Renata A. Tassi

Landscape of somatic single-nucleotide and copy-number mutations in uterine serous carcinoma

Uterine serous carcinoma (USC) is a biologically aggressive subtype of endometrial cancer. We analyzed the mutational landscape of USC by whole-exome sequencing of 57 cancers, most of which were matched to normal DNA from the same patients. The distribution of the number of protein-altering somatic mutations revealed that 52 USC tumors had fewer than 100 (median 36), whereas 5 had more than 3,000 somatic mutations. The mutations in these latter tumors showed hallmarks of defects in DNA mismatch repair. Among the remainder, we found a significantly increased burden of mutation in 14 genes. In addition to well-known cancer genes (i.e., TP53, PIK3CA, PPP2R1A, KRAS, FBXW7), there were frequent mutations in CHD4/Mi2b, a member of the NuRD–chromatin-remodeling complex, and TAF1, an element of the core TFIID transcriptional machinery. Additionally, somatic copy-number variation was found to play an important role in USC, with 13 copy-number gains and 12 copy-number losses that occurred more often than expected by chance. In addition to loss of TP53, we found frequent deletion of a small segment of chromosome 19 containing MBD3, also a member of the NuRD–chromatin-modification complex, and frequent amplification of chromosome segments containing PIK3CA, ERBB2 (an upstream activator of PIK3CA), and CCNE1 (a target of FBXW7-mediated ubiquitination). These findings identify frequent mutation of DNA damage, chromatin remodeling, cell cycle, and cell proliferation pathways in USC and suggest potential targets for treatment of this lethal variant of endometrial cancer.

A KRAS-Variant in Ovarian Cancer Acts as a Genetic Marker of Cancer Risk

Ovarian cancer (OC) is the single most deadly form of womens cancer, typically presenting as an advanced disease at diagnosis in part due to a lack of known risk factors or genetic markers of risk. The KRAS oncogene and altered levels of the microRNA (miRNA) let-7 are associated with an increased risk of developing solid tumors. In this study, we investigated a hypothesized association between an increased risk of OC and a variant allele of KRAS at rs61764370, referred to as the KRAS-variant, which disrupts a let-7 miRNA binding site in this oncogene. Specimens obtained were tested for the presence of the KRAS-variant from nonselected OC patients in three independent cohorts, two independent ovarian case-control studies, and OC patients with hereditary breast and ovarian cancer syndrome (HBOC) as well as their family members. Our results indicate that the KRAS-variant is associated with more than 25% of nonselected OC cases. Further, we found that it is a marker for a significant increased risk of developing OC, as confirmed by two independent case-control analyses. Lastly, we determined that the KRAS-variant was present in 61% of HBOC patients without BRCA1 or BRCA2 mutations, previously considered uninformative, as well as in their family members with cancer. Our findings strongly support the hypothesis that the KRAS-variant is a genetic marker for increased risk of developing OC, and they suggest that the KRAS-variant may be a new genetic marker of cancer risk for HBOC families without other known genetic abnormalities.

Serum Human Epididymis Protein 4 and Risk for Ovarian Malignancy Algorithm as New Diagnostic and Prognostic Tools for Epithelial Ovarian Cancer Management

Background: The aim of this work was to analyze the diagnostic and prognostic value of serum human epididymis protein 4 (HE4) and Risk for Ovarian Malignancy Algorithm (ROMA) in epithelial ovarian cancer (EOC). Methods: Preoperative serum samples of 419 women (140 healthy controls, 131 ovarian benign cysts, 34 endometriosis, and 114 EOC) were tested for CA125 and HE4 using fully automated methods (Abbott ARCHITECT) and validated cutoff values. Results: For the discrimination of benign masses from EOC, in premenopausal women, the sensitivity and specificity were 92.3% and 59.4% for CA125, 84.6% and 94.2% for HE4, and 84.6% and 81.2% for ROMA, whereas in postmenopausal women, the sensitivity and specificity were 94.3% and 82.3% for CA125, 78.2% and 99.0% for HE4, and 93.1% and 84.4% for ROMA. In patients with EOC, elevated CA125, HE4, and ROMA levels were associated with advanced Federation of Gynaecologists and Obstetricians (FIGO) stage, suboptimally debulking, ascites, positive cytology, lymph node involvement, and advanced age (all P ≤ 0.05). Elevated HE4 and ROMA (both P ≤ 0.01), but not CA125 (P = 0.0579), were associated with undifferentiated tumors. In multivariable analysis, elevated HE4 and ROMA (all P ≤ 0.05) were independent prognostic factors for shorter overall, disease-free, and progression-free survival. Conclusions and Impact: This study underlines the high specificity of HE4 in discriminating endometriosis and ovarian benign cysts from EOC and the high sensitivity of CA125 in detecting EOC. We showed HE4 and ROMA as independent prognostic factors. Multicenter studies are needed to draw firm conclusions about the applicability of HE4 and ROMA in clinical practice. Cancer Epidemiol Biomarkers Prev; 20(12); 2496–506. ©2011 AACR.

Diagnostic and prognostic impact of serum HE4 detection in endometrial carcinoma patients

Background:To date, no good marker for screening or disease monitoring of endometrial cancer (EC) is available. The aims of this study were to investigate HE4 gene, protein expression and serum HE4 (sHE4) levels in a panel of ECs and normal endometria (NEs) and to correlate sHE4 with patient clinicopathological characteristics and prognosis.Methods:Using quantitative real-time PCR we tested 46 ECs and 20 NEs for HE4 gene expression. Protein expression was analysed by immunohistochemistry on tissue microarrays in 153 ECs and 33 NEs. Pre-operative serum samples from 138 EC and 76 NE patients were analysed with HE4–EIA assay. Association between sHE4 and patient clinicopathological characteristics or outcome was evaluated.Results:Protein and HE4 gene were significantly upregulated in EC tissues and sera, compared with controls. High sHE4 levels were significantly associated with worse EC clinical characteristics. By univariate survival analysis, high sHE4 levels significantly correlated with decreased overall survival, progression-free survival and disease-free survival, retaining their independent prognostic value on the poorly differentiated EC cohort.Conclusion:We demonstrate, for the first time, that high sHE4 levels correlates with an aggressive EC phenotype and may constitute an independent prognostic factor for poorly differentiated-ECs. Determination of sHE4 could be clinically useful in identifying high-risk EC patients for a more aggressive adjuvant therapy.

HE4 and epithelial ovarian cancer: Comparison and clinical evaluation of two immunoassays and a combination algorithm☆

BACKGROUND Two commercial immunoassays for HE4 have been compared and the diagnostic accuracy of HE4, CA 125 and the combinatory ROMA algorithm for epithelial ovarian cancer (EOC) has been evaluated. METHODS HE4 and CA125 were measured on sera obtained from 259 women (73 healthy, 90 with benign ovarian or adnexal diseases, 96 with EOC). The ARCHITECT CMIA HE4 assay was compared with the Fujirebio EIA HE4, and the risk for EOC by the combinatory ROMA algorithm (HE4+CA 125) was assessed with both HE4 assays. RESULTS The CMIA HE4 assay showed a good linearity (r>0.9998) and precision (interassay and total CVs <4%). The correlation with EIA HE4 was linear (r=0.994), with an average bias of 0.4%. By ROC curve analysis, the sensitivity for EOC at a fixed specificity of 90%, 95% and 99% was 89.6%, 84.4% and 79.2% by CMIA HE4, 84.4%, 83.3% and 79.2% by EIA HE4, 86.5%, 76.0% and 59.4% by CMIA CA125. The accuracy of the ROMA algorithm determined by CMIA or EIA HE4 was very similar (AUC 87.1% vs. 87.6%; p=n.s.) and greater in menopause. CONCLUSIONS The two HE4 assays showed a good correlation and similar clinical value, with a greater precision for CMIA. HE4 was more specific and accurate than CA125, supporting its use in addition to clinical and imaging criteria for the discrimination of benign from malignant ovarian lesions. The ROMA algorithm showed a good accuracy for discriminating women at high risk for EOC.

A KRAS variant is a biomarker of poor outcome, platinum chemotherapy resistance and a potential target for therapy in ovarian cancer

Germline variants in the 3′ untranslated region (3′UTR) of cancer genes disrupting microRNA (miRNA) regulation have recently been associated with cancer risk. A variant in the 3′UTR of the KRAS oncogene, referred to as the KRAS variant, is associated with both cancer risk and altered tumor biology. Here, we test the hypothesis that the KRAS variant can act as a biomarker of outcome in epithelial ovarian cancer (EOC), and investigate the cause of altered outcome in KRAS variant-positive EOC patients. As this variant seems to be associated with tumor biology, we additionally test the hypothesis that this variant can be directly targeted to impact cell survival. EOC patients with complete clinical data were genotyped for the KRAS variant and analyzed for outcome (n=536), response to neoadjuvant chemotherapy (n=125) and platinum resistance (n=306). Outcome was separately analyzed for women with known BRCA mutations (n=79). Gene expression was analyzed on a subset of tumors with available tissue. Cell lines were used to confirm altered sensitivity to chemotherapy associated with the KRAS variant. Finally, the KRAS variant was directly targeted through small-interfering RNA/miRNA oligonucleotides in cell lines and survival was measured. Postmenopausal EOC patients with the KRAS variant were significantly more likely to die of ovarian cancer by multivariate analysis (hazard ratio=1.67, 95% confidence interval: 1.09–2.57, P=0.019, n=279). Perhaps explaining this finding, EOC patients with the KRAS variant were significantly more likely to be platinum resistant (odds ratio=3.18, confidence interval: 1.31–7.72, P=0.0106, n=291). In addition, direct targeting of the KRAS variant led to a significant reduction in EOC cell growth and survival in vitro. These findings confirm the importance of the KRAS variant in EOC, and indicate that the KRAS variant is a biomarker of poor outcome in EOC likely due to platinum resistance. In addition, this study supports the hypothesis that these tumors have continued dependence on such 3′UTR lesions, and that direct targeting may be a viable future treatment approach.

Trop-2 overexpression as an independent marker for poor overall survival in ovarian carcinoma patients.

BACKGROUND Prognostic factors currently available are insufficient to predict the clinical course of epithelial ovarian cancer (EOC). In a previous microarray study we identified the human trophoblast cell surface antigen Trop-2 as one of the top differentially expressed genes in serous papillary EOCs compared to normal human ovarian surface epithelial (HOSE) short-term cultures. The aim of the present investigation was to analyse Trop-2 expression at mRNA and protein level and to assess its prognostic significance in EOC. METHODS Using quantitative real-time PCR we tested a total of 104 fresh-frozen EOC tissues and 24 HOSE for Trop-2 mRNA expression. Trop-2 protein expression was then examined by immunohistochemistry in matched formalin-fixed paraffin-embedded EOC samples and in 13 normal ovaries. Finally, we correlated Trop-2 expression to EOC conventional clinicopathological features and patient outcomes. RESULTS We found a significant Trop-2 mRNA and protein upregulation in EOCs compared to normal controls (p<0.001). Trop-2 protein overexpression was significantly associated with the presence of ascites (p=0.04) and lymph node metastases (p=0.04). By univariate survival analysis, Trop-2 protein overexpression was significantly associated with decreased progression-free (p=0.02) and overall survival (p=0.01). Importantly, Trop-2 protein overexpression was an independent prognostic marker for shortened survival time in multivariate Cox regression analysis (p=0.04, HR=2.35, CI(95%)=1.03-5.34). CONCLUSIONS Our results indicate, for the first time, that Trop-2 protein overexpression correlates with an aggressive malignant phenotype and may constitute a novel prognostic factor for EOC. The targeting of Trop-2 overexpression by immunotherapeutic strategies may represent an attractive and potentially effective approach in patients harbouring EOC.

Human epididymis protein 4 as a serum marker for diagnosis of endometrial carcinoma and prediction of clinical outcome.

Abstract Background: The purpose of this study was to assess the diagnostic and prognostic impact of preoperative serum determination of human epididymis protein 4 (sHE4), and to investigate its potential correlation with clinicopathological features and survival endpoints in endometrial cancer patients. Methods: Preoperative serum samples from 193 endometrial cancer patients and 125 women with normal endometrium were measured for sHE4 and serum CA125 (sCA125) concentrations by quantitative chemiluminescent microparticle immunoassays on the automated Architect instrument. Results: sHE4 concentrations were significantly higher in endometrial cancer patients regardless of tumour stage and grade compared with normal controls. Setting the specificity at 95%, the sensitivities in detecting endometrial cancer patients were 66% for HE4, 33% for CA125 and 64% for the combination of the two markers. High concentrations of both HE4 and CA125 significantly correlated with all clinicopathological features characterising a more aggressive tumour phenotype. In multivariate analysis, only high preoperative sHE4 concentrations, but not sCA125, were independent prognostic factors for shorter Overall Survival, Disease-Free Survival and Progression-Free Survival. Conclusions: HE4 is more sensitive and specific than CA125 in distinguishing endometrial cancer patients from women with normal endometrium, regardless of tumour stage and grade. sHE4 appears to be associated with a more aggressive tumour variant and it could be clinically useful, in identifying high-risk endometrial cancer patients, for a tailored surgical and postoperative therapy. HE4 significant correlation with decreased Overall Survival, Disease Free Survival and Progression Free Survival suggests its potential role as a novel prognostic marker for endometrial cancer.

Trefoil factor 3: a novel serum marker identified by gene expression profiling in high-grade endometrial carcinomas

This study identifies the genetic fingerprint of poorly differentiated endometrioid endometrial carcinomas (G3-EEC) and analyses the potential utility of trefoil factor 3 (TFF3) as novel serum marker in G3-EEC. Affymetrix microarrays were used to identify the gene expression patterns of 19 snap-frozen G3-EEC and 15 normal endometrium (NE) biopsies. Quantitative real-time PCR (qRT-PCR) and immunohistochemistry were used to validate TFF3 expression. Finally, TFF3 serum levels were determined by ELISA in 25 G3-EEC patients, 42 healthy controls, and in 13 endometrial hyperplasia patients. Hierarchical cluster analysis showed TFF3 as the top differentially expressed gene between 363 upregulated genes in G3-EEC, when compared with NE. Trefoil factor 3 gene expression levels analysed by qRT-PCR significantly correlated with Affymetrix results (P<0.001; rs=0.85). By immunohistochemistry, TFF3 protein was significatively more expressed in EEC compared with NE (P<0.01), with cytoplasmatic positivity in 79% G3-EEC and 18% NE. Patients harbouring G3-EECs had significantly higher TFF3 serum concentration by ELISA when compared with healthy patients (P<0.001) or patients harbouring endometrial hyperplasia (P=0.012). In conclusion, TFF3 is highly expressed at gene and protein level in G3-EEC. Further investigations on a wider set of samples are warranted to validate TFF3 as a novel serum marker for early detection and/or monitoring of G3-EEC patients.

Mutational landscape of uterine and ovarian carcinosarcomas implicates histone genes in epithelial–mesenchymal transition

Significance Some cancers, termed carcinosarcomas (CSs), have mixed cell types, with either epithelial or mesenchymal features. Sequencing the genomes of uterine and ovarian CSs demonstrated that these different cell types derive from a common precursor cell that has many mutations typical of epithelial cancers. In addition, we find that these tumors have a significant burden of point mutations and amplification of histone genes, suggesting a potential role of these mutations in sarcomatous transformation. Consistent with this finding, expression of specific histone gene mutations in uterine carcinoma cells changed gene expression toward a mesenchymal state. These findings have potential implications for the treatment of these cancers. Carcinosarcomas (CSs) of the uterus and ovary are highly aggressive neoplasms containing both carcinomatous and sarcomatous elements. We analyzed the mutational landscape of 68 uterine and ovarian CSs by whole-exome sequencing. We also performed multiregion whole-exome sequencing comprising two carcinoma and sarcoma samples from six tumors to resolve their evolutionary histories. The results demonstrated that carcinomatous and sarcomatous elements derive from a common precursor having mutations typical of carcinomas. In addition to mutations in cancer genes previously identified in uterine and ovarian carcinomas such as TP53, PIK3CA, PPP2R1A, KRAS, PTEN, CHD4, and BCOR, we found an excess of mutations in genes encoding histone H2A and H2B, as well as significant amplification of the segment of chromosome 6p harboring the histone gene cluster containing these genes. We also found frequent deletions of the genes TP53 and MBD3 (a member with CHD4 of the nucleosome remodeling deacetylase complex) and frequent amplification of chromosome segments containing the genes PIK3CA, TERT, and MYC. Stable transgenic expression of H2A and H2B in a uterine serous carcinoma cell line demonstrated that mutant, but not wild-type, histones increased expression of markers of epithelial–mesenchymal transition (EMT) as well as tumor migratory and invasive properties, suggesting a role in sarcomatous transformation. Comparison of the phylogenetic relationships of carcinomatous and sarcomatous elements of the same tumors demonstrated separate lineages leading to these two components. These findings define the genetic landscape of CSs and suggest therapeutic targets for these highly aggressive neoplasms.