Bustin Stephen A, Mueller Reinhold
Institute of Cell and Molecular Science, Barts and the London, Queen Mary's School of Medicine and Dentistry, University of London, UK.
Mol Aspects Med. 2006 Apr-Jun;27(2-3):192-223. doi: 10.1016/j.mam.2005.12.002. Epub 2006 Jan 30.
Molecular diagnostics offers the promise of accurately matching patient with treatment, and a resultant significant effect on improved disease outcome. More specifically, the real-time reverse transcription polymerase chain reaction (qRT-PCR), with its combination of conceptual simplicity and technical utility, has the potential to become a valuable analytical tool for the detection of mRNA targets from tissue biopsies and body fluids. Its potential is particularly promising in cancer patients, both as a prognostic assay and for monitoring response to therapy. Colorectal cancer provides an instructive paradigm for this potential as well as the problems associated with its use as a clinical assay. Currently, histopathological staging, which provides a static description of the anatomical extent of tumour spread within a surgical specimen, defines patient prognosis. The detection of lymph node (LN) metastasis constitutes the most important prognostic factor in colorectal cancer and as the primary indicator of systemic disease spread, LN status determines the choice of postoperative adjuvant chemotherapy. However, its limitations are emphasised by the considerable prognostic heterogeneity of patients within a given tumour stage: not all patients with LN-negative cancers are cured and not all patients with LN-positive tumours die from their disease. This has resulted in a search for more accurate staging protocols and has seen the introduction of the concept of "molecular staging", the incorporation of molecular parameters into clinical tumour staging. Quantification of disease-associated mRNA is one such parameter that utilises the qRT-PCR assay's potential for generating quantitative results. These are not only more informative than qualitative data, but contribute to assay standardisation and quality management. This review provides an assessment of the practical value to the clinician of RT-PCR-based molecular diagnostics. It points out reasons for the many contradictory results encountered in the literature and concludes that there is an urgent need for standardisation at every level, starting with pre-assay sample acquisition and template preparation, assay protocols and post-assay analysis.
分子诊断有望实现患者与治疗的精准匹配，并对改善疾病预后产生显著影响。更具体地说，实时逆转录聚合酶链反应（qRT-PCR），因其概念简单与技术实用性的结合，有潜力成为一种用于从组织活检和体液中检测mRNA靶点的有价值分析工具。其潜力在癌症患者中尤其显著，既可用作预后检测，也可用于监测治疗反应。结直肠癌为这一潜力以及将其用作临床检测相关的问题提供了一个具有启发性的范例。目前，组织病理学分期对手术标本内肿瘤扩散的解剖范围进行静态描述，以此定义患者预后。淋巴结（LN）转移的检测是结直肠癌最重要的预后因素，作为系统性疾病扩散的主要指标，LN状态决定了术后辅助化疗的选择。然而，给定肿瘤分期内患者预后存在相当大的异质性，这凸显了其局限性：并非所有LN阴性癌症患者都能治愈，也并非所有LN阳性肿瘤患者都会死于该疾病。这导致人们寻求更准确的分期方案，并引入了“分子分期”的概念，即将分子参数纳入临床肿瘤分期。疾病相关mRNA的定量就是这样一个利用qRT-PCR检测产生定量结果潜力的参数。这些结果不仅比定性数据更具信息性，还有助于检测标准化和质量管理。本综述评估了基于RT-PCR的分子诊断对临床医生的实用价值。它指出了文献中出现许多矛盾结果的原因，并得出结论，迫切需要在各个层面进行标准化，从检测前的样本采集和模板制备、检测方案到检测后分析。
