Genetic Epidemiology

这个遗传流行病学项目的许多调查都来自于对癌症高风险家庭的观察或其他病因学研究。一项对来自费城和旧金山黑色素瘤诊所的718名非西班牙裔白人皮肤黑色素瘤患者进行病例对照研究的试点研究正在计划中。来自意大利东北部183例黑色素瘤病例和179例对照病例的问卷调查数据、肿瘤和DNA被用于评估黑色素皮质素-1受体（MC1R）基因（人类色素沉着的主要调节因子）和BRAF致癌基因的体细胞突变。在身体暴露在阳光下的区域和有限的慢性太阳损伤的黑色素瘤患者中，我们发现MC1R种系变异与BRAF癌基因体细胞突变的黑色素瘤之间存在很强的相关性。我们在一个独立的人群中证实了这种关联。收集了其他意大利人群的数据，以扩展黑色素瘤风险与色素沉着和免疫相关基因之间关系的分析；对这些新增人口的评价正在进行中。导致黑色素瘤发展的潜在途径之一包括失去对普通黑色素细胞痣的调节，这些黑色素细胞痣获得非典型或发育不良的特征，可以进一步发展为肿瘤。为了研究这一途径，我们目前正在收集来自意大利东北部同一受试者的正常皮肤、普通黑素细胞痣、发育不良痣、黑色素瘤和黑色素瘤转移灶的多个组织样本。我们将收集扩展到另一个意大利站点（LAquila），以增加分析的统计能力。不幸的是，大多数在拉奎拉收集的材料在2009年毁灭性的拉奎拉地震中被毁。我们计划在一系列组织样本和种系DNA中研究细胞周期、端粒和转导通路中多个基因突变的表达和存在，以探索通过痣参与黑色素瘤发展的机制。对来自DCEG成人脑肿瘤病例对照研究的365例胶质瘤患者的亲属进行了个人/家族病史和其他危险因素的访谈。与人口控制相比，一级亲属患癌症风险的分析已经完成；结果报告正在进行中。一项儿童髓母细胞瘤的回顾性单机构研究的问卷调查数据显示，几乎没有证据表明髓母细胞瘤患者的亲属患癌症的风险增加。脊索瘤是一种罕见的原发性恶性骨肿瘤，主要发生在胚胎脊索干细胞未能正常退化的轴骨中。我们正在与波士顿马萨诸塞州总医院放射肿瘤科合作，确定脊索瘤家族，以帮助绘制和确定脊索瘤易感基因。该项目包括从最可能有脊索瘤遗传易感性的患者亚组（即诊断为脊索瘤<18岁的患者）获取个人和家族病史、颊细胞和肿瘤组织切片。在过去的一年中，我们完成了55例脊索瘤患者的登记。我们正在获取他们的个人和家族病史、口腔细胞和肿瘤组织。此外，我们正在准备对该方案进行修订，以扩大研究范围，再纳入150名任何年龄和部位诊断为脊索瘤的患者。通过与耶鲁大学组织微阵列（TMA）核心设备的合作，我们已经成功地构建了1500个来自波兰乳腺癌研究的侵袭性肿瘤的TMA。我们用免疫组织化学（IHC）对这些肿瘤的一部分（N=842）进行了18个涉及激素生物合成、代谢和受体介导途径的分子标记的染色。对这些标志物的分析表明，乳腺癌的危险因素可能因分子亚型和以激素标志物共同表达为特征的激素途径而异。我们还使用新开发的自动定量分析（AQUA）对六种标记（er - α, er - β， PR, HER2， EGFR和CK5）的所有tma进行了染色。两种方法（AQUA和IHC）的比较表明，AQUA分析TMAs所代表的肿瘤提供了可靠的、定量的标记物表达测量。我们还将一些市售的成像分析软件与病理学家的测量结果进行了比较，我们的数据表明，IHC标记物的自动分析代表了一种在流行病学调查中分析大量乳腺癌组织的有前途的方法。我们还探索了成像分析在1547个非侵入性组织核中标记物表达评分的实用性，包括正常tdlu和在32个TMA块上构建的DCIS。除了对固定组织中的候选标记物进行TMA分析外，我们还对来自波兰病例子集的冷冻肿瘤进行了基因表达和拷贝数变化的肿瘤谱分析，以更好地定义与不同病因途径相关的分子亚型。肾细胞癌（RCC）的发病率在中欧和东欧是世界上最高的。von Hippel - lindo - hypoxia Inducible Factor （VHL-HIF）通路与肾癌的发生有关。我们研究了VHLHIF通路中常见基因变异在散发性RCC和透明细胞RCC易感性中的作用。我们确定了与肾癌风险相关的VHL-HIF通路中基因的常见遗传变异。这些变异的基因分型结果现已获得，目前正在另外几个研究人群中进行检验以确认。我们正在继续开展基于瑞典相关登记数据的研究，以更好地定义家族中共同聚集的淋巴细胞恶性肿瘤的模式。我们对不确定意义单克隆γ病（MGUS）的前体条件进行了详细的分析。我们发现MGUS患者的亲属发生MGUS的风险增加了3倍，发生多发性骨髓瘤（MM）的风险增加了3倍。Waldenstrom巨球蛋白血症和CLL的风险也增加了。不同MGUS亚型间存在差异。MM患者的亲属罹患MGUS或MM的风险增加。MGUS和MM患者的亲属罹患任何实体瘤的风险均升高，尽管风险很小（HR=1.1, 95% CI=1.0-1.2）。我们还根据世界卫生组织的分类将淋巴瘤分类为亚型，从而改进了我们对淋巴瘤聚集的估计。我们发现弥漫性大b细胞淋巴瘤（DLBCL）患者的亲属发生DLBCL的风险增加了10倍，发生霍奇金淋巴瘤的风险增加了2倍，但发生滤泡性淋巴瘤（FL）的风险没有增加。同样，FL患者的亲属发生FL的风险增加了4倍，所有惰性b细胞淋巴瘤的风险增加了2倍，但DLBCL的风险没有增加。

Many of the investigations in this genetic epidemiology project arise from observations in families at high risk of cancer or in other etiologic studies. A pilot study to follow-up patients from a case-control study of 718 non-Hispanic white patients with cutaneous melanoma from melanoma clinics in Philadelphia and San Francisco is being planned. Questionnaire data, tumor, and DNA from a case-control study of 183 incident melanoma cases and 179 controls conducted in North-Eastern Italy were used to evaluate the melanocortin-1 receptor (MC1R) gene, the major regulator of human pigmentation, and somatic mutations of the BRAF oncogene. In subjects with melanoma arising on sun exposed areas of the body and with limited chronic solar damage, we found a strong association between MC1R germline variants and melanoma with somatic mutations in the BRAF oncogene. We confirmed this association in an independent population. Data from other Italian populations have been collected to extend the analyses of association between melanoma risk and pigmentation and immune-related genes; evaluation of these additional populations is in process. One of the potential pathways that leads to the development of melanoma includes the loss of regulation of common melanocytic nevi, which acquire atypic or dysplastic characteristics that can further evolve in neoplasia. To study this pathway, we are currently collecting multiple tissue samples of normal skin, common melanocytic nevi, dysplastic nevi, melanoma and metastasis from melanoma from the same subjects from North-Eastern Italy. We extended the collection to another Italian site (LAquila) to increase the statistical power for analyses. Unfortunately most of the material collected at LAquila was destroyed during the devastating 2009 LAquila earthquake. We are planning to study the expression and presence of mutations in multiple genes of the cell cycle, telomere, and transduction pathways in the serial tissue samples and germline DNA to explore the mechanisms involved in melanoma development through nevi. Relatives of 365 of the glioma cases from a DCEG comprehensive case-control study of adults with brain tumors were interviewed about personal/family medical history and other risk factors. Analyses to examine the risk of cancer among the first degree relatives compared to population controls have been completed; write-up of the results is in process. Examination of questionnaire data from a retrospective single institution study of childhood medulloblastoma showed little evidence for increased cancer risks among relatives of medulloblastoma patients. Chordoma is a rare primary malignant bone tumor that arises mainly in the axial skeleton from rests of embryonic notochordal stem cells that failed to undergo normal regression. We are collaborating with the Department of Radiation Oncology, Massachusetts General Hospital, Boston, to identify chordoma families to help map and identify a chordoma susceptibility gene. The project involves obtaining personal and family medical history, buccal cells and slides of tumor tissue from the subgroup of patients most likely to have a genetic predisposition to chordoma: those diagnosed with chordoma <18 years. During the past year we completed enrollment of 55 chordoma patients. We are in the process of obtaining personal and family medical history, buccal cells and tumor tissue from them. In addition we are preparing an amendment to this protocol to expand the study to include 150 additional patients diagnosed with chordoma at any age and site. In collaboration with Yale University Tissue Microarray (TMA) core facility, we have successfully built TMAs of 1,500 invasive tumors collected from the Polish Breast Cancer Study. We have immunohistochemically (IHC) stained a subset of these tumors (N=842) for 18 molecular markers involved in hormone biosynthesis, metabolism, and receptor mediated pathways. Analyses of these markers suggest that risk factors for breast cancer may vary by molecular subtypes and by hormone pathways characterized by co-expression of the hormonal markers. We have also stained all TMAs for six markers (ER-alpha, ER-beta, PR, HER2, EGFR, and CK5) using a newly developed Automated Quantitative Analysis (AQUA). Comparison of the two approaches (AQUA and IHC) demonstrated AQUA analyses of tumors represented in TMAs provide reliable, quantitative measures of marker expression. We have also compared some commercially available imaging analysis software to pathologists measurement and our data suggested that automated analysis of IHC markers represents a promising approach for analyzing large numbers of breast cancer tissues in epidemiologic investigations.. We are also exploring the utility of the imaging analysis in scoring marker expression in 1,547 non-invasive tissue cores including normal TDLUs and DCIS constructed on 32 TMA blocks. In addition to TMA analyses of candidate markers in fixed tissues, we have conducted tumor profiling for gene expression and copy number changes in frozen tumors from a subset of Polish cases to better define molecular subtypes that are associated with distinct etiologic pathways. Renal cell carcinoma (RCC) rates in Central and Eastern Europe are among the highest in the world. The von Hippel Lindau-Hypoxia Inducible Factor (VHL-HIF) pathway has been implicated in kidney cancer tumorigenesis. We investigated the role of common variants in genes in the VHLHIF pathway in the susceptibility of sporadic RCC and clear cell RCC. We identified common genetic variants in genes in the VHL-HIF pathway associated with kidney cancer risk. Genotyping results for these variants are now available and are being examined for confirmation in several additional study populations. We are continuing to conduct studies based on Swedish linked registry data to better define the pattern of lymphoid malignancies that co-aggregate in families. We have conducted detailed analyses of the precursor condition, monoclonal gammopathy of uncertain significance (MGUS). We found that relatives of MGUS patients had a 3-fold increased risk of developing MGUS and 3-fold risk of developing multiple myeloma (MM). Risks for Waldenstrom macroglobulinemia and CLL were also increased. Some differences were seen by MGUS subtype. Relatives of patients with MM were at increased risk for MGUS or MM. The risk of any solid tumor was elevated among relatives of both MGUS and MM patients although the risk was small (HR=1.1, 95% CI=1.0-1.2). We have also refined our estimates of lymphoma aggregation by classifying lymphoma into subtypes sing the WHO classification. We found that relatives of patients with diffuse large b-cell lymphoma (DLBCL) had a 10-fold increased risk of developing DLBCL, a 2-fold elevated risk for Hodgkin lymphoma, but no increased risk for developing follicular lymphoma (FL). Similarly, relatives of patients with FL had a 4-fold increased risk for developing FL, a 2-fold increased risk for all indolent B-cell lymphomas but no increased risk for DLBCL.