A clinical review of a novel blood test use in rural Alabama for multi-cancer detection, analyzing methylation patterns of cell-free DNA and future strategies.

Abstract

e15183 Background: In 2022 608,366 people worldwide died of cancer and the number is only growing. Galleri is a clinically validated multi-cancer early detection (MCED) blood test that screens for many of the deadliest cancers before they become symptomatic. In a clinical study, on an average, fewer than 2 out of 100 people with a negative result received a cancer diagnosis (Negative Predictive Value was 98.5%) showing high specificity of this test. The test works by examining the cell free DNA (cfDNA) specifically targeting methylation patterns and using its extensive database to analyze whether there's an abnormal pattern. If detected, the test predicts the most likely origin of the cancer signal, to help guide the diagnostic workup. We present clinical data in 2 years (2023-2024) from a community based cancer center in Rural Alabama. Methods: Retrospective Data Analysis. Results: In our analysis, we have 27 patients in one cancer center in rural Alabama tested with Galleri. 2 had prior diagnosis of cancer in remission. 25 did not have any prior cancer diagnosis. 5 patients tested positive (2 Lung cancers, 2 Breast cancers, 1 Kidney Cancer) and 22 patients tested negative. There were 11 males and 16 females. The average age of the patients who tested positive was 74.6 years and the average age of the patients who tested negative was 59.9 years. From 27 patients, 5 tested positive through the galleri test and later diagnostic workup showed a total of 6/28 had cancer diagnosis (one false negative) so our Negative predictive value (NPV) was 77.7%. Of the 5 patients detected to have cancer 3 had metastatic disease (2 breast, 1 kidney) and 2 had early stage cancer (lung cancer). FDA is reviewing the Galleri multi-cancer early detection test for approval. Our small sample size is due to the cost of the study (self -pay) and lack of FDA approval at this time. We also propose how a test based in Saliva can be used as an MCED test and its pros and cons. Also based on our limited experience we have found two cases of Genitourinary (GU) cancers where the test was negative and patients subsequently were found to have GU malignancies. Conclusions: The Galleri test has tremendous potential in saving lives of patients with cancers esp. early stage cancers and can be widely adopted in community after approval. It can also detect cancers for which there are no available screening tests available adding to the utility of the test.