“The earlier that cancer can be found, the higher the chance of successful treatment and survival. Yet, too often cancer goes undetected until it has progressed to an advanced stage“.  Pushing at an open door there, as many Neuroendocrine Cancer patients will confirm. 

Those words introduce a new cancer screening test called “Galleri^TM ” – labelled as a “multi-cancer early detection test”.  The Galleri test looks for signals present in the blood that may be associated with cancer at the time of your blood draw. If a cancer signal is detected, Galleri results can point to where in the body the cancer is coming from to help your healthcare provider guide next steps.  As at the date of this blog post, the list of cancers can be found here but I will list what I found below any related to Neuroendocrine Neoplasms (NENs).  As you can imagine, NENs are not homogenous (of the same kind; alike), they are the opposite, they are heterogenous (all different) and I guess this provides a challenge to those looking at screening and marker tests. I found the following listed:

• Merkel Cell Carcinoma – a Neuroendocrine Carcinoma (NEC) of the skin
• Neuroendocrine Tumors of the Appendix
• Neuroendocrine Tumors of the Colon and Rectum
• Neuroendocrine Tumors of the Pancreas

Clearly not completely covering Neuroendocrine Neoplasms. They do list stuff simply stating parts of the anatomy, for example, some entries just say, “Small Intestine”, Lung”, “Stomach”, “Liver”, whether that includes Neuroendocrine Neoplasms of these organs is up for debate.  My immediate thoughts are they do not have enough data to declare them separately as they have done with Appendix, Colon and Rectum and Pancreas.  The link is here. 

The sensitivity and specificity of the tests is not 100% but some cancers in the study produced figures in the 90s but others were low. It seems to be more successful in advanced cancer – this makes sense according to informed comments on the basis that “more advanced cancers typically shed more DNA into the bloodstream”.  One of the studies only picked up 18% of early, stage 1 cancers.

Data on all 50 types lists at the link above is sparse currently, I’m hoping to dig it out later.  Nonetheless, the important thing about a screening test is that it points out something suspicious which then needs to be validated by the normal marker and imaging tests for that particular cancer.  

Worth emphasising this is NOT a test for routine diagnosis or for routine surveillance of NENs, it’s a screening test.  As Grail confirm themselves, “The Galleri test does not detect all cancers and should be used in addition to routine cancer screening tests. Results should be interpreted by a healthcare provider. A “Cancer Signal Not Detected” result does not rule out cancer. A “Cancer Signal Detected” result requires confirmatory diagnostic evaluation (e.g. imaging), and if cancer is not confirmed, it may not be present, may not be detectable by diagnostic follow-up testing or may be located in a different part of the body. False-positive and false-negative test results do occur.”  Read more about the 3 clinical studies here:

Whether this is something to get excited about is too early to say.  I always double check stuff against Cancer Research UK’s scientific blog and found they have an article dated April 2020, I’ll let you read it yourself – here. 

The test only seems to be available in USA and I did note this on the manufacture’s website “The Galleri test is intended to be complementary to, and not a replacement of, U.S. guideline-recommended cancer screening.”

I intend to follow this story and keep this blog post live.  I’d like to think this progress will lead to finding better marker tests for Neuroendocrine Cancer which can also be used in both diagnostics and surveillance scenarios.