Molecular genetics of hereditary renal cancer: new genes and diagnostic and therapeutic opportunities

Renal cell carcinoma may be sporadic or occur in the setting of an inherited cancer syndrome, such as von Hippel-Lindau or Birt-Hogg-Dube syndrome. Although the clinical spectrum of heritable renal cancer syndromes varies significantly, commonalities include the often young age of presentation, multifocal and bilateral nature of renal lesions, and autosomal dominant pattern of inheritance. Molecular studies have recently begun to elucidate the genetic abnormalities and subsequent alterations in downstream intracellular signaling cascades that underlie the development of these syndromes. This review will highlight the clinicopathologic and molecular features associated with the diverse array of heritable renal cancer syndromes and emphasize the potential cellular pathways that may be utilized to develop novel treatment strategies for patients with these syndromes.     

Molecular heterogeneity in glioblastoma: therapeutic opportunities and challenges

Glioblastoma (GBM) has been recognized as a clinical and pathologic entity for more than a century. Throughout its history, its cells of origin have been in question. Its behavior is aggressive and despite decades of effort, median survival is just beginning to improve. Surgical techniques and radiotherapy schemas continue to be refined, but the most recent progress has been achieved through improved medical therapies. These are the result of both pharmacological advances and a deeper understanding of the biological characteristics of GBM. Due to a combination of its complex phenotype and organ-specific clinical manifestations, efforts to refine GBM treatment with targeted therapies largely have been frustrated. In this review, we discuss recent attempts to exploit new molecular insights, consider the reasons for slow progress in developing better treatments, and examine future therapeutic options.     

An immunohistochemical study of sarcomatoid liver carcinomas.

Six cases of primary hepatic carcinomas with a significant amount of sarcomatoid elements were examined by using immunohistochemical stainings. Four of the six cases were associated with ordinary hepatocellular carcinoma (HCC), one with cholangiocellular carcinoma (CCC), and one with mixed HCC and CCC. Alpha-fetoprotein and alpha-1-antitrypsin were negative in sarcomatoid cells of all cases; vimentin stained positively in sarcomatoid tumor cells in two of the six cases; and cytokeratin (CK8) was detected in five cases. The CK8 was not detected in tumor cells of two cases of hepatic angiosarcoma, two of metastatic leiomyosarcomas, and one of metastatic fibrosarcoma, although vimentin stained positively in all these true sarcomas. It was concluded that sarcomatoid dedifferentiation of liver carcinomas might derive from both HCC and CCC. In addition CK8 might be an excellent marker to make a differential diagnosis of sarcomatoid cancers from true metastatic or primary sarcomas of the liver.     

肺肉瘤样癌的临床病理分析

目的探讨肺肉瘤样癌（pulmonary sarcomatoid carcinoma,PSC）的临床病理学特征,以提高对肺肉瘤样癌的早期诊断。方法回顾性分析6例肺肉瘤样癌的临床特征、影像学表现及病理学特征。结果6例患者最常见的呼吸系统临床表现为咳嗽、咳痰（100．O％）,其次5例为痰中带血（83．3％）和4例胸痛（66．7％）;影像学表现为增强CT扫描可见肿块实体部分轻度强化,转移淋巴结环形强化1例,肺内转移3例,纵隔转移2例,腋窝淋巴结转移2例,胸膜及胸壁侵犯3例,胸腔积液3例,肋骨转移1例,肝转移1例,脑转移2例;病理诊断3例为多形性癌,2例梭形细胞癌,1例为巨细胞癌。结论肺肉瘤样癌临床少见,其临床表现无特异性,肺部增强cT检查具有一定的特异性,诊断仍需依靠病理学检查,免疫组织化学有助于确诊。     

Molecular classification of human carcinomas by use of gene expression signatures

Classification of human tumors according to their primary anatomical site of origin is fundamental for the optimal treatment of patients with cancer. Here we describe the use of large-scale RNA profiling and supervised machine learning algorithms to construct a first-generation molecular classification scheme for carcinomas of the prostate, breast, lung, ovary, colorectum, kidney, liver, pancreas, bladder/ureter, and gastroesophagus, which collectively account for approximately 70% of all cancer-related deaths in the United States. The classification scheme was based on identifying gene subsets whose expression typifies each cancer class, and we quantified the extent to which these genes are characteristic of a specific tumor type by accurately and confidently predicting the anatomical site of tumor origin for 90% of 175 carcinomas, including 9 of 12 metastatic lesions. The predictor gene subsets include those whose expression is typical of specific types of normal epithelial differentiation, as well as other genes whose expression is elevated in cancer. This study demonstrates the feasibility of predicting the tissue origin of a carcinoma in the context of multiple cancer classes.     

Molecular classification of tamoxifen-resistant breast carcinomas by gene expression profiling.

PURPOSE: To discover a set of markers predictive for the type of response to endocrine therapy with the antiestrogen tamoxifen using gene expression profiling. PATIENTS AND METHODS: The study was performed on 112 estrogen receptor-positive primary breast carcinomas from patients with advanced disease and clearly defined types of response (ie, 52 patients with objective response v 60 patients with progressive disease) from start of first-line treatment with tamoxifen. Main clinical end points are the effects of therapy on tumor size and time until tumor progression (progression-free survival [PFS]). RNA isolated from tumor samples was amplified and hybridized to 18,000 human cDNA microarrays. RESULTS: Using a training set of 46 breast tumors, 81 genes were found to be differentially expressed (P < or = .05) between tamoxifen-responsive and -resistant tumors. These genes were involved in estrogen action, apoptosis, extracellular matrix formation, and immune response. From the 81 genes, a predictive signature of 44 genes was extracted and validated on an independent set of 66 tumors. This 44-gene signature is significantly superior (odds ratio, 3.16; 95% CI, 1.10 to 9.11; P = .03) to traditional predictive factors in univariate analysis and also significantly related with a longer PFS in univariate (hazard ratio, 0.54; 95% CI, 0.31 to 0.94; P = .03) as well as in multivariate analyses (P = .03). CONCLUSION: Our data show that gene expression profiling can be used to discriminate between breast cancer patients with progressive disease and objective response to tamoxifen. Additional studies are needed to confirm if the predictive signature might allow identification of individual patients who could benefit from other (adjuvant) endocrine therapies.     

Analysis of apoptosis protein expression in early-stage colorectal cancer suggests opportunities for new prognostic biomarkers.

PURPOSE: Although most stage II colon cancers are potentially curable by surgery alone, approximately 20% of patients relapse, suggesting a need for establishing prognostic markers that can identify patients who may benefit from adjuvant chemotherapy. We tested the hypothesis that differences in expression of apoptosis-regulating proteins account for differences in clinical outcome among patients with early-stage colorectal cancer. EXPERIMENTAL DESIGN: Tissue microarray technology was employed to assay the expression of apoptosis-regulating proteins by immunohistochemistry in 106 archival stage II colorectal cancers, making correlations with disease-specific survival. The influence of microsatellite instability (MSI), tumor location (left versus right side), patient age, and gender was also examined. RESULTS: Elevated expression of several apoptosis regulators significantly correlated with either shorter (cIAP2; TUCAN) or longer (Apaf1; Bcl-2) overall survival in univariate and multivariate analyses. These biomarkers retained prognostic significance when adjusting for MSI, tumor location, patient age, and gender. Moreover, certain combinations of apoptosis biomarkers were highly predictive of death risk from cancer. For example, 97% of patients with favorable tumor phenotype of cIAP2(low) plus TUCAN(low) were alive at 5 years compared with 60% of other patients (P = 0.00003). In contrast, only 37% of patients with adverse biomarkers (Apaf1(low) plus TUCAN(high)) survived compared with 83% of others at 5 years after diagnosis (P< 0.0001). CONCLUSIONS: Immunohistochemical assays directed at detection of certain combinations of apoptosis proteins may provide prognostic information for patients with early-stage colorectal cancer, and therefore could help to identify patients who might benefit from adjuvant chemotherapy or who should be spared it.     

Adult primary pulmonary primitive neuroectodermal tumor: Molecular features and translational opportunities

Primitive neuroectodermal tumors (PNET) arising directly from the lung are very rare but particularly aggressive neoplasms. We report a case of a 31-y-old man with primary pulmonary neuroectodermal tumor. We review the clinical as well as pathological features. As typical for these tumors, the diagnosis was initially delayed in our patient and prognosis was poor despite aggressive surgical resection, postoperative chemotherapy and local irradiation. Recent biological insights have revealed unique chromosomal translocations crucial to the pathogenesis of these tumors, most notably the EWS-FLI-1 translocation. We provide an overview of the molecular features of the Ewing Sarcoma Family of Tumors (ESFT) including PNET and their potential implications for therapeutic targeting.     

膀胱肉瘤样癌的病理诊断和临床分析膀胱肉瘤样癌的病理诊断和临床分析

目的:分析6例膀胱肉瘤样癌病理诊断、临床治疗情况及其随访结果。方法:HE染色后观察癌组织病理形态特征,SP免疫组化法检测其免疫表型。总结本病的临床及病理资料、诊治及预后。结果:病理结果显示6例膀胱肉瘤样癌均有不同级别的尿路上皮癌成分,同时伴有50％以上的肉瘤样成分。免疫组化结果显示,肉瘤样癌区域vimentin（VIM）及CK均阳性。治疗及预后情况显示,6例中3例行经尿道膀胱肿瘤切除术（TUR-BT）,其中1例死亡,另外2例随访中;1例行膀胱部分切除术,术后间断行膀胱灌注化疗,之后失去随访;2例会诊病例资料不详。结论:膀胱肉瘤样癌是一种罕见的具有上皮性和间叶性双重分化特征的膀胱恶性肿瘤,其恶性程度高,预后不良。因其临床症状不特异,诊断主要依靠病理及免疫组化检查。早期诊断及积极的手术治疗能够有效的改善预后,提高患者生存率。     

Histopathological classification of esophageal carcinomas

Esophageal carcinomas are steadily rising worldwide; they rank sixth among tumors. Adenocarcinoma is the most common histological type in Western countries while squamous carcinoma is more common in the developing countries. Both types are preceded by pre-neoplastic lesions rappresented by Barrett's esophagus for adenocarcinoma and low and high grade dysplasia for squamous carcinoma. Some continuity exists between dysplastic lesions and frankly invasive tumors. Moreover rare hystological types have been described. The surgical pathologist plays an important role in evaluating small endoscopic biopsies as well as in examining surgical specimens from esophagectomy. In the former case the role is exclusively diagnostic while in the latter surgical radicality, cancer stage and outcomes of neoadjuvant therapies are assessed. All these data are crucial not only for prognosis but also for therapy planning.     

Molecular classification of head and neck squamous cell carcinomas using patterns of gene expression

The prognostication of head and neck squamous cell carcinoma (HNSCC) is largely based upon the tumor size and location and the presence of lymph node metastases. Here we show that gene expression patterns from 60 HNSCC samples assayed on cDNA microarrays allowed categorization of these tumors into four distinct subtypes. These subtypes showed statistically significant differences in recurrence-free survival and included a subtype with a possible EGFR-pathway signature, a mesenchymal-enriched subtype, a normal epithelium-like subtype, and a subtype with high levels of antioxidant enzymes. Supervised analyses to predict lymph node metastasis status were approximately 80% accurate when tumor subsite and pathological node status were considered simultaneously. This work represents an important step toward the identification of clinically significant biomarkers for HNSCC.     

Leukemia in severe congenital neutropenia: defective proteolysis suggests new pathways to malignancy and opportunities for therapy

Severe congenital neutropenia (SCN), a heterogeneous disorder that includes Kostmann syndrome, predisposes to myelodysplasia and acute myelogenous leukemia. Recently identified heterozygous mutations in the gene ELA2, encoding neutrophil elastase on human chromosome 19pter, account for the majority of autosomal dominant cases of SCN, including those demonstrating neoplastic progression. The involvement of the serine protease neutrophil elastase, localized to the granules of neutrophils and monocytes, implies an unexpected role for proteolytic regulation of hematopoiesis. Continued elucidation of the clinical features, molecular genetics, and biochemistry is likely to provide insight into novel pathways of leukemia induction with attendant prospects for new avenues of therapy.     

Unraveling the mechanisms of endocrine resistance in breast cancer: new therapeutic opportunities.

Two thirds of breast cancers express the estrogen receptor (ER), which contributes to tumor development and progression. ER-targeted therapy is therefore widely used in breast cancer to inhibit signaling through ER and disrupt breast cancer growth. This therapeutic strategy, particularly using the antiestrogen tamoxifen, is proven to increase the cure rates in early breast cancer, improve patient outcomes in advanced disease, and reduce breast cancer incidence in the prevention setting. Despite the recent integration of more powerful endocrine agents into breast cancer care, resistance to all forms of endocrine therapy remains a major problem. New insight into ER biology and progress in understanding resistance mechanisms, mediated by molecular crosstalk between ER and various growth factor signaling pathways, are generating tremendous promise for new therapeutic opportunities to target resistance and improve breast cancer disease outcomes.     

Bronchopulmonary Kulchitzky cell carcinomas. A new classification scheme for typical and atypical carcinoids

Typical and atypical carcinoids constitute less than 5% of lung tumors. They and small cell undifferentiated lung cancers (SCLC) belong to the same family of apudomas arising from bronchopulmonary Kulchitzky cells. To reflect the overlap among these cancers, the authors suggest calling them Kulchitzky cell carcinomas (KCC); to indicate their spectrum of aggressiveness, the authors suggest calling typical carcinoids KCC-I, atypical carcinoids KCC-II, and small cell cancers KCC-III. One hundred fifty-six KCCs were reviewed: 115 were KCC-I and 41 were KCC-II. The ratio of women to men equals 2:1. At time of initial diagnosis, all patients with KCC-I, except one patient, were in Stage I. Among patients with KCC-II, 16 (39%) were in Stages II or III at time of presentation. The incidence of carcinoid syndrome was 1.9%. Treatment was lobectomy in 112 (72%) of patients, the remainder having lesser resections or pneumonectomy in approximately equal distribution. Our data cannot support the use of radical resection in the treatment of KCC because none of the patients died of local recurrence. The mean diameters of KCC-I and -II tumors were 1.5 and 2.8 cm, respectively. Increased mitotic activity and tumor necrosis were reliable criteria for diagnosing KCC-II. Electron microscopic examination did not help in differentiating KCC-I and KCC-II. Thorough sampling of the entire tumor was found to be mandatory for precise diagnosis and for differentiation from KCC-III (SCLC). Measurement of nuclear DNA was done using integrated optical density (IOD) by image analysis. The IODs of KCC-I, -II and -III were 1.36, 1.55 and 1.94, respectively. These significant differences (P less than 0.001) correlated with the aggressiveness of the cancers. Of patients with KCC-I, 1.7% succumbed to KCC; this included one patient reported to have died of KCC-III (SCLC). Of 41 patients with KCC-II, 11 (27%) died of KCC; this includes at least 3 deaths from KCC-III.     

Trastuzumab: mechanisms of resistance and therapeutic opportunities

Many breast cancer patients with HER2 overexpression do not respond to initial therapy with trastuzumab (Herceptin), and the vast majority of those who initially respond to the agent develop resistance to treatment within 1 year. This review will discuss several molecular mechanisms that can lead to the development of trastuzumab resistance, including loss of PTEN, activation of alternative pathways, receptor-antibody interaction block, and circulating HER2 extracellular domain, as well as the possibility of exploring these aberrations as therapeutic targets that could help avoid or overcome resistance to trastuzumab.