Screen for Colon Cancer: FIT Test & Colonoscopy Explained

Colon cancer, also known as bowel cancer, is the third most common cancer worldwide and accounts for 10% of all cancer cases. It predominantly affects people ages 50 and above [1], people with a chronic condition such as inflammatory bowel disease as well as people with a family history [3].Younger people are also increasingly affected though [2].

The good news is: Even though colon cancer is the second leading cause of cancer-related deaths [1], it's also one of the most treatable ones if detected early [3] In this article, we’ll explain the two most important screening methods: the FIT test and colonoscopy. Learn how the selftest FIT and the colonoscopy procedure works, who should get screened, and why early detection can save your live.

The Ministry of Health in Germany as well as health insurance providers promote performing a FIT stool test once a year starting at age 50 [3]. This is because colon cancer is one of the most common cancer types and is almost always treatable through a simple colonoscopy, if detected early [4]. Detecting precancerous lesions or tumors early is crucial in preventing a late-stage diagnosis with poor treating outcomes. Around 90% of people diagnosed at stage I survive the colon cancer diagnosis at least five years after or more, compared to only around 10% at stage IV [5].

The most well-established screening options are a colonoscopy or the rapid test known as fecal immunochemical test (FIT Tests). A FIT Test can be carried out at home. While a colonoscopy provides a direct examination of the intestinal mucosa, a FIT test offers a non-invasive alternative. But how does colon cancer develop and when do colonoscopy and FIT stool tests for early screening come into play?

Colon cancer, medically known as colorectal carcinoma, occurs in the large intestine or rectum due to uncontrolled cell growth, forming tumors that affect healthy tissue. About 90% of colon cancer cases develop slowly over an average of ten years from benign intestinal polyps. These can be detected early and, in most cases, simply removed during a colonoscopy.

The process begins when the genetic material in a single cell of the intestinal mucosa mutates and starts to divide, forming a benign polyp. As these polyp cells continue to divide, the polyp grows larger. The good news: even a large polyp can be easily removed through a colonoscopy. However, when genetic mutation of the polyp cell occurs, the cells turn cancerous and begin to grow aggressively in the intestine [6].

Colon cancer is increasingly affecting younger individuals. While in Germany, diagnoses among those over 50 declined between 2002 and 2014, they rose in the 25 to 49 age group (Köhn S., 2019). The American Cancer Society reported that 20% of colon cancer cases in 2019 were patients under the age of 55 [2].

Despite rising cases, younger adults are still being overlooked—screening often starts too late, when symptoms already appear. Many are only diagnosed once the disease has advanced. This is because screening is typically promoted for those aged 50 and above. Younger patients are often diagnosed at later stages, with serious consequences. At a higher risk are especially those, with a family history of colon cancer or chronic inflammatory bowel diseases, making an early colonoscopy a justifiable argument and recommendable preventive measure [3].

FIT tests are a simple, non-invasive alternative that allow for self-testing at home in under 20 minutes. In oder to detect signs of polyps or tumor development early, it is recommended to carry out a FIT Test for an annual colon cancer screening regardless of age.

Many people do not have symptoms of colon cancer in an early stage, nor are symptoms specifically gender related or tied to the tumor’s location in the colon [8]. The following symptoms appear both in men and women, and call for preventive action:

1. Changes in bowel habits: persistent diarrhea, constipation, or alternating between the two.

2. Cramping abdominal pain and frequent, urgent bowel movements, often without stool passage.

3. Pale complexion and anemia: a potential sign of hidden gastrointestinal bleeding (occult bleeding).

4. Unexplained weight loss and persistent fatigue.

5. Visible blood in stool or dark, tar-like stool.

6. Increased mucus in stool.

These symptoms may also be caused by benign conditions such as hemorrhoids or intestinal inflammation. However, the earlier colon cancer is detected, the better are the chances of successful treatment [9].

Discover Preventis SmarTest® FIT Home

A colonoscopy is a visual examination of the intestinal mucosa, in which irregularities such as polyps or small tumors can be detected directly. It involves inserting a flexible tube with a light and camera – called a colonoscope – through the rectum and colon up to the small bowel.

Since a colonoscopy allows for a direct visualization of the bowel, polyps can often be removed immediately and analyzed in a laboratory. However, the procedure of a colonoscopy requires thorough bowel preparation, including dietary restrictions and the intake of special detoxifying solutions.

Colon cancer can be detected early through rapid, at home testing collecting a tiny amount of stool sample and applying it onto a rapid test cassette. As a less invasive method of colon cancer screening, the fecal immunochemical test (FIT Test), detects occult blood (hemoglobin) in stool samples through specific antibodies and serves as an early detection screening tool.

But how is occult blood in stool related too colon cancer? Occult blood are tiny amounts of blood in stool that are not visible to the naked eye. If the concentration of occult blood in stool exceeds a certain threshold, it indicates that in the gastrointestinal tract there is bleeding, which could stem from polyps. These are the precursors to colon cancer, or early-stage tumors and often go unnoticed without symptoms.

FIT Tests are rapid tests that can be completed in under 20 minutes. A recent study by the German Cancer Research Institute (DKFZ) compared the performance of the smartphone-based stool test Preventis SmarTest® FIT Home, with that of a laboratory-based FIT test. The study found that the diagnostic performance of the self-test is comparable to that of the laboratory FIT test [11].

Like a laboratory FIT test, Preventis SmarTest® FIT Home allows for the quantitative detection of hemoglobin in stool via the smartphone camera. Colonoscopies are typically performed every five to ten years. FIT tests can be performed more regularly, making the test a valuable complementary screening tool to colonoscopy. It is recommended to perform a FIT Test once a year to increases the sensitivity of colon cancer screening [10].

FIT-Testing requires no preparatory measures such as dietary restrictions. The main advantages of Preventis SmarTest® FIT Home lie in its ease of use, as it can be carried out by lay users at home, its lab-comparable accuracy and ohigh applicability[11].

Learn more about the Study

With the Preventis SmarTest® FIT Home, a small stool sample is collected and – similar to a COVID-19 rapid test – mixed into a sample solution. The solution is then applied to the test cassette. After just 15 minutes, the result can be analyzed via the SmarTest-App: simply take a photo of the test cassette using your smartphone camera. The app evaluates the result and provides a precise numerical value like a lab-test – fast, reliable, and without the need for a lab.

Discover Preventis SmarTest® FIT Home

Colon cancer is almost always curable if detected early, and screening can be done easily. The key is regular preventive measures such as colonoscopy or at-home FIT testing. A stool test provides an initial assessment and should ideally be used in addition to colonoscopy. Unlike colonoscopy, FIT testing is a non-invasive method that requires no preparation. Because no instruments are inserted into the body, there is no risk of tissue injury.

Take the first step and screen yourself for colon cancer at home.The sooner you act, the better.

Discover Preventis SmarTest® FIT Home