A Biomarker-related Approach to Screening for HPV-related Oropharyngeal Cancer

 描述(申请人提供)：口咽癌(OPC)在男性中的发病率显著增加，男性比女性高出四到五倍。1大多数OPC是在晚期被诊断出来的，需要强化治疗，从而导致显著的长期发病率。HPV感染已经取代吸烟成为OPC的主要原因，约70%的OPC是由HPV感染引起的，主要是HPV16型。与其他癌症不同，没有可靠的肿瘤前病变可用于早期发现干预措施，口腔巴氏涂片在发现早期OPC病变方面无效。因此，对生物标志物方法的依赖对于OPC筛查干预措施的发展是必要的。OPC的分子途径与宫颈癌相似：HPV感染的一部分持续存在(病变发展的先兆)，随后HPV整合到宿主基因组，HPV癌蛋白E6和E7的过度表达导致p16过度表达，以及非随机的染色体获得。由于HPV相关的OPC和宫颈癌在生物学上是相似的，我们开发OPC生物标记物最有效的方法是利用宫颈癌生物标记物研究提供的知识。目前，被接受的检测口腔HPV的标准标本是口腔含漱液。在这里，我们提出了一种创新的方法，通过将宫颈癌生物标记物应用于新的标本和癌症：口腔含漱液和OPC，来开发OPC早期检测干预。快速移植到临床是可能的，因为我们提出了一种非侵入性的标本类型，具有足够的材料来支持多个生物标记物测量，以及一组在宫颈被证明有用的标记物，我们的初步数据表明了这一点的可行性。我们的目标是开发一种敏感的 以及诊断OPC的特异性生物标志物组合。假设与细胞破坏、HPV病毒特征和宿主细胞表观遗传学改变相关的口腔含漱生物标记物可以作为肿瘤组织中这些标记物存在的替代品，并可以区分OPC病例和无癌男性。在这个发展的R21应用中，我们建议招募100例OPC病例(治疗前)和一组频率与年龄匹配的无癌男性(高危人群)，以解决以下特定目标：1)在OPC病例中，评估在肿瘤和口腔漱口标本中测量的生物标记物(HPV基因型、p16、HPV16甲基化L1、E2、E5蛋白甲基化和宿主甲基化)的相关性；2)评估在Aim 1中相关性最高的口腔漱口生物标记物，以建立检测OPC的切点(阳性阈值)，并评估单个生物标记物在病例和非癌症男性中的患病率；以及3)确定检测OPC的口腔含漱生物标志物的最佳组合。在次级目标中，我们将识别染色体异常、宿主基因甲基化特征和先天免疫因素，这些因素可能作为补充诊断OPC标志物。

 DESCRIPTION (provided by applicant): Oropharyngeal cancer (OPC) incidence is significantly increasing in men and is four- to fivefold higher in men compared to women.1 The majority of OPCs are diagnosed at late stages, requiring intensive treatment that leads to significant long-term morbidity. HPV infection has replaced smoking as the primary cause of OPC, with ~70% of OPCs caused by HPV infection, predominantly with HPV type 16. Unlike other cancers, there is no reliably detected pre-neoplastic lesion to utilize in early detection interventions, and oral Pap smears are ineffective in detecting early OPC lesions. Therefore, reliance on a biomarker approach is necessary for the development of OPC screening interventions. The molecular pathway to OPC is similar to that of cervical cancer: a subset of HPV infections persist (obligate precursor to lesion development), followed by HPV integration into the host genome, overexpression of HPV oncoproteins E6 and E7 leading to p16 overexpression, and nonrandom chromosomal gains. As HPV-related OPC and cervical cancer are biologically similar, our most effective approach in developing OPC biomarkers is to leverage knowledge informed by cervical cancer biomarker studies. Currently, the accepted standard specimen for detecting oral HPV is the oral gargle. Here, we propose an innovative approach for the development of an OPC early detection intervention by applying cervical cancer biomarkers to a new specimen and cancer: the oral gargle and OPC. Rapid translation to the clinic is possible, as we propose a specimen type that is non-invasive, with sufficient material to support multiple biomarker measurements, and a panel of markers with proven utility at the cervix, for which our preliminary data show feasibility. Our goal is to develop a sensitive and specific biomarker panel that is diagnostic of OPC. The hypothesis is that oral gargle biomarkers related to cellular disruption, HPV viral characteristics, and host cell epigenetic alterations can be used as surrogates for the presence of these markers in tumor tissue and can distinguish OPC cases from cancer-free men. In this developmental R21 application, we propose to enroll 100 OPC cases (pre-treatment) and a frequency age-matched set of cancer-free men (at risk population) to address the following Specific Aims: 1) Among OPC cases, assess the correlation of biomarkers (HPV genotype, p16, HPV 16 methylation of L1, E2, E5 proteins, and host methylation) measured in tumor and oral gargle specimens; 2) Evaluate the most promising oral gargle biomarkers with high correlation in Aim 1 in cancer-free men to establish cut-points (thresholds for positivity) for the detection of OPC, and assess the prevalence of individual biomarkers among cases and cancer-free men; and 3) Determine the optimal combination of oral gargle biomarkers to detect OPC. In secondary aims, we will identify chromosomal aberrations, host gene methylation signatures, and innate immune factors that may serve as supplemental diagnostic OPC markers.