Does the Addition of Mutations of CTNNB1 S45F to Clinical Factors Allow Prediction of Local Recurrence in Patients With a Desmoid Tumor? A Local Recurrence Risk Model

BACKGROUND

The initial approach to the treatment of desmoid tumors has changed from surgical resection to watchful waiting. However, surgery is still sometimes considered for some patients, and it is likely that a few patients would benefit from tumor removal if the likelihood of local recurrence could be predicted. However, to our knowledge, there is no tool that can provide guidance on this for clinicians at the point of care.

QUESTION/PURPOSE

We sought to explore whether a combined molecular and clinical prognostic model for relapse in patients with desmoid tumors treated with surgery would allow us to identify patients who might do well with surgical excision.

METHODS

This was a retrospective, single-center study of 107 patients with desmoid tumors who were surgically treated between January 1980 and December 2015, with a median follow-up of 106 months (range 7 to 337 months). We correlated clinical variables (age, tumor size, and localization) and CTNNB1 gene mutations with recurrence-free survival. Recurrence-free survival was estimated using a Kaplan-Meier curve. Univariate and multivariable analyses of time to local recurrence were performed using Cox regression models. A final nomogram model was constructed according to the final fitted Cox model. The predictive performance of the model was evaluated using measures of calibration and discrimination: calibration plot and the Harrell C-statistic, also known as the concordance index, in which values near 0.5 represent a random prediction and values near 1 represent the best model predictions.

RESULTS

The multivariable analysis showed that S45F mutations (hazard ratio 5.25 [95% confidence interval 2.27 to 12.15]; p < 0.001) and tumor in the extremities (HR 3.15 [95% CI 1.35 to 7.33]; p = 0.008) were associated with a higher risk of local recurrence. Based on these risk factors, we created a model; we observed that patients considered to be at high risk of local recurrence as defined by having one or two factors associated with recurrence (extremity tumors and S45F mutation) had an HR of 8.4 compared with patients who had no such factors (95% CI 2.84 to 24.6; p < 0.001). From these data and based on the multivariable Cox models, we also developed a nomogram to estimate the individual risk of relapse after surgical resection. The model had a concordance index of 0.75, or moderate discrimination.

CONCLUSION

CTNNB1 S45F mutations combined with other clinical variables are a potential prognostic biomarker associated with the risk of relapse in patients with desmoid tumors. The developed nomogram is simple to use and, if validated, could be incorporated into clinical practice to identify patients at high risk of relapse among patients opting for surgical excision and thus help clinicians and patients in decision-making. A large multicenter study is necessary to validate our model and explore its applicability.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Patient-Derived Renal Cell Carcinoma Xenografts Capture Tumor Genetic Profiles and Aggressive Behaviors

BACKGROUND: Patient-derived xenografts (PDX) have emerged as one of the most promising model systems to study cancer biology and to develop new antineoplastic drugs. Renal cell carcinoma (RCC) represents up to 90% of all kidney tumors, exhibits aggressive behavior, and has a propensity for metastasis. At diagnosis, 30% of patients with RCC have metastases, while up to 50% of those with localized disease treated with curative protocols experience recurrence. OBJECTIVE: This study aimed to establish an RCC PDX platform to identify novel clinical and molecular biomarkers of recurrence risk in order to facilitate precision medicine. METHODS: Tumor samples were obtained from surgical specimens of 87 RCC patients; fragments were implanted in immunodeficient NOD/SCID/gamma (NSG) mice. Seventeen fragments were implanted subcutaneously in an initial group while a second group of 70 samples were implanted orthotopically in the subcapsular space. RESULTS: A total of 19 PDX developed only after orthotopic implantation, and included 15 cases of clear cell RCC subtype, 3 cases of papillary subtype, and one unclassifiable tumor. One PDX of clear cell RCC recapitulated the phenotype of vena caval tumor thrombus extension that had been diagnosed in the source patient. PDX characterization by immunohistochemistry and targeted sequencing indicated that all PDXs preserved RCC identity and major molecular alterations. Moreover, the capacity of tumor engraftment was a strong prognostic indicator for patients with locally advanced disease. CONCLUSION: Taken together, these results suggest that the orthotopic xenograft model of RCC represents a suitable tool to study RCC biology, identify biomarkers, and to test therapeutic candidates.

Pseudoangiosarcomatous squamous cell carcinoma: first case report on penis

Pseudoangiosarcomatous squamous cell carcinoma, also called pseudovascular, pseudoangiomatoid or adenoid pseudovascular carcinoma, is an uncommon and highly aggressive variant of squamous cell carcinoma. Histologically, it is characterized by proliferation of atypical keratinocytes with acantholysis and formation of pseudovascular spaces, forming anastomosed channels lined with neoplastic cells that invade the dermis. These cells are positive for cytokeratin and negative for vascular markers such as CD31 and CD34. There are few reports of this variant in the literature. Skin, breast, lung and vulva involvement have been described, but to the best of our knowledge, no cases involving the penis has been described. This study aims to describe the first case of angiosarcomatous squamous cell carcinoma of the penis. The patient presented with a painful lesion in the penis associated with urinary retention. Macroscopic findings exhibited an ulcerative vegetating lesion that involving the entire glans and part of the penile body, as well as infiltration of penile structures and scrotal skin. Microscopy shows atypical proliferation of sarcomatous keratinocyte pattern mimicking vascular spaces. Human papilloma virus (HPV) biomarkers and polymerase chain reaction (PCR) were all negative. Advanced penile squamous cell carcinoma with aggressive lymph node metastasis. This report presents the first case of penile pseudoangiosarcomatous squamous cell carcinoma, as an important differential diagnosis.

Insights Into the Somatic Mutation Burden of Hepatoblastomas From Brazilian Patients

Hepatoblastoma is a very rare embryonal liver cancer supposed to arise from the impairment of hepatocyte differentiation during embryogenesis. In this study, we investigated by exome sequencing the burden of somatic mutations in a cohort of 10 hepatoblastomas, including a congenital case. Our data disclosed a low mutational background and pointed out to a novel set of candidate genes for hepatoblastoma biology, which were shown to impact gene expression levels. Only three recurrently mutated genes were detected: CTNNB1 and two novel candidates, CX3CL1 and CEP164. A relevant finding was the identification of a recurrent mutation (A235G) in two hepatoblastomas at the CX3CL1 gene; evaluation of RNA and protein expression revealed upregulation of CX3CL1 in tumors. The analysis was replicated in two independents cohorts, substantiating that an activation of the CX3CL1/CX3CR1 pathway occurs in hepatoblastomas. In inflammatory regions of hepatoblastomas, CX3CL1/CX3CR1 were not detected in the infiltrated lymphocytes, in which they should be expressed in normal conditions, whereas necrotic regions exhibited negative labeling in tumor cells, but strongly positive infiltrated lymphocytes. Altogether, these data suggested that CX3CL1/CX3CR1 upregulation may be a common feature of hepatoblastomas, potentially related to chemotherapy response and progression. In addition, three mutational signatures were identified in hepatoblastomas, two of them with predominance of either the COSMIC signatures 1 and 6, found in all cancer types, or the COSMIC signature 29, mostly related to tobacco chewing habit; a third novel mutational signature presented an unspecific pattern with an increase of C>A mutations. Overall, we present here novel candidate genes for hepatoblastoma, with evidence that CX3CL1/CX3CR1 chemokine signaling pathway is likely involved with progression, besides reporting specific mutational signatures.

Complete metastasectomy in renal cell carcinoma: a propensity-score matched by the International Metastatic RCC Database Consortium prognostic model

Introduction

We evaluated overall survival (OS) benefit of complete metastasectomy (CM) in metastatic renal cell carcinoma (mRCC) using a propensity score-matched (PSM) analysis to balance groups by age, gender and by the International Metastatic RCC Database Consortium prognostic model (IMDC).

Methods

We included patients (pts) treated at the AC Camargo Cancer Center between 2007 and 2016. Pairs were matched by age, gender and IMDC. Kaplan–Meier survival estimates and Cox proportional hazard models were used to evaluate OS on CM and no-CM group.

Results

We found 116 pts with clear cell mRCC. After PSM, the number was reduced to 74 (37 CM, 37 no-CM). The median OS for CM and no-CM was 98.3 months and 40.5 months, respectively (hazard ratio 0.24 95%CI 0.11–0.53 p < 0.001). The OS benefit of CM was confirmed on favourable and intermediate IMDC but was absent on poor IMDC. The CM group received less systemic therapy than the no-CM group. Ten pts in the CM group still have no evidence of disease (NED).

Conclusion

After matching for age, gender and IMDC, we found CM impacts on OS and also diminishes the need for systemic treatment. Survival benefit was confirmed for favourable/intermediate IMDC but not for the poor IMDC prognostic model. Further studies correlating IMDC and metastasectomy are needed to guide clinical decision-making.

Incidence and distribution of UroSEEK gene panel in a multi-institutional cohort of bladder urothelial carcinoma

Noninvasive approaches for early detection of bladder cancer are actively being investigated. We recently developed a urine- based molecular assay for the detection and surveillance of bladder neoplasms (UroSEEK). UroSEEK is designed to detect alterations in 11 genes that include most common genetic alterations in bladder cancer. In this study, we analyzed 527 cases, including 373 noninvasive and 154 invasive urothelial carcinomas of bladder from transurethral resections or cystectomies performed at four institutions (1991-2016). Two different mutational analysis assays of a representative tumor area were performed: first, a singleplex PCR assay for evaluation of the TERT promoter region (TERTSeqS) and second, a multiplex PCR assay using primers designed to amplify regions of interest of 10 (FGFR3, PIK3CA, TP53, HRAS, KRAS, ERBB2, CDKN2A, MET, MLL, and VHL) genes (UroSeqS). Overall, 92% of all bladder tumors were positive for at least one genetic alteration in the UroSEEK panel. We found TERT promoter mutations in 77% of low-grade noninvasive papillary carcinomas, with a relatively lower incidence of 65% in high-grade noninvasive papillary carcinomas and carcinomas in situ; p = 0.017. Seventy-two percent of pT1 and 63% of muscle-invasive bladder tumors harbored TERT promoter mutations with g.1295228C>T alteration being the most common in all groups. FGFR3 and PIK3CA mutations were more frequent in low-grade noninvasive papillary carcinomas compared with high-grade noninvasive papillary carcinomas and carcinomas in situ (p < 0.0001), while the opposite was true for TP53 (p < 0.0001). Significantly higher rates of TP53 and CDKN2A mutation rates (p = 0.005 and 0.035, respectively) were encountered in muscle-invasive bladder tumors compared with those of pT1 stage. The overwhelming majority of all investigated tumors showed at least one mutation among UroSEEK assay genes, confirming the comprehensive coverage of the panel and supporting its potential utility as a noninvasive urine-based assay.

Tissue-based molecular markers in upper tract urothelial carcinoma and their prognostic implications

Upper tract urothelial carcinoma (UTUC) is a rare and aggressive disease that is associated with high rates of recurrence and death. Radical nephroureterectomy (RNU) with excision of the bladder cuff is considered the standard of care for high-risk UTUC, whereas kidney-sparing techniques can be indicated for select patients with low-risk disease. There is a significant lack of clinical and pathological prognostic factors for stratifying patients with regard to making treatment decisions. Incorporation of tissue-based molecular markers into prognostic tools could help accurately stratify patients for clinical decision-making in this heterogeneous disease. Although the number of studies on tissue-based markers in UTUC has risen dramatically in the past several years-many of which are based on single centers and small cohorts, with a low level of evidence-many discrepancies remain between their results. Nevertheless, certain biomarkers are promising tools, necessitating prospective multi-institution studies to validate their function.

Non-invasive detection of urothelial cancer through the analysis of driver gene mutations and aneuploidy

Current non-invasive approaches for detection of urothelial cancers are suboptimal. We developed a test to detect urothelial neoplasms using DNA recovered from cells shed into urine. UroSEEK incorporates massive parallel sequencing assays for mutations in 11 genes and copy number changes on 39 chromosome arms. In 570 patients at risk for bladder cancer (BC), UroSEEK was positive in 83% of those who developed BC. Combined with cytology, UroSEEK detected 95% of patients who developed BC. Of 56 patients with upper tract urothelial cancer, 75% tested positive by UroSEEK, including 79% of those with non-invasive tumors. UroSEEK detected genetic abnormalities in 68% of urines obtained from BC patients under surveillance who demonstrated clinical evidence of recurrence. The advantages of UroSEEK over cytology were evident in low-grade BCs; UroSEEK detected 67% of cases whereas cytology detected none. These results establish the foundation for a new non-invasive approach for detection of urothelial cancer.

KRAS mutation status is highly homogeneous between areas of the primary tumor and the corresponding metastasis of colorectal adenocarcinomas: one less problem in patient care

Background: Mutations in KRAS are negative predictors of the response to anti-EGFR therapies in the treatment of metastatic colorectal cancer. Yet, the ideal tissue to test for KRAS mutation-primary or metastatic-remains unknown, as is the validity of testing only 1 area of the primary tumor. The aim of this study was to determine the heterogeneity of KRAS mutational status between areas of the primary lesion and between paired primary CRC and the corresponding lymph node (LN), liver, and lung metastasis with a high-sensitivity sequencing method. Design: DNA from 2 or 3 areas from the primary tumor and 1 area of metastatic tissue was obtained from formalin-fixed paraffin-embedded specimens from 102 metastatic CRC patients. Mutations in KRAS codons 12, 13, and 61 were analyzed by pyrosequencing.

RESULTS

Ninety-one cases had DNA extracted from more than 1 area of the primary tumor. Only 1 patient showed intratumor heterogeneity, which involved KRAS mutation type, not KRAS mutational status. We examined KRAS mutations in 97 primaries and matched metastatic samples, recording 2 discordant cases, representing 2.1% of our cohort of matched samples. Conclusion:KRAS status is highly homogeneous throughout primary CRC tumor areas and consistent between the primary tumor and metastatic tissue in the same patient. Our data suggest that testing KRAS mutations in only 1 area of the primary or metastatic tissue is suitable for predicting the response to anti-EGFR treatment and guiding clinical decisions.

Spectrum of genetic mutations in de novo PUNLMP of the urinary bladder

Our group and others have previously demonstrated the presence of TERT promoter mutations (TERT-mut) in 60-80% of urothelial carcinomas and some of their histologic variants. Five other genes have been frequently implicated in bladder cancer: FGRF3, TP53, PIK3CA, HRAS, and CDKN2A. In the current study, we sought to determine the prevalence of mutations in TERT and these five other genes in de novo papillary urothelial neoplasms of low malignant potential (PUNLMP) of the urinary bladder. A retrospective search of our archives for PUNLMP was performed and 30 de novo cases were identified and included in the study. We found mutations in TERT (TERT-mut) and FGFR3 (FGFR3-mut) to be the most common alterations in the cohort (63 and 60%, respectively). The majority of the TERT-mut-positive tumors (84%) had a g.1295228C > T alteration with the remaining tumors demonstrating g.1295250C > T. Approximately one fourth of tumors had TP53 mutations. These findings support the potential utility of a uniform genetic mutation panel to detect bladder cancers of various subtypes.

Abstract 1956: Mirnas hsa-miR-214-3p, -378a-3p e -34a-5p as biomarkers for uterine mesenchymal neoplasms

Background: Uterine mesenchymal tumors have specific mechanisms of development that are largely unknown. One of the molecular mechanisms which may be involved in the appearance and progression of these tumors is the regulation of gene expression by miRNAs. These molecules are small non-coding RNAs that play important roles in several biological pathways. The identification of miRNAs that show particular differences in expression profile can help broaden the diagnostic methods available for these tumors. Objectives: To evaluate the expression profile of microRNAs described as sequences related to tumors development in uterine leiomyosarcomas samples, comparing to leiomyomas and normal myometrium. Methods: We selected 37 samples of uterine leiomyosarcoma (LMS), 16 unconventional leiomyomas (LMA), 10 conventional leiomyomas (LM) and 2 myometrium (used as reference samples). Samples were obtained from the Discipline of Gynecology of the Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo and Department of Pathology of the A C Camargo Cancer Center, both in Sao Paulo, Brazil. The total RNA was obtained and used to perform the synthesis of cDNA.The real time PCR reactions was performed using the Kit miScript SYBR Green PCR (Qiagen) for analysis from the 84 miRNAs sequences already described in the literature as tumor development related sequences. Results: The data analysis from the 84 sequences of microRNA showed wide variation in the regulation of these molecules expression. After computational analysis, we selected only those miRNAs with different expression profile between LM, LMA and LMS. The goal was to obtain a molecular signature that differentiate and identify each tumor using normal tissue as a reference. We found that hsa-mir-214-3p and hsa-miR-378-3p (fold regulation of -2.32 and -2.97; respectively) presented down-regulation in samples from the uterine LMS. In LMA we found a down regulation of hsa-miR-34a-5p (-3.12 fold regulation). Conclusions: We identified three miRNAs (hsa-mir-214-3p, and -378-3p and -34a-5p) differentially expressed in LMA and LMS. Analyzes of target genes of these miRNAs may identify specific proteins for use in the differential diagnosis, prognosis and patients management in these tumors.

Citation Format: Laura G. dos Anjos, Gustavo A. Maciel, Isabela W. Cunha, Edmund C. Baracat, Kátia C. Carvalho. Mirnas hsa-miR-214-3p, -378a-3p e -34a-5p as biomarkers for uterine mesenchymal neoplasms. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1956.

Prognostic role of decreased E-cadherin expression in patients with upper tract urothelial carcinoma: a multi-institutional study

PURPOSE

To assess the role of E-cadherin as prognostic biomarker in upper tract urothelial carcinoma (UTUC) in a large multi-institutional cohort of patients.

METHODS

Immunohistochemistry technique was used to evaluate E-cadherin expression in 678 patients with unilateral, sporadic UTUC treated with RNU. E-cadherin expression was considered decreased if 10 % or more cells had decreased expression (<90 %).

RESULTS

Decreased E-cadherin expression was observed in 353 patients (52.1 %) and was associated with advanced pathological stage (P < 0.001), higher grade (P < 0.001), lymph node metastasis (P = 0.006), lymphovascular invasion (P < 0.001), concomitant carcinoma in situ (P < 0.001), multifocality (P = 0.004), tumor necrosis (P = 0.020) and sessile architecture (P < 0.001). Within a median follow-up of 30 months (interquartile range 15-57), 171 patients (25.4 %) experienced disease recurrence and 150 (21.9 %) died from UTUC. In univariable analyses, decreased E-cadherin expression was significantly associated with worse recurrence-free survival (P < 0.001) and cancer-specific survival CSS (P = 0.006); however, in multivariable analyses, it was not (P = 0.74 and 0.84, respectively). The lack of independent prognostic value of E-cadherin remained true in all subgroup analyses.

CONCLUSION

In UTUC patients treated with RNU, decreased E-cadherin expression is associated with features of biologically and clinically aggressive disease and worse outcome in univariable, but not multivariable, analyses. If E-cadherin's association with factors of advanced disease is confirmed on UTUC biopsy specimens, it could be used to help in the clinical decision-making regarding kidney-sparing approaches and/or neo-adjuvant chemotherapy.

Nuclear unphosphorylated STAT3 correlates with a worse prognosis in human glioblastoma

Glioblastoma (GBM) is currently the most aggressive form of brain tumor identified, and STAT3 is known to play an important role in gliomagenesis. Moreover, while several studies have used pharmacological approaches to modulate STAT3 activity, the results have been contradictory. In this study, expressions of STAT3, pSTAT3 (Y705), and pSTAT3 (S727) were evaluated using immunohistochemistry assays of tissue microarrays containing non-neoplastic tissue (NN, n=12), grade II astrocytomas (n=33), grade III astrocytomas (n=12), and GBM (n=85) specimens. In GBM specimens, STAT3 was overexpressed and exhibited greater nuclear localization compared with lower grade astrocytomas and NN. Conversely, nuclear localization of pSTAT3 (Y705) and pSTAT3 (S727) exhibited a similar phenotype in both GBMs and NNs. MET was also detected as a non-canonical pathway marker for STAT3. For tumors with higher levels of STAT3 nuclear localization, and not pSTAT3 (Y705) and pSTAT3 (S727), these specimens exhibited increased levels of MET expression. Thus, a non-canonical pathway may mediate a proportion of the STAT3 that translocates to the nucleus. Moreover, tumors which exhibited greater nuclear localization of STAT3 corresponded with patients that presented with lower rates of recurrence-free survival and overall survival. In contrast, the phosphorylated forms of STAT3 did not correlate with patient survival. These findings suggest that phosphorylation-independent mechanisms may mediate the nuclear translocation and activation of STAT3. Further studies are needed to identify the mechanisms involved, especially those that provide targets to achieve efficient inhibition and control of GBM progression.

Abstract A32: Urine as a potential liquid biopsy for detecting tumor DNA in Wilms tumor patient: Detection of somatic mutations in urine opens perspectives of monitoring chemotherapy response in WT patients

Detection of tumor DNA in urine has been shown as viable method of diagnosis not only for urinary tract (e.g., kidney and bladder) cancers but also for other types, e.g. prostate. Applications of such method, resemble those which use plasma DNA and include cancer detection, monitoring of tumor growth or recurrence and response to chemotherapy or radiation therapy. As far as we know, there is a lack of studies applying urine DNA detection in Wilms tumor (WT), an embryonary kidney cancer type.

Here we show evidences of detection for two somatic variants in the urine DNA of one WT patient. By using NGS exome sequencing of tumor tissue and leukocytes samples of the same patient we were able to find new somatic variants: a frame-shift indel in TNRC18 and a misssense SNV in INTS1 gene. Target sequencing applied to the DNA from the patient's urine revealed the presence of these two somatic variants. More interestingly, both variants could not be found in the urine DNA of this patient after treatment (chemotherapy and nephrectomy). Additionally, these genes are poorly characterized in WT contributing for the comprehension of the cellular processes that are operating in tumorigenesis of WT. Altogether, our findings contribute with the mutational repertoire of WT and reveals the potential of using urine DNA sequencing as a noninvasive cancer screening approach.

Citation Format: Ana C. K. Miguez, Rodrigo F. Ramalho, Elisa N. Ferreira, Bruna D. F. Barros, Claudia A. A. de Paula, Renan Valieris, Louise D. C. Mota, Jorge E. Souza, Isabela W. Cunha, Cecília L. Costa, Sandro J. de Souza, Dirce M. Carraro. Urine as a potential liquid biopsy for detecting tumor DNA in Wilms tumor patient: Detection of somatic mutations in urine opens perspectives of monitoring chemotherapy response in WT patients. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr A32.

Abstract 4822: Lack of expression of FOXO3 correlates with poor prognosis on uterine sarcomas

Background: Uterine sarcomas are rare mesodermic tumors that represent approximately 3% of all uterine cancers. They display histological diversity and aggressive behavior, with early dissemination and high mortality when compared with epithelial tumors. Due to their diversity and rarity, there is no consensus related to risk factors for poor prognostic and appropriated treatment. The knowledge of the gene expression regulation can contribute to a better understanding of these neoplasms. Recently it was demonstrated an essential role for the forkhead transcription factor FOXO3 in the regulation of diverse cellular functions and tumors development. Our aim was to study the expression profile of the transcription factor FOXO3 in several histological types of uterine sarcoma. Method: we evaluated 100 samples of uterine sarcomas (including leiomyosarcomas, carcinosarcomas, adenosarcomas and endometrial stromal sarcomas), leiomyomas and myometrium obtained from patients during the period of 2000 to 2012. FOXO3 protein expression was assessed by immunohistochemistry. mRNA expression was evaluated by quantitative Real Time PCR. The results were submitted to statistical analyses together with patient's data. Results: We observed that carcinosarcomas (CSS) and adenosarcomas (ADS) showed the highest FOXO3 protein signal, considering exclusively the mesenchymal component. Concerning to muscular tumors (leiomyoma and leiomyosarcoma), we found an increasing enhancement of this protein expression from the myometrium to myoma and leiomiosarcoma, both in protein and transcriptional levels. Statistical analysis showed that tumors with weak or lack of FOXO3 protein present poor prognosis, regardless of their histological type. Conclusion: FOXO3 protein expression seems to be a relevant role in uterine sarcomas, however further analyses are needed.

Citation Format: Thais G. Almeida, Natalia Garcia, Isabela W. Cunha, Glauco Baiocchi, Fernando A. Soares, Gustavo A. Maciel, Edmund C. Baracat, Katia C. Carvalho. Lack of expression of FOXO3 correlates with poor prognosis on uterine sarcomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4822. doi:10.1158/1538-7445.AM2015-4822

Abstract 4827: Gene copy number and protein expression of growth factor receptors EGFR and HER2 and their prognostic potential in penile squamous cell carcinoma

BACKGROUND: Penile squamous cell carcinoma (PSCC) is a disease typical of less developed regions of the globe, and its molecular mechanisms are not clearly understood. Novel EGFR-targeted therapies have arisen as a potential treatment alternative and, although the mechanisms of EGFR activation in PSCC are unknown. For that, we have addressed the protein expression and gene copy number (CGN) of EGFR and HER2 in a large cohort of PSCC patients.

METHODS: Immunohistochemistry (IHC) against EGFR and HER2 was performed in samples from 183 PSCC patients using the biotin-free polymer method. Overexpressing cases were those showing strong and complete membrane staining in more than 10% of the tumor cells. Seventy-three cases were submitted to dual color fluorescence in situ hybridization (FISH) for evaluation of GCN of both genes (and their respective centromere) and were classified as disomy (2 signals of the gene and chromosome centromere in each nucleus), polysomy (more than 2 signals of the gene and centromere), or gene gains (cases with a gene signal:centromeric signal ratio exceeding 2).

RESULTS: Regarding EGFR, almost half of cases (91, or 49.7%) overexpressed the marker, 81 (54.5%) presented low expression, and 9 (4.9%) showed no staining at all. Overexpression associated with presence of recurrence (p = 0.031). Most cases presented disomy of chromosome 7 (46/68, or 67.6%), 16 cases (23.5%) were polysomies, and 6 cases (9.9%) EGFR gains (up to 6 copies of the gene x 2 signals of chromosome 7 centromere). Increased EGFR copies due to polysomy or amplification was associated with higher histologic grade and shorter cancer-specific survival (p = 0.008 and p = 0.019, respectively) but not with protein overexpression (p = 0.403). No membrane expression of HER2 was seen, but a cytoplasmic staining was found in 214.9% (28) of cases, all of them high grade tumors. Cytoplasmic HER2 (cHER2) associated with EGFR overexpression (p = 0.017), and reduced cancer-specific survival (p = 0.014). No amplifications of HER2 were seen, but chromosome 17 polysomy was present in 16 (21.9%) of 73 valid cases. Cases presenting polysomy of chromosome 17 (P17) presented recurrence (p = 0.008), higher histological grade tumors (p = 0.030) and perineural invasion (p = 0.045) more frequently. Cancer-specific survival of P17 patients was also shorter (p = 0.014).

CONCLUSIONS: Our results suggest a possible prognostic role for EGFR overexpression and HER2 cytoplasmic staining, stratifying patients at increased risk of disease recurrence or death. GCN analysis of the studied genes showed that increased EGFR gene copies is a strong predictor of cancer death, as well as polysomy of chromosome 17 is. We believe an important unbalance in chromosome number might explain the poor outcome seen in patients.

Funding: Capes and FAPESP.

Note: This abstract was not presented at the meeting.

Citation Format: Alice M. Silva-Amancio, Jose I. Neves, Isabela W. Cunha, Walter da Costa, Gustavo C. Guimarães, Fernando A. Soares. Gene copy number and protein expression of growth factor receptors EGFR and HER2 and their prognostic potential in penile squamous cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4827. doi:10.1158/1538-7445.AM2015-4827

Abstract A29: Identification of somatic and de novo mutations by exome sequencing in sporadic Wilms tumor

Background: Wilms Tumor (WT) is the most common pediatric kidney cancer and in approximately 2% of cases presents a familial predisposition. In both sporadic and inherited WT cases, several genes have been identified as being somatically mutated. The most frequent WT mutated genes are WT1, CTNNB1 and WTX, that together account for approximately 30% of cases. In addition, mutation in other genes such as TP53, IGF2, DIS3L2, FBXW7, MYCN, and DICER have also been described in few cases. However, up to 60-70% of Wilms tumors remain without any associated driver mutation. In this sense, the aim of this project was to identify novel somatic and de novo alterations possibly associated with WT tumorigenesis through exome sequencing. Methods: The study design consisted of performing exome sequencing of 4 samples related to a sporadic WT patient: patient blood and tumor samples, in addition to mother's and father's blood samples. Coding regions of genomic DNA were enriched using SureSelect Human All Exon 50Mb Kit (Agilent). Libraries construction and sequencing at SOLiD 4 and 5500xl were performed following the manufacturer's instructions. Resulting sequences were mapped to a reference genome with Bioscope and NovoalignCS software. Sequence variants were identified with SAMtools and filtered if present on dbSNP database. Initially a small set of de novo and somatic mutations were selected to be validated by sanger sequencing. Results: From 84 unknown de novo alterations, we selected 11 for validation according to the following criteria: all loss of function variants (1 splice site and 2 nonsenses; 8 missense variants that were classified as pathogenic in the prediction programs SIFT and/or Polyphen2 and were not at highly repetitive or homologous regions of the genome. From these 11 candidates, only one was confirmed to be a de novo mutation, while the remaining ten were either false positive or inherited variants. Regarding somatic alterations, 8 candidate mutations were identified and selected for validation. After sanger sequencing, only one was validated as a somatic mutation, one variant was also present in patient's blood and 6 alterations were not confirmed in the tumor, suggesting it to be sequencing artifacts. The gene affected by the validated somatic mutation encodes an important protein involved in RNA regulation and cell differentiation, and was not described to be mutated in any tumor type until now. Remarkably, this somatic mutation affects a highly conserved amino acid of this gene and this residue is a known binding site for a magnesium cofactor that is essential for the protein activity. The presence of this mutation was further evaluated in a cohort of 97 Wilms tumor samples and found to be present in 10% of cases. Preliminary functional studies of HEK293 cells transfected with an expression vector of this mutation demonstrated an impaired activity of the mutated protein. Conclusion: In this study we were able to identify one de novo and one somatic novel mutations in Wilms tumor. Initial results from our group suggest that this somatic mutation represents a driver and frequent event in this type of tumor.

Citation Format: Giovana T. Torrezan, Elisa N. Ferreira, Mayra T M Castro, Adriana M. Nakahata, Pedro A. Galante, Daniel T. Ohara, Bruna D. Barros, Mariana Maschietto, Isabela W. Cunha, Cecilia M L Costa, Beatriz D. Camargo, Dirce M. Carraro. Identification of somatic and de novo mutations by exome sequencing in sporadic Wilms tumor. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr A29.

Abstract 3327: Epidermal growth factor receptors and penile carcinoma: The role of EGFR and HER2 expression as prognostic and predictive markers

BACKGROUND: Growth factor receptors have recently been described as potential therapeutic targets for penile carcinoma patients, and there are reports on benefits from the clinical use of monoclonal antibodies against EGFR. However, knowledge on the molecular basis of the disease is scarce. For that, we have addressed the expression of EGFR and HER2, as well as mutational and amplification status of EGFR in samples from penile squamous cell carcinoma (PSCC) patients.

METHODS: Clinicopathologic features and survival data from 183 PSCC patients were reviewed from hospital records and immunohistochemistry (IHC) against EGFR and HER2 was performed. Positive cases were those showing strong and complete membrane staining in more than 10% of the tumor cells. HER2 was also classified as positive according to the presence of cytoplasmic staining (cHER2). Sixty cases were submitted to dual-color fluorescence in situ hybridization (FISH) and were classified as unaltered (those harboring 2 signals for each probe) or FISH positive (either if polysomic - harboring more than 2 signals for each probe - or amplified - cases with an EGFR signal:centromeric signal ratio exceeding 2). EGFR exons 18, 19, 20 and 21 from 27 independent frozen cases were sequenced. Variables were compared by the Pearson chi-square or Fisher´s exact test. Survival rates were calculated using the Kaplan-Meier method and compared by log-rank test. Alpha error was set at 5%.

RESULTS: IHC analysis showed that, for EGFR expression, 91 cases (49.7%) were positive and 92 negative, out of which 9 (4,9%) showed no staining at all. Positive cases were associated with higher incidence of recurrence and exophytic growth (p=0.031 and p=0.023, respectively). Membrane staining of HER2 was not seen in any case whereas cHER2 was found in 20.3% (29) of cases, all of them high grade tumors. No low grade tumor presented this staining pattern. cHER2 was also associated with EGFR expression (p=0.017). Regarding FISH, 36 cases were unaltered whereas 32 were FISH positive (out of which 16 presented chromosome 7 polysomy and 6 EGFR amplifications). FISH positivity did not associate with EGFR expression (p=0.403). No mutation in the studied EGFR exons was observed. A polymorphism without clinical significance (p.Q787Q in exon 20) was found in 19/27 cases. cHER2 expression and FISH positivity were an independent risk factor for cancer-specific and overall survival, respectively.

CONCLUSIONS: Success of targeted therapies is highly linked to appropriate patients selection and our findings might indicate that EGFR has a key role in penile carcinogenesis, making PSCC patients potential candidates for EGFR-targeted therapies since both EGFR expression and chromosome 7 polysomy are associated with poor prognosis. A possible interaction between membranous EGFR and cytoplasmic HER2 could favor the use of tyrosine-kinase inhibitors instead of monoclonal antibodies.

Citation Format: Alice M. T. Silva-Amancio, Isabela W. Cunha, Gustavo C. Guimaraes, Fernando A. Soares. Epidermal growth factor receptors and penile carcinoma: The role of EGFR and HER2 expression as prognostic and predictive markers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3327. doi:10.1158/1538-7445.AM2014-3327

Gene expression profiling in leiomyosarcomas and undifferentiated pleomorphic sarcomas: SRC as a new diagnostic marker

Background

Undifferentiated Pleomorphic Sarcoma (UPS) and high-grade Leiomyosarcoma (LMS) are soft tissue tumors with an aggressive clinical behavior, frequently developing local recurrence and distant metastases. Despite several gene expression studies involving soft tissue sarcomas, the potential to identify molecular markers has been limited, mostly due to small sample size, in-group heterogeneity and absence of detailed clinical data.

Materials and Methods

Gene expression profiling was performed for 22 LMS and 22 UPS obtained from untreated patients. To assess the relevance of the gene signature, a meta-analysis was performed using five published studies. Four genes (BAD, MYOCD, SRF and SRC) selected from the gene signature, meta-analysis and functional in silico analysis were further validated by quantitative PCR. In addition, protein-protein interaction analysis was applied to validate the data. SRC protein immunolabeling was assessed in 38 UPS and 52 LMS.

Results

We identified 587 differentially expressed genes between LMS and UPS, of which 193 corroborated with other studies. Cluster analysis of the data failed to discriminate LMS from UPS, although it did reveal a distinct molecular profile for retroperitoneal LMS, which was characterized by the over-expression of smooth muscle-specific genes. Significantly higher levels of expression for BAD, SRC, SRF, and MYOCD were confirmed in LMS when compared with UPS. SRC was the most value discriminator to distinguish both sarcomas and presented the highest number of interaction in the in silico protein-protein analysis. SRC protein labeling showed high specificity and a positive predictive value therefore making it a candidate for use as a diagnostic marker in LMS.

Conclusions

Retroperitoneal LMS presented a unique gene signature. SRC is a putative diagnostic marker to differentiate LMS from UPS.

Recurrent somatic mutation in DROSHA induces microRNA profile changes in Wilms tumour

Wilms tumour (WT) is an embryonal kidney neoplasia for which very few driver genes have been identified. Here we identify DROSHA mutations in 12% of WT samples (26/222) using whole-exome sequencing and targeted sequencing of 10 microRNA (miRNA)-processing genes. A recurrent mutation (E1147K) affecting a metal-binding residue of the RNase IIIb domain is detected in 81% of the DROSHA-mutated tumours. In addition, we identify non-recurrent mutations in other genes of this pathway (DGCR8, DICER1, XPO5 and TARBP2). By assessing the miRNA expression pattern of the DROSHA-E1147K-mutated tumours and cell lines expressing this mutation, we determine that this variant leads to a predominant downregulation of a subset of miRNAs. We confirm that the downregulation occurs exclusively in mature miRNAs and not in primary miRNA transcripts, suggesting that the DROSHA E1147K mutation affects processing of primary miRNAs. Our data underscore the pivotal role of the miRNA biogenesis pathway in WT tumorigenesis, particularly the major miRNA-processing gene DROSHA.

Wilms tumour (WT) is the most common paediatric kidney cancer and few driver genes related to its development have been identified. Here, the authors identify DROSHA mutations that may contribute to WT tumorigenesis through their effect on primary microRNA processing.

Artificial dermis (Matriderm®) followed by skin graft as an option in dermatofibrosarcoma protuberans with complete circumferential and peripheral deep margin assessment

Dermatofibrosarcoma protuberans (DFSP) is a locally invasive neoplasia with a pattern of infiltrative growth that leads to extended resections. To avoid unnecessary resections and spare tissues, its treatment requires an adequate assessment of the margins. We present a case where artificial dermis (Matriderm®) was used followed by skin graft for reconstruction. We present a 50-year-old woman with a DFSP in the occipital region. She was referred to us after a first surgery with positive margins. A wide local excision with a 2-cm margin was performed and periosteal tissue was also removed, which led to exposure of the skull. Matriderm was placed on the bone surface and dressings were changed every other day. Meanwhile, margins were evaluated by the complete circumferential and peripheral deep margin assessment (CCPDMA) and were positive for DFSP in the superior margin. After 4 weeks the area was completely covered by granulation tissue and a new resection followed by reconstruction with a skin graft was performed. With regard to the difficulties in the margin assessment in DFSP, we present artificial dermis (Matriderm) as an option for reconstructive surgery in these patients, especially when a skin graft cannot be performed as a first option.

Regulation of stress-inducible phosphoprotein 1 nuclear retention by protein inhibitor of activated STAT PIAS1

Stress-inducible phosphoprotein 1 (STI1), a cochaperone for Hsp90, has been shown to regulate multiple pathways in astrocytes, but its contributions to cellular stress responses are not fully understood. We show that in response to irradiation-mediated DNA damage stress STI1 accumulates in the nucleus of astrocytes. Also, STI1 haploinsufficiency decreases astrocyte survival after irradiation. Using yeast two-hybrid screenings we identified several nuclear proteins as STI1 interactors. Overexpression of one of these interactors, PIAS1, seems to be specifically involved in STI1 nuclear retention and in directing STI1 and Hsp90 to specific sub-nuclear regions. PIAS1 and STI1 co-immunoprecipitate and PIAS1 can function as an E3 SUMO ligase for STI. Using mass spectrometry we identified five SUMOylation sites in STI1. A STI1 mutant lacking these five sites is not SUMOylated, but still accumulates in the nucleus in response to increased expression of PIAS1, suggesting the possibility that a direct interaction with PIAS1 could be responsible for STI1 nuclear retention. To test this possibility, we mapped the interaction sites between PIAS1 and STI1 using yeast-two hybrid assays and surface plasmon resonance and found that a large domain in the N-terminal region of STI1 interacts with high affinity with amino acids 450-480 of PIAS1. Knockdown of PIAS1 in astrocytes impairs the accumulation of nuclear STI1 in response to irradiation. Moreover, a PIAS1 mutant lacking the STI1 binding site is unable to increase STI1 nuclear retention. Interestingly, in human glioblastoma multiforme PIAS1 expression is increased and we found a significant correlation between increased PIAS1 expression and STI1 nuclear localization. These experiments provide evidence that direct interaction between STI1 and PIAS1 is involved in the accumulation of nuclear STI1. This retention mechanism could facilitate nuclear chaperone activity.

Abstract 5308: CD9, CD63 and CD82 tetraspanins expression profile in vulvar carcinomas

Background: Vulvar carcinomas are approximately 95 % of all vulvar tumors. This cancer presents good prognosis since early diagnosed, and survival depends of inguinal lymphonode commitment, with about 30% of patients presents lymphonode metastasis. The mechanisms involved in biological behavior of vulvar cancer remain unclear and its treatment involves physical mutilation and psychosocial factors of patients. Therefore, identification of features related with this tumors development or genesis can contribute to its knowledge and treatment. The tetraspanins are proteins that are involved in several biological processes including cell proliferation, adhesion, invasion and migration. Their reduction or lack of expression is frequently reported in metastatic and poor prognosis tumors. Our aim was to analyze CD9, CD63 and CD82 tetraspanins expression profile in vulvar carcinoma compared to normal tissue. Methods: All samples were obtained from Pathology Department of Hospital A. C. Camargo, Sao Paulo, Brazil. TMA block was constructed with 150 paraffin-embedded samples and was used in immunohistochemical assay. The tissue sections were incubated with specific antibodies against CD9, CD63 and CD82, following manufacturer's instruction. The slides were evaluated and scored semiquantitatively by assessing the staining intensity in tumor cells and the frequency of positive cells. Results: The Immunohistochemical analysis showed that all tetraspanins were expressed in tumor samples with different intensity and frequency. CD63 were expressed by a higher samples number (90%), with stronger staining both cytoplasm (79%) and nucleus (11%). Lack of CD63 expression was described in metastatic melanomas lesions, while no metastatic lesions shows higher levels of this protein. Seventy five percent of our samples expressed CD9, exclusively on cellular membrane. CD82 showed positive reaction in 45% of the samples with weakly or moderate staining, both nucleus and cytoplasm. The association of the downregulation of CD9 and/or CD82 with a worse prognosis has been shown in breast, cervical, endometrial, esophageal, head and neck, and others carcinomas. Moreover, CD82 is considered to be an important metastasis suppressor. Conclusion: Our preliminary results showed that tetraspanins may have an important role in vulvar carcinomas and CD82/CD63 nuclear expression must be better investigated. Further analyses are ongoing.

Citation Format: Katia C. Carvalho, Rafael M. Rocha, Isabela W. Cunha, Fernando A. Soares. CD9, CD63 and CD82 tetraspanins expression profile in vulvar carcinomas. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5308. doi:10.1158/1538-7445.AM2013-5308

Abstract 4400: The levels of Prion protein and its ligand HOP modulate glioblastoma proliferation and predict a lower survival outcome

A main concern in glioblastoma (GBM) therapy is the resistance of these tumors to current treatment protocols. The identification of molecules that can be target to treat these tumors is of major interest. The prion protein (PrPC) is a glycosylphosphatidylinositol-anchored protein very abundant in neurons and astrocytes and its interaction with a diverse number of ligands modulates cell survival and differentiation. One of these ligands is the secreted co-chaperone Hsp70-Hsp90 organizing protein (HOP), which reaches the extracellular space in exosome-like microvesicles. HOP is secreted by a number of cancer cells and seems to be a relevant biomarker in ovarian tumors. However, the role of PrPC-HOP complex in tumor biology is largely unknown. Herein, 185 cases o gliomas (33 grade I, 46 grade II, 15 grade II and 91 GBM) arranged in tissue microarrays were evaluated for the expression of PrPC and its ligand HOP. Both proteins were highly expressed in GBM when compared to tumors of grade I, II or III and also when compared to non-tumor samples (p&lt;0.05 for all comparisons). High expression levels of both proteins in GBMs were direct correlated with a higher tumor proliferation, measured by the number of cells positive for Ki-67. Patients with high levels of both proteins presented a lower survival than those with high levels of HOP but lower levels of PrPC (p=0.017). The treatment of a human GBM cell line U87MG, which presents high expression of PrPC, with soluble HOP increases proliferation by three times however any effect was observed when cells were treated with a soluble HOP lacking the PrPC binding site (HOPΔ230-245). Both HOP or HOPΔ230-245 have no effect in U87MG cells whose PrPC expression was knocked down by 98%. In accordance, the intra-tumor infusion of HOP, but not HOPΔ230-245, increased tumor growth in nude mice bearing U87MG orthotopic xenografts. Remarkably, U87MG cells in which PrPC expression was knocked down were unable to growth tumors in nude mice. Together these results demonstrated that PrPC and HOP are significantly expressed in GBMs and higher levels of these proteins are associated to the patient group presenting a lower survival. The manipulation of PrPC and HOP interaction in cell cultures or in vivo affects tumor growth indicating that the interference with their engagement may represent a therapeutic target in GBMs.

Supported by The State of São Paulo Foundation.

Citation Format: Marilene H. Lopes, Nicole Gilda Queiroz, Tiago Goss Santos, Bruna R. Rodrigues, Isabela W. Cunha, Bruno Costa Silva, Vilma R. Martins. The levels of Prion protein and its ligand HOP modulate glioblastoma proliferation and predict a lower survival outcome. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4400. doi:10.1158/1538-7445.AM2013-4400

Abstract 1165: Evaluation of HPV infection in penile cancer and its association with p16 and MGMT protein expression levels and pathologic variables

INTRODUCTION: Penile carcinoma is an infrequent tumor. However, in developing countries it is a common disease and in specific regions it may represents the most frequent tumor among men. The most important prognostic clinical factor is the presence of lymph node metastasis, which is associated with significant reduced survival to the penile carcinoma patients. Nevertheless, until the present date it was not possible to establish clinical or molecular prognostic markers. Various factors are associated with increased risk for de development of this disease, such as poor hygienic habits, lack of circumcision and HPV infection. HPV DNA can be detected in 20% to 80% of penile squamous cell carcinomas (PSCC). However, the role of HPV on patients’ prognosis is still uncertain. METHODS: We evaluated the frequency of HPV infection in 189 PSCC samples. The presence or absence of HPV DNA was established using generic primers (GP5+/GP6+) specific for the L1 gene of several HPVs. Specimens positive for HPV DNA were genotyped by dot blot hybridization using radioactive probes. We also evaluated the expression levels of the proteins p16 and MGMT through immunohistochemistry. These two proteins show aberrant levels in a wide range of tumors. Protein expression was quantified using an automated image system (ScanScope XT - Aperio), which determined the percentage and intensity of positive cells. The quantification was used to determine if there was loss of expression or normal (positive) expression. RESULTS: HPV infection, characterized by detection of viral DNA on the samples, was observed in 19.6% (37) of the cases. Among the positive HPV samples, 51.3% were infected by HPV16, 21.6% by HPV18 and 2.7% by both HPV16 and 18 concomitantly. The presence of HPV infection was more frequent among tumors with thickness lower than 5mm, suggesting that PSCC with HPV are less aggressive. This finding is in agreement with some studies that showed better prognosis of tumors with HPV infection. The immunohistochemistry assays showed reduced p16 expression in 35.4% (63) and loss of MGMT in 90.1% (146) cases. None association was observed between HPV infection and p16 protein expression. It is well established that the presence of HPV is associated with p16 positive expression. One interesting observation was that MGMT positive expression was associated with positive viral infection. Until this moment, there is no study describing this association in PSCC neither in other tumor types. It was observed an association between p16 reduced levels and poor differentiated tumors, this pathologic variable is associated with bad prognosis. MGMT loss of expression was associated with the presence of lymph node metastasis, suggesting that expression status of this protein can be a molecular marker for PSCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1165. doi:1538-7445.AM2012-1165

Abstract 5577: HER2 cytoplasmic staining and penile cancer

BACKGROUND: Although rare in developed regions, penile carcinoma is a serious concern for undeveloped countries such as Brazil, where it can represent up to 10% of all malignancies. HER2 is a well-known growth factor membrane receptor that has its expression level usually associated with aggressive disease. Recently, some studies have shown that soluble fractions of HER2 intracellular domain are found in tumors cytoplasm and they still activate intracellular pathways related to cell proliferation and survival. MATERIAL AND METHODS: Immunohistochemistry against HER2 was carried out in 195 penile carcinoma samples selected from the files of AC Camargo Hospital, Brazil, using the monoclonal CB11 antibody (Novocastra™), which recognizes specifically HER2 intracellular domain. Cases were classified as positive or negative according to membrane and to cytoplasmic staining. All statistical analyses were performed by the SPSS for Windows 18.0, SPSS Inc. Comparison between category variables was performed by the Pearson chi-square test or the Fisher's exact test. Survival rates were calculated using the Kaplan-Meier method and the curves were compared by means of the log-rank test. In all statistical tests, the alpha error was set at 5%. RESULTS: None of the cases showed membrane staining for HER2. However, a clear and strong cytoplasm staining was observed in 28 cases (14,9%), as shown in figure 1. The staining was limited to the tumor cells and does not represent background or artifact. Univariate analyses showed that overexpression is associated with higher histologic grade (p &lt;0,001) and lower overall survival (p=0,007). Multivariate analyses showed that HER2 in the cytoplasm is an independent risk factor for death (RR=2,966; IC 95% [1,6-5,2]; p &lt;0,001). CONCLUSIONS: Corroborating with recent findings that cytoplasmic fragments of HER2 can be active kinases, the present study suggests that the presence of HER2 in tumor cytoplasm is a prognostic marker in penile carcinoma. We have also demonstrated that, although no membrane staining was seen, presence of HER2 in cytoplasm is an independent risk factor for death in this neoplasm.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5577. doi:1538-7445.AM2012-5577

Abstract 1115: Protein overexpression is not associated with increased gene copy number of epidermal growth factor receptor (EGFR) in penile carcinoma

Squamous cell carcinoma of the penis affects mainly people with poor hygiene habits in undeveloped countries, accounting for up to 20% of all malignancies in men. EGFR is a tyrosine-kinase receptor that has its expression levels increased in diverse tumors, especially in carcinomas. This study has aimed at evaluating the gene alterations associated with cases with high protein expression levels.

Immunohistochemistry (IHC) against EGFR was performed in 195 penile carcinoma samples selected from the files of AC Camargo Hospital, Brazil. Cases showing strong and complete membrane staining in more than 10% of the tumor cells were considered positive and any other staining pattern was considered negative. All positive cases and a fraction of negative cases were submitted to dual-color fluorescence in situ hybridization (FISH). Reactions were carried out using fluorescenet-labeled probes for EGFR locus and chromosome 7 centromere (Zytovision™) in samples overexpressing EGFR. Cases with 2 signals of each probe were considered non-altered, those with more than 2 signals of each probe were considered polissomyc and those with more EGFR signals compared to centromere signals were considered amplified.

In this series, 67 (49,7%) penile carcinoma samples overexpressed EGFR by IHC and protein overexpression was significantly associated with greater risk of recurrence in univariate analysis (p=0,031). Negative cases represented 50,3% of the sample, but only 9 (5%) showed no membrane staining at all. The other 45% of the negative sample (83 cases) showed little to moderate incomplete membrane staining. Regarding FISH, 65 cases (45,8%) were uninterpretable and, out of 72 valid cases, 49 (68,1%) were non-altered cases, 17 (23,6%) were polissomyc, and 6 (8,3%) cases presented EGFR amplification. Considering IHC results, 50 were positive. Out of those, 33 (66%) had no gene number alteration, 12 (24%) were polissomies and 5 (10%) were amplified. Negative cases represented 22 valid cases out of which 16 (72,1%) showed no gene number alteration, 5 (22,8%) showed polissomy of cromossome 7 and 2 cases (9,1%) had an amplification of EGFR gene.As both positive and negative samples in IHC showed similar results in FISH analysis, it seems that EGFR overexpression, although associated with worse prognosis, is not associated either with gene copy number nor with polyssomy of chromosome 7 in penile tumors. Further studies concerning mutational analysis and clinical data are needed to explain this high and frequent protein besides being useful for identifying patients who might benefit from EGFR-target therapy. Moreover, the high number of uninterpretable cases in FISH seems to be related to technical artifacts due to the higher quantity of cytokeratin levels blocking probe penetration in cell cytoplasm and nuclei of these tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1115. doi:10.1158/1538-7445.AM2011-1115

Abstract 4807: P16 and MGMT hypermethylation status evaluation in squamous cell penile carcinomas by pyrosequencing

Penile carcinoma is an uncommon disease and the most frequent subtype is squamous cell carcinoma. This cancer represents less than 1% of all cases in developed countries. However, in some regions of developing countries it represents 20% of all male cancers. The main risk factors associated to this tumor are poor hygienic habits, low quality of life, HPV infections and high number of sexual partners. Very little is known about penile carcinoma, including its pathogenesis, etiology and molecular biology features. In this study, we evaluated the hypermethylation status of two genes that present high frequencies of methylation in various tumor types. P16 plays an important role in cell cycle control. It encodes the protein p16 that binds to CDK proteins and inhibits pRB phosphorilation, blocking cell cycle progression. MGMT encodes a DNA repair protein that removes alkyl groups from guanines. The protein mgmt is peculiar once it acts alone and not in complexes like other DNA repair proteins. Hypermethylation of these genes is already described in a large variety of tumors, leads to gene silencing and has an important role in tumoregenesis. Here, we determined the frequency of hypermethylation among penile carcinoma samples and the percentage of aberrant methylation for each sample. The samples were submitted to bisulfite conversion, amplification and sequencing employing the pyrosequencing methodology, which is a quantitative methodology allowing percentage determination of each CpG dinucleotide analyzed. The hypermethylation status and methylation levels were evaluated in 33 squamous cell penile carcinoma samples. We observed P16 hypermethylation in 9% of the samples and MGMT was methylated in 27%, with levels of methylation varying from 10.71% to 35.43% and 12.20% to 62.60%, respectively. The low frequency of samples showing P16 hypermethylation could be explained by the presence of HPV infection, which is described in approximately 70.00% to 80.00% of penile carcinomas. It is well known that in the presence of HPV there is no P16 DNA methylation, suggesting that the HPV E7 protein influences the Rb pathway in these samples. MGMT hypermethylation frequency is in accordance with what was described by other groups and that showed no association to clinical characters of the samples analysed. Little is known about the influence of DNA hypermethylation on penile carcinoma tumorigenesis but our results show that the epigenetic alteration of P16 and MGMT genes are not tumor markers for penile carcinoma. To our knowledge it is the first study describing the epigenetic status of penile carcinomas in the Brazilian population.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4807. doi:10.1158/1538-7445.AM2011-4807

ErbB receptors and fatty acid synthase expression in aggressive head and neck squamous cell carcinomas

SUMMARY

Overexpression of ErbB receptors is frequent in head and neck squamous cell carcinomas (HNSCC) and seems to be correlated with tumor progression and metastasis. Fatty acid synthase (FASN), the key lipogenic enzyme responsible for the endogenous synthesis of fatty acids, is regulated by ErbB2 and overexpressed in several human malignancies.

METHODS

This study was performed to examine the immunohistochemical expression patterns of ErbB1, ErbB2, ErbB3, ErbB4, and FASN in a tissue microarray, containing 33 representative areas from aggressive primary HNSCC (whose patients had distant metastasis), and 21 matched lung metastasis.

RESULTS

Strong correlation among the expression of ErbB family receptors was found (ErbB1-ErbB2 P = 0.008, ErbB1-ErbB4 P = 0.018, EbB2-ErbB3 P = 0.001, ErbB2-ErbB4 P = 0.006, ErbB3-ErbB4 P=0.012) in the HNSCC. FASN expression was significantly associated with ErbB2 (P = 0.024). Lymphatic permeation was correlated with ErbB3 (P = 0.033) and histological grade with ErbB4 staining (P = 0.050). ErbB1 and ErbB2 were found mainly in patients with smoking habit (P = 0.011 and P = 0.027), and ErbB2 was associated with alcohol consumption and clinical stage (P = 0.014 and P = 0.031). Finally, FASN was overexpressed in lung metastasis, in comparison with matched HNSCC samples (P = 0.006).

CONCLUSIONS

  The results showed that high FASN immunohistochemical expression is a feature of HNSCC lung metastasis, and ErbB1-ErbB2, ErbB1-ErbB4, ErbB2-ErbB3, ErbB2-ErbB4, and ErbB3-ErbB4 expression levels are correlated in the respective primary tumors, being ErbB2 the preferred coexpression partner of all the other ErbB receptors.

GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

OBJECTIVE

To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry.

INTRODUCTION

Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data.

METHODS

Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types.

RESULTS

Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Forty-seven per cent of prostate adenocarcinomas were positive, as were 29% of thyroid, 10% of gastric and 5% of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42% of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6% and 9.4% of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression.

CONCLUSION

Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined.

Evaluation of estrogen receptor alpha, estrogen receptor beta, progesterone receptor, and cKIT expression in desmoids tumors and their role in determining treatment options

The present study evaluates the protein expression of estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta), progesterone receptor (PR) and cKIT in a wide number of desmoids tumors and their role in determining treatment options. Fifty-nine cases classified as muscle aponeurotic fibromatosis were selected. Samples were grouped by tumor location in: head and neck, extremity and abdominal/trunk; type of resection of the primary tumor (complete resection with adequate margins, marginal resection and resection with inadequate margins); type of treatment (exclusive surgery, surgery followed by radiation therapy and surgery followed by tamoxifen or cyclooxygenase inhibitor). A tissue microarray (TMA) was built and the immunohistochemical reactions were performed against ERalpha, ERbeta, PR, and c-kit. All cases were negative for ERalpha, PR and c-KIT. 53/59 cases were positive for ERbeta. No significant difference was observed among clinical variables and the ERbeta status. The estimated 5 and 10 year local recurrence free survival (LRFS) for the patients with complete or marginal resection was 75% and 75%, respectively. Tumor location (p = 0.006) and type of resection (p = 0.001) were predictive of local relapse in the univariate analysis. All patients treated with post-operative tamoxifen were LRFS (p = 0.035). Head and neck and extremities lesions showed higher recurrence rates compared to abdominal/trunk lesions. Marginal resection was associated with local recurrence. In conclusion, although this is a retrospective study, the results presented can contribute to better understanding of the mechanisms under desmoid tumor development and can propose tamoxifen as a therapeutic option to be tested in prospective trials.

Unusual primary ocular neoplasm in a child: leiomyosarcoma of the ciliary body

Primary uveal-tract neoplasms are extremely rare in childhood; the most common lesions found are melanocytic. We report here the case of a 7-year-old girl who underwent enucleation of the right eye with clinical suspicion of choroid melanoma as a result of a ciliary body mass that extended to the posterior chamber. Histologically, the neoplasm featured spindle cell morphology, atypia, and mitoses. The tumor expressed smooth muscle alpha actin, pan-actin HHF-35, and desmin, whereas immunohistochemistry for melanocytic markers, such as S-100, Melan-A, and HMB-45, was negative. Based on these features, the diagnosis of leiomyosarcoma of the ciliary body was firmly established. Although several leiomyomas have been reported in the literature, there are only 2 previously reported cases of primary leiomyosarcoma of the uveal tract. Immunohistochemical expression of muscle proteins allowed distinction from the most common melanocytic tumors arising in this location.

Differential expression of fatty acid synthase (FAS) and ErbB2 in nonmalignant and malignant oral keratinocytes

The aim of this study was to investigate fatty acid synthase (FAS) and ErbB2 expression in nonmalignant oral epithelium and oral or head and neck squamous cell carcinomas (OSCC/HNSCC). Morphologically normal, hyperkeratotic, and dysplastic oral epithelium as well as well-differentiated and poorly differentiated OSCC were immunohistochemically evaluated for FAS, ErbB2, and Ki-67. These proteins were also analyzed in a tissue microarray with 55 HNSCC. SCC-9 cells were used to study FAS and ErbB2 during differentiation. FAS expression was higher in hyperkeratosis, dysplasias, and OSCC than in normal epithelium. Well-differentiated OSCC/HNSCC were more positive for FAS than the poorly differentiated tumors. ErbB2 was observed at the surface of nonmalignant and well-differentiated OSCC/HNSCC keratinocytes and in the cytoplasm of poorly differentiated cells. Ki-67 index was progressively higher from normal oral epithelium to OSCC, inversely correlated with cell surface ErbB2, and positively correlated with intracytoplasmic ErbB2. Finally, SCC-9 cell cultures were enriched in membrane ErbB2-positive cells after differentiation by anchorage deprivation. In conclusion, FAS is overexpressed in OSCC/HNSCC and hyperkeratotic oral epithelium and ErbB2 is found at the cell surface of differentiating keratinocytes and in the cytoplasm of poorly differentiated tumor cells. Ki-67 index is higher in epithelial dysplasias and OSCC than in morphologically normal oral epithelium.

FISH analysis of 107 prostate cancers shows that PTEN genomic deletion is associated with poor clinical outcome

This study examines the clinical impact of PTEN genomic deletions using fluorescence in situ hybridisation (FISH) analysis of 107 prostate cancers, with follow-up information covering a period of up to 10 years. Tissue microarray analysis using interphase FISH indicated that hemizygous PTEN losses were present in 42/107 (39%) of prostatic adenocarcinomas, with a homozygous PTEN deletion observed in 5/107 (5%) tumours. FISH analysis using closely linked probes centromeric and telomeric to the PTEN indicated that subband microdeletions accounted for ∼70% genomic losses. Kaplan–Meier survival analysis of PTEN genomic losses (hemizygous and homozygous deletion vs not deleted) identified subgroups with different prognosis based on their time to biochemical relapse after surgery, and demonstrated significant association between PTEN deletion and an earlier onset of disease recurrence (as determined by prostate-specific antigen levels). Homozygous PTEN deletion was associated with a much earlier onset of biochemical recurrence (P=0.002). Furthermore, PTEN loss at the time of prostatectomy correlated with clinical parameters of more advanced disease, such as extraprostatic extension and seminal vesicle invasion. Collectively, our data indicates that haploinsufficiency or PTEN genomic loss is an indicator of more advanced disease at surgery, and is predictive of a shorter time to biochemical recurrence of disease.

Sarcomas often express constitutive nitric oxide synthases (NOS) but infrequently inducible NOS

Nitric oxide (NO) has a dual action in tumors, with both pro-tumor and anti-tumor activities. NO is produced by nitric oxide synthases (NOS). There are three enzyme isoforms: two of them are constitutively produced (neuronal or brain NOS and endothelial NOS), and one is an inducible form (iNOS). NOS expression has been shown in several epithelial tumors, but there is no report addressing NOS expression in sarcomas. The authors evaluated the expression of NOS in 97 cases of various sarcomas spotted in duplicate in a tissue array paraffin block. Eighty-four of the 97 tumor specimens (86.6%) expressed nNOS, and most of them showed a strong expression of the isoenzyme. Only chondrosarcomas and liposarcomas had significant numbers of negative cases, and all pleomorphic sarcomas, alveolar soft part sarcomas, angiosarcomas, gastrointestinal stromal tumors, and synovial sarcomas showed some degree of positivity. Forty-three cases (44.4%) showed eNOS immunostaining, but only 15.5% showed a strong signal, with emphasis on angiosarcomas, chondrosarcomas, alveolar soft part sarcomas, and synovial sarcoma. Strong expression of iNOS was observed in only 9 cases (9.3%), with weak expression in another 26 cases (26.8%). Strong expression of iNOS was found in malignant peripheral nerve sheet tumors, liposarcomas, pleomorphic sarcomas, fibrosarcomas, chondrosarcomas, and synovial sarcomas. Apparently alveolar soft part sarcomas are unusual in their capacity of expression of NOS isoforms, and in a very peculiar pattern. In conclusion, sarcomas in general commonly express constitutive NOS, and only a few types of sarcomas can express iNOS, the isoenzymes capable of releasing large amounts of NO. More comprehensive studies should be performed to better understand the clinical importance of NOS expression and NO production in sarcomas.

Characterization of a cancer/testis (CT) antigen gene family capable of eliciting humoral response in cancer patients

Cancer/testis (CT) antigens are immunogenic proteins expressed in normal gametogenic tissues and in different types of tumors. CT antigens are promising candidates for cancer immunotherapy, and the identification of novel CT antigens is a prerequisite for the development of cancer vaccines. We have identified a CT antigen, named CTSP-1, with partial similarity to the breast differentiation antigen NY-BR-1. CTSP-1 presents several splicing and polyadenylation variants and has a very restricted expression pattern among normal tissues. CTSP-1 is exclusively expressed in normal testis and is aberrantly expressed in 47.6% (10 of 21) of tumor cell lines and in 44.4% (75 of 169) of tumors from different histological types. The highest percentages of positive expression were observed in melanomas (59.0%) followed by prostate (58.0%) and lung (57.0%) tumors. CTSP-1 is part of a highly conserved gene family, and members of this family also have a restricted expression pattern and similar protein structure. Antibodies against members of this gene family were detected in 10% (14 of 141) of plasma samples from patients with a wide spectrum of tumors. The highest percentages of antibody response were observed in patients with prostate (20.8%), thyroid (20.0%), and breast (16.6%) tumors. Because of its very restricted expression pattern in normal tissues and immunogenicity in different types of tumors, CTSP-1 should be considered a promising candidate for cancer immunotherapy.

SATR-1 hypomethylation is a common and early event in breast cancer

Genome stability and normal gene expression are maintained by a fixed and predetermined DNA methylation pattern, which becomes abnormal in malignant cells. Hypomethylation of satellite DNA sequences is frequently found in tumors and has been associated with an increased frequency of DNA rearrangements and chromosome instability. In this work, we used methylation-sensitive arbitrarily primed polymerase chain reaction (MSAP-PCR) to identify differentially methylated DNA fragments in normal and tumor breast samples. We identified a novel differentially methylated fragment located on chromosome 5 with high similarity to a SATR-1 satellite sequence. This fragment was found to be hypomethylated in 63% of breast tumor cell lines and in 86% of breast tumors relative to normal breast tissue. We found that normal tissue adjacent to breast tumors displayed a variable decrease in methylation and that the decrease observed for most of these adjacent samples was higher than observed for normal breast tissue derived from reduction mammoplasty. The methylation decrease was, however, significantly higher in tumor samples than in adjacent tissue (chi2= 154, 1 df, P < 10(-4)), suggesting that SATR-1 hypomethylation frequently occurs in the early stages of tumor development. Our results highlight the importance of global DNA hypomethylation as a contributing factor in breast tumorigenesis.