Emanuela D'Angelo

Small cell carcinoma of the ovary, hypercalcemic type, displays frequent inactivating germline and somatic mutations in SMARCA4

Small cell carcinoma of the ovary of hypercalcemic type (SCCOHT) is an extremely rare, aggressive cancer affecting children and young women. We identified germline and somatic inactivating mutations in the SWI/SNF chromatin-remodeling gene SMARCA4 in 69% (9/13) of SCCOHT cases in addition to SMARCA4 protein loss in 82% (14/17) of SCCOHT tumors but in only 0.4% (2/485) of other primary ovarian tumors. These data implicate SMARCA4 in SCCOHT oncogenesis.

Comparative clinicopathologic and immunohistochemical analysis of uterine sarcomas diagnosed using the World Health Organization classification system

Uterine sarcomas are rare tumors that account for 3% to 7% of uterine cancers. Their histopathologic classification was revised by the World Health Organization (WHO) in 2003. The objectives of this study were to determine the frequency of different subtypes of uterine sarcoma applying the WHO criteria to a series of cases, compare the outcome of patients with different subtypes, and compare their immunoprofiles using a panel of immunomarkers. Thirty-four uterine sarcomas were identified for a 20-year period (1988-2008). Eighteen benign tumors of smooth muscle or endometrial stromal origin served as a comparison group. A tissue microarray was prepared and immunostaining performed for 10 selected oncoproteins involved in cell proliferation (Ki-67, P53, p16, and phosphatase and tensin homolog [PTEN]), cell differentiation (CD10, h-caldesmon, estrogen receptor, and progesterone receptor), and apoptosis (bcl-2 and Twist). Hierarchical clustering analysis of the immunohistochemical results was performed. The uterine sarcomas were classified as follows: 20 leiomyosarcomas, 9 endometrial stromal sarcomas, and 5 undifferentiated endometrial sarcomas. The outcome for patients with uterine sarcoma was poor, irrespective of histologic type, even for those with stage I tumors. Of the patients with follow-up available, 12 (67%) of 18 with leiomyosarcoma, 4 of 5 with undifferentiated sarcoma, and 4 of 7 with endometrial stromal sarcoma experienced recurrence and 8 patients with high-grade sarcomas died of tumor. In our series, most uterine sarcomas were leiomyosarcomas. Comparison was made between leiomyosarcomas that recurred and those with a favorable outcome and 3 patients with leiomyosarcoma without evidence of recurrence on long-term follow-up had tumors that were negative/low expressors of Ki-67, p53, p16, and Twist, with strong expression of bcl-2. A subset of undifferentiated endometrial sarcomas composed of cells with uniform nuclei may be a separate entity from those with nuclear anaplasia and may be related to low-grade endometrial stromal sarcomas. It may be possible to identify a subset of leiomyosarcomas with a favorable prognosis based on staining with a panel of immunomarkers for cell proliferation and apoptosis.

Prognostic significance of FOXL2 mutation and mRNA expression in adult and juvenile granulosa cell tumors of the ovary

Recently, mutation of the FOXL2 gene has been consistently identified in adult granulosa cell tumors of the ovary. The purpose of this study is to investigate whether the FOXL2 mutation and mRNA expression have a role in the pathogenesis of juvenile and adult granulosa cell tumors and influence tumor progression. Thirty-four adult granulosa cell tumors and 20 juvenile granulosa cell tumors were examined for the presence of the FOXL2 (C402G) mutation. Expression levels were studied by quantitative PCR and immunohistochemistry. We found that FOXL2 (C402G) mutation was present in 19/27 (70%) of the adult type tumors but in none of the juvenile granulosa cell tumors (0/18). No correlation was encountered between the presence of FOXL2 mutation and various clinicopathologic parameters except for the presence of a different sex-cord component, which was more frequently found in the subgroup of wild-type adult granulosa cell tumors than in the mutated tumors. Patients with tumors harboring the FOXL2 (C402G) mutation had a worse disease-free survival than those with the wild-type gene. Expression levels of FOXL2 mRNA had an impact on disease-free survival in both adult and juvenile granulosa cell tumors. We also found that the mutated tumors had a higher immunohistochemical expression of the FOXL2 protein, and there was a linear correlation between mRNA and immunohistochemical FOXL2 expression in both adult and juvenile granulosa cell tumors. Patients with juvenile granulosa cell tumors and higher FOXL2 protein expression had worse overall survival and disease-free survival than those with negative or weakly immunoreactive tumors. Our data suggest that FOXL2 mutation and mRNA expression are of prognostic importance in both adult and juvenile granulosa cell tumors.

Dual loss of the SWI/SNF complex ATPases SMARCA4/BRG1 and SMARCA2/BRM is highly sensitive and specific for small cell carcinoma of the ovary, hypercalcaemic type.

Small cell carcinoma of the ovary, hypercalcaemic type (SCCOHT) is a lethal and sometimes familial ovarian tumour of young women and children. We and others recently discovered that over 90% of SCCOHTs harbour inactivating mutations in the chromatin remodelling gene SMARCA4 with concomitant loss of its encoded protein SMARCA4 (BRG1), one of two mutually exclusive ATPases of the SWI/SNF chromatin remodelling complex. To determine the specificity of SMARCA4 loss for SCCOHT, we examined the expression of SMARCA4 by immunohistochemistry in more than 3000 primary gynaecological tumours. Among ovarian tumours, it was only absent in clear cell carcinoma (15 of 360, 4%). In the uterus, it was absent in endometrial stromal sarcomas (4 of 52, 8%) and high‐grade endometrioid carcinomas (2 of 338, 1%). Recent studies have shown that SMARCA2 (BRM), the other mutually exclusive ATPase of the SWI/SNF complex, is necessary for survival of tumour cells lacking SMARCA4. Therefore, we examined SMARCA2 expression and discovered that all SMARCA4‐negative SCCOHTs also lacked SMARCA2 protein by IHC, including the SCCOHT cell lines BIN67 and SCCOHT1. Among ovarian tumours, the SMARCA4/SMARCA2 dual loss phenotype appears completely specific for SCCOHT. SMARCA2 loss was not due to mutation but rather from an absence of mRNA expression, which was restored by treatment with the histone deacetylase inhibitor trichostatin A. Re‐expression of SMARCA4 or SMARCA2 inhibited the growth of BIN67 and SCCOHT1 cell lines. Our results indicate that SMARCA4 loss, either alone or with SMARCA2, is highly sensitive and specific for SCCOHT and that restoration of either SWI/SNF ATPase can inhibit the growth of SCCOHT cell lines.

Uterine leiomyosarcomas: Tumor size, mitotic index, and biomarkers Ki67, and Bcl-2 identify two groups with different prognosis

BACKGROUND Prognostic factors for uterine leiomyosarcomas are not well established. Although most tumors are associated with poor prognosis even when apparently confined to the uterus (stage I), some cases that exhibited morphologic features of malignancy had prolonged survival. METHODS Using tissue microarrays of 84 uterine leiomyosarcomas, we investigated conventional clinico-pathologic parameters, including International Federation of Gynecology and Obstetrics (FIGO) stage, together with expression of Ki67, p53, p16, and Bcl-2, attempting to distinguish leiomyosarcomas with different prognosis. The rate of CD163 immunoreactive tumor macrophages was also investigated. RESULTS Tumor size and mitotic index were significant prognostic factors by univariate (p=0.018 and p=0.003, respectively) and multivariate (p=0.006 and p=0.001) analyses. Of the biomarkers investigated, only Ki67 immunoreaction was significant by univariate analysis and was associated with adverse prognosis (p=0.01). However, combination of tumor size, mitotic index, Ki67, and Bcl-2 worked even better. Using these 4 parameters, unsupervised hierarchical clustering identified 2 groups of tumors with different prognosis (p=0.001): group 1 consisted mostly of smaller leiomyosarcomas (<10cm) with mitotic index <20 MF/10 HPF, negative Ki67, and positive or negative Bcl-2 immunostaining. These tumors were associated with better prognosis. In contrast, group 2 leiomyosarcomas which were mostly≥10cm in diameter had higher mitotic index (≥ 20 MF/10 HPF), and were positive for Ki67 and negative for Bcl-2 had worse prognosis. Also, the number of CD163-macrophages was greater in group 2 than group 1 (p=0.007). CONCLUSIONS Tumor size and mitotic index are morphologic predictors of malignancy in uterine leiomyosarcomas. Combination of tumor size, mitotic index, Ki67, and Bcl-2 protein expression allows distinguishing 2 groups of leiomyosarcomas with different survival. Leiomyosarcomas associated with poor outcome had a higher number of CD163 stromal macrophages.

Endometrial stromal sarcomas with sex cord differentiation are associated with PHF1 rearrangement.

Endometrial stromal tumors may pose diagnostic challenges particularly when they exhibit variant histologic appearances, involve extrauterine sites, or present as metastatic disease. In such cases, use of immunohistochemical markers and identification of specific nonrandom chromosomal rearrangements may be helpful. Over the last decade, fluorescence in situ hybridization (FISH) has been progressively incorporated as a diagnostic tool for the evaluation of endometrial stromal tumors. The purpose of this study was to review a series of these tumors and compare the results of FISH analysis with the clinicopathologic characteristics. Three endometrial stromal nodules (ESNs), 13 endometrial stromal sarcomas (ESSs), and 7 undifferentiated endometrial sarcomas (UESs) were reviewed. Three metastases from 1 of the ESS cases were also analyzed. Nine of these tumors (1 ESN, 8 ESSs, and 1 UES) exhibited unusual histologic features, including smooth muscle (3), sex cord (7), epithelioid (1), fibromyxoid (1), and skeletal muscle (2) differentiation. A tissue microarray was prepared, and FISH analysis was performed using break-apart and fusion probes for JAZF1, SUZ12, EPC1, and PHF1 genes. FISH was successful in 22 cases, and rearrangements involving JAZF1, SUZ12, EPC1, and PHF1 genes were detected in 10 of the 22 (45%) uterine tumors, including 2 of the 3 ESNs and 8 of 12 ESSs. Genetic rearrangements were found neither in the 3 metastases of the ESS nor in any of the UESs. It is noteworthy that a correlation between sex cord differentiation and PHF1 rearrangement was encountered in ESSs (P=0.008). In our series, all ESSs showing sex cords had PHF1 genetic rearrangement, suggesting that such rearrangements may induce sex cord differentiation.

Expression profiling of 22 genes involved in the PI3K-AKT pathway identifies two subgroups of high-grade endometrial carcinomas with different molecular alterations.

Previously, we showed that PIK3CA and p53 alterations in uterine endometrial carcinomas correlate with poor prognosis. However, the contribution of phosphatidylinositol 3-kinase (PI3K) –AKT deregulation to endometrial carcinogenesis is not completely understood. The purpose of this study was to analyze alterations of this pathway in endometrial carcinomas and correlate them with the most common genetic abnormalities. Expression profiling of 22 genes involved in PI3K–AKT signaling pathway was analyzed in 38 endometrial carcinomas using TaqMan low-density array (TLDA) analysis. The gene expression pattern was analyzed by hierarchical clustering analysis. Unsupervised clustering divided the high-grade endometrial carcinomas into two clusters. One cluster identified tumors with alterations in the PI3K–AKT signaling pathway (exon 20 PIK3CA mutations and/or PTEN mutations 9/15; 60%), and p16 protein overexpression (8/13; 62%). Almost all non-endometrioid adenocarcinomas (serous and clear cell adenocarcinomas) were segregated into this cluster. In contrast, the other cluster identified tumors with p53 alterations (6/6; 100%), p16 protein overexpression (5/5; 100%), and exon 9 PIK3CA mutations (2/6; 33%). Exon 20 PIK3CA and PTEN mutations were not found in this subgroup. Low-grade endometrial carcinomas clustered in a third subgroup characterized by high frequency of PTEN mutations (10/17; 59%) and microsatellite instability (6/17; 35%). Our results show that gene expression profile differences in the PI3K–AKT signaling pathway identify two subgroups of high-grade endometrial carcinomas with different molecular alterations (PI3K–AKT pathway vs p53 alterations) that may have distinct roles in endometrial carcinogenesis. Identification of these subgroups can provide insight into the biology of these tumors and may facilitate the development of future treatments.

Gene expression analysis identifies two groups of ovarian high-grade serous carcinomas with different prognosis.

Gene expression profiling is an important tool to evaluate genetic heterogeneity in carcinomas and is useful to develop expression-based classifications for many types of cancer, as well as markers of disease outcome. In this study, we have investigated the expression profile of 22 genes involved in the PI3K–AKT pathway in 26 high-grade ovarian carcinomas (19 serous and 7 clear cell carcinomas). Unsupervised hierarchical clustering divided high-grade ovarian carcinomas into three groups. Although all clear cell carcinomas clustered in one group, high-grade serous carcinomas were segregated into two separate groups with different prognosis (P=0.05). High expression of CASP3, XIAP (X-linked inhibitor of apoptosis) , NFKB1, FAS, and GSK3B mRNAs identified high-grade serous carcinomas with better prognosis. In multivariate analysis, these cluster groups were of prognostic significance independent of age, tumor size, and tumor stage (P=0.008). To validate the mRNA expression data, we studied the immunohistochemical expression of caspase-3 and XIAP on a tissue microarray. Immunoreaction for caspase-3 was concordant with the results obtained by mRNA expression analysis (Spearman r=0.762, P=0.000). Caspase-3 was exclusively expressed by the macrophages. Furthermore, co-expression of caspase-3 and XIAP identified high-grade serous carcinomas with different prognosis (P=0.03). Our results suggest that there are different biological subtypes of high-grade serous carcinomas.

Molecular analyses of juvenile granulosa cell tumors bearing AKT1 mutations provide insights into tumor biology and therapeutic leads

Juvenile granulosa cell tumors (JGCTs) of the ovary are pediatric neoplasms representing 5% of all granulosa cell tumors (GCTs). Most GCTs are of adult type (AGCTs) and bear a mutation in the FOXL2 gene. The molecular basis of JGCTs is poorly understood, although mutations in the GNAS gene have been reported. We have detected in-frame duplications within the oncogene AKT1 in >60% of the JGCTs studied. Here, to evaluate the functional impact of these duplications and the existence of potential co-driver alterations, we have sequenced the transcriptome of four JGCTs and compared them with control transcriptomes. A search for gene variants detected only private alterations probably unrelated with tumorigenesis, suggesting that tandem duplications are the best candidates to underlie tumor formation in the absence of GNAS alterations. We previously showed that the duplications were specific to JGCTs. However, the screening of eight AGCTs samples without FOXL2 mutation showed the existence of an AKT1 duplication in one case, also having a stromal luteoma. The analysis of RNA-Seq data pinpointed a series of differentially expressed genes, involved in cytokine and hormone signaling and cell division-related processes. Further analyses pointed to the existence of a possible dedifferentiation process and suggested that most of the transcriptomic dysregulation might be mediated by a limited set of transcription factors perturbed by AKT1 activation. Finally, we show that commercially available AKT inhibitors can modulate the in vitro activity of various mutated forms. These results shed light on the pathogenesis of JGCTs and provide therapeutic leads for a targeted treatment.

Simultaneous carcinomas of the breast and ovary: utility of Pax-8, WT-1, and GATA3 for distinguishing independent primary tumors from metastases.

Breast carcinomas rarely metastasize to the ovary and are even more rarely present clinically as primary ovarian tumors. However, patients with breast cancer not infrequently develop independent primary ovarian carcinomas. In these cases, distinction between independent primaries and metastatic tumors is crucial. Several comparative immunohistochemical studies have been reported, but few included significant clinicopathologic data and none investigated cases of ovarian and breast carcinomas from the same patients. In this study, we compared 18 cases of patients with bona fide independent breast and ovarian carcinomas (15 high-grade serous and 3 clear cell carcinomas), with 9 cases of patients with known mammary carcinomas (7 lobular and 2 ductal carcinomas) metastatic to the ovary. Immunohistochemical stains for Pax-8, WT-1, and GATA3 were carried out on tissue microarrays (TMA). Most primary ovarian carcinomas were larger than the metastatic tumors (P=0.001) and were diagnosed at an advanced stage. All primary ovarian tumors showed marked nuclear pleomorphism, whereas only 2 metastatic breast carcinomas had Grade 3 nuclei (P=0.000). The vast majority of ovarian metastases (7/9) showed the typical pattern of lobular breast carcinoma. Pax-8 and WT-1 expression were found in 16 of 18 (88%) and 13 of 18 (72%) primary ovarian carcinomas, respectively. In contrast, all primary ovarian carcinomas were negative for GATA3. The 2 Pax-8-negative ovarian carcinomas were also negative for WT-1. With the exception of 3 triple-negative carcinomas, all primary breast carcinomas were positive for GATA3. All metastatic breast carcinomas were positive for GATA3 and negative for Pax-8. WT-1 expression was seen in only 1 of 9 metastatic breast carcinomas (11%). Patients with ovarian metastases had worse prognosis than patients with independent breast and ovarian carcinomas (P=0.000). Pax-8, WT-1, and GATA3 immunoreactions are useful in the distinction between independent primaries and metastatic mammary carcinomas to the ovary in the light of clinicopathologic findings.