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What is the Galleri Test for Cancer Screening?

The Galleri test is a blood test used for early cancer detection. It is designed to detect more than 50 types of cancer, including those that are often difficult to diagnose early, such as pancreatic, ovarian, and esophageal cancers. The test works by analyzing the levels of circulating tumor DNA (ctDNA) in the blood, which are fragments of DNA shed by cancer cells.

Indications for Galleri Test for Cancer Screening

The Galleri test is intended for individuals who do not have a known cancer diagnosis and who have an average risk of developing cancer. It is not a diagnostic test but rather a screening tool that can help identify individuals who may benefit from further evaluation and diagnostic testing. If the test results indicate a high likelihood of cancer, additional diagnostic tests, such as imaging studies or tissue biopsies, would be recommended to confirm the diagnosis.

Who is Eligible for the Galleri Test?

You are eligible for a Galleri test if:

  • You are 50 years of age or older
  • You are not pregnant
  • You have not been diagnosed with or treated for cancer in the last 3 years (excluding basal or squamous skin cancers or hormonal therapy for breast cancer)
  • Have one or more of the following lifestyle risk factors:
    • Survivor of childhood or young adult cancer
    • Have a first-degree relative who has had cancer (parent, child, and/or full sibling)
    • Obesity
    • Heavy alcohol use (regularly over 8 servings per week)
    • Tobacco use (over 20 pack year history)

What Happens During the Galleri Test for Cancer Screening?

A healthcare provider collects a blood sample from the individual undergoing screening. This blood sample contains circulating tumor DNA shed by cancer cells, as well as DNA from normal cells. The collected blood sample undergoes advanced DNA sequencing and analysis techniques. During sequencing, the DNA from the sample is analyzed to identify genetic alterations or mutations that are associated with cancer. The Galleri test uses machine learning algorithms and computational methods to analyze the sequencing data. These algorithms compare the genetic information from the blood sample to a database of known cancer-related genetic alterations. By comparing the genetic alterations detected in the blood sample to the database, the Galleri test can identify patterns or signatures that are indicative of the presence of certain types of cancer. The test is designed to detect more than 50 types of cancer, including those that are often challenging to diagnose early.


Based on the analysis results, the Galleri test provides a risk assessment for the presence of cancer. It may indicate a low, intermediate, or high risk of cancer based on the genetic alterations detected in the blood sample. If the Galleri test indicates a high risk of cancer, further evaluation and diagnostic testing are recommended. This may include imaging studies (such as CT scans or MRIs) or tissue biopsies to confirm the presence of cancer and determine its extent.

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