What should you know about Guardant360 blood test?

The test uses a blood sample to look for genetic changes or other tumour signals that may be present in the bloodstream. The result can sometimes help a specialist consider targeted treatment, further testing, or monitoring. A result may be actionable, uninformative, or unable to provide enough material for interpretation. It does not replace examination, scans, pathology, or a discussion of your full medical history.

Your oncology team should explain why the test is being offered, whether any preparation is needed, and how the result could affect the next decision. Bring a list of medicines and previous reports. Ask how the sample will be handled and when the result will be reviewed. Do not change cancer treatment based on a result without speaking with the treating specialist.

Contact your care team promptly for new or worsening breathlessness, severe pain, confusion, persistent vomiting, heavy bleeding, or a rapid decline in general condition. These symptoms need clinical assessment regardless of a blood-test result. A routine blood test may also be used when checking concerns such as [Anaemia](/conditions/anaemia/) or [Chronic Kidney Disease](/conditions/chronic-kidney-disease/), but those tests answer different questions.

Ask what the test is intended to find, whether tissue testing is also needed, what an inconclusive result would mean, and which treatment choices could be affected. Ask who will explain the report and how it fits with scans and pathology.