Centre Eugène Marquis, Rennes, France.
INSERM U1242, Université de Rennes 1, Rennes, France.
Cancer Biomark. 2017 Dec 6;20(4):435-441. doi: 10.3233/CBM-170191.
Pyrosequencing is recognized as a strong technique to analyze the MGMT status of glioblastoma patients. The most commonly used assay, quantifies the methylation levels of CpGs 74 to 78. A more recent CE-marked In Vitro Diagnostic Medical Device (CE-IVD) assay, Therascreen, analyzes CpGs 76-79.
We performed a comparison of these two assays to evaluate the potential impact of this shift in analyzed CpGs. Therascreen analysis was centrally performed for 102 glioblastoma patients, who were part of a prospective multicenter trial.
A strong correlation was observed for the mean values of the 4 or 5 analyzed CpGs, with lower values recorded using the Therascreen assay, especially for values greater than 20%. When considering a classification in 3 categories (> 12%: methylated; ⩽ 8%: unmethylated; 9-12%: grey zone), 93% of patients were identically classified between the two assays. Using a binary classification, 95% and 97% of patients were identically classified with cut-offs of 8% and 12%, respectively. A strong prognostic significance was observed for both assays: median overall survival were 15.9 months and 34.9 months for respectively unmethylated and methylated patients with either test.
The results demonstrate that these assays may be used interchangeably.
焦磷酸测序被认为是分析胶质母细胞瘤患者 MGMT 状态的强有力技术。最常用的检测方法，定量分析 CpG 74 到 78 的甲基化水平。最近有一个经过 CE 标记的体外诊断医疗器械（CE-IVD）检测方法 Therascreen，分析 CpG 76-79。
我们对这两种检测方法进行了比较，以评估分析 CpG 改变的潜在影响。Therascreen 分析是针对 102 名胶质母细胞瘤患者进行的中心检测，这些患者是一项前瞻性多中心试验的一部分。
观察到 4 或 5 个分析 CpG 的平均值之间存在很强的相关性，使用 Therascreen 检测方法记录到的数值较低，尤其是对于大于 20%的数值。当考虑分为 3 个类别（>12%：甲基化；⩽8%：未甲基化；9-12%：灰色地带）时，两种检测方法对 93%的患者进行了相同的分类。使用二分类，两种检测方法的截断值分别为 8%和 12%时，95%和 97%的患者被相同地分类。两种检测方法均具有强烈的预后意义：未甲基化和甲基化患者的中位总生存期分别为 15.9 个月和 34.9 个月。
这些结果表明这两种检测方法可以互换使用。
