Abstract 6093: Evaluation of preanalytical and physiological variables affecting cfDNA-based multi-cancer early detection test
Authors: Bao Hua , Chen Xiaoxi , Wu Xuxiaochen , Tang Wanxiangfu , Wu Min , Tang Shiting , Wu Xue , Shao Yang 
Published: March 2024

Abstract
Background: The multi-cancer early detection (MCED) tests utilizing blood-based circulating cell-free DNA (cfDNA) have gained significant attention in the market as a promising approach for early cancer detection. However, potential effects of preanalytical and physiological variables, including extraction methods, preservation techniques, and physiological factors such as diet, on the accuracy and reliability of MCED results remains poorly investigated. In this study, we aimed to evaluate the impact of physiological variables during blood collection and preanalytical procedures on the outcomes of a MCED test.
Methods: A total of 105 plasma samples from 19 healthy donors was collected and analyzed using a MCED test (MERCURY) which leverages the low-coverage whole-genome sequencing and a set of genome-wide features based on cfDNA fragmentomics. Samples were controlled for preanalytical procedures, including transportation condition and preservation time or physiological conditions (before/after meal or exercise) at blood collection.
Results: Repeat blood collection (N=4) from the 5 healthy participants consistently yielded negative results for cancer (PPA: 100.0%; 95% CI [56.6%,100.0%]). Among the 5 healthy participants, plasma samples frozen within 1 year (7 days, 3 months, 9 months) showed the same agreement with the reference condition as non-frozen samples (PPA: 100.0%; 95% CI [56.6%,100.0%]), except for one sample frozen for 1 year, which showed a higher risk score and became a positive signal (PPA:80.0%; 95% CI [37.6%,96.4%]). Transportation conditions within 2 hours, 24 hours, 48 hours, and 96 hours at room temperature or 4℃ did not affect the test outcomes, as all samples remained in agreement with the reference condition as of 2 hours at 4℃ (PPA:100.0%; 95% CI [61.0%,100.0%]). Physiological conditions, including pre- and post-meal as well as pre- and post-exercise states, did not exert any influence on the test results, as all samples exhibited agreement with the reference condition (PPA:100.0%; 95% CI [43.9%,100.0%]).
Conclusions: The results of this study suggest that variables such as time of blood collection and plasma freezing time may not significantly affect the accuracy of the MCED test in healthy participants. Transportation conditions and physiological conditions evaluated in this study did not have a notable influence on the test outcomes. Nevertheless, it is advised that the freezing duration of plasma samples should not exceed one year.
Citation Format: Hua Bao, Xiaoxi Chen, Xuxiaochen Wu, Wanxiangfu Tang, Min Wu, Shiting Tang, Xue Wu, Yang Shao. Evaluation of preanalytical and physiological variables affecting cfDNA-based multi-cancer early detection test [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6093.