What percentage of positive cologuard tests are cancer?

If you are worry about your cologuard tests and whether it would return positive, take a chill pill, the percentage of positive cologuard tests being cancerous has never been 100%.

If you’re scratching your head like “what the heck is this cologuard test all about?” then let me give you break it down for you real quick below.

What is a cologuard test?

Cologuard is a test that can help screen for colon and rectal cancer. Your colon sheds cells from its lining every single day, and those cells come out with your…uhh…you know, the stuff you poop out. Now, if there are any cancer cells present, they might have some wonky changes in their DNA that can be detected by the Cologuard test kit.

What percentage of positive cologuard tests are cancer?

Based on the manufacturer’s website, the test has a reported sensitivity of 92.3% and a specificity of 87.3%. What does this mean? Well, if the test comes back positive, there is a pretty high chance that the individual has colorectal cancer – approximately 92.3%.

However, it’s important to keep in mind that a positive test result doesn’t necessarily mean that a person has cancer. Abnormal DNA or blood in the stool, which are detected by the test, can be caused by a variety of factors, including non-cancerous conditions.

But here’s where it gets tricky, folks. As much as we want these tests to be perfect, there are still some instances where they get it wrong. For example, a study on the FDA’s website found that 13% of patients received a positive result on their Cologuard test, even though they did not have colon cancer or polyps. And on the flipside, 8% of patients showed negative results, even though there were cancer or polyps present in their colon. So while it’s not very common to receive a false positive on a Cologuard test, it is possible; and bear in mind that false negatives are possible, too.

Since cologuard test can return false positives and not 100% foolproof, it is recommended that patients who got a positive cologurad test result to do further testing, such as a colonoscopy , in order to confirm whether cancer is present or to investigate other potential causes of the positive result.

Okay, I know what you are thinkging, what the heck is a colonoscopy right? It is like one medical term after another!

What is a colonoscopy?

A colonoscopy is a medical test that allows a doctor to look inside your large intestine (or colon) to check for any problems. During the test, a flexible tube with a camera on the end is inserted into your rectum and slowly guided through your colon, allowing the doctor to see the inside of the colon and look for abnormalities such as polyps, which could potentially develop into colon cancer.

It is a routine procedure that is performed under sedation, and generally takes about 30 minutes to complete.

A colonoscopy is also considered as the most effective method for detecting colon cancer as it allows your physician to examine your entire colon and rectum.

Well, if a colonoscopy is considered the best and a lot more accurate, then why don’t we all just start with a colonoscopy and skip the cologuard test?

Pros of a cologuard test

  1. It’s non-invastive
    Cologuard test, as mentioned, only need your stool sample. So compared to Colonscopy, it would not be poking cameras into your body and the entire process is a lot safer.
  2. It can be done at home
    Cologuard test is a home testing kit. It could be done in the comfort of your own home without a nurse or a doctor’s supervision. As we’ve mentioned, it’s seriously just collecting your poop, then send it back to the lab! Remember to wash your hands afterwards though.
  3. No need for preparation or anesthesia
    Unlike colonscopy, the patient does not need to go on a diet or a hunger strike before the procedure. You can keep your normal diet, just try not to get constipated. This test is best for people who might just:
    – need a regular check up
    – HATE the idea of anesthesia
    Since there are a lot of concerns on the use of anesthesia, the potential danger, and the fact that it is best to not be under anesthesia the best you could, the option of cologuard test as a stand-in for colonscopy is a godsend to many people.

That being said, as mentioned, a cologuard test is not perfect. If you get a positive cologuard test, you are usually advised to follow up with a colonoscopy.

Who should NOT do a cologuard test?

Individuals with any of the following should go straight for colonoscopy instead of a cologuard test:

  • Family or personal history of colon cancer
  • Inflammatory bowel diseases
  • Genetic syndromes which increase the risk of colon cancer

Given that the cologuard test is less accurate than a colonscopy, these high risk individuals should go for more frequent or earlier screening, or more invasive diagnostic testing. It’s important to consult with a healthcare provider to determine the most appropriate screening test and schedule based on individual risk factors and medical history.

How to prepare for a cologuard test?

Now, let’s get to the specifics and talk about how to get our hands (hopefully just figuratively) dirty. The preparation for a Cologuard test is relatively simple and does not require any specific diet or medication changes. However, there are some general guidelines to follow to ensure the most accurate results.

Before taking the test, it’s important to read and follow the instructions carefully to ensure that you collect the stool sample correctly. You should also avoid taking certain medications or supplements that could interfere with the results of the test. These include nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, iron supplements, and vitamin C supplements.

Avoid these types of food before your cologuard test:

  • red meat
  • raw fruits
  • vegetables
  • nuts
  • seeds
  • popcorn

It’s best to avoid these foods for at least three days before collecting the stool sample.

What is the process of the test?
1. Poop
2. Collect some of the poop in the sample holder provided
3. Send it back to the lab
4. (Additional but important point): make sure the poop is well-contained in the sample holder for your dear mailmen

How will the test feel?

It should not bring you any discomfort as it only requires you to have a normal bowel movement. It 100% should not feel different from your normal bowel movement, just PUSH enough for a sample.

What is a normal result?

A normal result of a Cologuard test means that no abnormalities were detected in the stool sample.

This means that there was no sign of blood or DNA mutations that could indicate the presence of colorectal cancer or precancerous polyps.

However, it is important to note, that a normal result does not mean that a person is completely free of any risk of developing colorectal cancer. Regular screening is still recommended for individuals who are at average or high risk for colorectal cancer.

If the result is abnormal, don’t panic. As we’ve talked about time and time again in this article. False positives are possible, and it may be positive for something completely unrelated to cancer. That being said, you should contact your family doctor or a specialist for further consulting. A colonoscopy will most likely be suggested.

Don’t scare yourself with potential false alarms if you are currently waiting for your cologuard test result! Take a deep breathe, it’s gonna be okay!

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