Departement de Biologie, Centre Eugène Marquis, Rue de la Bataille Flandres Dunkerque, CS 44229, 35042 Rennes Cedex, France.
Cancer. 2012 Sep 1;118(17):4201-11. doi: 10.1002/cncr.27392. Epub 2012 Jan 31.
There is a strong need to determine the best technique for O(6) -methylguanine-DNA-methyltranferase (MGMT) analysis, because MGMT status is currently used in clinical trials and occasionally in routine clinical practice for glioblastoma patients.
The authors compared analytical performances and predictive values of 5 techniques in a series of 100 glioblastoma patients who received standard of care treatment (Stupp protocol).
MGMT promoter was considered methylated in 33%, 33%, 42%, and 60% of patients by methylation-sensitive high-resolution melting, MethyLight, pyrosequencing (with an optimal risk cutoff at 8% for the average percentage of the 5 CpGs tested), and methylation-specific polymerase chain reaction (MS-PCR), respectively. Fifty-nine percent of the samples had <23% (the optimal risk cutoff) of MGMT-positive tumor cells. The best predictive values for overall survival (OS), after adjustment for age and performance status, were obtained by pyrosequencing (hazard ratio [HR], 0.32; P < .0001), MS-PCR (HR, 0.37; P < .0001), and immunohistochemistry (HR, 0.43; P = .0005) as compared with methylation-sensitive high-resolution melting (HR, 0.52 P = .02) and MethyLight (HR, 0.6; P = .05). For progression-free survival (PFS), the best predictive values were obtained with pyrosequencing (HR, 0.35; P < .0001), methylation-sensitive high-resolution melting (HR, 0.46; P = .002), and MS-PCR (HR, 0.49; P = .002). Combining pyrosequencing and immunohistochemistry slightly improved predictive power for OS, but not for PFS. Poor reproducibility and interobserver variability were, however, observed for immunohistochemistry.
Good prediction of survival in addition to high reproducibility and sensitivity made pyrosequencing the best among the 5 techniques tested in this study.
目前，MGMT 状态被用于胶质母细胞瘤患者的临床试验和偶尔的常规临床实践中，因此，强烈需要确定分析 O(6)-甲基鸟嘌呤-DNA-甲基转移酶（MGMT）的最佳技术。
作者在 100 名接受标准治疗（Stupp 方案）的胶质母细胞瘤患者的一系列样本中比较了 5 种技术的分析性能和预测价值。
用甲基化敏感性高分辨率熔解、MethyLight、焦磷酸测序（对于测试的 5 个 CpG 的平均百分比，最佳风险临界值为 8%）、和甲基化特异性聚合酶链反应（MS-PCR），分别有 33%、33%、42%和 60%的患者的 MGMT 启动子被认为是甲基化的。59%的样本中 MGMT 阳性肿瘤细胞的比例<23%（最佳风险临界值）。经过年龄和表现状态调整后，焦磷酸测序（危险比 [HR]，0.32；P<.0001）、MS-PCR（HR，0.37；P<.0001）和免疫组织化学（HR，0.43；P=.0005）在总生存期（OS）方面具有最佳的预测价值，与甲基化敏感性高分辨率熔解（HR，0.52；P=.02）和 MethyLight（HR，0.6；P=.05）相比。在无进展生存期（PFS）方面，焦磷酸测序（HR，0.35；P<.0001）、甲基化敏感性高分辨率熔解（HR，0.46；P=.002）和 MS-PCR（HR，0.49；P=.002）具有最佳的预测价值。然而，焦磷酸测序和免疫组织化学相结合略微提高了 OS 的预测能力，但对 PFS 没有影响。然而，免疫组织化学的重复性和观察者间变异性较差。
除了具有较高的重现性和敏感性外，焦磷酸测序还可以很好地预测生存，因此是本研究中测试的 5 种技术中最好的。
