Germline SMARCE1 mutations predispose to both spinal and cranial clear cell meningiomas

We recently reported SMARCE1 mutations as a cause of spinal clear cell meningiomas. Here, we have identified five further cases with non-NF2 spinal meningiomas and six with non-NF2 cranial meningiomas. Three of the spinal cases and three of the cranial cases were clear cell tumours. We screened them for SMARCE1 mutations and investigated copy number changes in all point mutation-negative samples. We identified two novel mutations in individuals with spinal clear cell meningiomas and three mutations in individuals with cranial clear cell meningiomas. Copy number analysis identified a large deletion of the 5' end of SMARCE1 in two unrelated probands with spinal clear cell meningiomas. Testing of affected and unaffected relatives of one of these individuals identified the same deletion in two affected female siblings and their unaffected father, providing further evidence of incomplete penetrance of meningioma disease in males. In addition, we found loss of SMARCE1 protein in three of 10 paraffin-embedded cranial clear cell meningiomas. Together, these results demonstrate that loss of SMARCE1 is relevant to cranial as well as spinal meningiomas. Our study broadens the spectrum of mutations in the SMARCE1 gene and expands the phenotype to include cranial clear cell meningiomas.

Clear cell cystic variant of calcifying epithelial odontogenic tumor

Calcifying epithelial odontogenic tumor (CEOT) is a solid, locally aggressive, benign odontogenic neoplasm characterized by sheets and nests of polyhedral epithelial cells exhibiting eosinophilic and less often clear cytoplasm, occasional nuclear pleomorphism without mitotic activity, calcifications, and deposits of amyloid. A cystic variant has been reported only twice. Herein, we present an additional example of cystic CEOT occurring in a 31-year-old male and featuring clear cell epithelial lining with deposits of amyloid and osteodentin.

Genome-wide association study of subtype-specific epithelial ovarian cancer risk alleles using pooled DNA

Epithelial ovarian cancer (EOC) is a heterogeneous cancer with both genetic and environmental risk factors. Variants influencing the risk of developing the less-common EOC subtypes have not been fully investigated. We performed a genome-wide association study (GWAS) of EOC according to subtype by pooling genomic DNA from 545 cases and 398 controls of European descent, and testing for allelic associations. We evaluated for replication 188 variants from the GWAS [56 variants for mucinous, 55 for endometrioid and clear cell, 53 for low-malignant potential (LMP) serous, and 24 for invasive serous EOC], selected using pre-defined criteria. Genotypes from 13,188 cases and 23,164 controls of European descent were used to perform unconditional logistic regression under the log-additive genetic model; odds ratios (OR) and 95 % confidence intervals are reported. Nine variants tagging six loci were associated with subtype-specific EOC risk at P < 0.05, and had an OR that agreed in direction of effect with the GWAS results. Several of these variants are in or near genes with a biological rationale for conferring EOC risk, including ZFP36L1 and RAD51B for mucinous EOC (rs17106154, OR = 1.17, P = 0.029, n = 1,483 cases), GRB10 for endometrioid and clear cell EOC (rs2190503, P = 0.014, n = 2,903 cases), and C22orf26/BPIL2 for LMP serous EOC (rs9609538, OR = 0.86, P = 0.0043, n = 892 cases). In analyses that included the 75 GWAS samples, the association between rs9609538 (OR = 0.84, P = 0.0007) and LMP serous EOC risk remained statistically significant at P < 0.0012 adjusted for multiple testing. Replication in additional samples will be important to verify these results for the less-common EOC subtypes.

Large-scale evaluation of common variation in regulatory T cell-related genes and ovarian cancer outcome

The presence of regulatory T cells (Treg) in solid tumors is known to play a role in patient survival in ovarian cancer and other malignancies. We assessed inherited genetic variations via 749 tag single-nucleotide polymorphisms (SNP) in 25 Treg-associated genes (CD28, CTLA4, FOXP3, IDO1, IL10, IL10RA, IL15, 1L17RA, IL23A, IL23R, IL2RA, IL6, IL6R, IL8, LGALS1, LGALS9, MAP3K8, STAT5A, STAT5B, TGFB1, TGFB2, TGFB3, TGFBR1, TGRBR2, and TGFBR3) in relation to ovarian cancer survival. We analyzed genotype and overall survival in 10,084 women with invasive epithelial ovarian cancer, including 5,248 high-grade serous, 1,452 endometrioid, 795 clear cell, and 661 mucinous carcinoma cases of European descent across 28 studies from the Ovarian Cancer Association Consortium (OCAC). The strongest associations were found for endometrioid carcinoma and IL2RA SNPs rs11256497 [HR, 1.42; 95% confidence interval (CI), 1.22-1.64; P = 5.7 × 10(-6)], rs791587 (HR, 1.36; 95% CI, 1.17-1.57; P = 6.2 × 10(-5)), rs2476491 (HR, = 1.40; 95% CI, 1.19-1.64; P = 5.6 × 10(-5)), and rs10795763 (HR, 1.35; 95% CI, 1.17-1.57; P = 7.9 × 10(-5)), and for clear cell carcinoma and CTLA4 SNP rs231775 (HR, 0.67; 95% CI, 0.54-0.82; P = 9.3 × 10(-5)) after adjustment for age, study site, population stratification, stage, grade, and oral contraceptive use. The rs231775 allele associated with improved survival in our study also results in an amino acid change in CTLA4 and previously has been reported to be associated with autoimmune conditions. Thus, we found evidence that SNPs in genes related to Tregs seem to play a role in ovarian cancer survival, particularly in patients with clear cell and endometrioid epithelial ovarian cancer.

Envisioning the next WHO head and neck classification

The next WHO classification should abandon "salivary duct carcinoma"; conventional salivary duct carcinoma should be classified as "high-grade salivary duct carcinoma". Low-grade salivary duct carcinoma should replace the current nosology of "low-grade cribriform cystadenocarcinoma". Cystadenocarcinoma should be classified with the descriptor "Not Otherwise Specified" and should be considered an exclusionary diagnostic category. On the other hand, "Not Otherwise Specified" does not fit for hyalinizing clear cell carcinoma (HCCC). The EWSR1-ATF1 fusion is specific for HCCC within the context of salivary neoplasia. We recommend adding "hyalinizing" even though this feature is not present in all cases; the benefit of which is the mental association with a salivary clear cell malignancy. Sinonasal Renal Cell-like Adenocarcinoma (SNRCLA) is a distinct clear cell neoplasm and should be added to the next WHO classification. Future studies will bear out whether SNRCLA is even a low-grade carcinoma, or may be reclassified as "adenoma". Lastly, the next WHO monograph should include the Risk Model in the general introductory statements on oral squamous cell carcinoma, under a subheading of "Histological Prognosticators". The positive predictive value for developing locoregional recurrence in patients with low-stage oral cavity squamous carcinoma (OSCC) and "worst pattern of invasion type-5" (WPOI-5) is 42 %. Low-stage high-risk OSCC with a combination of features other than WPOI-5 is associated with 32 % likelihood for locoregional progression. WPOI-5 also predicts occult metastatic disease (p = 0.0001, Chi squared, 2 DF). Thus the Risk Model can also be used to make decisions regarding staged elective neck dissections.

Cytoreductive nephrectomy in patients with metastatic non-clear-cell renal cell carcinoma (RCC)

OBJECTIVE

To determine whether patients with metastatic non-clear-cell renal cell carcinoma (RCC) benefit from cytoreductive nephrectomy (CN).

PATIENTS AND METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) programme to identify a population-based sample of 4914 patients diagnosed with metastatic RCC between 2000 and 2009. Of the 4914 patients, 591 had non-clear-cell histology. The median follow-up was 20 months. The primary outcome measure was RCC-specific mortality.

RESULTS

Approximately 64% of patients underwent CN. Patients with non-clear-cell histology who underwent CN had lower RCC-specific and all-cause mortality than those who did not (P < 0.001 in both cases). After adjustment for age, gender, race, marital status, year of diagnosis, geographical location and histology, the associations between CN and lower RCC-specific mortality (hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.48-0.80, P < 0.001) and between CN and all-cause mortality (HR 0.45, 95% CI 0.37-0.55, P < 0.001) remained highly significant. Among patients diagnosed between 2006 and 2009 (targeted therapy era), the results remained unchanged (HR 0.50, 95% CI 0.34-0.72, P < 0.001 and HR 0.43, 95% CI 0.31-0.59, P < 0.001, respectively). An interaction model found lower all-cause mortality for all histologies after CN.

CONCLUSIONS

Patients from the SEER programme with metastatic non-clear-cell RCC, including those treated in the targeted therapy era, appear to derive a survival benefit from CN, an association which remained significant regardless of histological subtype. This observation suggests that CN should remain standard in patients with advanced RCC who are deemed to be surgical candidates.

Clear cell hidradenoma

Clear cell hidradenoma or nodulocystic hidradenoma or acrospiroma are histologically distinct relatively rare tumors of sweat gland duct origin, found mainly in adults with a female preponderance. We report a case of eccrine hidradenoma in a 31-year-old man who presented with an asymptomatic, solitary nodule on occipital region. A few reports are available in literature regarding presence of this tumor on occipital region of young man and present case is being reported because of its rarity in this region of scalp and in this sex.

Risk of ovarian cancer and the NF-κB pathway: genetic association with IL1A and TNFSF10

A missense single-nucleotide polymorphism (SNP) in the immune modulatory gene IL1A has been associated with ovarian cancer risk (rs17561). Although the exact mechanism through which this SNP alters risk of ovarian cancer is not clearly understood, rs17561 has also been associated with risk of endometriosis, an epidemiologic risk factor for ovarian cancer. Interleukin-1α (IL1A) is both regulated by and able to activate NF-κB, a transcription factor family that induces transcription of many proinflammatory genes and may be an important mediator in carcinogenesis. We therefore tagged SNPs in more than 200 genes in the NF-κB pathway for a total of 2,282 SNPs (including rs17561) for genotype analysis of 15,604 cases of ovarian cancer in patients of European descent, including 6,179 of high-grade serous (HGS), 2,100 endometrioid, 1,591 mucinous, 1,034 clear cell, and 1,016 low-grade serous, including 23,235 control cases spanning 40 studies in the Ovarian Cancer Association Consortium. In this large population, we confirmed the association between rs17561 and clear cell ovarian cancer [OR, 0.84; 95% confidence interval (CI), 0.76-0.93; P = 0.00075], which remained intact even after excluding participants in the prior study (OR, 0.85; 95% CI, 0.75-0.95; P = 0.006). Considering a multiple-testing-corrected significance threshold of P < 2.5 × 10(-5), only one other variant, the TNFSF10 SNP rs6785617, was associated significantly with a risk of ovarian cancer (low malignant potential tumors OR, 0.85; 95% CI, 0.79-0.91; P = 0.00002). Our results extend the evidence that borderline tumors may have a distinct genetic etiology. Further investigation of how these SNPs might modify ovarian cancer associations with other inflammation-related risk factors is warranted.

Hepatocyte nuclear factor-1β is not a specific marker of clear cell carcinoma in serous effusions

BACKGROUND

The transcription factor hepatocyte nuclear factor-1β (HNF1β) has been reported to be a specific clear cell carcinoma marker, but its role in the diagnosis of serous effusions is largely unexplored. The objective of this study was to assess the diagnostic role of 2 commercial antibodies against HNF1β in effusion specimens.

METHODS

Effusions (n = 101), consisting of 43 ovarian adenocarcinomas (26 serous, 14 clear cell, 3 endometrioid), 37 nonovarian adenocarcinomas, 10 malignant mesotheliomas, 2 nonepithelial cancers, and 9 reactive specimens, were immunostained using antibodies from Santa Cruz Biotechnology Inc (Santa Cruz, Calif) and Atlas Antibodies AB (Stockholm, Sweden).

RESULTS

Use of the Santa Cruz antibody was associated with cytoplasmic or background staining in some specimens, whereas distinct staining with minimal background was observed using the Atlas antibody. The Santa Cruz antibody performed better in differentiating clear cell carcinoma from serous ovarian carcinoma and breast carcinoma, whereas staining was consistently negative in benign and malignant mesotheliomas using both antibodies. Distinct nuclear expression of HNF1β was observed in lung and gastrointestinal carcinomas, most often using the Atlas antibody.

CONCLUSIONS

The HNF1β antibody from Atlas performed better than its counterpart from Santa Cruz in terms of staining quality, but was less specific for clear cell carcinoma. Although HNF1β may be of diagnostic value in differentiating clear cell from serous carcinoma in cases with proven genital origin, the role of this marker is questionable in the differential diagnosis between the former tumors and adenocarcinomas of other origin, particularly in the setting of metastasis from an unknown primary tumor.

Circulating aldosterone induces the apical accumulation of the proton pumping V-ATPase and increases proton secretion in clear cells in the caput epididymis

Clear cells express the vacuolar proton-pumping H(+)-ATPase (V-ATPase) and acidify the lumen of the epididymis, a process that is essential for male fertility. The renin-angiotensin-aldosterone system (RAAS) regulates fluid and electrolyte balance in the epididymis, and a previous study showed binding of aldosterone exclusively to epididymal clear cells (Hinton BT, Keefer DA. Steroid Biochem 23: 231-233, 1985). We examined here the role of aldosterone in the regulation of V-ATPase in the epididymis. RT-PCR showed expression of the mineralocorticoid receptor [MR; nuclear receptor subfamily 3, group C member 2 (NR3C2)] and 11-β-dehydrogenase isozyme 2 (HSD11β2) mRNAs specifically in clear cells, isolated by fluorescence-activated cell sorting from B1-enhanced green fluorescent protein (EGFP) mice. Tail vein injection of adult rats with aldosterone, 1,2-dioctanoyl-sn-glycerol (DOG), or 8-(4-chlorophenylthio)-cAMP (cpt-cAMP) induced V-ATPase apical membrane accumulation and extension of V-ATPase-labeled microvilli in clear cells in the caput epididymis but not in the cauda. V-ATPase activity was measured in EGFP-expressing clear cells using the intracellular pH (pHi)-sensing dye seminaphthorhodafluor-5F-5-(and 6)-carboxylic acid, acetoxymethyl ester acetate (SNARF-5F). Aldosterone induced a rapid increase in the rate of Na(+)- and bicarbonate-independent pHi recovery following an NH4Cl-induced acid load in clear cells isolated from the caput but not the cauda. This effect was abolished by concanamycin A, spironolactone, and chelerythrine but not myristoylated-protein kinase inhibitor (mPKI) or mifepristone. Thus aldosterone increases V-ATPase-dependent proton secretion in clear cells in the caput epididymis via MR/NR3C2 and PKC activation. This study, therefore, identifies aldosterone as an active member of the RAAS for the regulation of luminal acidification in the proximal epididymis.

Octreotide and celecoxib synergistically encapsulate VX2 hepatic allografts following transcatheter arterial embolisation

To evaluate the encapsulation of VX2 hepatic allografts in rabbits induced by octreotide and celecoxib administration following transcatheter arterial embolisation (TAE), rabbits with hepatic VX2 allografts were divided into four groups: control, TAE, octreotide + celecoxib (O+C) and the multimodality therapy (TAE+O+C). Allograft metastasis, capsule thickness and percentage of clear cells were measured and vascular endothelial growth factor (VEGF) and CD31 were detected by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) analysis. The extrahepatic metastases of each intervention group were significantly fewer than those of the control group, with the TAE+O+C group exhibiting the fewest extrahepatic metastases. The TAE+O+C group had the greatest proportion of clear cells and thickest capsule on day 30. Increased capsule thickness was negatively correlated with tumour metastasis. In addition, VEGF expression levels assessed by immunohistochemistry and RT-PCR in the three intervention groups were significantly lower than those in the control group. Furthermore, the TAE+O+C group had a significantly reduced CD31 count induced by TAE. These results demonstrate that TAE, followed by long-term administration of octreotide and celecoxib, synergistically inhibits VX2 hepatic allograft metastasis by increasing the proportion of clear cells, promoting encapsulation and inhibiting angiogenesis.

Potential role of (124)I-girentuximab in the presurgical diagnosis of clear-cell renal cell cancer

Renal cell carcinoma (RCC) is a biologically heterogeneous disease, with many small renal masses (SRMs) exhibiting an indolent natural history, while others progress more rapidly to become life-threatening. Existing multiphase contrast-enhanced imaging methods, such as computed tomography or magnetic resonance imaging, cannot definitively distinguish between benign and malignant solid tumors or identify histologic subtype, and early results of molecular imaging studies (positron emission tomography [PET]) in the evaluation of SRMs have not improved on these established modalities. Alternative molecular markers/agents recognizing aberrant cellular pathways of cellular oxidative metabolism, DNA synthesis, and tumor hypoxia tracers are currently under development and investigation for RCC assessment, but to date none are yet clinically applicable or available. In contrast, immuno-PET offers highly selective binding to cancer-specific antigens, and might identify radiographically recognizable and distinct molecular targets. A phase I proof-of-concept study first demonstrated the ability of immuno-PET to discriminate between clear-cell RCC (ccRCC) and non-ccRCC, utilizing a chimeric monoclonal antibody to carbonic anhydrase IX (cG250, girentuximab) labeled with ¹²⁴I (¹²⁴I-girentuximab PET); the study examined patients with renal masses who subsequently underwent standard surgical resection. A follow-up phase III multicenter trial confirmed that ¹²⁴I-cG250-PET can accurately and noninvasively identify ccRCC with high sensitivity (86%), specificity (87%), and positive predictive value (95%). In the challenge to appropriately match treatment of an incidentally identified SRM to its biological potential, this highly accurate and histologically specific molecular imaging modality demonstrates the ability of imaging to provide clinically important preoperative diagnostic information, which can result in optimal and personalized therapy.

Immunophenotypes of glycogen rich clear cell carcinoma

PURPOSE

Glycogen rich clear cell carcinoma (GRCC) of the breast is a rare subtype of invasive ductal carcinoma and involves a poor prognosis. In the literature, less than 150 cases have been reported. Many researchers have attempted to characterize GRCC according to electron microscope, flow cytometry, or clinical data. However, an organized study of the immunophenotype of GRCC has yet to be reported.

MATERIALS AND METHODS

Here, we present three cases of GRCC and their immunohistochemical profiles.

RESULTS

Histologically, all three cases contained periodic acid stain (PAS) positive and d-PAS labile granules in their clear cytoplasm. Case I showed positivity for only estrogen receptor (ER) and c-erbB2. Case II exhibited positivity for progesterone receptor and negativity for ER and c-erbB2. Case III presented with triple negative invasive carcinoma. The expression pattern of E-cadherin was concordant with epidermal growth factor receptor and c-kit, but discordant with ki-67. Among these three cases, p53-positive cases exhibited a low proliferative index (ki-67: 15%), while p53-negative cases showed a high proliferative index (ki-67: 50-60%).

CONCLUSION

In conclusion, the immunophenotype of GRCC is not uniform, but is similar to that of conventional ductal carcinoma.

Targeted therapeutic strategies for the management of renal cell carcinoma

PURPOSE OF REVIEW

This article reviews recent developments in the use of systemic targeted therapies for the treatment of advanced clear and nonclear cell renal cell carcinoma (RCC). The genetic/molecular basis of each form of RCC is discussed and current treatments and clinical trials are described.

RECENT FINDINGS

The treatment of advanced RCC continues to be a major challenge for uro-oncologists. The rapid growth in therapeutic options has brought much needed improvements in overall and progression-free survival, although durable complete responses remain elusive. The recent identification of mutations in genes involved in chromatin remodeling will likely lead to the investigation of whether components of this critical process can also be valid therapeutic targets in clear cell RCC. Similarly, efforts to decipher the molecular mechanisms underlying nonclear cell variants of RCC are beginning to engender novel therapeutic strategies directed against these rarer forms of kidney cancer. Despite the availability of multiple treatment options, several challenges remain: selecting the best first-line or subsequent therapy for a given patient, the optimal sequencing of the various agents available, designing trials with appropriate comparison arms and endpoints, and identifying well tolerated and effective drug combinations.

SUMMARY

Agents targeting the vascular endothelial growth factor and mammalian target of rapamycin pathways remain the mainstay in the management of metastatic RCC. Ongoing and future studies are expected to facilitate the development of therapeutic regimens that incorporate agents with improved tolerability and enhanced efficacy by continuing to capitalize on the strides made by basic and translational scientists in uncovering the mechanisms underlying the various forms of RCC.

Intraparenchymal clear cell ependymoma

Clear cell ependymoma (CCE) is an uncommon variant of ependymoma having a predilection for the supratentorial region. Histologically, it bears an uncanny resemblance to oligodendroglioma, central neurocytoma, hemangioblastoma and metastasis from clear cell carcinoma. Here, we report a rare case of clear cell ependymoma in a 45-year-old male, which histomorphologically resembled anaplastic oligodendroglioma on intraoperative smears, frozen section and routine light microscopy. Immunohistochemistry, however, helped to arrive at the correct diagnosis. Unlike other clear cell tumors of the brain parenchyma, CCE is known to follow an aggressive course and, hence, obtaining a correct diagnosis is imperative since it has a direct therapeutic and prognostic connotation.

Update on targeted therapies for clear cell renal cell carcinoma

PURPOSE OF REVIEW

The article reviews the evolution of targeted therapies for clear cell renal cell carcinoma (RCC) and recent developments in the field. The vast majority of work in kidney cancer deals with clear cell RCC, which is the most common variant of this malignancy. The identification of loss of function of the von Hippel-Lindau protein as the basis for clear cell RCC, in addition to the well designed clinical trials that have ensued, provide an outstanding model for the development of mechanism-based targeted therapy in cancer.

RECENT FINDINGS

The treatment of advanced and metastatic RCC continues to be a major challenge for uro-oncologists despite the approval of six targeted therapies over the past 5 years. This rapid growth in therapeutic options has brought much needed improvements in overall and progression-free survival, although durable complete responses are rare. However, the plurality of treatments also poses challenges in terms of selecting the best therapy for a given patient, designing trials with appropriate comparison arms and endpoints, identifying well tolerated and effective drug combinations or sequences, and determining the role of targeted therapies in the neoadjuvant and adjuvant settings.

SUMMARY

Vascular endothelial growth factor and mammalian target of rapamycin-targeted therapies continue to play a critical role in the management of advanced and metastatic RCC. Ongoing research to identify novel agents continues to build upon the work done during the elucidation of the von Hippel-Lindau/clear cell RCC pathway. It is hoped that ongoing and planned studies will enable development of therapeutic regimens that will incorporate agents with improved toxicity and better efficacy as well as defining a role for a multidisciplinary approach to the management of advanced RCC.

GLUT-1 expression in pancreatic neoplasia: implications in pathogenesis, diagnosis, and prognosis

OBJECTIVES

GLUT-1 has been found to have an important role in the upregulation of various cellular pathways and implicated in neoplastic transformation correlating with biological behavior in malignancies. However, literature regarding the significance of GLUT-1 expression in pancreatic neoplasia has been limited and controversial.

METHODS

Immunohistochemical expression of GLUT-1 was tested in a variety of pancreatic neoplasia including ductal adenocarcinomas (DAs), pancreatic intraepithelial neoplasms (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and serous cystadenomas.

RESULTS

There was a progressive increase in the expression of GLUT-1 from low- to higher-grade dysplastic lesions: All higher-grade PanINs/IPMNs (the ones with moderate/high-grade dysplasia) revealed noticeable GLUT-1 expression. Among the 94 DAs analyzed, there were minimal/moderate expression in 46 and significant expression in 24 DAs. However, all 4 clear-cell variants of DAs revealed significant GLUT-1 immunolabeling, as did areas of clear-cell change seen in other DAs. Moreover, all 12 serous cystadenomas expressed significant GLUT-1. GLUT-1 expression was also directly correlated with DA histological grade (P = 0.016) and tumor size (P = 0.03).

CONCLUSIONS

GLUT-1 may give rise to the distinctive clear-cell appearance of these tumors by inducing the accumulation of glycogen in the cytoplasm. Additionally, because GLUT-1 expression was related to histological grade and tumor size of DA, further studies are warranted to investigate the association of GLUT-1 with prognosis and tumor progression.

International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma

INTRODUCTION

Adenocarcinoma is the most common histologic type of lung cancer. To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small nonresection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies.

METHODS

An international core panel of experts representing all three societies was formed with oncologists/pulmonologists, pathologists, radiologists, molecular biologists, and thoracic surgeons. A systematic review was performed under the guidance of the American Thoracic Society Documents Development and Implementation Committee. The search strategy identified 11,368 citations of which 312 articles met specified eligibility criteria and were retrieved for full text review. A series of meetings were held to discuss the development of the new classification, to develop the recommendations, and to write the current document. Recommendations for key questions were graded by strength and quality of the evidence according to the Grades of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

The classification addresses both resection specimens, and small biopsies and cytology. The terms BAC and mixed subtype adenocarcinoma are no longer used. For resection specimens, new concepts are introduced such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure lepidic growth (AIS) or predominant lepidic growth with ≤ 5 mm invasion (MIA) to define patients who, if they undergo complete resection, will have 100% or near 100% disease-specific survival, respectively. AIS and MIA are usually nonmucinous but rarely may be mucinous. Invasive adenocarcinomas are classified by predominant pattern after using comprehensive histologic subtyping with lepidic (formerly most mixed subtype tumors with nonmucinous BAC), acinar, papillary, and solid patterns; micropapillary is added as a new histologic subtype. Variants include invasive mucinous adenocarcinoma (formerly mucinous BAC), colloid, fetal, and enteric adenocarcinoma. This classification provides guidance for small biopsies and cytology specimens, as approximately 70% of lung cancers are diagnosed in such samples. Non-small cell lung carcinomas (NSCLCs), in patients with advanced-stage disease, are to be classified into more specific types such as adenocarcinoma or squamous cell carcinoma, whenever possible for several reasons: (1) adenocarcinoma or NSCLC not otherwise specified should be tested for epidermal growth factor receptor (EGFR) mutations as the presence of these mutations is predictive of responsiveness to EGFR tyrosine kinase inhibitors, (2) adenocarcinoma histology is a strong predictor for improved outcome with pemetrexed therapy compared with squamous cell carcinoma, and (3) potential life-threatening hemorrhage may occur in patients with squamous cell carcinoma who receive bevacizumab. If the tumor cannot be classified based on light microscopy alone, special studies such as immunohistochemistry and/or mucin stains should be applied to classify the tumor further. Use of the term NSCLC not otherwise specified should be minimized.

CONCLUSIONS

This new classification strategy is based on a multidisciplinary approach to diagnosis of lung adenocarcinoma that incorporates clinical, molecular, radiologic, and surgical issues, but it is primarily based on histology. This classification is intended to support clinical practice, and research investigation and clinical trials. As EGFR mutation is a validated predictive marker for response and progression-free survival with EGFR tyrosine kinase inhibitors in advanced lung adenocarcinoma, we recommend that patients with advanced adenocarcinomas be tested for EGFR mutation. This has implications for strategic management of tissue, particularly for small biopsies and cytology samples, to maximize high-quality tissue available for molecular studies. Potential impact for tumor, node, and metastasis staging include adjustment of the size T factor according to only the invasive component (1) pathologically in invasive tumors with lepidic areas or (2) radiologically by measuring the solid component of part-solid nodules.

Impact of genetics on the diagnosis and treatment of renal cancer

Kidney cancer is a heterogeneous disease comprised of a number of histologic subtypes, each associated with unique genetic mutations, clinical features, and sensitivity to treatment. By examining families affected with the hereditary kidney cancer syndromes von Hippel-Lindau, hereditary papillary renal cell carcinoma, hereditary leiomyomatosis and renal cell carcinoma, and Birt-Hogg-Dubé, researchers have been able to identify the genes responsible for these syndromes. This work has revealed that kidney cancer is fundamentally a metabolic disorder, and as such, novel targeted therapies specific to their molecular biology have been developed and employed in both the hereditary and sporadic forms of renal cell carcinoma.

Clear cell unicystic ameloblastoma

Clear cell differentiation in unicystic ameloblastoma with inclusion of many other histologic variants in the same tumor is a very rare occurrence. Here, we report a case of a well-circumscribed large mandibular swelling in a 22 - year old female. The lesion was histopathologically diagnosed as unicystic ameloblastoma which showed multiple histologic patterns and clear cell differentiation. The tumor was treated with surgical enucleation and chemical cauterization. A follow up of 20 months has shown no recurrence after initial surgery.

Is serous cystadenoma of the pancreas a model of clear-cell-associated angiogenesis and tumorigenesis?

BACKGROUND

Similar to the other von Hippel-Lindau (VHL)-related tumors such as renal cell carcinomas and capillary hemangioblastomas, serous cystadenomas (SCAs) of the pancreas are also characterized by clear cells. Over the years, we have also noticed that the tumor epithelium shows a prominent capillary network.

METHODS

Eighteen cases of SCA were reviewed histologically, and immunohistochemical analysis was performed for CD31 and vascular endothelial growth factor (VEGF) as well as the molecules implicated in clear-cell tumorigenesis: GLUT-1, hypoxia-inducible factor-1 (HIF-1alpha), and carbonic anhydrase IX (CA IX).

RESULTS

There was an extensively rich capillary network that appears almost intraepithelially in all cases of SCA, which was confirmed by CD31 stain that showed, on average, 26 capillaries per every 100 epithelial cells. VEGF expression was identified in 10/18 cases. Among the clear-cell tumorigenesis markers, CA IX was detected in all cases, GLUT-1 and HIF-1alpha in most cases.

CONCLUSION

As in other VHL-related clear-cell tumors, there is a prominent capillary network immediately adjacent to the epithelium of SCA, confirming that the clear-cell- angiogenesis association is also valid for this tumor type. Molecules implicated in clear-cell tumorigenesis are also consistently expressed in SCA. This may have biologic and therapeutic implications, especially considering the rapidly evolving drugs against these pathways. More importantly, SCA may also serve as a model of clear-cell-associated angiogenesis and tumorigenesis, and the information gained from this tumor type may also be applicable to other clear-cell tumors.

CA-125 change after chemotherapy in prediction of treatment outcome among advanced mucinous and clear cell epithelial ovarian cancers: a Gynecologic Oncology Group study

BACKGROUND

There are limited data regarding unique clinical or laboratory features associated with advanced clear cell (CC) and mucinous (MU) epithelial ovarian cancers (EOC), particularly the relationship between CA-125 antigen levels and prognosis.

METHODS

A retrospective review of 7 previously reported Gynecologic Oncology Group phase 3 trials in patients with stage III/IV EOC was conducted. A variety of clinical parameters were examined, including the impact of baseline and changes in the CA-125 level after treatment of CC and MU EOC on progression-free (PFS) and overall survival (OS).

RESULTS

Clinical outcomes among patients with advanced CC and MU EOC were significantly worse when compared with other cell types (median PFS, 9.7 vs 7.0 vs 16.7 months, respectively, P < .001; median OS, 19.4 vs 11.3 vs 40.5 months, respectively, P < .001). Suboptimal debulking was associated with significantly decreased PFS and OS among both. Although baseline CA-125 values were lower in CC (median, 154 micron/mL) and MU (100 micron/mL), compared with other cell types (275 micron/mL), this level did not appear to influence outcome among these 2 specific subtypes of EOC. However, an elevated level of CA-125 at the end of chemotherapy was significantly associated with decreased PFS and OS (P < .01 for all).

CONCLUSIONS

Surgical debulking status is the most important variable at prechemotherapy predictive of prognosis among advanced CC and MU EOC patients. Changes in the CA-125 levels at the end treatment as compared with baseline can serve as valid indicators of PFS and OS, and likely the degree of inherent chemosensitivity.

Expression of claudin-7 in benign kidney and kidney tumors

Claudins, a family of tight junction-related transmembrane proteins, have been implicated in the pathogenesis of various human neoplasms. Expression of claudin-7 was increased in chromophobe renal cell carcinoma in a recent oligonucleotide microarray study. We studied the expression of claudin-7 in benign and neoplastic kidneys by immunohistochemical staining. Distal nephron (distal convoluted tubule and thick ascending limb of Henle's loop) epithelium showed strong membranous staining in 100% (174/174) of the cases. Chromophobe renal cell carcinoma was positive for claudin-7 expression in 100% (36/36) of cases, while papillary renal cell carcinoma, oncocytoma and clear cell renal cell carcinoma were positive in 90% (71/80), 45% (21/47) and 7% (7/98) of the cases, respectively. Differential expression of Claudin-7 in different types of renal cell neoplasms can be useful in their differential diagnosis, particularly when used in a panel of markers. In addition, results from this study support previous reports of distal nephron origin for chromophobe renal cell carcinoma and oncocytoma. The data also suggest that, as far as claudin-7 expression is concerned, papillary renal cell carcinoma may be more closely related to the distal nephron, rather than the proximal nephron.