Multicenter Genetic, Epigenetic & Expression Analysis of DCIS outcome predictors

描述(申请人提供)：这个项目的目标是确定从导管原位癌(DCIS)到浸润性乳腺癌进展过程中发生的分子变化。这一点至关重要，因为只有在达到组织侵袭的里程碑之后，癌症才有可能转移并导致患者死亡。浸润性乳腺癌是在从ADH到导管原位癌(DCIS)再到浸润性乳腺癌的过程中依次获得的多个分子改变。我们将确定可能是DCIS特有的或可能随着恶性潜能的增加而累积的基因改变。7Rationale：虽然导管原位癌(DCIS)的治愈率超过90%，但这是以相当高的治疗相关发病率为代价的。我们迫切需要能够识别预测DCIS长期预后的关键基因改变的预后标记物，因为大多数DCIS永远不会成为浸润性癌，可能是因为它们缺乏关键的基因变化、复制的寿命，或者仅仅是这样做所需的时间。我们的实验设计利用了最新的技术发展，允许对DNA样本进行基因和表观遗传学改变的全基因组测试，即使在可从DCIS存档样本中获得的非常有限的材料中也是如此。DCIS可能代表了尝试各种克隆进化途径的阶段，直到特定的遗传和/或表观遗传变化的组合允许组织入侵。有迹象表明，基因突变和表观遗传沉默都可能在致癌过程中起作用，这些替代方案可能可以互换使用，甚至在同一癌细胞中以互补的方式使用。因此，有必要对这两种类型的变更进行综合分析。7设计：本研究为多中心纵向病例对照研究。我们已经确定了结果已知的纯DCIS病例的独特队列，以实现对100例病例和100名对照的多中心全基因组筛查研究，最初将仅限于高加索血统的患者，以获得同种患者群体，并最大限度地成功验证我们的假设，即DCIS中存在预后标志物。感兴趣的候选标记物将通过定量聚合酶链式反应方法进一步表征，目的是创建一种单一的、预测预后的多重聚合酶链式反应标记，该标记可用于通常在DCIS评估的诊断阶段获得的有限临床材料。然后，我们将在一个独立的测试队列中验证该分析，该队列包括100例进展性DCIS病例和100例保持无疾病的DCIS病例，这些病例来自爱荷华州SEER残留组织储存库(RTR)提供的基于人群的储存库。我们还将使用位于夏威夷的另一个基于人口的储存库，以测试从高加索样本开发的预后标记是否可以成功地用于不同的种族群体。这将指导未来的工作，特别是关于探索多重检测在不同人群中预测能力的必要性。 与公共卫生相关：该项目的首要目标是开发强大的、基于DNA的预测性遗传标记，这些标记将有助于识别少数侵袭前乳腺癌(DCIS)病例，鉴于目前缺乏可用于对单纯DCIS患者进行分层的分子指导，这些病例确实进展为浸润性疾病。目前每年有60,000多名被诊断为单纯DCIS的妇女中，只有不到30%的人会在接受手术切除后10年内发展为复发的乳房疾病。有了适当的标记物，许多人可以避免激进治疗的成本和发病率。此外，对更好地治疗那些疾病进展风险较高的患者的新方法的评估仍将是一个问题，只要大多数病例无论采取何种干预措施都能取得良好效果。

DESCRIPTION (provided by applicant): The goal of this project is to identify the molecular alterations that occur in the progression from ductal carcinoma in situ (DCIS) to invasive breast cancer. This is of critical importance because it is only after the milestone of tissue invasion has been achieved that a cancer has the potential to metastasize and kill a patient. Invasive breast cancers harbor multiple molecular alterations that were sequentially acquired during progression from ADH to ductal carcinoma in situ (DCIS) to invasive breast cancer. We will identify the genetic alterations that may be specific to DCIS or may be cumulative with increasing malignant potential. 7Rationale: While the cure rate for ductal carcinoma in situ (DCIS) is over 90%, this comes at the cost of considerable treatment-related morbidity. We urgently need the prognostic markers that would identify key genetic alterations predictive of the long-term outcome of DCIS, since most DCIS never become invasive carcinomas, presumably because they lack critical genetic changes, the replicative lifespan, or simply the time necessary to do so. Our experimental design exploits recent technological developments that permit genome- wide testing of DNA samples for genetic and epigenetic alterations, even in the very limited material available from archival DCIS samples. DCIS may represent a stage at which various pathways of clonal evolution are attempted, until a particular combination of genetic and/or epigenetic changes allows tissue invasion. Indications are that genetic mutations and epigenetic silencing may both be operative in carcinogenesis, and that these alternatives may be used interchangeably, even in a complementary fashion in the same cancer cell. Therefore, a combined analysis of both types of alterations is necessary. 7Design: This study is designed as multicenter, longitudinal, case-control study of DCIS. We have identified unique cohorts of pure DCIS cases with known outcomes to enable a multicenter genome-wide screening study of 100 cases and 100 controls, which will be initially limited to patients of Caucasian origin in order to obtain a homogenous patient population and maximize the probability of successfully validating our hypothesis that prognostic markers exist in DCIS. Candidate markers of interest will be further characterized by quantitative PCR methods, with the goal of creating a single, prognostic multiplex PCR signature that can be used on the limited clinical material typically obtained in the diagnostic phase of the evaluation of DCIS. We will then validate the assay in an independent test cohort of 100 cases of DCIS with progressive disease vs. 100 cases of DCIS that remain disease free, obtained from the population-based repository provided by the Iowa SEER residual tissue repository (RTR). We will also use an additional population-based repository located in Hawaii, to test if the prognostic signature developed from Caucasian samples can be used successfully in a different ethnic group. This will guide future work, particularly regarding the necessity of exploring the predictive power of the multiplex assay in different populations. PUBLIC HEALTH RELEVANCE: The overarching goal of this project is to develop robust, DNA-based predictive genetic markers that will be useful in identifying the minority of cases of preinvasive breast cancer (DCIS), that do in fact progress to invasive disease, given the current lack of molecular guidance available to stratify patients with pure DCIS. Of the over 60,000 women currently diagnosed with pure DCIS per year, less than 30% will develop recurrent breast disease within 10 years of undergoing a surgical resection. With appropriate markers, many could be spared the cost and morbidity of aggressive therapy. Furthermore, the assessment of new approaches to better treat those patients at high risk of disease progression will remain problematic as long as most cases would do well regardless of intervention.