Bhardwaj Megha, Schrotz-King Petra, Brenner Hermann
Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany.
Division of Preventive Oncology, German Cancer Research Center (DKFZ) and National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany.
Life (Basel). 2022 Mar 2;12(3):359. doi: 10.3390/life12030359.
In recent years the blood proteome has been increasingly researched for biomarkers for early detection of colorectal cancer (CRC). Blood samples from screening studies are often subject to preanalytical variability and repeated freeze−thaw cycles. We aimed to assess the correlation of repeat measurements of 27 candidate protein markers for CRC screening taken three years and multiple freeze−thaw cycles apart. The concentrations of 27 protein markers were measured in plasma samples of 39 newly detected CRC cases from a cohort of 9245 participants of screening colonoscopies. The proteins were measured using proximity extension assays (PEA) carried out on the same set of samples twice, three years apart, with an average of three freeze−thaw cycles in between the two measurements. Pearson’s product moment correlation coefficients were calculated. Correlation coefficients ranged from +0.43 to +0.97, with a median of 0.67 and an interquartile range of +0.58 to +0.84, with all p-values of correlation being <0.01 (<0.0005 for 22 proteins, <0.001 for 4 proteins). Repeat measurements of the 27 protein biomarkers for CRC screening performed three years later, and on average three freeze−thaw cycles apart, showed moderate to high levels of correlation. Apart from the effects of freeze−thaw cycles, slightly different preprocessing performed on the data may have contributed to recorded differences between measurements.
近年来，人们越来越多地研究血液蛋白质组，以寻找用于早期检测结直肠癌（CRC）的生物标志物。筛查研究中的血样常常受到分析前变异性和反复冻融循环的影响。我们旨在评估在相隔三年且经过多次冻融循环的情况下，对27种用于CRC筛查的候选蛋白质标志物进行重复测量之间的相关性。在9245名接受筛查结肠镜检查的参与者队列中，对39例新确诊的CRC病例的血浆样本测量了27种蛋白质标志物的浓度。使用邻近延伸分析（PEA）对同一组样本进行了两次蛋白质测量，两次测量相隔三年，两次测量之间平均有三次冻融循环。计算了Pearson积矩相关系数。相关系数范围为+0.43至+0.97，中位数为0.67，四分位间距为+0.58至+0.84，所有相关性的p值均<0.01（22种蛋白质<0.0005，4种蛋白质<0.001）。三年后对27种用于CRC筛查的蛋白质生物标志物进行重复测量，且平均相隔三次冻融循环，结果显示出中度至高度的相关性。除了冻融循环的影响外，对数据进行的略有不同的预处理可能也导致了测量结果之间的差异。
