diameter of the organ, leading to obstruction of the faeces passage (and changes in bowel patterns) and blood streaks in the faeces.
If the cancer is present in the ascending part of the colon it is likely to have symptoms such as discomfort on the right side of the abdomen, anaemia and rectal bleeding. Cancer tumors located in the rectum often lead to blood being seen in the toilet.