The future of cancer treatment
starts with you.

Join the GRECO-Breast research study to help us personalize breast cancer treatment



About GRECO-Breast

The GRECO-Breast research study examines how the Guardant360® blood test impacted your unique cancer journey.

Your doctor previously ordered Guardant360 to identify cancer-causing mutations and other genetic features that make your breast cancer unique—information that can be used to explore available treatment options.

Privacy and Security

Protecting your health information is our top priority.

Your personal health information stays private.
You have full control over who can access your health information. Your personal data will never be shared without your permission



How do I join the GRECO-Breast study?

We've made it as easy as 1-2-3 to be part of GRECO-Breast.

Step 1

Tell us you want to enroll.

Click “I’m Ready To Enroll Today” below and we will send you the study consent form with more information about the study. We will also send a form for you to provide basic information about your health care providers.

Step 2

Give us permission to collect your medical records.

We will ask you to sign an online consent form that allows us to access your cancer-related medical records. We’ll take it from there—we’ll reach out directly to your doctors, labs, and hospitals to obtain copies.

Step 3

You’re Enrolled!

Thank you for volunteering to take part in this study!



Everyone is on their own unique cancer journey. Those who join GRECO-Breast do so for their own reasons, including:

Advance Research

Contribute to research that may lead to treatment breakthrough.

Help Others

What we learn from you may help future patients with breast cancer.

Become Involved

Take an action role in your healthcare.

Only you can decide if joining this research study is right for you.


Learn More


The GRECO study is sponsored by Guardant Health, a leader in blood-based testing technologies for cancer diagnosis and treatment.

Pioneering Approach

Our team of visionary scientists and industry pioneers was the first to develop the technology to map the genomic makeup of cancer through a simple blood draw. Our proprietary blood tests are being used by thousands of oncologists nationwide to identify treatments options that give patients the best chance at beating cancer and to screen for cancer early, when it is possible to cure.

Trusted Technology

Many cancers, including breast cancer, shed trace amounts of DNA, called circulating tumor DNA or ctDNA. Guardant360® looks for ctDNA in the bloodstream, allowing for the detection and interpretation of cancer mutations through a simple blood test, instead of invasive tissue-based methods.

Harnessing the power of blood to conquer cancer with data.

Learn how Guardant is harnessing the power of blood to change the trajectory of cancer and making advances that move us closer to a blood test that screens for cancer.



Have additional questions  about GRECO-Breast?

(650) 618-8226


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