E-Book

E-Book 3rd Congress

  • An overview of the GRAIL test as a novel laboratory approach for detecting circulating tumor DNA
  • Alireza Khanahmad,1,*
    1. Department of Hematology and Medical Laboratory Sciences, Faculty of Allied Medicine, Kerman University of Medical Sciences, Kerman, Iran


  • Introduction: Cancer treatment is a major challenge for medical systems worldwide. It is proven that the decrease in mortality of malignancies is associated with early diagnosis. Limitations of the currently available laboratory tests such as the possibility of false results, invasive sampling, and high costs have made clinical and laboratory scientists design new panels for cancer diagnosis. Imaging, application of the biosensors, evaluation of the biomarkers, and investigation of the circulating tumor DNA (CT-DNA) have been introduced as cancer screening strategies in recent years. Small DNA fragments with a short half-life shed by tumor cells into the blood circulation are called CT-DNA. Apoptosis, necrosis, or active secretion are the possible mechanisms of releasing CT-DNA. In addition, Tumor origin, tumor stage, gender, and age are mentioned as variable factors that affect CT-DNA levels. Although detecting CT-DNA in the bloodstream is a hard procedure due to the simultaneous presence of circulating normal DNA, several laboratory tests are designed to evaluate the level of CT-DNA including GRAIL, IvyGene, CancerSEEk, ELSA-seq, PanSeer, and TEC-Seq. This study overviews the GRAIL (Gallery) test as a new strategy of CT-DNA evaluation for cancer screening.
  • Methods: A comprehensive search of the related keywords was done in the PubMed database. The most recent English articles were included.
  • Results: Machine learning and artificial intelligence (AI) are the basis for detecting and differentiating DNA methylation patterns of normal and tumor-circulating DNA in the GRAIL test. The test can screen and diagnose more than 50 types of malignancies by evaluating a panel with more than 100000 methylation sites in the whole genome of CT-DNAs. Several multi-centered and multi-patient clinical trials have investigated the efficacy of the GRAIL test. Studies showed that the GRAIL test can hold promise in the early-stage diagnoses of cancers. Thus, utilizing this test can result in a subsequent 39% reduction in 5-year mortality of cancers and a 26% reduction in overall cancer-related mortalities. However, the development of survival in cancer patients is highly dependent on cancer type. For example, an altered stage of diagnosis improves the survival rate for patients with prostatic cancer but does not affect the survival rate for patients with ovarian cancer.
  • Conclusion: Designing new strategies for early-detecting neoplasms is undeniably crucial. Among recently designed strategies, the GRAIL test is the most widely investigated multiple cancer early detection (MCED) test. However, its pros and cons are not fully identified.
  • Keywords: GRAIL test, gallery test, circulating tumor DNA, neoplasm, screening