Development and Validation of the Gene Expression Predictor of High-grade Serous Ovarian Carcinoma Molecular SubTYPE (PrOTYPE).

PURPOSE: Gene expression-based molecular subtypes of high-grade serous tubo-ovarian cancer (HGSOC), demonstrated across multiple studies, may provide improved stratification for molecularly targeted trials. However, evaluation of clinical utility has been hindered by nonstandardized methods, which are not applicable in a clinical setting. We sought to generate a clinical grade minimal gene set assay for classification of individual tumor specimens into HGSOC subtypes and confirm previously reported subtype-associated features. EXPERIMENTAL DESIGN: Adopting two independent approaches, we derived and internally validated algorithms for subtype prediction using published gene expression data from 1,650 tumors. We applied resulting models to NanoString data on 3,829 HGSOCs from the Ovarian Tumor Tissue Analysis consortium. We further developed, confirmed, and validated a reduced, minimal gene set predictor, with methods suitable for a single-patient setting. RESULTS: Gene expression data were used to derive the predictor of high-grade serous ovarian carcinoma molecular subtype (PrOTYPE) assay. We established a de facto standard as a consensus of two parallel approaches. PrOTYPE subtypes are significantly associated with age, stage, residual disease, tumor-infiltrating lymphocytes, and outcome. The locked-down clinical grade PrOTYPE test includes a model with 55 genes that predicted gene expression subtype with >95% accuracy that was maintained in all analytic and biological validations. CONCLUSIONS: We validated the PrOTYPE assay following the Institute of Medicine guidelines for the development of omics-based tests. This fully defined and locked-down clinical grade assay will enable trial design with molecular subtype stratification and allow for objective assessment of the predictive value of HGSOC molecular subtypes in precision medicine applications.See related commentary by McMullen et al., p. 5271.

[BORDERLINE OVARIAN TUMORS: CURRENT ISSUES AND REHABILITATION PROBLEMS].

Objective of the review - to demonstrate the topicality of borderline ovarian tumors; to analyze the current state of the rehabilitation in patients who undergo specific antitumor treatment. Borderline ovarian tumors (BOT) more frequently occur in young patients (below age 40 years); herewith five-year survival rate exceeds 95%. The cumulative data on pathogenesis, clinical progression, therapy and rehabilitation possibilities together with epidemiological features gave an opportunity to take a fresh look not only at the disease itself but at the necessity of rehabilitation of patients and quality of their life. The problem of complex rehabilitation programs implementation is being thoroughly discussed. Among the important features of such programs are sufficient duration, personalized approach, continuity in the management of oncogynecological patients by various medical specialists, the complexity with the compulsive psychotherapeutic assistance. Index of the successful rehabilitation measures implementation is the recovery of the biological, psychophysiological and social functions. The dynamic conduct of rehabilitation programs will give the opportunity to improve medical state not only of the concrete woman but the state of the whole nation.

Ovarian high-grade serous carcinoma with a noninvasive growth pattern simulating a serous borderline tumor.

Ovarian serous borderline tumors (SBTs) being a precursor of low-grade serous carcinomas are morphologically characterized by noninvasive growth and low-grade cytology. On the other hand, many pathologists regard cytologically high-grade, noninvasive (HG-noninv) ovarian serous tumors resembling SBTs in low magnification as conventional high-grade serous carcinomas (HGSCs) by personal experiences. Nonetheless, there are no established molecular characteristic of such tumors. In this study, therefore, we attempted to provide the molecular evidence. We selected 37 ovarian serous tumors that exhibited a cytologically HG-noninv growth pattern, including 36 tumors that coexisted with conventional invasive HGSC components (HG-inv) and a single tumor exclusively composed of pure HG-noninv. Histologically, all HG-noninv showed many mitotic figures, and serous tubal intraepithelial carcinomas were identified in 3 tumors with HG-noninv. Immunohistochemically, most HG-noninv showed aberrant p53 expression, frequent IMP3 positivity, p16 overexpression, a high MIB-1 labeling index, and infrequent PAX2. By molecular analysis, the pure HG-noninv and 13 HGSCs with HG-noninv showed TP53 mutations, but KRAS/BRAF mutations were not detected in any of them. In 1 tumor, we detected an identical TP53 mutation in both HG-noninv and HG-inv components by using laser capture microdissection. These immunohistochemical and molecular features of HG-noninv were similar to those of conventional invasive HGSCs but different from those of SBTs. In conclusion, our results showed that a cytologically HG-noninv growth pattern simulating an SBT is a morphological spectrum of HGSC, but not a true SBT.

Molecular subtypes of serous borderline ovarian tumor show distinct expression patterns of benign tumor and malignant tumor-associated signatures.

Borderline ovarian tumors show heterogeneity in clinical behavior. Most have excellent prognosis, although a small percentage show recurrence or progressive disease, usually to low-grade serous carcinoma. The aim of this study was to understand the molecular relationship between these entities and identify potential markers of tumor progression and therapeutic targets. We studied gene expression using Affymetrix HGU133plus2 GeneChip microarrays in 3 low-grade serous carcinomas, 13 serous borderline tumors and 8 serous cystadenomas. An independent data set of 18 serous borderline tumors and 3 low-grade serous carcinomas was used for validation. Unsupervised clustering revealed clear separation of benign and malignant tumors, whereas borderline tumors showed two distinct groups, one clustering with benign and the other with malignant tumors. The segregation into benign- and malignant-like borderline molecular subtypes was reproducible on applying the same analysis to an independent publicly available data set. We identified 50 genes that separate borderline tumors into their subgroups. Functional enrichment analysis of genes that separate borderline tumors to the two subgroups highlights a cell adhesion signature for the malignant-like subset, with Claudins particularly prominent. This is the first report of molecular subtypes of borderline tumors based on gene expression profiling. Our results provide the basis for identification of biomarkers for the malignant potential of borderline ovarian tumor and potential therapeutic targets for low-grade serous carcinoma.

Commercial molecular panels are of limited utility in the classification of pancreatic cystic lesions.

The PathfinderTG biomarker panel is useful in the evaluation of pancreatic cysts that have clinical features suspicious for malignancy, but its utility in classifying fine-needle aspiration biopsies from small pancreatic cystic lesions is yet to be proven. We used morphology to classify 20 pancreatic cyst cytology aspirates, all of which met radiographic criteria for close observation. Cases were cytologically classified as consistent with pseudocyst, serous cystadenoma, or mucinous neoplasm with low-grade, intermediate-grade, or high-grade dysplasia and analyzed for carcinoembryonic antigen. Redpath Integrated Pathology Inc. rendered diagnoses of nonmucinous (reactive/indolent or serous) or mucinous (low-risk or at risk) cyst on the basis of results of the PathfinderTG panel (KRAS mutations, DNA content, and loss of heterozygosity at microsatellites linked to tumor suppressor genes). Cytologic and commercial laboratory diagnoses were concordant in only 7 (35%) cases. Seven cysts classified as mucinous with low-grade dysplasia by cytology were interpreted as nonmucinous on the basis of the PathfinderTG panel, 2 of which were resected mucinous cysts. Two pancreatitis-related pseudocysts were misdiagnosed as low-risk mucinous cysts; 1 mucinous cyst with low-grade dysplasia was considered at risk for neoplastic progression using the PathfinderTG panel. Only 1 cyst misclassified as pseudocyst by cytology, but low-risk mucinous cyst by molecular analysis, proved to be a mucinous cystic neoplasm with low-grade dysplasia after surgical resection. We conclude that the PathfinderTG panel may aid the classification of pancreatic lesions, but is often inaccurate and should not replace cytologic evaluation of these lesions.

Copy number aberrations in benign serous ovarian tumors: a case for reclassification?

PURPOSE: Serous ovarian carcinomas are the predominant epithelial ovarian cancer subtype and it has been widely believed that some or all of these may arise from precursors derived from the ovarian surface epithelium or fimbriae, although direct molecular evidence for this is limited. This study aimed to conduct copy number (CN) analysis using a series of benign and borderline serous ovarian tumors to identify underlying genomic changes that may be indicative of early events in tumorigenesis. EXPERIMENTAL DESIGN: High resolution CN analysis was conducted on DNA from the epithelial and fibroblast components of a cohort of benign (N = 39) and borderline (N = 24) serous tumors using the Affymetrix OncoScan assay and SNP6.0 arrays. RESULTS: CN aberrations were detected in the epithelium of only 2.9% (1 of 35) of serous cystadenomas and cystadenofibromas. In contrast, CN aberrations were detected in the epithelium of 67% (16 of 24) of the serous borderline tumors (SBT). Unexpectedly, CN aberrations were detected in the fibroblasts of 33% (13 of 39) of the benign serous tumors and in 15% (3 of 20) of the SBTs. Of the 16 cases with CN aberrations in the fibroblasts, 12 of these carried a gain of chromosome 12. CONCLUSIONS: Chromosome 12 trisomy has been previously identified in pure fibromas, supporting the concept that a significant proportion of benign serous tumors are in fact primary fibromas with an associated cystic mass. This is the first high resolution genomic analysis of benign serous ovarian tumors and has shown not only that the majority of benign serous tumors have no genetic evidence of epithelial neoplasia but that a significant proportion may be more accurately classified as primary fibromas.

Gene expression profiling of advanced-stage serous ovarian cancers distinguishes novel subclasses and implicates ZEB2 in tumor progression and prognosis.

To elucidate the mechanisms of rapid progression of serous ovarian cancer, gene expression profiles from 43 ovarian cancer tissues comprising eight early stage and 35 advanced stage tissues were carried out using oligonucleotide microarrays of 18,716 genes. By non-negative matrix factorization analysis using 178 genes, which were extracted as stage-specific genes, 35 advanced stage cases were classified into two subclasses with superior (n = 17) and poor (n = 18) outcome evaluated by progression-free survival (log rank test, P = 0.03). Of the 178 stage-specific genes, 112 genes were identified as showing different expression between the two subclasses. Of the 48 genes selected for biological function by gene ontology analysis or Ingenuity Pathway Analysis, five genes (ZEB2, CDH1, LTBP2, COL16A1, and ACTA2) were extracted as candidates for prognostic factors associated with progression-free survival. The relationship between high ZEB2 or low CDH1 expression and shorter progression-free survival was validated by real-time RT-PCR experiments of 37 independent advanced stage cancer samples. ZEB2 expression was negatively correlated with CDH1 expression in advanced stage samples, whereas ZEB2 knockdown in ovarian adenocarcinoma SKOV3 cells resulted in an increase in CDH1 expression. Multivariate analysis showed that high ZEB2 expression was independently associated with poor prognosis. Furthermore, the prognostic effect of E-cadherin encoded by CDH1 was verified using immunohistochemical analysis of an independent advanced stage cancer samples set (n = 74). These findings suggest that the expression of epithelial-mesenchymal transition-related genes such as ZEB2 and CDH1 may play important roles in the invasion process of advanced stage serous ovarian cancer.

The morphological classification of a serous cystic tumor (SCT) of the pancreas and evaluation of the preoperative diagnostic accuracy of computed tomography.

BACKGROUND: Although the honeycomb microcystic type is common and typical for a serous cystic tumor (SCT), clinical and radiological features are diverse. Systematic classification of SCT subtypes is not well established. The purpose of this study was to classify the subtypes of SCT and to clarify its clinical and pathological characteristics. METHODS: Clinical data from 52 patients with a pathologically confirmed SCT were prospectively collected using a standard data form. According to cyst size and multiplicity, on gross and radiological evaluation, the cysts were classified as microcystic when they were smaller than 2 cm, and macrocystic when larger than 2 cm. The microcystic tumors were subdivided into honeycomb and solid types, while the macrocystic tumors into unilocular and multilocular types based on the number of cysts. RESULTS: There were 22 cases with microcystic SCTs that were subclassified into the honeycomb (n = 21) and solid types (n = 1), while 30 cases were macrocystic type and were subclassified into multilocular (n = 16) and unilocular types (n = 14). There were no differences between four subtypes with regard to gender, tumor location, and size. The preoperative diagnostic accuracy of the unilocular macrocystic SCT was only 35.7%, while that of honeycomb microcystic SCT and multilocular macrocystic SCT were 81% and 87.5%, respectively (P = 0.005). CONCLUSION: Microcystic SCTs and multilocular macrocystic SCTs can be accurately diagnosed preoperatively; therefore conservative treatment and observation are possible in some cases. However, the unilocular macrocystic SCT is difficult to differentiate from the other pancreatic cystic tumors with malignant potential, therefore resection must be considered.

[Management of ovarian cysts]. / Prise en charge des kystes ovariens.

Ovarian cysts occur frequently in women of reproductive age. These are usually functional cysts which resolve spontaneously and whose evolution can be followed with ultrasound. Non-functional cysts have diverse histologic origins. The most common are serous and mucinous cystadenomas which arise from the epithelial wall of the ovary, endometriomas which arise in the setting of pelvic endometriosis, and dermoid cysts which arise from the germinal cells of the ovary. Endovaginal ultrasound with Doppler enhancement is the best imaging technique to establish the nature of cysts and to distinguish cysts suspicious for malignancy which require more invasive investigation. Pelvic laparoscopy is the surgical approach of choice for the treatment of non-functional benign ovarian cysts. Conservative treatment to shell out the cyst and preserve functional ovarian tissue should be reserved for women desirous of future pregnancies. The risk of ovarian cancer remains a major preoccupation of the surgeon. Where malignancy is suspected, laparoscopy is contraindicated and a median laparotomy is appropriate for radical extirpative surgery. This article describes the diagnostic techniques which allow a laparoscopic approach to presumably benign cysts and discusses surgical techniques specifically adapted to their different histologic nature of ovarian cysts.

Logistic regression model to distinguish between the benign and malignant adnexal mass before surgery: a multicenter study by the International Ovarian Tumor Analysis Group.

PURPOSE: To collect data for the development of a more universally useful logistic regression model to distinguish between a malignant and benign adnexal tumor before surgery. PATIENTS AND METHODS: Patients had at least one persistent mass. More than 50 clinical and sonographic end points were defined and recorded for analysis. The outcome measure was the histologic classification of excised tissues as malignant or benign. RESULTS: Data from 1,066 patients recruited from nine European centers were included in the analysis; 800 patients (75%) had benign tumors and 266 (25%) had malignant tumors. The most useful independent prognostic variables for the logistic regression model were as follows: (1) personal history of ovarian cancer, (2) hormonal therapy, (3) age, (4) maximum diameter of lesion, (5) pain, (6) ascites, (7) blood flow within a solid papillary projection, (8) presence of an entirely solid tumor, (9) maximal diameter of solid component, (10) irregular internal cyst walls, (11) acoustic shadows, and (12) a color score of intratumoral blood flow. The model containing all 12 variables (M1) gave an area under the receiver operating characteristic curve of 0.95 for the development data set (n = 754 patients). The corresponding value for the test data set (n = 312 patients) was 0.94; and a probability cutoff value of .10 gave a sensitivity of 93% and a specificity of 76%. CONCLUSION: Because the model was constructed from multicenter data, it is more likely to be generally applicable. The effectiveness of the model will be tested prospectively at different centers.

Serous borderline tumours of the ovary.

Serous borderline tumours of the ovaryIn this Expert Opinion we have invited articles from two leading groups, to discuss serous borderline tumours (serous tumours of low malignant potential) of the ovary from their own perspectives. Controversy remains over heterogeneity within this group of tumours and their relationship to ovarian cancer. Our authors discuss the histopathological classification of these tumours in relation to morphological appearances, molecular and clinical data. The significance of a micropapillary pattern is discussed, and issues related to extra-ovarian implants.

Benign ovarian serous tumors: a re-evaluation and proposed reclassification of serous "cystadenomas" and "cystadenofibromas".

OBJECTIVE: Serous cystadenomas and cystadenofibromas of the ovaries are currently regarded as neoplasms and are considered the most common ovarian neoplasms. The purpose of this study is to determine what proportion of benign serous tumors contain an epithelial proliferation (the hallmark of a neoplastic process in nearly all other sites) that can be considered neoplastic as opposed to reactive in nature. METHODS: An unselected series of 113 ovarian serous tumors (76 serous cystadenomas and 37 serous cystadenofibromas) were histologically evaluated. A 1-mm in diameter area of epithelial proliferation was considered potentially neoplastic. RESULTS: Eight tumors (7%) displayed at least 1 mm of epithelial proliferation (1% of serous cystadenomas and 19% of serous cystadenofibromas). CONCLUSION: The vast majority of benign serous tumors may not be bona fide epithelial neoplasms, but rather, may represent cystically dilated glandular inclusions (cystadenomas) and fibromas with epithelial inclusions (cystadenofibromas). A recently published study evaluating clonality in serous cystadenomas found that the vast majority are polyclonal and thus supports this hypothesis. These findings have important implications for the pathogenesis of ovarian cancer, for the distribution of ovarian neoplasms, and for the interpretation of molecular biological studies of ovarian tumors.

Serous borderline (low malignant potential, atypical proliferative) ovarian tumors: workshop perspectives.

Although the category of serous borderline ovarian tumor (S-BOT) was established more than 30 years ago, the nomenclature and prognostic significance of various histological features of these neoplasms continues to engender controversy. The Borderline Ovarian Tumor Workshop was held in Bethesda, MD, in August 2003 in an attempt to examine the existing data, establish areas of agreement, and identify areas needing further investigation. This report addresses 6 areas of controversy regarding S-BOT: (1) tumors with and without a micropapillary architecture (typical vs micropapillary type), (2) peritoneal implants, (3) stromal microinvasion, (4) ovarian surface involvement, (5) lymph node involvement, and (6) recurrent tumors. Each of these issues is addressed by summarizing the data in the literature on which the discussions were based, areas of agreement that emerged, divergent opinions and the reasoning behind them, and the conclusions of the participants with recommended nomenclature.

Cystic neoplasms of the pancreas.

Although a minority of pancreatic cystic tumors are neoplastic, proper diagnosis of these neoplasms is important owing to their varied clinical course and behavior. The clinicopathologic features of pancreatic cystic neoplasms, including mucinous cystic neoplasms, intraductal papillary mucinous neoplasms, solid pseudopapillary tumors, and serous microcystic adenomas, are discussed in this review.

Noninvasive and invasive micropapillary (low-grade) serous carcinoma of the ovary: a clinicopathologic analysis of 135 cases.

Reports describing the behavior of micropapillary serous carcinomas (MPSCs) of the ovary have focused on those that are noninvasive. There are only very limited data on the behavior of those that are invasive. To further characterize the behavior of MPSCs, invasive versus noninvasive primary tumors were distinguished based on the presence or absence of destructive infiltrative growth. To qualify for inclusion, invasive MPSCs, like the noninvasive tumors, were required to display a micropapillary architecture and low-grade nuclei. A total of 135 cases of MPSC were identified: 96 noninvasive and 39 invasive. On follow-up, survival for 10 patients with stage I noninvasive and invasive MPSCs was 100%, and survival for women with stage II and III noninvasive and invasive MPSCs with noninvasive implants was 80%. In contrast, the 5-year and 10-year survival for patients with stage II and III noninvasive MPSCs with invasive implants was 85% and 55%, respectively. The 5-year and 10-year survival for women with invasive MPSCs and invasive implants was 55% and 45%, respectively. The median time from diagnosis to death for women with noninvasive and invasive MPSCs with invasive implants was 60 months (range 33-240 months). The indolent behavior of these low-grade carcinomas distinguishes them from conventional serous carcinomas, which are high-grade aggressive neoplasms. Five of six patients with small (<5 mm) MPSCs in whom follow-up was available presented with high stage disease. Of these five women, three are alive and well and two are alive with disease (one with invasive and one with noninvasive implants). Nearly three fourths of noninvasive MPSCs were associated with atypical proliferative serous tumors, adenofibromas, or both, and 62% of invasive MPSCs were associated with noninvasive MPSCs, atypical proliferative serous tumors, and adenofibromas, alone or in combination. In addition to the frequent mixtures of these tumor components, transitions between them were common. These data in conjunction with recent molecular genetic studies strongly suggest that MPSCs (low-grade carcinomas) arise from atypical proliferative serous tumors unlike conventional serous carcinomas (high-grade carcinomas), which appear to develop de novo. The findings provide further support for the hypothesis that there are distinct pathways of carcinogenesis for low-grade and high-grade serous carcinoma of the ovary.

Micropapillary serous carcinoma of the ovary has distinct patterns of chromosomal imbalances by comparative genomic hybridization compared with atypical proliferative serous tumors and serous carcinomas.

Recent studies have subdivided serous borderline tumors into 2 categories: atypical proliferative serous tumors (APSTs), which have a relatively benign course, and micropapillary serous carcinomas (MPSCs), which behave like low-grade carcinoma. This study was undertaken to determine, using comparative genomic hybridization (CGH), whether cytogenetic changes support this hypothesis. Nine cases of APST, 10 of MPSC, and 11 of invasive serous carcinoma (SC) were analyzed by CGH. Tumor DNA was extracted from frozen or paraffin-embedded tissue from the primary ovarian tumor, using either sections with at least 70% tumor cells or tissue after relative enrichment by microdissection. Chromosomal imbalances were identified in 3 of 9 APST, 6 of 10 MPSC, and 11 of 11 SC. Three or more chromosomal imbalances were found in 0 of 9 APST, 4 of 10 MPSC, and 9 of 11 SC. Recurrent copy number alterations were grouped into 4 classes correlating with the different tumor types. Class I changes were present in APST and in MPSC or SC and included +8q (7 of 11 SC, 2 of 10 MPSC, 2 of 9 APST), -9p (5 of 11 SC, 0 of 10 MPSC, 1 of 9 APST), and +12 (+12p in 3/11 SC, +12 in 2 of 10 MPSC, +12 in 1 of 9 APST). Class II changes were found only in MPSC and SC, but not in APST. The most frequent examples were +3q (10 of 11 SC, 1 of 10 MPSC), -4q (5 of 11 SC, 1 of 10 MPSC), and -17p (5 of 11 SC, 1 of 10 MPSC). Class III changes were limited to SC, like -16q (7 of 11 SC) and -18q (6 of 11 SC). Class VI changes were unique to MPSC. Gain of 16p (3 of 10 MPSC) was the only aberration in this group. This aberration was not only unique to MPSC but was also the most frequent finding in MPSC. These data support the hypothesis that noninvasive serous tumors of the ovary can be subdivided into 2 categories: APST and MPSC. The number of imbalances in MPSC is substantially higher than in APST and lower than in SC. Some changes in MPSC are shared with SC and APST and others with SC only, suggesting that a subset of MPSC may represent a stage in progression from APST to SC. Other cases of MPSC with independent genetic alterations may represent another subset of tumors that are a distinct entity from APST and SC.

Histology of cystic tumors of the pancreas.

The cystic tumors of the pancreas constitute a considerable diagnostic challenge because of their overlapping clinical, radiologic, and pathologic features. They may be difficult to differentiate from one another and from benign lesions such as pseudocysts. Because many of the tumors in this group are potentially curable, correct diagnosis is essential for proper patient management. Even when correctly diagnosed, thorough microscopic evaluation is required for the mucin-producing tumors to correctly determine their degree of malignant progression in any given case. Most recently, molecular analysis of these tumors has demonstrated definitively that the serous and mucinous types of cystic neoplasms of the pancreas are unrelated pathogenetically. Conversely, molecular data indicate similarities between the mucinous types of cystic tumors and ductal adenocarcinoma of the pancreas, but the essential molecular differences that underlie the differences in biological behavior are as yet undetermined.