An overview of Stool DNA Test
A stool DNA test is a screening method used to detect colon cancer and precancerous growths called polyps in individuals with no symptoms. The test analyzes a stool sample for changes in the genetic material of cells, known as DNA, and looks for hidden blood in the stool. The test can identify cancerous or precancerous cells that have been shed into the stool due to their continuous shedding in small amounts.
What is Stool DNA Test used for?
A stool DNA test is used for colon cancer screening in people with no symptoms and for detecting growths of cells, called polyps, that could one day become cancer. The test looks for DNA changes and small amounts of blood shed into the stool, which may come from colon cancer or colon polyps. It helps identify early signs of cancer or polyps, allowing for timely intervention and treatment.
How to prepare for Stool DNA Test?
No preparation is required for a stool DNA test. You can eat and drink as usual before the test and continue using your current medications. There's no need to perform bowel preparation or clean out the colon before the test. You will receive a stool DNA test kit that includes a container to collect the stool sample and a preservative solution to add to the sample before submission. The test only requires one stool sample.
How is Stool DNA Test conducted?
A stool DNA test is conducted by collecting a stool sample and submitting it to a designated laboratory for analysis. You will receive a stool DNA test kit that includes a container that attaches to the toilet and a preservative solution to add to the stool sample before sealing the container. The test requires only one stool sample, and you can eat and drink as usual before the test and continue using your current medications. Once the sample is submitted, the laboratory will look for DNA changes and signs of blood in the stool as indicators of colon cancer or colon polyps.
How are Stool DNA Test results reported?
Stool DNA test results are typically reported as positive or negative. A negative result means that no DNA changes or signs of blood were found in the stool sample, indicating a low risk for colon cancer. A positive result may indicate the presence of cancer or precancerous polyps, requiring further testing such as a colonoscopy. However, false-positive or false-negative results can occur, so additional tests may be necessary to confirm the findings. Always consult with your health care provider for interpretation and follow-up recommendations based on your individual situation.
Understanding the report
Stool DNA test results are interpreted based on the presence or absence of DNA changes and signs of blood in the stool sample. If DNA changes and signs of blood are not found in the stool, the test is considered negative. If DNA changes and signs of blood are detected, the test is considered positive. A negative result means that no colon cancer or colon polyps are detected, and the individual may be asked to repeat the test in three years for further screening. A positive result requires further testing, usually with a colonoscopy, to examine the inside of the colon for polyps and cancer. It's important to note that stool DNA tests are not always accurate, and there is a possibility of false-positive or false-negative results. Additionally, the test is not recommended for individuals with colon cancer symptoms, a history of colon cancer, colon polyps, or inflammatory bowel disease, or those with a strong family history of colon cancer or certain genetic syndromes that increase the risk of cancer.
Limitations and Considerations
Some limitations of the stool DNA test include:
- False-positive results: The test is not always accurate and can sometimes show signs of cancer when none is present. This is called a false-positive result.
- False-negative results: The test may miss some cancers, which is called a false-negative result.
- Limited use in certain populations: The stool DNA test is generally not used to screen for colon cancer in people with symptoms, a strong family history, or specific genetic conditions that increase the risk of cancer.
- Additional testing required: If the test result is positive, further testing, such as a colonoscopy, is usually recommended to examine the inside of the colon for polyps and cancer.