Diagnosis of colon cancer

On suspicion of rectal cancer or colon cancer, the doctor can use different methods to diagnosis it.

Where: The Colonoscopy is the most reliable method to diagnose or exclude cancer?


Many colon cancer tumors located in the rectum. The doctor can therefore discover changes to the intestinal mucosa easily through a painless and risk-free palpation using his finger. If tumor is present in deeper regions than it can be investigate using the endoscopy of the rectum (Sigmoidoscope). If changes exist, than it is further investigate usually by using a colonoscopy.

Test for blood in the stool

Hemoccult test : Fecal occult blood test can be used to determine blood in the stool. Here, the test person collect stool sample depending on a test area foe three consecutive days , and passes the samples to their doctor. The test also shows low levels of blood in the stool, which cannot be seen with the naked eye.

Blood in the stool may indicate colon cancer – but it may also have numerous other causes. A positive test result should always be followed by further studies concerning the safety. Conversely, there may be cancer, even if no blood is present in the stool.

Therefore, the Hemoccult test is not a reliable method for the diagnosis of colorectal cancer, but only help to diagnose a possible cancer point.


Colonoscopy is the most reliable method to diagnose colorectal cancer. In cases of suspected cancer, the doctor will therefore always use a colonoscopy to completely diagnose it. It help us to examine entire colon to determine cancer. In this study the examiner take tissue sample from cancer suspected area and examine it under microscope.The fecal occult blood test is controversial because it can at most offer a rough guide. An additional colonoscopy is still virtually necessary in all cases of suspected cancer……

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Testing for the presence of tumor spread (staging)

If the suspicion of cancer could be confirmed in the colonoscopy, the exact extent of the spread of the cancer to be detected with further investigations. Only then can a conclusion about the operability of colon cancer taken and the classification to be made in one of the cancer stages. For this the following tests are performed:

Rectal Ultrasound (Sonography): This can be determined how far the tumor has already spread in the intestinal wall.

Abdomen Ultrasound (sonography): The ultrasound looks for daughter metastases (metastases), especially in the liver. Also, in order to assess the spleen, kidney and pancreas.

Computed tomography of the thorax, abdomen and pelvis: with a computed tomography (CT) daughter metastases can also be detected in the body, such as in the lung or liver. CT angiography is also useful in which blood vessels can be represented.

Radiograph of the chest: In a radiograph daughter metastases (metastases) in the lung can be detected.

Tumor markers in the blood

In addition, so-called tumor markers can be detected in blood. Tumor markers are substances, which are released from tumors propagated into the blood. In colon cancer carcino-embryonic antigen (CEA) may be increased. The CEA is an endogenous substance, which is also produced by the cancer cells and enters the bloodstream. However, the provision of this tumor marker is, not an appropriate examination for early detection of colorectal cancer. The determination of CEA is only useful for monitoring the course after therapy. After the operation, the values ​​sink to a normal range. With the formation of a renewed tumor (relapse), the value increases again. Thus, a recurrence of colon cancer by regular determination of CEA can be detected early in the blood.

Genetic counseling

Genetic counseling is done for hereditary colorectal cancer (HNPCC, FAP and other rare forms). Here, a study of the genetic material is carried out and checked whether the typical mutations are present. Most regular colonoscopies are necessary in FAP often a precautionary removal of bowel segments.

For more general information…..

Stages of Colon cancer

Causes of Colon cancer

Symptoms of Colon cancer

Treatments of Colon cancer