Issue link: https://viewer.e-digitaledition.com/i/1414760
Could a Multi-Cancer Early Detection Blood Test Signal a Seismic Shift for Cancer Screening? BY THOMAS CROCKER GALLERI, A TEST DE VELOPED BY CALIFORNIA-BA SED HE ALTHCARE COMPANY GR AIL, CAN DE TECT DOZENS OF T YPES OF CANCER — MOST OF WHICH CURRENTLY L ACK A RECOMMENDED SCREENING TEST — WITH A SINGLE BLOOD SAMPLE. WHAT COULD THAT ME AN FOR THE WAY CLINICIANS SCREEN FOR AND TRE AT CANCER? THE AMERICAN CANCER Society proj- ects that 608,570 people will die of cancer in the U.S. in 2021. A key reason for the toll is a dearth of screening tests for all but a handful of cancer types. That leaves many cases of cancer to go undetected until their late, symptomatic stages when the burden of treatment is greater and the risk of mortality higher. "Current g uideline-recommended screening tests in the U.S. save lives, but there are only five that exist, and they screen for a single cancer at a time — colon, cervical, breast, prostate and, in high-risk patients, lung cancer," says Michael V. Seiden, MD, PhD, President of the US Oncology Network. "The most pressing, unmet need in early cancer detection is thus to identify cancers for which there are no existing recommended screen- ing tests." Study results demonstrate Ga lleri can do just that. In 2020, a substudy of the Circulating Cell-free Genome Atlas (CCGA) study — a case-controlled valida- tion study including more than 15,000 participants with and without cancer — published in Annals of Oncology found that Galleri could identify more than 50 cancer types in all stages with a false-positive rate of 0.7%. The test pinpointed the organ of cancer origin with 93% accuracy. A previous CCGA substudy from 2019 had found that Galleri could detect more than 20 cancer types with a low false-positive rate and precise localization. In 2021, Annals of O ncology pub- lished the results of the third and final CCGA substudy. " T h i s c l i n ic a l v a l id a t ion c ohor t included more than 4,000 participants with and without cancer," says Dr. Seiden, who is part of the CCGA team. "The speci- ficity was 99.5% (0.5% false-positive rate). The test detected cancer signal from more than 50 types of cancer … and predicted the cancer signal origin in 89% of cases. Being able to identify where in the body the cancer is located with high accuracy is critical to help physicians direct next steps for diagnostic workups." 1 4