Description of a Novel System for Grading of Endometrial Carcinoma and Comparison With Existing Grading Systems

Association between intratumoral lymphatic microvessel density (LMVD) and clinicopathologic features in endometrial cancer: a retrospective cohort study

BACKGROUND

Lymph node metastasis in endometrial cancer significantly decreases survival rate. Few data on the influence of intratumoral lymphatic microvessel density (LMVD) on survival in endometrial cancer are available. Our aim was to assess the intratumoral LMVD of endometrial carcinomas and to investigate its association with classical pathological factors, lymph node metastasis and survival.

METHODS

Fifty-seven patients with endometrial carcinoma diagnosed between 2000 and 2008 underwent complete surgical staging and evaluation of intratumoral LMVD and other histologic variables. Lymphatic microvessels were identified by immunohistochemical staining using monoclonal antibody against human podoplanin (clone D2-40) and evaluated by counting the number of immunostained lymphatic vessels in 10 hot spot areas at 400× magnification. The LMVD was expressed by the mean number of vessels in these 10 hot spot microscopic fields. We next investigated the association of LMVD with the clinicopathologic findings and prognosis.

RESULTS

The mean number of lymphatic vessels counted in all cases ranged between 0 and 4.7. The median value of mean LMVD was 0.5, and defined the cut-off for low and high LMVD. We identified low intratumoral LMVD in 27 (47.4%) patients and high LMVD in 30 (52.6%) patients. High intratumoral LMVD was associated with lesser miometrial and adnaexal infiltration, lesser cervical and peritoneal involvement, and fewer fatal cases. Although there was lower lymph node involvement among cases with high LMVD, the difference did not reach significance. No association was seen between LMVD and FIGO staging, histological type, or vascular invasion. On the other hand, low intratumoral LMVD was associated with poor outcome. Seventy-five percent of deaths occurred in patients with low intratumoral LMVD.

CONCLUSION

Our results show association of high intratumoral LMVD with features related to more localized disease and better outcome. We discuss the role of lymphangiogenesis as an early event in the endometrial carcinogenesis.

Endometrial giant cell carcinoma: a case series and review of the spectrum of endometrial neoplasms containing giant cells

Poorly differentiated endometrial carcinomas of specific type include the rarely reported endometrial carcinoma with a malignant giant cell component [endometrial giant cell carcinoma (GCC)]. Since the initial description in 1991, there has only been 1 subsequent case report of this entity. We report another 5 cases. The patients ranged in age from 53 to 83 years, presenting with vaginal bleeding, anemia, or a pelvic mass. Four of the 5 tumors contained areas of endometrial adenocarcinoma of usual type, with a variable giant cell component. The conventional cell types present included 1 case with clear cell carcinoma (30% of tumor volume), 2 with high-grade endometrioid carcinoma (50% and 70% of tumor volume, respectively) and 1 with serous histology (10% of tumor volume). One was composed exclusively of giant cell carcinoma. The giant cell component in all cases consisted of poorly cohesive nests of bizarre multinucleated giant cells with mononuclear tumor cells. A striking peritumoral and intratumoral inflammatory cell infiltrate composed of lymphocytes, plasma cells and focal eosinophils, and neutrophils was present and emperipolesis was noted in 4 of the 5 cases. The giant cells showed focal staining for epithelial markers (AE1/AE3 and CAM 5.2). Three of the patients presented with stage 1A disease, 1 with stage 1B disease, and 1 tumor was advanced, presenting as stage IIIC2. One patient in whom the tumor was exclusively of the giant cell type, developed lung metastasis 4 years after diagnosis and 1 patient is disease free after 14 years. The remaining 3 patients showed no evidence of disease with 15 to 32 months of follow-up. As histotype supplemented by staging information is critical in selection of treatment modalities and in prognostication in uterine malignancies, accurate classification is mandated. Here, we present a series of endometrial carcinomas containing a component of GCC and discuss the spectrum of giant cell-containing uterine neoplasms. At this time, however, the cumulative data on endometrial GCC are limited and the prognostic significance of the presence and the extent of a giant cell component in endometrial carcinoma remains uncertain.

Controversies in surgical staging of endometrial cancer

Endometrial cancer is the most common gynaecological malignancy and its incidence is increasing. In 1998, international federation of gynaecologists and obstetricians (FIGO) required a change from clinical to surgical staging in endometrial cancer, introducing pelvic and paraaortic lymphadenectomy. This staging requirement raised controversies around the importance of determining nodal status and impact of lymphadenectomy on outcomes. There is agreement about the prognostic value of lymphadenectomy, but its extent, therapeutic value, and benefits in terms of survival are still matter of debate, especially in early stages. Accurate preoperative risk stratification can guide to the appropriate type of surgery by selecting patients who benefit of lymphadenectomy. However, available preoperative and intraoperative investigations are not highly accurate methods to detect lymph nodes and a complete surgical staging remains the most precise method to evaluate extrauterine spread of the disease. Laparotomy has always been considered the standard approach for endometrial cancer surgical staging. Traditional and robotic-assisted laparoscopic techniques seem to provide equivalent results in terms of disease-free survival and overall survival compared to laparotomy. These minimally invasive approaches demonstrated additional benefits as shorter hospital stay, less use of pain killers, lower rate of complications and improved quality of life.

Endometrial carcinoma: controversies in histopathological assessment of grade and tumour cell type

Histopathological assessment of tumour grade and cell type is central to the management of endometrial carcinoma, guiding the extent of surgery and the use of adjuvant radiation therapy and chemotherapy. Endometrioid carcinomas are usually low grade but high-grade examples are encountered, and they have a significantly worse prognosis, similar to that of high-grade subtypes such as serous and clear cell carcinoma. This article reviews the various grading systems that have been proposed for use with endometrioid endometrial carcinoma, and discusses the recent progress in cell type assignment, including the use of immunohistochemistry as a diagnostic adjunct.

FIGO staging of endometrial adenocarcinoma: a critical review and proposal

The optimal staging of tumors would reflect their biology and patterns of spread, permit accurate prognostication, and facilitate therapeutic decision-making. The last revision of the International Federation of Obstetricians and Gynecologists (FIGO) staging of uterine corpus tumors was in 1988, and it represented the transition from a clinical to a surgico-pathologic system. With 20 years of experience, we can now review the accuracy, reproducibility, and utility of this system. Pathologists are in a unique position to study each of these characteristics, comment on their ability to apply the criteria in daily practice, and offer suggestions to further improve the FIGO system. This paper selectively reviews some of the more problematic aspects of the current FIGO system, including the following: the distinction of tumors confined to the endometrium from those which are superficially myoinvasive; the method and utility of histologic grading of endometrial adenocarcinoma; the utility and reproducibility of the diagnosis of cervical epithelial and stromal invasion; the striking heterogeneity within and among stage III A, B, and C tumors and their differing prognostic significance. It concludes with recommendations for changes in a future revision of the FIGO staging of endometrial carcinoma.

Should Preoperative Pathology Be Used to Select Patients for Surgical Staging in Endometrial Cancer?

Introduction:

The decision to offer surgical staging in endometrial cancer is often based on preoperative histology and grade from endometrial biopsy or dilatation and curettage. The primary objective of this study was to evaluate the concordance between preoperative and final pathology from a population-based study of endometrial cancer to address whether preoperative biopsy is a reliable determinant in selecting patients for surgical staging.

Methods:

Retrospective cohort study in Ontario, Canada, from 1996 to 2000. The study included all women with a preoperative diagnosis of endometrioid adenocarcinoma on endometrial biopsy or dilatation and curettage, followed by definitive surgery. All other histological types were excluded. Surgical staging rates were compared according to preoperative pathology. Primary outcome measure was the concordance between preoperative and final pathology, expressed as a Spearman correlation coefficient (ρ). A multivariable logistic regression estimated the effects of demographic variables and grade on our outcome measure.

Results:

There were 1804 evaluable cases in this study. For preoperative grades 1, 2, and 3 endometrioid adenocarcinoma, surgical staging rates were 9.1%, 13.7%, and 25.6%, respectively. Concordance rates with final pathology were 73%, 52%, and 53%, respectively. There was only moderate concordance between preoperative and final pathology (ρ = 0.52). There was no significant difference in concordance rates according to age, year, or hospital volume, but lower concordance rates among teaching hospitals.

Conclusion:

Preoperative biopsy has only a moderate ability to predict final pathology in endometrial cancer, and therefore, additional factors should be considered in selecting patients for a surgical staging procedure.

Low-grade endometrial adenocarcinoma: a diagnostic algorithm for distinguishing atypical endometrial hyperplasia and other benign (and malignant) mimics

The distinction between endometrial hyperplasia and well-differentiated adenocarcinoma of the endometrium continues to be a difficult differential diagnosis in surgical pathology. Evidence-based diagnostic criteria for well-differentiated endometrial adenocarcinoma focus on histologic features that predict myoinvasion in the hysterectomy specimen. Only 2 diagnostic criteria with significant power aid in this distinction: complex glandular architectural patterns (glandular confluence, intraglandular complexity, and hierarchical papillary architecture) and marked cytologic atypia beyond that typically defined as atypical hyperplasia (ie, prominent macronucleoli visible at low power and marked nuclear pleomorphism). Application of these 2 criteria in problematic endometrial proliferations allows stratification of patients into 3 risk categories: very low risk (< 0.05% risk of myoinvasion at hysterectomy)=complex atypical hyperplasia; intermediate risk (5.5% risk of myoinvasion at hysterectomy)=complex atypical hyperplasia, cannot exclude well-differentiated adenocarcinoma (borderline); and high risk (20% risk of myoinvasion at hysterectomy)=well-differentiated adenocarcinoma. In order to optimize the use of these diagnostic criteria, a variety of gland forming lesions that may mimic well-differentiated endometrioid adenocarcinoma must first be excluded. In addition, unusual morphologic patterns of low-grade endometrioid adenocarcinoma should be recognized, as they may cause confusion with other, higher grade (and therefore, more clinically aggressive) endometrial processes.

Tumor cell type can be reproducibly diagnosed and is of independent prognostic significance in patients with maximally debulked ovarian carcinoma

Ovarian surface epithelial carcinomas are routinely subclassified by pathologists based on tumor cell type and grade. It is controversial whether cell type or grade is superior in predicting patient response to treatment or survival, in patients stratified by stage of disease. The aim of this study was to uniformly apply updated criteria for cell-type and grade assignment to a series of 575 cases of ovarian surface epithelial carcinoma. All patients were optimally surgically debulked, with no macroscopic residual disease after primary surgery. Slides from these cases were reviewed by a single pathologist, who was blinded to patient outcomes. In 50 cases, 2 additional pathologists reviewed the slides independently to determine interobserver variation in assessment of cell type and grade. The distribution of tumor stage was as follows: stage I--233 cases, stage II--246 cases, stage III--96 cases. The most common cell type encountered was serous carcinoma (229/575, 40%), followed by clear cell (149/575, 26%), endometrioid (139/575, 24%), and mucinous (36/575, 6%). Serous carcinomas were significantly more likely to present with advanced stage disease (76/229 [33.2%] were stage III, and 82% of all stage III tumors were serous), whereas all nonserous cell types were stage I or II at diagnosis in greater than 90% of cases. Both FIGO grade and Silverberg grade stratified patients into groups with significantly different risks of relapse and survival, but the Silverberg grading system was a more powerful prognosticator. In multivariate analysis, stage was the most powerful prognostic indicator (P < .0001), followed by tumor cell type (P = .015), but grade was not of independent significance. Interobserver variation in assignment of cell type was very good (kappa = 0.77) with moderate reproducibility in assignment of Silverberg grade (kappa = 0.40) and minimal reproducibility in assignment of FIGO grade (kappa = 0.27). Thus, in this series of cases of ovarian surface epithelial carcinomas with no macroscopic residual disease after primary debulking surgery, assignment of tumor cell type was both more reproducible and provided superior prognostic information compared with assignment of tumor grade. As tumor cell type also correlates with underlying molecular abnormalities and may predict response to chemotherapy, this suggests that tumor cell type could be used to guide treatment decisions for patients with ovarian surface epithelial carcinoma.

Reproducibility of grading systems for endometrial endometrioid carcinoma and their relation with pathologic prognostic parameters

The FIGO grading for endometrial endometrioid carcinomas is widely accepted. In 2000, a novel binary architectural grading system was suggested that divided endometrioid carcinomas into low- and high-grade tumors. We aimed to evaluate the interobserver reproducibility of the FIGO, the architectural binary, and nuclear grading systems and the correlation between these grading systems and pathologic prognostic factors for endometrial endometrioid carcinoma. Eighty-eight endometrial endometrioid carcinomas from hysterectomy specimens were reevaluated by two pathologists independently. Kappa values for the FIGO, the binary, and the nuclear grading systems were 0.65, 0.67, and 0.09, respectively. The reproducibility of the FIGO and the binary grading systems was similar and substantial. FIGO grade 1 (60.2%) patients were comparable to binary low-grade (63.6%) patients. Most of the FIGO grade 3 (83%) patients were binary high grade. FIGO grade 2 patients were distributed between binary low and high grades. The FIGO grade 1 and 2 cases judged to be of binary high grade had deep myometrial invasion, and more cases had vascular invasion in comparison with FIGO grade 1 and 2 cases judged to be of binary low grade. In uni- and multivariate analyses, both grading systems, depth of myometrial invasion, vascular invasion, cervical involvement, and stage had no effect on overall survival. But binary high grade and vascular involvement are adverse prognostic factors on recurrence-free survival. Binary high-grade patients can be assigned as high-risk patients.

Identification of prognostically relevant and reproducible subsets of endometrial adenocarcinoma based on clustering analysis of immunostaining data

Panels of immunomarkers can provide greater information than single markers, but the problem of how to optimally interpret data from multiple immunomarkers is unresolved. We examined the expression profile of 12 immunomarkers in 200 endometrial carcinomas using a tissue microarray. The outcomes of groups of patients were analyzed by using the Kaplan-Meier method, using the log-rank statistic for comparison of survival curves. Correlation between clustering results and traditional prognosticators of endometrial carcinoma was examined by either Fisher's exact test or chi2-test. Multivariate analysis was performed using a proportional hazards method (Cox regression modeling). Seven of the 12 immunomarkers studied showed prognostic significance in univariate analysis (P<0.05) and 1 marker showed a trend toward significance (P=0.06). These eight markers were used in unsupervised hierarchical clustering of the cases, and resulted in identification of three cluster groups. There was a statistically significant difference in patient survival between these cluster groups (P=0.0001). The prognostic significance of the cluster groups was independent of tumor stage and patient age on multivariate analysis (P=0.014), but was not of independent significance when either tumor grade or cell type was added to the model. The cluster group designation was strongly correlated with tumor grade, stage, and cell type (P<0.0001 for each). Interlaboratory reproducibility of subclassification of endometrial adenocarcinoma by hierarchical clustering analysis was verified by showing highly reproducible assignment of individual cases to specific cluster groups when the immunostaining was performed, interpreted, and clustered in a second laboratory (kappa=0.79, concordance rate=89.6%). Unsupervised hierarchical clustering of immunostaining data identifies prognostically relevant subsets of endometrial adenocarcinoma. Such analysis is reproducible, showing less interobserver variability than histopathological assessment of tumor cell type or grade.

Clinicopathologic Analysis of 187 High-grade Endometrial Carcinomas of Different Histologic Subtypes: Similar Outcomes Belie Distinctive Biologic Differences

The clinical and histopathologic features of 187 high-grade endometrial cancers [FIGO grade 3 endometrioid (EC-3), serous (SC), and clear cell (CC)] were studied to determine whether clinicopathologic differences between these various histologic subtypes existed. The study group consisted of 89 EC-3s, 61 SCs, and 37 CCs. Treatment regimens were individualized. SCs and CCs were significantly more likely than EC-3s to occur in patients older than 65 years (P=0.03), and SCs tended to occur more frequently in patients of African descent than EC-3s and CCs (P=0.07), although this was not statistically significant. EC-3s had the highest rate of associated endometrial hyperplasia (P=0.05). SCs were most likely to have high-stage disease at presentation (>or=stage IIB; P=0.01), with peritoneal dissemination at diagnosis being much more common compared with EC-3s and CCs (P=0.004). Median follow-up was 39 months, and median overall survival was 47 months. Five-year survivals were 45% (EC-3), 36% (SC), and 50% (CC)-differences that were not statistically significant. In contrast, the impact of stage on survival was significant (P<0.001). Among all other factors evaluated, only age greater than 65 years was a negative predictor (risk ratio, 2.23; P<0.001), whereas a family history of cancer reduced the risk of death when controlling for stage (risk ratio, 0.54; P=0.005). When controlling for stage, race, reproductive history, personal history of cancer, histologic subtype, depth of myometrial invasion, lymphovascular invasion, presence of an endometrial polyp, presence of hyperplasia, or staging adequacy did not affect prognosis. High-grade endometrial cancers of different histologic subtypes treated in an individualized manner are associated with similar clinical outcomes, but differences in age at presentation, race distribution, association with hyperplasia, stage, and sites of tumor dissemination support the idea that these represent distinct disease entities as defined by traditional histopathologic classification of endometrial cancers.

The pattern of Protease Activated Receptor 1 (PAR1) expression in endometrial carcinoma

OBJECTIVE

Protease Activated Receptors (PARs) form a family of G-protein-coupled proteins uniquely activated by proteolytic cleavage. While the role of either soluble or matrix-immobilized protease in tumor invasion is well established, the part of cell surface PARs is beginning to emerge. We sought to investigate the expression pattern of Protease Activated Receptor 1 (hPar1) in endometrial carcinoma, the most common type of gynecological malignancy.

METHODS

Tissue biopsy specimens taken from seventy-four formalin-fixed, paraffin-embedded endometrial tissue blocks were obtained from archival material. Analysis of PAR1 expression was evaluated by riboprobe in situ hybridization for detection of RNA and immunohistochemistry techniques for localization of protein. Histological scoring was performed.

RESULTS

The levels of hPar1 mRNA and protein were high and abundant in high-grade endometrial carcinoma, regardless of the histological subtype. In contrast, no hPar1 was detected in endometrial epithelia with conserved glandular structure represented by normal, hyperplastic or low-grade carcinomas.

CONCLUSIONS

PAR1 over-expression is selectively confined to the highly aggressive, high-grade endometrial carcinoma and absent in tissue obtained from benign endometrium or low-grade endometrial cancer. This finding highlights the significance of hPar1 gene involvement in invasive endometrial carcinoma and appoints it an attractive candidate for anti-cancer therapy.

My approach to the interpretation of endometrial biopsies and curettings

A major proportion of the workload in many histopathology laboratories is accounted for by endometrial biopsies, either curettage specimens or outpatient biopsy specimens. The increasing use of pipelle and other methods of biopsy not necessitating general anaesthesia has resulted in greater numbers of specimens with scant tissue, resulting in problems in assessing adequacy and in interpreting artefactual changes, some of which appear more common with outpatient biopsies. In this review, the criteria for adequacy and common artefacts in endometrial biopsies, as well as the interpretation of endometrial biopsies in general, are discussed, concentrating on areas that cause problems for pathologists. An adequate clinical history, including knowledge of the age, menstrual history and menopausal status, and information on the use of exogenous hormones and tamoxifen, is necessary for the pathologist to critically evaluate endometrial biopsies. Topics such as endometritis, endometrial polyps, changes that are induced by hormones and tamoxifen within the endometrium, endometrial metaplasias and hyperplasias, atypical polypoid adenomyoma, adenofibroma, adenosarcoma, histological types of endometrial carcinoma and grading of endometrial carcinomas are discussed with regard to endometrial biopsy specimens rather than hysterectomy specimens. The value of ancillary techniques, especially immunohistochemistry, is discussed where appropriate.

Claudin 1 differentiates endometrioid and serous papillary endometrial adenocarcinoma

OBJECTIVE

The expression of claudins, the main tight junction proteins involved in cell adhesion and carcinogenesis, was studied in endometrioid (type I) and seropapillary (type II) endometrial adenocarcinoma. The characteristics and possible diagnostic potential of claudin expression pattern were investigated in the two cancer types having different prognosis.

METHODS

Protein and mRNA expression of claudins was evaluated in 17 endometrioid carcinomas and 15 seropapillary adenocarcinomas by immunohistochemistry and real-time PCR in comparison with 38 cases of hyperplasia, normal proliferative and secretory endometrium samples. Further, protein expressions used in diagnostics (estrogen and progesterone receptors, p53, PCNA and beta-catenin) were also studied.

RESULTS

In endometrioid carcinoma and hyperplasia low claudin 1 and high claudin 2 protein contents, whereas in seropapillary adenocarcinoma high claudin 1 and low claudin 2 levels were detected. Intense protein expression was noted for claudins 3, 4, 5, and 7, without significantly different patterns in carcinoma, hyperplasia, secretory, and proliferative endometrium. Real-time PCR results confirmed differences in claudin 1 but not claudin 2 mRNA expression, whereas some minor discrepancies were observed in comparison with immunohistochemistry patterns.

CONCLUSION

The two types of endometrial adenocarcinomas were well distinguished by claudins 1 and 2 by immunohistochemistry, claudins 3, 4, and 7, however, did not prove useful in distinguishing the two entities. The similar claudin pattern seen in hyperplasia and endometrioid carcinoma and the differences regarding seropapillary adenocarcinoma support the dualistic model of endometrial carcinogenesis. The claudin pattern of the two tumor types might reflect a different cellular or pathogenetic pathway as well as a different cell adhesion behavior explaining the invasive properties.