High-Grade Endometrial Carcinoma: Serous and Grade 3 Endometrioid Carcinomas Have Different Immunophenotypes and Outcomes

Undifferentiated Carcinoma of the Endometrium: An Expanded Immunohistochemical Analysis Including PAX-8 and Basal-Like Carcinoma Surrogate Markers

Undifferentiated carcinoma of the endometrium (UCAe) is an aggressive, underrecognized high-grade carcinoma that can occur either in pure form or in conjunction with low-grade endometrioid adenocarcinoma (i.e. dedifferentiated carcinoma). The typical solid growth pattern of UCAe can create a diagnostic dilemma as it is frequently misinterpreted as the solid component of an endometrial carcinoma or as a sarcoma. In addition, the high nuclear:cytoplasmic ratio, high mitotic index, and geographic necrosis are reminiscent of basal-like carcinoma of breast (BLCB). This study was undertaken to determine the role of a selected group of immunomarkers in the distinction of UCAe from other endometrial carcinomas, and assess the expression of DNA mismatch repair proteins, and surrogate BLCB immunomarkers in this type of tumor. Cases of UCAe were stained with antibodies against keratin cocktail, CK8/18, PAX-8, and estrogen receptor: 35 cases; progesterone receptor and Her-2/neu: 33 cases; CD44, e-cadherin, p16, and p53: 32 cases; and CK5/6, EGFR, and c-Kit: 18 cases. In addition, mismatch repair protein markers MLH1, MSH2, MSH6, and PMS2 were performed in 34 cases. We found that PAX-8 expression was lost in most cases (83%). In addition, estrogen and progesterone receptors were negative in 83% and 82% of cases, respectively. Seventy-seven percent of cases were positive for keratin cocktail and keratin 8/18, whereas only 11% of cases were positive for keratin 5/6. p16 was diffusely positive in 34% of cases, whereas p53 was expressed in >75% of the tumor cells in 31% of cases. MLH1 and PMS2 were concurrently lost in 50% of cases, whereas MSH2 and MSH6 were lost in 1 case (3%). E-cadherin and CD44 were completely lost in 50% of cases, whereas Her-2/neu was negative in all cases. EGFR was negative in 67% of cases, whereas 22% of cases showed diffuse membranous staining for this marker. UCAe is a high-grade carcinoma of Müllerian origin which tends to be negative for PAX-8. The loss of this marker appears to be a more reliable discriminator than the loss of keratin expression in the differential diagnosis with endometrioid carcinoma or serous carcinoma. UCAe tends to be diffusely positive for p53, but patchy positive for p16. Although UCAe appears to share not only some histologic features with BLCB, but also some of its immunohistochemical features (loss of estrogen receptor, progesterone receptor, and Her-2/neu, a tendency to loose e-cadherin and to express CD44), UCAe appears not to be related to BLCB because it usually lacks the expression EGFR, CK5/6, and c-Kit.

TP53 Mutational Spectrum in Endometrioid and Serous Endometrial Cancers

Endometrial carcinomas (ECs) are heterogeneous at the genetic level. Although TP53 mutations are highly recurrent in serous endometrial carcinomas (SECs), these are also present in a subset of endometrioid endometrial carcinomas (EECs). Here, we sought to define the frequency, pattern, distribution, and type of TP53 somatic mutations in ECs by performing a reanalysis of the publicly available data from The Cancer Genome Atlas (TCGA). A total of 228 EECs (n=186) and SECs (n=42) from the TCGA data set, for which an integrated genomic characterization was performed, were interrogated for the presence and type of TP53 mutations, and for mutations in genes frequently mutated in ECs. TP53 mutations were found in 15% of EECs and 88% of SECs, and in 91% of copy-number-high and 35% of polymerase (DNA directed), epsilon, catalytic subunit (POLE) integrative genomic subtypes. In addition to differences in prevalence, variations in the type and pattern of TP53 mutations were observed between histologic types and between integrative genomic subtypes. TP53 hotspot mutations were significantly more frequently found in SECs (46%) than in EECs (15%). TP53-mutant EECs significantly more frequently harbored a co-occurring PTEN mutation than TP53-mutant SECs. Finally, a subset of TP53-mutant ECs (22%) was found to harbor frameshift or nonsense mutations. Given that nonsense and frameshift TP53 mutations result in distinct p53 immunohistochemical results that require careful interpretation, and that EECs and SECs display different patterns, types, and distributions of TP53 mutations, the use of the TP53/p53 status alone for the differential diagnosis of EECs and SECs may not be sufficient.

Immunohistochemistry in Gynecologic Pathology: An Example-Based Practical Update

CONTEXT

- Immunohistochemical stains are routinely applied in the pathology diagnostic workup of gynecologic lesions. The rapidly expanding repertoire of available markers helps in refining the diagnostic criteria for each disease entity; however, limitations and pitfalls exist.

OBJECTIVE

- To provide a practical, relevant update on the use of immunohistochemistry for commonly encountered differential diagnoses in gynecologic pathology.

DATA SOURCES

- Literature review and authors' diagnostic experience.

CONCLUSIONS

- Immunohistochemistry is a helpful adjunct tool in gynecologic pathology. Although the primary application is in the diagnostic workup, novel prognostic and predictive markers, and immunostains to screen for genetic cancer syndromes, have also been recently introduced in the field.

Molecular Pathology: Predictive, Prognostic, and Diagnostic Markers in Uterine Tumors

This article focuses on the diagnostic, prognostic, and predictive molecular biomarkers in uterine malignancies, in the context of morphologic diagnoses. The histologic classification of endometrial carcinomas is reviewed first, followed by the description and molecular classification of endometrial epithelial malignancies in the context of histologic classification. Taken together, the molecular and histologic classifications help clinicians to approach troublesome areas encountered in clinical practice and evaluate the utility of molecular alterations in the diagnosis and subclassification of endometrial carcinomas. Putative prognostic markers are reviewed. The use of molecular alterations and surrogate immunohistochemistry as prognostic and predictive markers is also discussed.

Endometrial Carcinomas With Clear Cells: A Study of a Heterogeneous Group of Tumors Including Interobserver Variability, Mutation Analysis, and Immunohistochemistry With HNF-1β

Endometrial clear cell carcinoma (CC) is an uncommon tumor and often carries a poor prognosis. It has histologic features that overlap with other endometrial carcinomas and is frequently misclassified. Accurate classification is crucial, however, to improve treatment options. The objectives of this study were (1) to assess diagnostic interobserver variability among 5 gynecologic pathologists for tumors originally diagnosed as CC or with a component of CC (n=44); (2) to determine the utility of immunohistochemical markers estrogen receptor and HNF-1β; and (3) to detect mutations in select genes. Clinical data and morphologic features were also recorded. Agreement among reviewers was only moderate: only 46% of the original CC remained classified as such. After reclassification, estrogen receptor was positive in 8% of CC, 67% of endometrioid carcinomas (EC), and 47% of serous carcinomas (SC). Sensitivities of HNF-1β in CC, SC, and EC were 62%, 27%, and 17%, respectively, whereas specificity for CC versus EC or SC was 78%. Mutations in PIK3CA, PIK3R1, PTEN, KRAS, and NRAS were detected in 41% of 37 cases that had adequate material for study. At least 1 mutation was identified in 33% of CC, 67% of EC, and 33% of SC. This group of patients had poor outcomes: 72% of the patients with follow-up information had died of disease. In summary, this study suggests that the current pool of CC is a heterogeneous group of tumors from the morphologic, immunophenotypic, and molecular point of views and that only a percentage of them represent true CC.

The Genomic Heterogeneity of FIGO Grade 3 Endometrioid Carcinoma Impacts Diagnostic Accuracy and Reproducibility

The Cancer Genome Atlas (TCGA) identified 4 groups of endometrial carcinomas based on an integrated genomic characterization: POLE ultramutated (POLE), microsatellite instability-high, copy number-low (CN-L), and copy number-high (CN-H). In that study, CN-H comprised all of the serous carcinoma cases and 25% of all International Federation of Gynecology and Obstetrics (FIGO) Grade 3 endometrioid carcinoma cases. In this study, 2 expert gynecologic pathologists undertook a morphologic reassessment of the FIGO Grade 3 endometrioid carcinoma subset of the TCGA study cohort, including an analysis for evidence of serous differentiation. Interobserver variability κvalues are reported for the histologic evaluation of all 4 genomic clusters, and diagnostic discrepancies are discussed. Overall, there were 55 agreements, 6 disagreements, and 14 deferrals. Of the 75 cases analyzed, 6 cases had a consensus morphologic diagnosis of serous carcinoma, but only 2 of these cases had a serous carcinoma genotype, whereas the remaining 4 cases were genotypically endometrioid carcinoma. For the CN-H group, 2 of 15 cases were serous carcinoma by morphology and genotype, whereas at least 1 pathologist interpreted the remaining 13 cases as endometrioid carcinoma. The interobserver agreement rate was highest in the CN-L group (90%; κ=0.9), compared with the other genomic groups (POLE: 62%, κ=0.55; microsatellite instability-high: 78%, κ=0.74; and CN-H: 53%, κ=0.48). Our review confirms that most high-grade endometrial carcinomas diagnosed by TCGA as FIGO Grade 3 endometrioid carcinoma are indeed endometrioid carcinomas by morphology and genotype, and that the reproducibility of histologic diagnosis between pathologists varies between the TCGA-integrated genomic clusters.

Pathology of Endometrial Carcinoma

On a clinicopathological and molecular level, two distinctive types of endometrial carcinoma, type I and type II, can be distinguished. Endometrioid carcinoma, the typical type I carcinoma, seems to develop through an estrogen-driven "adenoma carcinoma" pathway from atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (AEH/EIN). It is associated with elevated serum estrogen and high body mass index and expresses estrogen and progesterone receptors. They are mostly low grade and show a favorable prognosis. A subset progresses into high-grade carcinoma which is accompanied by loss of receptor expression and accumulation of TP53 mutations and behaves poorly. Other frequently altered genes in type I carcinomas are K-Ras, PTEN, and ß-catenin. Another frequent feature of type I carcinomas is microsatellite instability mainly caused by methylation of the MLH1 promoter. In contrast, the typical type II carcinoma, serous carcinoma, is not estrogen related since it usually occurs in a small uterus with atrophic endometrium. It is often associated with a flat putative precursor lesion called serous endometrial intraepithelial carcinoma (SEIC). The molecular pathogenesis of serous carcinoma seems to be driven by TP53 mutations, which are present in SEIC. Other molecular changes in serous carcinoma detectable by immunohistochemistry involve cyclin E and p16. Since many of the aforementioned molecular changes can be demonstrated by immunohistochemistry, they are useful ancillary diagnostic tools and may further contribute to a future molecular classification of endometrial carcinoma as recently suggested based on The Cancer Genome Atlas (TCGA) data.

New classification of endometrial cancers: the development and potential applications of genomic-based classification in research and clinical care

Endometrial carcinoma (EC) is the fourth most common cancer in women in the developed world. Classification of ECs by histomorphologic criteria has limited reproducibility and better tools are needed to distinguish these tumors and enable a subtype-specific approach to research and clinical care. Based on the Cancer Genome Atlas, two research teams have developed pragmatic molecular classifiers that identify four prognostically distinct molecular subgroups. These methods can be applied to diagnostic specimens (e.g., endometrial biopsy) with the potential to completely change the current risk stratification systems and enable earlier informed decision making. The evolution of genomic classification in ECs is shared herein, as well as potential applications and discussion of the essential research still needed in order to optimally integrate molecular classification in to current standard of care.

The significance of markers in the diagnosis of endometrial cancer

Endometrial cancer is one of the most common cancers experienced by women throughout the world. It is also the most common malignancy within the female reproductive system, representing 37.7% of all disorders. The incidence increases with age, and is diagnosed most frequently in women between 45 and 65 years old. In the last few years, numerous studies have been performed to identify tumour biomarkers. Biomarkers include not only protein routinely used as tumour markers but also genes and chromosomes. The limiting factor in the use of markers in the diagnosis of endometrial cancer is their lack of specificity. However, specific markers for endometrial cancer are the subject of much research attention. Although moderately elevated levels of markers are present in a number of inflammatory or non-malignant diseases, significantly increased levels of markers indicate the development of cancer. Recently, research has been focused on the identification of molecular changes leading to different histological subtypes of endometrial cancer. In this paper the authors reviewed several currently investigated markers. Progress in these investigations is very important in the diagnostics and treatment of endometrial cancer. In particular, the identification of novel mutations and molecular profiles should enhance our ability to personalise adjuvant treatment with genome-guided targeted therapy.

LAT1 is a putative therapeutic target in endometrioid endometrial carcinoma

l-type amino acid transporters (LAT1-4) are expressed in various cancer types and are involved in the uptake of essential amino acids such as leucine. Here we investigated the expression of LAT1-4 in endometrial adenocarcinoma and evaluated the contribution of LATs to endometrial cancer cell growth. Analysis of human gene expression data showed that all four LAT family members are expressed in endometrial adenocarcinomas. LAT1 was the most highly expressed, and showed a significant increase in both serous and endometrioid subtypes compared to normal endometrium. Endometrioid patients with the highest LAT1 levels exhibited the lowest disease-free survival. The pan-LAT inhibitor BCH led to a significant decrease in cell growth and spheroid area in four endometrial cancer cell lines tested in vitro. Knockdown of LAT1 by shRNA inhibited cell growth in HEC1A and Ishikawa cells, as well as inhibiting spheroid area in HEC1A cells. These data show that LAT1 plays an important role in regulating the uptake of essential amino acids such as leucine into endometrial cancer cells. Increased ability of BCH compared to LAT1 shRNA at inhibiting Ishikawa spheroid area suggests that other LAT family members may also contribute to cell growth. LAT1 inhibition may offer an effective therapeutic strategy in endometrial cancer patients whose tumours exhibit high LAT1 expression.

Molecular Analysis of Mixed Endometrial Carcinomas Shows Clonality in Most Cases

Mixed endometrial carcinoma refers to a tumor that comprises 2 or more distinct histotypes. We studied 18 mixed-type endometrial carcinomas-11 mixed serous and low-grade endometrioid carcinomas (SC/EC), 5 mixed clear cell and low-grade ECs (CCC/EC), and 2 mixed CCC and SCs (CCC/SC), using targeted next-generation sequencing and immunohistochemistry to compare the molecular profiles of the different histotypes present in each case. In 16 of 18 cases there was molecular evidence that both components shared a clonal origin. Eight cases (6 EC/SC, 1 EC/CCC, and 1 SC/CCC) showed an SC molecular profile that was the same in both components. Five cases (3 CCC/EC and 2 SC/EC) showed a shared endometrioid molecular profile and identical mismatch-repair protein deficiency in both components. A single SC/EC case harbored the same POLE exonuclease domain mutation in both components. One SC/CCC and 1 EC/CCC case showed both shared and unique molecular features in the 2 histotype components, suggesting early molecular divergence from a common clonal origin. In 2 cases, there were no shared molecular features, and these appear to be biologically unrelated synchronous tumors. Overall, these results show that the different histologic components in mixed endometrial carcinomas typically share the same molecular aberrations. Mixed endometrial carcinomas most commonly occur through morphologic mimicry, whereby tumors with serous-type molecular profile show morphologic features of EC or CCC, or through underlying deficiency in DNA nucleotide repair, with resulting rapid accrual of mutations and intratumoral phenotypic heterogeneity. Less commonly, mixed endometrial carcinomas are the result of early molecular divergence from a common progenitor clone or are synchronous biologically unrelated tumors (collision tumors).

Progesterone receptor expression is associated with longer overall survival within high-grade histotypes of endometrial carcinoma: A Canadian high risk endometrial cancer consortium (CHREC) study

OBJECTIVE

To assess the association of hormone receptor expression with outcome in high-grade endometrial carcinomas.

METHODS

This study included three sites participating in the Canadian High Risk Endometrial Cancer (CHREC) consortium. Sections from tissue microarrays containing cases with a diagnosis of endometrioid grade 3 (EC3) and endometrial serous carcinoma (ESC) were assessed for estrogen (ER) and progesterone receptor (PR) expression by immunohistochemistry. Expression was considered present if >1% of tumor cell nuclei were labeled. Associations with overall survival were assessed.

RESULTS

ER expression was present in 168/216 (78%) of EC3 and 124/192 (65%) of ESC. PR expression was present in 148/212 (70%) of EC3 and 83/196 (42%) of ESC. PR expression was significantly associated with favorable overall survival in EC3 and ESC (log rank, p=0.018 and p=0.0024) but ER expression was not. PR expression was significantly associated with favorable overall survival in EC3 independent of age, stage, center and lymph-vascular invasion (hazard ratio=0.457, 95% CI 0.257-0.811, p=0.0075) as well as in stage I and II ESC (hazard ratio=0.266, 95% CI 0.094-0.750, p=0.0123).

CONCLUSION

Our data provide support for the assessment of the PR expression status in EC3 and ESC. Future work will be required to determine how PR expression may be incorporated into management of patients with EC3 and ESC.

Androgen receptors are acquired by healthy postmenopausal endometrial epithelium and their subsequent loss in endometrial cancer is associated with poor survival

BACKGROUND

Endometrial cancer (EC) is a hormone-driven disease, and androgen receptor (AR) expression in high-grade EC (HGEC) and metastatic EC has not yet been described.

METHODS

The expression pattern and prognostic value of AR in relation to oestrogen (ERα and ERβ) and progesterone (PR) receptors, and the proliferation marker Ki67 in all EC subtypes (n = 85) were compared with that of healthy and hyperplastic endometrium, using immunohistochemisty and qPCR.

RESULTS

Compared with proliferative endometrium, postmenopausal endometrtial epithelium showed significantly higher expression of AR (P < 0.001) and ERα (P = 0.035), which persisted in hyperplastic epithelium and in low-grade EC (LGEC). High-grade EC showed a significant loss of AR (P < 0.0001), PR (P < 0.0001) and ERβ (P < 0.035) compared with LGEC, whilst maintaining weak to moderate ERα. Unlike PR, AR expression in metastatic lesions was significantly (P = 0.039) higher than that in primary tumours. Androgen receptor expression correlated with favourable clinicopathological features and a lower proliferation index. Loss of AR, with/without the loss of PR was associated with a significantly lower disease-free survival (P < 0.0001, P < 0.0001, respectively).

CONCLUSIONS

Postmenopausal endometrial epithelium acquires AR whilst preserving other steroid hormone receptors. Loss of AR, PR with retention of ERα and ERβ may promote the unrestrained growth of HGEC. Androgen receptor may therefore be a clinically relevant prognostic indicator and a potential therapeutic target in EC.

Prognostic importance of DNA ploidy in non-endometrioid, high-risk endometrial carcinomas

The present study investigated the predictive and prognostic impact of DNA ploidy together with other well-known prognostic factors in a series of non-endometrioid, high-risk endometrial carcinomas. From a complete consecutive series of 4,543 endometrial carcinomas of International Federation of Gynecology and Obstetrics (FIGO) stages I-IV, 94 serous carcinomas, 48 clear cell carcinomas and 231 carcinosarcomas were selected as a non-endometrioid, high-risk group for further studies regarding prognosis. The impact of DNA ploidy, as assessed by flow cytometry, was of particular focus. The age of the patients, FIGO stage, depth of myometrial infiltration and tumor expression of p53 were also included in the analyses (univariate and multivariate). In the complete series of cases, the recurrence rate was 37%, and the 5-year overall survival rate was 39% with no difference between the three histological subtypes. The primary cure rate (78%) was also similar for all tumor types studied. DNA ploidy was a significant predictive factor (on univariate analysis) for primary tumor cure rate, and a prognostic factor for survival rate (on univariate and multivariate analyses). The predictive and prognostic impact of DNA ploidy was higher in carcinosarcomas than in serous and clear cell carcinomas. In the majority of multivariate analyses, FIGO stage and depth of myometrial infiltration were the most important predictive (tumor recurrence) and prognostic (survival rate) factors. DNA ploidy status is a less important predictive and prognostic factor in non-endometrioid, high-risk endometrial carcinomas than in the common endometrioid carcinomas, in which FIGO and nuclear grade also are highly significant and important factors.

How to approach the many faces of endometrioid carcinoma

This article reviews the salient features of variants of endometrioid carcinoma (ECa) that can pose a diagnostic challenge and/or are associated with unique clinicopathological findings. Variants with distinct architectural and cytologic features include the following: (1) ECa with a villoglandular pattern (tumor with finger-like papillae lined by bland cells with a tendency for vascular/lymphatic invasion and lymph node metastasis once this pattern is seen within the myoinvasive component); (2) papillary ECa of intermediate grade (grade 2) (tumor that can be mistaken for serous carcinoma, as it contains papillae showing slightly irregular contours, moderately atypical cells, and it is associated with vascular/lymphatic invasion/lymph node metastasis, but with common association with mucinous metaplasia, MELF (microcystic, elongated, and fragmented) pattern of invasion, and wild p53 expression); (3) ECa with non-villous papillae (tumor containing pseudopapillae within glands with bland-appearing cytology commonly associated with abortive squamous differentiation and otherwise not different from usual ECa); (4) ECa with microglandular-like pattern (tumor that mimics microglandular hyperplasia of the cervix, often lacking the typical appearance of microglandular hyperplasia and showing Ki-67 index >10%, strong CD10 expression, and negative PAX-2, p63, and CD34); and (5) ECa with sex cord-like formations and hyalinization (tumor with interconnected cords and nests of bland epithelioid and spindled cells that merge with a typical component of low-grade ECa, usually associated with squamous differentiation and hyalinization). This tumor should be distinguished from carcinosarcoma and, in contrast to the latter, it shows nuclear β-catenin expression, ER/PR and patchy p16 positivity, tends to present at a low stage, and has a favorable prognosis and (6) dedifferentiated ECa (tumor showing a low-grade ECa juxtaposed to an undifferentiated carcinoma-the latter characterized by variably sized monotonous, often non-cohesive cells with brisk mitotic activity and usually arranged in sheets). Undifferentiated carcinoma tends to be negative for PAX8 and ER/PR with variable expression of keratins and can be associated with microsatellite instability (may be part of Lynch syndrome). Variants with distinct cytological features include the following: (1) ECa with clear cells (tumors with clearing due to 'clear' (glycogenated) squamous cells, distinct vacuoles, or not otherwise specified. EC with clear cells should be distinguished from clear cell carcinoma by the absence of the variety of architectural patterns, lack of cuboidal/flattened/hobnail cells, and lack of degree of atypia usually detected in clear cell carcinoma. In addition, they are ER/PR positive and Napsin A and p504S negative in contrast to clear cell carcinoma); (2) ECa with spindle cells (tumor with transition from spindle cells to the glandular component of a low-grade ECa. The spindle cells are keratin, ER/PR, and patchy p16 positive and show wild-type p53 expression); (3) ECa with mucinous differentiation (this tumor can be mistaken for a cervical adenocarcinoma, as they have overlapping features. Expression of ER/PR and vimentin in the context of a negative or patchy p16 positivity and the absence of high-risk HPV allows a correct diagnosis).

Practical issues in the diagnosis of serous carcinoma of the endometrium

Serous carcinoma (SC) represents ~10% of endometrial carcinomas, but is responsible for almost 40% of cancer deaths. This article reviews the main pathological features, differential diagnosis, and the usefulness of molecular pathology and immunohistochemistry in its diagnosis. Most helpful features for the diagnosis include: irregularly shaped and sized papillae, slit-like spaces, cell stratification and budding, highly atypical cells, architectural and cytological discordance in pseudoglandular tumors, as well as lack of endometrioid features. SC shows typically a predominant papillary growth, which is also found in some subtypes of endometrioid carcinoma of the endometrium (EEC). Distinction is easy when attention is paid to the presence of diffuse marked nuclear pleomorphism, but also to the complex papillary architecture. SC may also show a solid or pseudoglandular patterns, and in these cases differential diagnosis may be difficult with EEC grade 3. Moreover, a high proportion of SC may exhibit clear cells, and, thus, may be confused with clear cell carcinoma. Finally, it is sometimes difficult to distinguish mixed SC-EEC, from SC that combines papillary and pseudoglandular growths. Although there is not a single immunohistochemical marker for distinguishing SC from its mimickers, some antibodies are useful (p53, p16, IMP2, and IMP3), particularly when used in combination. Diagnosis of SC may be even more problematic in small biopsies; a diagnosis of high-grade endometrial carcinoma, SC component can not be excluded, is acceptable as a managerial approach, so it could be taken into account at the time of final surgery.

Nestin: A biomarker of aggressive uterine cancers

OBJECTIVE

Evidence of potential prognostic and predictive value for nestin was investigated in well-annotated uterine cancers (UCs).

METHODS

Nestin expression and previously-published biomarkers were evaluated by immunohistochemistry (IHC) in UC tissue microarrays. Biomarkers were categorized as low vs. high, and nestin was cut at 10% positive staining. Relationship between nestin and clinicopathologic factors, biomarkers and outcome were evaluated using exact/log-rank testing or logistic/Cox modeling.

RESULTS

There were 323 eligible cases, 34% had advanced stage disease, 37% had type II disease, and 5% were carcinosarcomas. High nestin, observed in 19% of cases, was more common in advanced vs. early stage disease, type II cancers or uterine carcinosarcoma vs. type I cancers, grade 3 disease, positive lymphovascular space invasion (LVSI) and tumors >6cm (p<0.05). Nestin was inversely correlated with ER, PR and TFF3, and correlated with p53 and IMP3. Women with high vs. low nestin had worse progression-free survival (PFS) and cancer-specific survival overall, and worse PFS in the subset who received no adjuvant therapy or radiation, or had early stage, type I disease or tumors with both low and high ER, PR, TFF3, PTEN, p53 or IMP3. The relationship between nestin and PFS was independent of stage, LVSI and risk categorization but not type of UC.

CONCLUSIONS

High nestin was more common in UCs with aggressive features and poor outcome. Nestin may represent a predictive biomarker for treatment selection for patients previously considered to be lower risk and a candidate for no or radiation-based adjuvant therapy, and compliment ER/PR testing.

Clinicopathologic and survival analyses of synchronous primary endometrial and epithelial ovarian cancers

AIM

The aim of the study was to describe clinicopathologic characteristics, survival outcomes and the factors associated with recurrence in patients diagnosed with synchronous primary endometrial and epithelial ovarian cancers.

MATERIAL AND METHODS

In this retrospective study, 50 patients who were diagnosed with synchronous primary endometrial and epithelial ovarian cancers and underwent surgery between 1998 and 2010 were reviewed.

RESULTS

In our study, the median age at the time of diagnosis was 53 years (range 28-79). The most common presenting symptom was abnormal uterine bleeding with a ratio of 36%. Fifty-four percent of the patients had endometrioid type endometrial cancer and endometrioid type ovarian cancer. All patients were surgically staged and the majority of the patients were in stage I for both endometrial cancer (58%) and ovarian cancer (60%). Nearly one-third (32%) of the patients had a recurrence during the follow-up period and by Cox regression analysis the level of cancer antigen 125 (P = 0.023) at diagnosis, serous or clear-cell histopathologic type ovarian cancer (P = 0.029) and stage of endometrial cancer above I (P = 0.048) were found to be independent risk factors associated with development of recurrence. Patients with endometrioid type endometrium histology and endometrioid type ovarian histology had favorable prognosis with 120.00 months mean disease-free survival and 92% disease-free survival rate at 36 months.

CONCLUSION

In our cohort, we found that endometrioid/endometrioid type synchronous primary endometrial and ovarian cancer had different clinical histopathologic characteristics and favorable prognosis compared to the other histologic types of these cancers. Histopathologic type of the ovarian cancer component, stage of endometrial cancer and level of cancer antigen 125 at diagnosis were observed to have a great influence on the development of recurrence and survival of synchronous primary carcinomas of the endometrium and ovary.

IMP3 expression in serous tumors of the ovary

Insulin-like growth factor II mRNA-binding protein (IMP3) is an oncofetal protein involved in embryogenesis, which is expressed in a variety of malignant neoplasms. It is rarely expressed in normal adult tissue and benign tumors. The aim of this study was to evaluate the expression of IMP3 in benign and malignant serous tumors of the ovary. Seventy-nine ovarian tumors were examined for IMP3 expression by immunohistochemical analysis, comprising 16 benign serous tumors, 19 borderline serous tumors, and 44 serous carcinomas. Positive staining was defined as brown staining in the cytoplasm. Negative staining was defined as absent staining or staining of <5% of tumor cells. The intensity of staining (weak, moderate, and strong) and percentage (0% to 100%) of neoplastic cells staining positive for cytoplasmic IMP3 staining were recorded in each case. Moderate to strong cytoplasmic staining for IMP3 was observed in 30 of 44 (68%) serous carcinomas of the ovary; in contrast, <5% of the borderline and benign serous tumors expressed IMP3 ranging from weak to strong cytoplasmic staining. Statistically, the difference in IMP3 expression between these groups of tumors was highly significant (P<0.0001). Our findings demonstrate moderate to strong expression of IMP3 in the majority of ovarian serous carcinomas as compared with benign/borderline serous tumors, which demonstrated weak to strong expression in a small minority (<5%) of the tumors. Thus, IMP3 may be a useful adjunctive tool in the pathologic evaluation of ovarian serous tumors.

DJ-1 in endometrial cancer: a possible biomarker to improve differential diagnosis between subtypes

OBJECTIVE

The objectives of this study were to characterize the well-defined endometrial cancer (EC) type I (endometrioid [EEC] G1-G2) versus the prototype of EC type II (serous [ESC]) and to evaluate the expression of specific biomarkers differentially expressed between 2 well-defined types, in those EC subtypes (such as EEC G3) disputed between types I and II.

METHODS

Data from 25 patients (10 EEC G1-G2, 8 EEC G3, 5 ESC, and 2 clear cell) submitted to the surgical treatment were collected. Two-dimensional electrophoresis and mass spectrometry (MS) analysis were performed on 5 EEC G1-G2 and 5 healthy endometrial samples of the same patients. Differentially expressed proteins, such as DJ-1, were validated by Western blot. In patients with EEC G1-G2, serum levels of DJ-1, an overexpressed oncoprotein related to EC pathogenesis and progression, were evaluated and then compared with levels identified in patients with ESC and healthy controls. The DJ-1 immunohistochemical (IHC) staining was performed on neoplastic and healthy endometrium collected from the same patients. The 8 stored samples of EEC G3 were submitted to DJ-1 IHC assays.

RESULTS

The 2-dimensional electrophoresis analysis identified 1040 protein spots differentially expressed in EEC G1-G2 compared with healthy endometrium. Forty-two spots were subjected to liquid chromatography-MS/MS analysis. Thirty-three up-regulated (like an annexin 2 [ANXA2] shorter isoform, CAPG [macrophage-capping protein], DJ-1/PARK7) and 9 down-regulated (like calreticulin and ubiquitin carboxyl-terminal hydrolase isozyme L1) proteins were identified and validated by Western blot. A significant increase in serum DJ-1 levels of EEC G1-G2 versus the healthy controls and in ESC versus EEC patients was observed. DJ-1 IHC score was significantly higher in ESC versus those EEC G1-G2. In 3 cases of EEC G3, the DJ-1 expression was similar to the ESC subtype.

CONCLUSIONS

The identification of proteins, such as DJ-1, differentially expressed, between well-defined EC types I and II allows to make a subtype-specific presurgical diagnosis and help surgeon to safely preoperatively choose a proper surgical treatment.

The Utility of Immunohistochemistry in the Differential Diagnosis of Gynecologic Disorders

Context

Immunohistochemistry has assumed an increasing role in the identification and characterization of gynecologic disorders including lesions with deceptively bland morphology, uncommon and underdiagnosed neoplasms, and neoplasms with specific genetic alterations associated with overexpression or loss of expression of specific proteins. The diagnostic accuracy has been significantly improved owing to the discovery and increasing experience with the tumor-associated biomarkers, and the increasing demand for precise tumor classification to assess suitability for the expanding therapeutic modalities including clinical trials.

Objective

To differentiate lesions of the gynecologic tract through the use of effective immunohistochemical panels.

Data Sources

Literature review and authors' personal practice experience.

Conclusions

The application of diagnostic and prognostic immunohistochemical panels has enabled pathologists to better guide therapeutic decisions and to better predict the clinical outcome. It is now well established that the use of ancillary testing, including immunohistochemistry, has a significant power in the identification, differentiation, and classification of reactive, premalignant, and malignant gynecologic disorders. This article discusses the utilities and pitfalls of the commonly used immunohistochemical markers in the context of overlapping morphologic features encountered in the uterus, ovaries, and fallopian tubes.

Histogram analysis of apparent diffusion coefficient map of diffusion-weighted MRI in endometrial cancer: a preliminary correlation study with histological grade

BACKGROUND

Until now, several investigators have explored the value of diffusion-weighted magnetic resonance imaging (DWI) for the preoperative tumor grading of endometrial cancer. However, the diagnostic value of DWI with quantitative analysis of apparent diffusion coefficient (ADC) has been controversial.

PURPOSE

To explore the role of histogram analysis of ADC maps based on entire tumor volume in determining the grade of endometrial cancer.

MATERIAL AND METHODS

This study was IRB-approved with waiver of informed consent. Thirty-three patients with endometrial cancer underwent DWI (b = 0, 600, 1000 s/mm(2)), and corresponding ADC maps were acquired. Regions of interest (ROIs) were drawn on all slices of the ADC map in which the tumor was visualized including areas of necrosis to derive volume-based histographic ADC data. Histogram parameters (5th-95th percentiles, mean, standard deviation, skewness, kurtosis) were correlated with histological grade using one-way ANOVA with Tukey-Kramer test for post hoc comparisons, and were compared between high (grade 3) and low (grades 1/2) grade using Student t-test. ROC curve analysis was performed to determine the optimum threshold value for each parameter, and their corresponding sensitivity and specificity.

RESULTS

The standard deviation, quartile, 75th, 90th, and 95th percentiles of ADC showed significant differences between grades (P ≤ 0.03 for all) and between high and low grades (P ≤ 0.024 for all). There were no significant correlations between tumor grade and other parameters. ROC curve analysis yielded sensitivities and specificities of 75% and 96%, 62.5% and 92%, 100% and 52%, 100% and 72%, and 100% and 88%, using standard deviation, quartile, 75th, 90th, and 95th percentiles for determining high grade with corresponding areas under the curve (AUCs) of 0.787, 0.792, 0.765, 0.880, and 0.925, respectively.

CONCLUSION

Histogram analysis of ADC maps based on entire tumor volume can be useful for predicting the histological grade of endometrial cancer. The 90th and 95th percentiles of ADC were the most promising parameters for differentiating high from low grade.

Immunohistochemical characterization of endometrial carcinomas: endometrioid, serous and clear cell adenocarcinomas in association with genetic analysis

Developments in immunohistochemistry, which are closely linked with the advances in the analyses of genetic abnormalities and their associated molecular disorders as early and late histogenetic events, have contributed greatly to the improvement of pathological diagnostic confirmation and validation. Immunohistochemistry has also generated great benefit to the innovation of therapeutic strategies for various kinds of cancers. In this article, the three representative histological types of corpus cancer, namely, endometrioid adenocarcinoma, serous adenocarcinoma and clear cell adenocarcinoma, will be histologically approached in association with their immunohistochemical profiles as well as genetic disorders. First, the focus will be on 'Conventional/prototypic features,' followed by 'Controversy over conventional histological subclassification,' and subsequently 'Tumorigenesis and re-subclassification'.

ARID1A loss correlates with mismatch repair deficiency and intact p53 expression in high-grade endometrial carcinomas

BAF250a (ARID1A) loss is a frequent event in high-grade endometrial cancers. It has been proposed that ARID1A is a driver gene, with ARID1A mutations occurring secondary to deregulated mismatch repair mechanism in gastric cancers, representing an alternative oncogenic pathway to p53 alteration. The prognostic significance of ARID1A loss is controversial. In this study, we investigated the frequency of BAF250a immunohistochemical loss in a cohort of high-grade endometrial cancers (n=190) and correlated it with mismatch repair (hMLH1, hMSH2, hMSH6, and hPMS2) and p53 protein expression. The 190 cases consisted of 82 high-grade endometrioid, 88 serous, 10 clear cell, and 10 mixed (carcinosarcomas and mixed histology). There was BAF250a loss in 55/190 (29%) cancers, most commonly in high-grade endometrioid carcinomas (46 vs 9% in serous carcinomas, P<0.0001). Loss of any mismatch repair proteins was observed in 63/190 (33%) cancers, most commonly in high-grade endometrioid carcinomas (57 vs 10% in serous carcinomas, P<0.0001). Aberrant p53 expression was found in 86/190 (45%) cancers, more commonly in serous carcinomas (77 vs 18% in high-grade endometrioid carcinomas, P<0.0001). BAF250a loss was associated with mismatch repair loss (P<0.0001) and normal p53 expression (P<0.0001). These associations were maintained in the subset analysis within the high-grade endometrioid (P=0.026 and P=0.0083, respectively) and serous carcinoma cases (P=0.0031 and P<0.0001, respectively). Survival analysis revealed a superior progression-free survival (P=0.017) for patients with BAF250a loss within the entire cohort but not within the high-grade endometrioid and serous subtypes. Additionally, data from The Cancer Genome Atlas were extracted to correlate mutations in ARID1A, TP53, and MMR genes; we found that ARID1A mutations were negatively associated with TP53 mutations but were unrelated to mismatch repair gene mutations. In conclusion, BAF250a loss is more common in high-grade endometrioid carcinomas than in other high-grade endometrial cancers and is associated with mismatch repair deficiency and normal p53 expression.

Reproducibility of histological cell type in high-grade endometrial carcinoma

Subclassification of endometrial carcinoma according to histological type shows variable interobserver agreement. The aim of this study was to assess specifically the interobserver agreement of histological type in high-grade endometrial carcinomas, recorded by gynecological pathologists from five academic centers across Canada. In a secondary aim, the agreement of consensus diagnosis with immunohistochemical marker combinations was assessed including six routine (TP53, CDKN2A (p16), ER, PGR, Ki67, and VIM) and six experimental immunohistochemical markers (PTEN, ARID1A, CTNNB1, IGF2BP3, HNF1B, and TFF3). The paired interobserver agreement ranged from κ 0.50 to 0.63 (median 0.58) and the intraobserver agreement from κ 0.49 to 0.67 (median 0.61). Consensus about histological type based on morphological assessment was reached in 72% of high-grade endometrial carcinomas. A seven-marker immunohistochemical panel differentiated FIGO grade 3 endometrioid from serous carcinoma with a 100% concordance rate compared with the consensus diagnosis. More practically, a three-marker panel including TP53, ER, and CDKN2A (p16) can aid in the differential diagnosis of FIGO grade 3 endometrioid from endometrial serous carcinoma. Our study demonstrates that the inter- and intraobserver reproducibility of histological type based on morphology alone are mostly moderate. Ancillary techniques such as immunohistochemical marker panels are likely needed to improve diagnostic reproducibility of histological types within high-grade endometrial carcinomas.

ZEB1 overexpression associated with E-cadherin and microRNA-200 downregulation is characteristic of undifferentiated endometrial carcinoma

Undifferentiated endometrial carcinomas are very aggressive high-grade endometrial carcinomas that are frequently under-recognized. This study aimed to analyze the molecular alterations underlying the development of these endometrial carcinomas, focusing on those related to dedifferentiation. We assessed a series of 120 tumors: 57 grade 1 and 2 endometrioid endometrial carcinomas, 15 grade 3 endometrioid endometrial carcinomas, 27 endometrial serous carcinomas, and 21 undifferentiated endometrial carcinomas. We found a high frequency of DNA mismatch repair deficiency (38%) and moderate rate of p53 overexpression (∼33%) in undifferentiated carcinomas. In contrast to the characteristic endometrioid phenotype, there was a dramatic downregulation of E-cadherin expression in the undifferentiated subtype. Quantitative methylation studies dismissed CDH1 promoter hypermethylation as the mechanism responsible for this change in gene expression, while immunohistochemistry revealed that the E-cadherin repressor ZEB1 was frequently overexpressed (62%) in undifferentiated endometrial carcinomas. This finding was accompanied by a sharp downregulation in the expression of the miR-200 family of microRNAs, well-known targets of ZEB1. Furthermore, there was enhanced expression of epithelial-to-mesenchymal transition markers in undifferentiated endometrial carcinomas, such as N-cadherin, cytoplasmic p120, and osteonectin. In addition, HMGA2, a regulator of epithelial-to-mesenchymal transition that is expressed in aggressive endometrial tumors, such as endometrial serous carcinomas and carcinosarcomas, was expressed in >20% of undifferentiated carcinomas. These results suggest that ZEB1 overexpression, associated with E-cadherin and miR-200s downregulation, and the expression of mesenchymal markers might enhance the metastatic potential of undifferentiated endometrial carcinomas, leading to a poor prognosis. In addition, our observations suggest that the immnohistochemical analysis of E-cadherin and ZEB1 can aid in the differential diagnosis of the more agressive undifferentiated endometrial carcinomas from grade 3 endometrioid carcinomas.

The emerging genomic landscape of endometrial cancer

BACKGROUND

Endometrial cancer is responsible for approximately 74 000 deaths annually among women worldwide. It is a heterogeneous disease comprising multiple histologic subtypes. In the US, the majority of deaths from endometrial carcinoma are attributed to the serous and endometrioid subtypes. An understanding of the fundamental genomic alterations that drive serous and endometrioid endometrial carcinomas lays the foundation for the identification of molecular markers that could improve the clinical management of patients presenting with these tumors.

CONTENT

We review the current state of knowledge regarding somatic genomic alterations that occur in serous and endometrioid endometrial tumors. We present this knowledge in a historical context by reviewing the genomic alterations that studies of individual genes and proteins have identified over the past 2 decades or so. We then review very recent comprehensive and systematic surveys of genomic, exomic, transcriptomic, epigenomic, and proteomic alterations in serous and endometrioid endometrial carcinomas.

SUMMARY

The recent mapping of the genomic landscape of serous and endometrioid endometrial carcinomas has produced the first comprehensive molecular classification of these tumors, which has distinguished 4 molecular subgroups: a POLE [polymerase (DNA directed), ε, catalytic subunit] ultramutated subgroup, a hypermutated/microsatellite-unstable subgroup, a copy number-low/microsatellite-stable subgroup, and a copy number-high subgroup. This molecular classification may ultimately serve to refine the diagnosis and treatment of women with endometrioid and serous endometrial tumors.

The clinicopathologic significance of p53 and BAF-250a (ARID1A) expression in clear cell carcinoma of the endometrium

TP53 mutation (and associated p53 protein overexpression) is probably a negative prognostic marker in endometrial cancers, but its relevance in the rarer histologic subtypes, including clear cell carcinomas, has not been delineated. Preclinical studies suggest functional interactions between p53 and the BAF250a protein, the product of a tumor suppressor gene ARID1A (adenine-thymine (AT)-rich interactive domain containing protein 1A) that is frequently mutated in ovarian clear cell carcinoma. In this study, we evaluated the significance of p53 and BAF250a expression, as assessed by immunohistochemistry, in a group of 50 endometrial clear cell carcinomas. Of 50 cases, 17 (34%) were p53+, and the remaining 33 cases had a p53 wild-type (p53-wt) immunophenotype. Of the 11 relapses/recurrences in the entire data set, 73% were in the p53+ group (P=0.008). On univariate analyses, the median overall survival for the p53-wt patients (83 months) was longer than the p53+ patients (63 months) (P=0.07), and the median progression-free survival for the p53-wt group (88 months) was significantly longer than the p53+ group (56 months) (P=0.01). On multivariate analyses, p53 expression was not associated with reduced overall or progression-free survival. In addition, p53 status was not significantly associated with pathologic stage or morphologic patterns. Of the 50 cases, 10 (20%) showed a complete loss of BAF250a expression. There was no significant correlation between p53 and BAF250a expression. The p53+/BAF250a-, p53+/BAF250a+, p53-wt/BAF250a+ and p53-wt/BAF250a- composite immunophenotypes were identified in 8%, 26%, 54% and 12% of cases, respectively, and neither loss of BAF250a expression nor composite p53/BAF250a expression patterns were associated with reduced overall or progression-free survival. In conclusion, a significant subset of CCC express p53, and these cases are apparently not definable by their morphologic features. P53 expression may be a negative prognostic factor in this histotype, and warrants additional studies. Loss of BAF250a expression has no prognostic significance in endometrial clear cell carcinomas.

Poor interobserver reproducibility in the diagnosis of high-grade endometrial carcinoma

Patients with high-grade subtypes of endometrial carcinoma (grade 3 endometrioid, serous, clear cell, or carcinosarcoma) have a relatively poor prognosis. The specific subtype may be used to guide patient management, but there is little information on the reproducibility of subtype diagnosis in cases of high-grade endometrial carcinoma. Fifty-six cases diagnosed as a high-grade subtype of endometrial carcinoma were identified from the pathology archives of Vancouver General Hospital. All slides for each case were reviewed independently by 3 pathologists, who diagnosed the specific tumor subtype(s) and assigned the percentage of each subtype for mixed tumors. Agreement between observers was categorized as follows: major disagreement: (A) no consensus for low-grade endometrioid versus high-grade carcinoma (any subtype), or (B) no consensus with respect to the predominant high-grade subtype present; minor disagreement: consensus was reached about the cell type of the predominant component of a mixed tumor, but there was disagreement about the subtype of the minor component. A tissue microarray was constructed from these cases and immunostained for p16, ER, PR, PTEN, and p53. In 35 of 56 (62.5%) cases, there was agreement between all 3 reviewers regarding the subtype diagnosis of the exclusive (in pure tumors) or predominant (in mixed tumors) high-grade component. Of these cases, there was a minor disagreement (ie, disagreement about the minor high-grade component subtype in a mixed tumor) in 4 cases (4/56, 7.1%). In 20 of 56 (35.8%) cases there was a major disagreement; in 17 (30.4%) of these cases there was no consensus about the major subtype diagnosis, whereas in 3 (5.4%) cases there was disagreement about whether a component of high-grade endometrial carcinoma was present. In the final case, all 3 reviewers diagnosed the case as low-grade endometrioid carcinoma, disagreeing with the original diagnosis of high-grade carcinoma. The most frequent areas of disagreement were serous versus clear cell (7 cases) and serous versus grade 3 endometrioid (6 cases). Immunostaining results using the 5-marker immunopanel were then used to adjudicate in the 6 cases in which there was disagreement between reviewers with respect to serous versus endometrioid carcinoma, and these supported a diagnosis of serous carcinoma in 4 of 6 cases and endometrioid carcinoma in 2 of 6 cases. Pairwise comparison between the reviewers for the 20 cases classified as showing major disagreement was as follows: reviewer 1 and reviewer 2 agreed in 5/20 cases, reviewer 1 and reviewer 3 agreed in 7/20 cases, and reviewer 2 and reviewer 3 agreed in 8/20 cases, indicating that disagreements were not because of a single reviewer holding outlier opinions. Diagnostic consensus among 3 reviewers about the exclusive or major subtype of high-grade endometrial carcinoma was reached in only 35/56 (62.5%) cases, and in 4 of these cases there was disagreement about the minor component present. This poor reproducibility did not reflect systematic bias on the part of any 1 reviewer. There is a need for molecular tools to aid in the accurate and reproducible diagnosis of high-grade endometrial carcinoma subtype.

Histological and immunohistochemical profiles predict lymph node status in women with low-intermediate risk endometrial cancer

OBJECTIVE

The aim of this study was to build a model to predict the risk of lymph node metastases (LNM) in women with low- or intermediate-risk endometrial cancer (EC) using histological and immunohistochemical markers.

METHODS

Samples were collected from 68 women with low- or intermediate-risk EC. European Society of Medical Oncology (ESMO) risk group, lymphovascular space involvement (LVSI), immunostaining expressions of Estrogen receptor (ER) and Progesteron receptor (PR) were used to build a recursive partitioning model to predict final lymph node status.

RESULTS

The number of women with final low- and intermediate risk EC was 34 (50%) each. LVSI was present in 7 women with low-risk (20%) and 28 (80%) with intermediate-risk EC. Nineteen women (28%) had LNM at final histology. A lower immunostaining of ER (p=0.02) and PR (p=0.03) was found in women with LNM compared with those without. Women were correctly classified by the model in 87% of cases; among the 56 women without LNM that were predicted, 48 (86%) had no LNM at final histology. Among the 12 women with LNM predicted, 11 (92%) had LNM at final histology.

CONCLUSIONS

Our results show that lymph node status can be predicted with a relatively high accuracy in women with low- or intermediate-risk EC. This can help physicians to better adapt surgical staging and adjuvant therapies.

ER+ /PR+ /TFF3+ /IMP3- immunoprofile distinguishes endometrioid from serous and clear cell carcinomas of the endometrium: a study of 401 cases

AIMS

Differentiating endometrioid adenocarcinoma (EAC) from uterine serous carcinoma (USC) and clear cell carcinoma (CCC) of the endometrium can be challenging. We undertook an immunohistochemical study to address this issue.

METHODS AND RESULTS

We evaluated 401 endometrial carcinomas cases by using four immunomarkers - oestrogen receptor (ER), progesterone receptor (PR), insulin-like growth factor II mRNA - binding protein 3 (IMP3), and intestinal trefoil factor 3 (TFF3)-on a tissue microarray. The cases included 311 EACs (G1, 146; G2, 104; and G3, 61), 69 USCs, and 21 CCCs. ER, PR and TFF3 were most frequently expressed in EACs (P < 0.001), and IMP3 was more frequently expressed in USCs and CCCs (P < 0.001). ER(+) /PR(+) /TFF3(+) /IMP3(-) was the best marker combination associated with EAC [exact odds ratio (OR) 112; 95% confidence interval (CI) 19-∞; P < 0.0001]. This marker combination remained very reliable after adjustment for tumour grade (exact OR 19.2; 95% CI 3-∞; P = 0.0004). Because distinguishing EAC G3 from USC and CCC on the basis of morphology may be difficult, the use of immunomarkers to improve reproducibility is highly recommended. We found the ER(+) /PR(+) /TFF3(+) /IMP3(-) immunoprofile to be the best combination for confirming a diagnosis of endometrioid adenocarcinoma (exact OR 19.2; 95% CI 3-∞; P = 0.0004).

CONCLUSIONS

We recommend using an ER/PR/TFF3/IMP3 immunohistochemical panel in selected cases of endometrial carcinoma where the differential diagnosis is challenging.

A comparison of uterine papillary serous, clear cell carcinomas, and grade 3 endometrioid corpus cancers using 2009 FIGO staging system

OBJECTIVE

This study was designed to compare survival outcomes of patients with uterine papillary serous carcinoma (UPSC) or clear cell carcinoma (CC) to those of patients with grade 3 endometrioid carcinoma (G3EC) according to 1988 and 2009 International Federation of Gynecology and Obstetrics (FIGO) staging systems.

METHODS

We retrospectively reviewed all patients with endometrial cancer treated at a single institution between 1995 and 2009. Among the 647 patients with endometrial cancer, 51 with G3EC and 46 with UPSC and CC histology were confirmed.

RESULTS

1988 FIGO stage, 2009 FIGO stage, and extrauterine metastasis were significantly different between the UPSC and CC group and G3EC group (p=0.002, p=0.041, and p=0.020, respectively). Restaging from the 1988 FIGO to the 2009 FIGO criteria increased the number of stage I cases by 10 (11.0%). Overall, 8 in the UPSC and CC and 2 in the G3EC group were down-staged to stage I. In the UPSC and CC group, the 3-year overall survival for 1988 FIGO stage I was 92.9%. When UPSC and CC patients were restaged using the 2009 staging system, the 3-year overall survival of 2009 FIGO stage I dropped to 81.6%. UPSC and CC was associated with poor OS outcome compared with G3EC, after adjustment for 2009 FIGO stage and other clinicopathologic factors.

CONCLUSION

We observed that UPSC and CC patients had different prognosis according to the old and new FIGO staging system. Our results suggest that UPSC and CC compared with the G3EC may retain the 1988 FIGO to be a slightly better discriminator than 2009 FIGO.

Expression of the oncofetal protein IGF2BP3 in endometrial clear cell carcinoma: assessment of frequency and significance

Insulin-like growth factor-II messenger RNA-binding protein 3 (IGF2BP3 or IMP3) is a biomarker whose expression has been found to be a negative prognostic factor in several neoplasms including ovarian clear cell carcinoma (CCC). In this study, we analyzed the frequency and clinicopathologic significance of IMP3 expression, as assessed by immunohistochemistry and as scored using a modified H-score system, in a cohort of 50 endometrial CCCs. Cases with scores of 0 to 100, 101 to 200, and 201 to 300 were classified as negative/mildly positive (n = 17), moderately positive (n = 20), and strongly positive (n = 13), respectively. A distinctive pattern of increased staining at the myoinvasive front (relative to the main tumor) was evident in 46% of the cases with evaluable foci of myometrial invasion. Moderate/strong IMP3 staining was associated with a tumor architectural pattern that has been reported to be of poor prognostic significance: at least 10% of the tumor composed of solid architecture or individual infiltrating tumor cells (P = .01). Increasing levels of IMP3 expression showed a trend toward decreasing relapse-free survival (RFS; median survival, 75.6, 81.3, and 48.4 months for the negative/mildly, moderately, and strongly positive groups, respectively [P = .09]). However, IMP3 expression was not significantly associated with reduced overall survival or RFS in a multivariate analytic model. The finding in a subset of our cases of increased IMP3 expression at the tumoral myoinvasive front is consistent with a role for IMP3 in invasiveness, as is the trend toward reduced RFS in cases expressing IMP3 at high levels. These preliminary findings suggest that IMP3 expression may be involved in the pathogenesis of CCC and is worthy of further exploration.

Clinicopathologic analysis of matched primary and recurrent endometrial carcinoma

It is unknown whether the type and grade of a primary endometrial carcinoma is reliably maintained in recurrence. All matched primary and recurrent endometrial carcinomas diagnosed from 2000 to 2010 at our institution were identified; 34 cases had available slides. Histologic classification was performed using modifications to the World Health Organization criteria. Immunohistochemical analysis for p53, p16, progesterone receptor (PR), and DNA mismatch-repair proteins (MMR) (MLH1, MSH2, MSH6, and PMS2) was performed. Endometrioid carcinoma recurrences were mostly local, whereas serous carcinoma recurrences were mostly peritoneal. Compared with endometrioid carcinoma patients, serous carcinoma patients were older, presented at high stage, and had shorter survival. Serous carcinomas were the most common recurrent endometrial carcinoma (18/34 cases). Overall, 21 cases (62%) displayed similar morphology when comparing primary and recurrent carcinomas, whereas 13 displayed discordant morphology. Seven of 13 endometrioid carcinomas (54%) had a morphologically discordant recurrence, compared with 3 of 14 serous carcinomas (21%), 1 of 4 morphologically ambiguous carcinomas (25%), and both mixed epithelial carcinomas. Serous and morphologically ambiguous carcinomas therefore demonstrated relative morphologic fidelity compared with endometrioid carcinomas. Four morphologically discordant cases demonstrated either pure clear cell carcinoma or clear cell features at recurrence. Seven of 23 matched pairs displayed discordant PR results, with 5 cases, including both endometrioid and serous carcinomas, showing diminished PR expression at recurrence. p53, p16, and DNA MMR staining results were generally concordant when evaluating matched pairs, with only occasional exceptions. Sixty-four percent of all pure endometrioid carcinomas and mixed epithelial carcinomas with an endometrioid component showed loss of expression of MLH1 and/or PMS2; no serous carcinoma demonstrated this abnormality. Clinical and immunohistochemical data supported the use of modifications to the World Health Organization diagnostic criteria. More importantly, the data suggest that when confronted with recurrent endometrial carcinoma, particularly a serous carcinoma, it is reasonable to base therapeutic decisions on the type of the primary tumor, especially if sampling or excising the recurrent tumor is problematic. However, in light of the PR results, sampling a recurrent endometrioid carcinoma may be worthwhile if hormonal therapy is planned. Recurrent endometrioid carcinoma may be enriched for tumors with DNA MMR abnormalities.

BRCA1 immunohistochemical staining as a prognostic indicator in uterine serous carcinoma

OBJECTIVES

The objective of this study was to investigate the relationship between BRCA1 protein expression, as determined by immunohistochemistry, and clinical outcome in uterine serous carcinoma (USC).

METHODS

A tissue microarray containing duplicate cores of 73 cases of USC was immunohistochemically stained with mouse anti-BRCA1 (Ab-1) mouse monoclonal (MS110) antibody. The cores were scored in a semiquantitative manner evaluating both the distribution and intensity of nuclear staining. BRCA1 protein expression was correlated with progression-free survival.

RESULTS

Seventy-two of 73 cases were assessable, and there was a statistically significant decreased progression-free survival for those cases exhibiting tumor cell nuclei staining of 76% or greater (P = 0.0023).

CONCLUSIONS

Our study illustrates that a low level of BRCA1 protein expression is a favorable prognostic indicator in USC, similar to what is observed in high-grade serous ovarian carcinoma. Further studies should focus on the BRCA1 status of USCs at a molecular level and also investigate whether BRCA1 protein expression is associated with response to chemotherapy in USC.

Application of Immunohistochemistry and Molecular Diagnostics to Clinically Relevant Problems in Endometrial Cancer Bojana Djordjevic, Shannon Westin, Russell R. Broaddus

A number of different clinical scenarios are presented in which lab-based analyses beyond the usual diagnosis based on light microscopic examination of H&E stained slides - immunohistochemistry and PCR-based assays such as sequencing, mutation testing, microsatellite instability analysis, and determination of MLH1 methylation - are most helpful for guiding diagnosis and treatment of endometrial cancer. The central goal of this information is to provide a practical guide of key current and emerging issues in diagnostic endometrial cancer pathology that require the use of ancillary laboratory techniques, such as immunohistochemistry and molecular testing. The authors present the common diagnostic problems in endometrial carcinoma pathology, types of endometrial carcinoma, description of tissue testing and markers, pathological features, and targeted therapy.