Hemoccult-Test®

introduction

The Haemoccult-Test® is a stool test that aims to find small remnants of bleeding in the stool that are not visible to the naked eye (occult = hidden). The test serves as a screening method for colorectal carcinoma, i.e. for a malignant tumor disease of the large intestine (colon) and / or the rectum. The damage to the wall layers caused by the carcinoma can lead to small bleeding that is not strong enough to be seen with the naked eye. The Hämoccult-Test® should therefore make even the smallest amounts of blood detectable and is also well suited as a screening instrument, since it can be carried out quickly and inexpensively.

When should you do a Haemoccult-Test®?

The Hämoccult-Test® belongs to the standard of the so-called colon cancer screening. This preventive care is aimed at the development of cancer in the colon and rectum and is intended to ensure early detection of the disease. It is hoped that cancer development will be diagnosed at an early stage so that many therapeutic options are possible. Since the risk of colon cancer increases from the age of about 50, the annual Haemoccult-Test® is planned. In addition, from the age of 55, a colonoscopy can be performed every 10 years, which is also used for early cancer detection.

In rare cases, the Haemoccult-Test® is recommended before the age of 50. This is especially true for people with a familial colon cancer risk, i.e. if first-degree relatives are affected by colon cancer or even genetic mutations with an increased risk of colon cancer are known in the family. As a rule, however, family members will have an earlier colonoscopy (before the age of 55 recommended in the guideline). The Haemoccult-Test® plays a rather subordinate role for this group of people.

Read more on the subject at: Test for blood in your stool

How often should you do a Haemoccult-Test®?

The Hämoccult-Test® is recommended once a year based on the colorectal cancer guidelines and is covered by the health insurance company at this frequency. It is assumed that an annual check-up for unspecific signs of colorectal cancer is sufficient without any further symptoms (such as stool changes). Those who have the stool test carried out less often run the risk of overlooking a well treatable precancerous stage and thus only getting a late diagnosis of the disease, in which better therapy options may no longer be sufficient to treat the disease.

On the other hand, it is usually not worthwhile to have the Haemoccult-Test® carried out more than once a year. Although the test is considered very reliable, it can produce false positive results (the test is positive even though there is no colon cancer). The more often the test is carried out, the more likely you will be tested positive, regardless of whether you actually have a disease. Therefore, it makes no sense to take the test at monthly or even weekly intervals.

What is a positive Haemoccult-Test®?

A positive test result is when the Haemoccult-Test® shows that there is occult blood (which cannot be seen with the naked eye) in the stool (the test can also detect visible blood deposits on the stool, as it only determines whether there is blood in the stool present). Therefore, a positive Haemoccult-Test® is initially a sign that further tests should be carried out. As a result, a colonoscopy, for example, is carried out, which can provide more precise information about the presence of colon cancer.

Do you have blood in your stool? Read more about it here: Blood in the stool

What are the reasons for a positive Haemoccult-Test®?

The Hämoccult-Test® is based on the principle that the presence of even small amounts of blood in stool can be detected. The Haemoccult-Test® is therefore always positive when there is blood in the stool.
This can have different causes. For example, there may be bleeding throughout the digestive tract. Not only the colon and rectum are affected. The small intestine or the stomach can also bleed due to changes in the mucous membrane and thus cause a positive Haemoccult-Test®. Frequently there is also a positive test result in the context of bleeding of the esophagus or mucous membrane bleeding in the mouth. Anyone who only had a nosebleed a short time before performing the test can also expect a positive Haemoccult-Test®.
However, unlike previous tests, the quality of the cancer screening test has improved. Before the Haemoccult-Test® there was the so-called Guaiac-Test®, which should also examine the stool for traces of blood. However, the Guaiac-Test® could not differentiate between human blood (from the digestive tract) and animal blood or muscle components (which enter the gastrointestinal tract when meat products are consumed) and therefore produced positive results significantly more frequently than the haemoccult test , which had to be investigated in further investigations.

What are the consequences of a positive hemoccult test?

The consequences of a positive test are initially only to carry out further tests. The Hämoccult-Test® is designed to detect as much blood as possible in the stool. This means that few diseases are overlooked, but one also finds many random positive results in people who are not sick.
This is why another form of preventive examination follows: the colonoscopy. A small camera on a guide wire is pushed through the anus into the rectum and from there into the colon. Changes in the intestinal wall can be detected with the camera. If necessary, a tissue sample can be taken directly, which can then be examined for malignant changes. If no abnormalities can be seen in this examination, cancer of the intestinal segments is very unlikely.

You can find more information about various tests for colon cancer here: These colon cancer tests exist, and they are so reliable!

How sure is the result?

The result of the Haemoccult-Test® indicates with great certainty the actual presence of blood in the stool. A high so-called sensitivity and specificity of the test means that almost all people with blood in their stool are recognized and only a few false positive test results are found. However, blood in the stool can indicate a wide variety of diseases and causes of bleeding and is therefore in no way to be equated with the presence of a (cancer) disease.

How is the Haemoccult-Test® carried out?

A Haemoccult-Test® usually consists of three test letters that are given to you in the doctor's office. These letters should be treated equally for three consecutive days. To do this, on the first day you take a small stool sample with the enclosed spatula and place it on the test letter. The procedure is repeated on the second and third day, so that at the end you receive test letters from three different days. The letters are then brought back to the doctor's practice, where the test results for the individual days can be read on the Hämoccult-Tests®.

Can I do a Haemoccult-Test® myself?

The Hämoccult-Test® can be carried out by a doctor or independently. You can also do the test yourself for the annual check-up. For this you often get a test set from the doctor to take home with you, in which the stool sample can be collected. Then you bring the test back to the doctor, who can read the correct test result. Since there are different sets for the Haemoccult-Test®, you should have a doctor's office explain how to do it. In principle, Hämoccult-Tests® can also be purchased online for personal use. The best way to work here is to use the instructions for use.

What can you not eat before the test?

Before a Haemoccult-Test® there are some foods that should be avoided, as they can falsify the test results despite the lack of blood in the stool. If you want to be on the safe side, it is best to avoid foods containing vitamin C. These include primarily citrus fruits such as oranges, lemons and limes. But other fruits (bananas) and vegetables (broccoli) can also lead to a false positive test result.
The older test variants for cancer screening also react positively to meat and the substances it contains from animal muscles. However, the new Haemoccult-Tests® can differentiate animal products from human blood, which is why eating meat in this case is generally harmless. However, if one also ingests animal blood, for example when consuming black pudding, this can in turn lead to a false positive test result. Furthermore, bleeding in the gastrointestinal tract, from the oral mucosa and nosebleeds can falsify the test results.

What does a test cost and does the health insurance company pay for it?

The Haemoccult-Test® is a comparatively inexpensive test. A test kit usually costs the doctor between thirty and forty euros, the evaluation of the test in the laboratory is added to the costs, but it varies greatly from laboratory to laboratory. If the Haemoccult-Test® is carried out as part of the annual colon cancer check-up, the health insurance company must cover the costs. Even if there are additional medical indications for a further implementation, this will be covered by the health insurance.

How does the test work?

The Hämoccult-Test® is used for the preventive examination of colon cancer by detecting so-called occult (hidden, invisible to the naked eye) blood in stool. Since the test can only differentiate between the presence and absence of blood in the stool, no statement can be made about the cause of the blood in the stool. A positive test therefore does not necessarily indicate a disease and must first be examined more closely using other diagnostic means.

How does the evaluation work?

How the exact evaluation of the Haemoccult-Test® works depends on the type of test set. The test is usually carried out by the doctor, who can either read the result himself or have the sample examined in the laboratory. If you want to carry out the Hämoccult-Test® privately, it is best to take the exact evaluation from the package insert. Usually there is a surface with fields for a positive and a negative test. Depending on whether the test set finds occult blood in the stool or not, this results in a marking of the field “positive” (= blood in the stool) or “negative” (= no blood in the stool).