(PQC3) Genomic Diversity and Microenvironment as Drivers of Metastasis in DCIS

描述(申请人提供)：导管原位癌(DCIS)是一种乳腺浸润性前病变，几乎占所有乳房X光检查发现的恶性肿瘤的30%[1，2]。在DCIS中，与许多癌前病变一样，主要的临床挑战是预测哪些病变可能进展为侵袭性和转移性疾病。在缺乏可靠的预后工具的情况下，所有的DCIS都被视为会进展，导致那些DCIS缺乏进展潜力的患者受到伤害。因此，准确和临床可操作的DCIS预后标记物是非常必要的。肿瘤的发展经历了随机突变和克隆扩张的过程，导致肿瘤之间和肿瘤内的广泛异质性[4]，这使得基于特定标记物预测预后具有挑战性。此外，肿瘤内的克隆多样性覆盖在异质微环境的背景上，这可以通过对不同肿瘤区域的不同转移群体施加不同的选择压力来加速进化过程[5，6]。种群中的遗传多样性是自然选择的燃料，是进化速度的关键决定因素[8，9]。遗传和微环境多样性越多，选择驱动克隆扩张的机会就越多，肿瘤适应新的选择压力的机会就越多。鉴于其随机性，我们对预测进展问题的解决方案不是衡量体细胞进化的产物(例如，是否存在突变)，而是衡量体细胞进化的过程(例如，遗传多样性)。

DESCRIPTION (provided by applicant): Ductal carcinoma in situ (DCIS) is a preinvasive lesion of the breast that makes up almost 30% of all mammographically detected malignancies [1,2]. In DCIS, as for many pre-malignant lesions, the main clinical challenge is predicting which lesions are likely to progress to invasive and metastatic disease. In the absence of reliable prognostic tools, all DCIS is treated as if it would progress, resulting in harm for those patients whose DCIS lacks potential for progression. Thus accurate and clinically actionable prognostic markers for DCIS are critically needed. Neoplasms progress through a process of random mutations and clonal expansions, leading to widespread heterogeneity both between and within neoplasms [4] that makes it challenging to predict prognosis on the basis of specific markers. Moreover, the clonal diversity within a neoplasm is overlaid upon a background of heterogeneous microenvironments, which can accelerate the evolutionary process [5,6] by imposing different selective pressures on different meta-populations in different tumor regions [7]. Genetic diversity in a population is the fuel for natural selection and is a key determinant of the rate of evolution [8,9]. The more genetic and microenvironmental diversity, the more opportunities for selection to drive clonal expansions and for the neoplasm to adapt to new selective pressures. Our solution to the problem of predicting progression given its stochastic nature is not to measure the products of somatic evolution (e.g., presence/absence of a mutation), but to measure the process of somatic evolution (e.g., genetic diversity).