Early endometrial carcinoma: clinicopathology, hormonal aspects, molecular genetics, diagnosis, and treatment

Impact of artificial intelligence on the diagnosis, treatment and prognosis of endometrial cancer

Endometrial cancer is one of the most prevalent tumours in females and holds an 83% survival rate within 5 years of diagnosis. Hypoestrogenism is a major risk factor for the development of endometrial carcinoma (EC) therefore two major types are derived, type 1 being oestrogen-dependent and type 2 being oestrogen independent. Surgery, chemotherapeutic drugs, and radiation therapy are only a few of the treatment options for EC. Treatment of gynaecologic malignancies greatly depends on diagnosis or prognostic prediction. Diagnostic imaging data and clinical course prediction are the two core pillars of artificial intelligence (AI) applications. One of the most popular imaging techniques for spotting preoperative endometrial cancer is MRI, although this technique can only produce qualitative data. When used to classify patients, AI improves the effectiveness of visual feature extraction. In general, AI has the potential to enhance the precision and effectiveness of endometrial cancer diagnosis and therapy. This review aims to highlight the current status of applications of AI in endometrial cancer and provide a comprehensive understanding of how recent advancements in AI have assisted clinicians in making better diagnosis and improving prognosis of endometrial cancer. Still, additional study is required to comprehend its strengths and limits fully.

Interferon‑stimulated gene 15 promotes progression of endometrial carcinoma and weakens antitumor immune response

Endometrial carcinoma (EC) is one of the most common gynecological cancers with a poor prognosis. Therefore, clarifying the details of the molecular mechanisms is of great importance for EC diagnosis and clinical management. Interferon-stimulated gene 15 (ISG15) plays an important role in the development of various cancers. However, its role in EC remains unclear. High ISG15 expression was observed in EC, which was associated with poor clinical outcomes and pathological stage of patients with EC, thus representing a promising marker for EC progression. Further exploratory analysis revealed that the elevated ISG15 levels in EC were driven by aberrant DNA methylation, independent of copy number variation and specific transcription factor aberrations. Accordingly, knockdown of ISG15 by small interfering RNA attenuated the malignant cellular phenotype of EC cell lines, including proliferation and colony formation in vitro. Finally, investigation of the molecular mechanisms indicated that ISG15 promoted the cell cycle G1/S transition in EC. Furthermore, ISG15 promoted EC progression by activating the MYC proto-oncogene protein signaling pathway. Moreover, ECs with high levels of ISG15 harbored a more vital immune escape ability, evidenced not only by significantly less invasive CD8⁺ T cells, but also higher expression of T cell inhibitory factors, such as programmed death-ligand 1. These results suggest a tumor-promoting role of ISG15 in EC, which may be a promising marker for diagnosis, prognosis and therapeutic immunity.

Histomolecular features of high-grade endometrial cancers

High-grade endometrial cancers (ECs) are an aggressive subset of ECs accounting for 70-80% of EC-related deaths. Currently, staging surgery, together with chemotherapy or radiotherapy, is the primary treatment strategy for these cancers. The widespread use of next-generation sequencing has led to a refined understanding of EC's genomics with important information for diagnosis and therapy for individual patients (precision medicine). However, advances in the genomics assessment of high-grade tumors have been slower due to their lower incidence than low-grade EC. This article will briefly introduce the current state of knowledge of the genomics of G3 endometrioid EC, serous uterine cancer, clear cell uterine carcinoma and uterine carcinosarcoma and discuss its implications for diagnosis and targeted therapy.

Network Pharmacology-Based Prediction of Active Ingredients and Potential Targets of ShengDiHuang Decoction for Treatment of Dysfunctional Uterine Bleeding

OBJECTIVE

To analyze the potential active ingredients and related crucial targets of the ShengDiHuang Decoction (SDHD) formula in the treatment of dysfunctional uterine bleeding (DUB) by using network pharmacology and verification experiment.

METHODS

In this study, we determined the potential active ingredients from the traditional SDHD formula and their targets with the network pharmacology method. The network of "compound-disease-target" was constructed by the software of Cytoscape. Software of DAVID was used to enrich pathways for these 87 targets of SDHD. Further, the therapeutic effect of SDHD on DUB was verified by observing the morphological changes of the uterus and ovaries and determining the expression of ERS2 and progesterone in the plasma.

RESULTS

52 compounds of Rheum and 5 compounds of Rehmannia were selected, and 87 potential targets were screened by network pharmacology. Furthermore, 7 main active ingredients were acquired by the ADME process. In addition, enrichment analysis of drug-target networks indicated that SDHD may play a role in overall coordination through "multicomponent and multitarget" in different organ patterns by regulating multiple pathways directly or indirectly. Finally, in the verification experiment of SDHD on DUB, it was found that SDHD can effectively repair the uterus and ovaries and also have an upregulation effect on the target ESR2 and increase the content of progesterone.

CONCLUSION

Overall, this study revealed potential mechanisms of multitarget and multicomponent about SDHD in the treatment of DUB and provided a scientific foundation for further studying the mechanism.

Serum HSP70 level in patients with endometrial cancer with and without diabetes

Diabetes mellitus (DM) is associated with an increased risk of endometrial carcinoma (EC). Heat shock proteins have a role in the modulation of both diseases. The aim of this study was to investigate extracellular HSP70 (eHSP70) level alternations in patients with two different types of EC (endometrioid and non-endometrioid) with and without type 2 diabetes. In a case-control study, 88 participants were enrolled in four groups including: 18 EC patients with DM, 19 EC patients without DM, 29 patients with DM, and 22 healthy individuals. Blood samples were taken before surgery in cancer patients. Estradiol, eHSP70, sex hormone-binding globulin (SHBG), FBS, and HbA1c were assessed. Serum HSP70 level was higher in patients with diabetes (52.24 ± 14.2 ng/ml) compared to healthy controls (39.04 ± 6.96) (p < .05). It was lower in EC (26.05 ± 12.28) compared to healthy controls (39.04 ± 6.96) (p < .05). eHSP70 was also lower in endometrioid-type carcinoma (22.57 ± 11) compared to non-endometrioid type (31.55 ± 12.38) (p < .05). Further analysis showed increased levels of eHSP70 in patients having both endometrioid-type carcinoma and diabetes (27.23 ± 11.41) compared to the same patients without DM (17.08 ± 7.78) (p < .05). Presence of diabetes in patients with endometrioid type carcinoma resulted in an increase in eHSP70 approaching the level of eHSP70 in patients with non-endometrioid histology.

CCNE1 amplification is associated with aggressive potential in endometrioid endometrial carcinomas

The clinicopathological significance of amplification was investigated of the gene encoding cyclin E (CCNE1) and we assessed whether CCNE1 was a potential target in endometrioid endometrial carcinomas. CCNE1 amplification and CCNE1 or F-box and WD repeat domain-containing 7 (FBXW7) expression in endometrial endometrioid carcinoma was assessed by immunohistochemistry and fluorescence in situ hybridization. CCNE1 knockdown by small interfering RNA (siRNA) was used to assess the CCNE1 function. The results showed that CCNE1 amplification was present in 9 (8.3%) of 108 endometrial carcinomas. CCNE1 amplification was correlated with high histological grade (Grade 3; P=0.0087) and lymphovascular space invasion (P=0.0258). No significant association was observed between CCNE1 amplification and FIGO stage (P=0.851), lymph node metastasis (P=0.078), body mass index (P=0.265), deep myometrial invasion (P=0.256), menopausal status (P=0.289) or patient age (P=0.0817). CCNE1 amplification was significantly correlated with shorter progression-free and overall survival (P=0.0081 and 0.0073, respectively). CCNE1 protein expression or loss of FBXW7 expression in endometrial endometrioid carcinoma tended to be correlated with shorter progression-free and overall survival; however, this difference was not statistically significant. Multivariate analysis showed that CCNE1 amplification was an independent prognostic factor for overall survival but not for progression-free survival (P=0.0454 and 0.2175, respectively). Profound growth inhibition was observed in siRNA-transfected cancer cells with endogenous CCNE1 overexpression compared with that in cancer cells having low CCNE1 expression. CCNE1 amplification was independent of p53, HER2, MLH1 and ARID1A expression but dependent on PTEN expression in endometrial carcinomas. These findings indicated that CCNE1 amplification was critical for the survival of endometrial endometrioid carcinomas. Furthermore, the effects of CCNE1 knockdown were dependent on the CCNE1 expression status, suggesting that CCNE1-targeted therapy may be beneficial for patients with endometrial endometrioid carcinoma having CCNE1 amplification.

Overexpression of Wnt7a is associated with tumor progression and unfavorable prognosis in endometrial cancer

BACKGROUND

Wnt7a is a secreted glycoprotein that regulates normal cellular proliferation and differentiation, as well as tumorigenesis and progression. The aim of the present study was to detect the level of expression of Wnt7a in endometrial cancer and explore its role in progression and prognosis of endometrial cancer.

METHODS

Immunohistochemistry was used to examine the expression of Wnt7a in 244 endometrial cancer specimens, in 48 benign endometrial lesion specimens, and 43 normal endometrium specimens. χ(2) Analysis, Kaplan-Meier analysis and log-rank test, and multivariate Cox proportional hazards analysis were applied for statistical analysis.

RESULTS

Wnt7a was overexpressed in endometrial cancer compared with normal endometrium and benign endometrial lesion (both P < 0.001). Wnt7a expression was correlated with histological grade, International Federation of Gynecology and Obstetrics stage, depth of myometrial invasion, vascular/lymphatic invasion, and lymph node metastasis. The results of Kaplan-Meier analysis indicated that Wnt7a expression was associated with overall survival (OS) and disease-free survival (DFS) of endometrial cancer. The survival of negative expression Wnt7a group had longer OS and DFS compared with the group with positive expression. The difference was significant (both P < 0.001, log-rank test). Multivariate Cox regression analysis revealed that Wnt7a expression status was an independent prognostic factor for both OS and DFS (P = 0.034 and P = 0.009, respectively) of patients with endometrial cancer.

CONCLUSIONS

Overexpression of Wnt7a may contribute to the progression of endometrial cancer and thus may serve as a new biomarker to predict the prognosis of endometrial cancer.

LAPTM4B gene polymorphism and endometrial carcinoma risk and prognosis

A novel gene called LAPTM4B (lysosome-associated protein transmembrane 4 beta) plays several crucial roles in carcinogenesis. In this case-control study, we investigated the relationship between LAPTM4B gene polymorphism and susceptibility to endometrial carcinoma (EC). In an adjusted multivariate logistic regression analyses, subjects with the LAPTM4B*1/2 and *2/2 genotypes respectively exhibited 1.572-fold (95% confidence interval (CI) = 1.041-2.375) and 2.335-fold (95% CI = 1.365-3.995) increases in the risk of developing EC relative to those carrying LAPTM4B*1/1. Patients with LAPTM4B *2 had both significantly shorter overall survival (OS) and shorter disease-free survival (DFS) (both p < 0.001). Multivariate analysis showed that LAPTM4B genotype is an independent prognostic factor for OS and DFS (both p < 0.001). These results suggest that LAPTM4B polymorphisms might play an important role in the aetiology of EC.

Clinicopathologic analysis of loss of AT-rich interactive domain 1A expression in endometrial cancer

Loss of the AT-rich interactive domain 1A (a putative tumor suppressor) protein BAF250a has recently been described as a frequent event in endometrial carcinoma. In this study, we determined the significance of the loss of AT-rich interactive domain 1A immunoreactivity for several clinicopathologic features of uterine endometrioid carcinoma. AT-rich interactive domain 1A expression was assessed by immunohistochemistry using 111 paraffin-embedded tissue specimens and clinical data collected by a retrospective medical record review. The correlations between loss of AT-rich interactive domain 1A protein and clinicopathologic and prognostic features were examined. In addition, the expression of PTEN, p53, Her2, and MLH1 was assessed by immunohistochemistry and compared with AT-rich interactive domain 1A expression. AT-rich interactive domain 1A immunoreactivity was undetectable in 27 (24%) of 111 analyzed endometrioid endometrial carcinomas. There was no significant difference between negative and positive cases of AT-rich interactive domain 1A in terms of any clinicopathologic features examined (International Federation of Gynecology and Obstetrics stage, grade, depth of myometrial invasion, lymph node metastasis, lymphovascular space invasion, body mass index, postmenopausal status, patient age at diagnosis, and estrogen and progesterone receptor status). The comparison between the expression of AT-rich interactive domain 1A and the expression of PTEN, p53, Her2, and MLH1 also revealed no significant association. There was no significant correlation between AT-rich interactive domain 1A expression and progression-free/overall survival of patients. This study provides the first examination of the clinicopathologic relationship between AT-rich interactive domain 1A protein expression and endometrial carcinoma. No significant differences between positive and negative cases of AT-rich interactive domain 1A were observed with respect to any clinicopathologic features or patient survival.

Carbonic anhydrase isozymes II, IX, and XII in uterine tumors

Histopathological diagnostics of gynecological malignancies continues to be challenging despite the well established criteria. For example, the morphological distinction of uterine leiomyosarcoma from certain variants of benign leiomyoma can be difficult. Herein, we investigated the expression of Carbonic anhydrase (CA) II, IX, and XII in the normal endometrium, leiomyomas, uterine sarcomas, and endometrial adenocarcinomas using immunohistochemistry. These isozymes are considered promising diagnostic markers and therapeutic targets. The normal endometrium showed high CA XII expression, whereas the signals were lower in endometrial adenocarcinoma (p < 0.004). Only sporadic CA IX staining was found in the normal endometrium, whereas the enzyme was overexpressed in most cases of endometrial adenocarcinoma (p < 0.005). CA II expression was slightly weaker in the normal endometrium than that in the adenocarcinomas (p < 0.008). Positive immunostaining reactions for CAs were observed in the uterine sarcomas, whereas all leiomyomas were negative for CA II and XII. A comparison between leiomyomas and sarcomas showed statistically significant differences for all studied isozymes (p < 0.001). Our study shows that CA isozymes could together serve as histopathological biomarkers for differential diagnosis between uterine leiomyosarcoma and leiomyoma. In addition to being found in leiomyosarcomas, CA II and IX were overexpressed in endometrial adenocarcinoma, where they might regulate the pH of the tumor microenvironment.

Inhibition of estrogen actions in human gynecological malignancies: new aspects of endocrine therapy for endometrial cancer and ovarian cancer

Endometrial carcinoma and possibly ovarian carcinoma are considered "estrogen-dependent tumors" in human gynecological malignancies. In endometrial carcinoma, the enzymes responsible for intratumoral estrogen metabolism and biosynthesis are different from those in human breast carcinoma, although both of them are considered "estrogen-dependent malignancies". Specific and effective endocrine treatment of endometrial carcinoma should be explored, although progestin agents have been widely used for a long time. Aromatase inhibitors, the most effective endocrine agents of breast carcinoma, retinoids, metabolites of vitamin A, and synthetic peroxisome proliferator-activated receptor (PPAR) gamma ligands, used for the treatment of insulin resistance in type II diabetes mellitus, may be the important candidates for possible endocrine treatment of endometrial carcinoma. In ovarian carcinoma, several clinical studies recently demonstrated that aromatase inhibitors had some therapeutic activity against recurrent ovarian carcinoma. However, at least at this juncture, further studies should be required to establish an aromatase inhibitor treatment as one form of endocrine therapy of ovarian carcinoma in future.

Chemokines and Cancer Progression: A Qualitative Review on the Role of Stromal Cell-derived Factor 1-alpha and CXCR4 in Endometrial Cancer

The goal of this paper was to examine the literature related to stromal cell-derived factor 1-alpha (SDF-1alpha) and its receptor CXCR4 in endometrial cancer, as expression of these biomarkers has been implicated in an aggressive phenotype in other common epithelial cancers. We conducted a qualitative review of all published studies examining the role of SDF-1alpha/CXCR4 in endometrial cancer progression and prognosis. Pubmed and Ovid MEDLINE databases were searched in order to identify relevant studies for this qualitative review. Four studies have examined the role of the SDF-1alpha/CXCR4 pathway on endometrial cancer progression. The findings were contradictory; two studies reported an inverse association between overexpression and mortality while two studies reported overexpression to be associated with hallmarks of aggressive endometrial cancer. Expression of stromal-derived proteins can potentially serve as biomarkers of aggressive disease as well as biomarkers for remission monitoring, however the endometrial cancer literature has lagged behind in this area. Furthermore, the current research suffers from lack of comparability among different studies due to the utilization of different tools and lack of common outcome definitions. Future studies in this area should use clinically meaningful protein expression categories, widely accepted outcome definitions, and larger samples of patients. Finally, although standard immunohistochemistry is a mainstay in tumor marker studies, automated detection methods may be more suitable as they do not rely on subjective interpretation.

Comparative evaluation of estrogen and progesterone receptor expression with connexins 26 and 43 in endometrial cancer

Progression of numerous neoplasms could involve alterations of gap junction channels composed of connexins (Cxs). Disorders of expression and cellular displacement of Cxs were also found in endometrial cancer. Gap junctional intercellular communication can be regulated by wide array of agents, for instance, growth factors, oncogenes, and steroid hormones. Nevertheless, expressions of Cxs and progesterone receptor (PR) were not compared in human tissues. This study focused on assessment of expression of estrogen receptor alpha (ERalpha) and PRs in relation to the expression of Cx26 and Cx43 in 88 cases of endometrial cancer and analysis of these proteins' expression in comparison with anatomoclinical features. Positive ERalpha and PR nuclear staining was present in 66 (75%) and 60 (68.2%) of all studied tumors, respectively. Positive correlation was found between expression of PR and histopathologic type of tumor (P = 0.026), and negative correlation was drawn with grading (G) (P = 0.002). There were positive reactions to Cx26 and Cx43 of mainly cytoplasmic location in 60 (68.2%) and 66 (75%) of studied cancers, respectively. Progesterone receptor expression correlated negatively with Cx26 in endometrial cancers (P = 0.016, r = -0.256). Moreover, ERalpha expression positively correlated with PR expression (P < 0.001, r = 0.678). On the ground of our findings, disorders of Cx expression and altered distribution pattern occur during endometrial carcinogenesis, and it seems that PR could participate in this fact. Loss of functional gap junctions may occur because of the aberrant expression and localization of Cx26 and Cx43 in endometrial cancer.

Insights into selected genetic diseases affecting the female reproductive tract and their implication for pathologic evaluation of gynecologic specimens

CONTEXT

Recent advances in the understanding of genetic conditions involving the female genital tract and mechanisms of carcinogenesis in this setting affect patient management and thus necessitate appropriate pathologic evaluation of specimens. In the past, specimens from prophylactic surgery were a rarity; however, they are now more frequently encountered and often require a significant variation from routine processing methods. Pathologists also receive more specimens requiring prospective workup for possible underlying genetic conditions such as microsatellite instability.

OBJECTIVE

To summarize the current knowledge of important genetic and hereditary conditions affecting the female reproductive organs while highlighting the resulting practical significance for specimen handling, "grossing," and microscopic evaluation in gynecologic pathology.

DATA SOURCES

This update is based on a review of recent peer-reviewed literature and the experience with cases at the parent institutions.

CONCLUSIONS

Gynecologic specimens received from patients with certain genetic conditions require specific clinicopathologic knowledge for appropriate pathologic examination. The evaluation of prophylactic resection specimens focuses on the detection of cancer precursors and possible occult disease, which may require a more thorough and detailed examination than an obvious carcinoma. Standardized protocols for handling prophylactic gynecologic resection specimens are available for some, but not all, types of specimens. The prospective evaluation of a gynecologic pathology specimen for potential genetic conditions such as microsatellite instability is a very recent subject. Currently, well-established protocols are not available; however, as clinical and prognostic significance has become more clearly elucidated, familiarity with this evolving field is increasingly important to properly assess these pathologic specimens.

ATR mutation in endometrioid endometrial cancer is associated with poor clinical outcomes

PURPOSE Mutations in the DNA damage response gene ATR (exon 10 A10 mononucleotide repeat) have been previously described in endometrial and other cancers with defective DNA mismatch repair. In vitro studies showed that endometrial cancer cell lines with A10 repeat tract truncating mutations have a failure in the ATR-dependent DNA damage response. Cell lines carrying A10 mutations fail to trigger Chk1 activation in response to ionizing radiation and topoisomerase inhibitors. We sought to determine the frequency and clinicopathologic significance of ATR mutations in patients with endometrioid endometrial cancer. PATIENTS AND METHODS The ATR exon 10 A10 repeat was analyzed by direct sequencing in 141 tumors with microsatellite instability (MSI-positive) and 107 microsatellite stable (MSI-negative) tumors. The relationships between mutations and clinicopathologic variables, including overall and disease-free survival, were assessed using contingency table tests and Cox proportional hazard models. Results ATR mutations were identified in 12 cases (4.8%; three cases with insertions and nine cases with deletions). Mutations occurred exclusively in MSI-positive tumors (P = .02), with an overall mutation rate of 8.5%. Mutation was not associated with age, race, surgical stage, International Federation of Gynecology and Obstetrics grade, or adjuvant treatment. Multivariate analyses revealed a significant association with reduced overall survival (hazard ratio [HR] = 3.88; 95% CI, 1.64 to 9.18; P = .002) and disease-free survival (HR = 4.29; 95% CI, 1.48 to 12.45; P = .007). CONCLUSION Truncating ATR mutations in endometrial cancers are associated with biologic aggressiveness as evidenced by reduced disease-free and overall survival. Knowledge of ATR mutation status may hold promise for individualized treatment and targeted therapies in patients with endometrial cancer.

FGFR2 as a molecular target in endometrial cancer

Although molecularly targeted therapies have been effective in some cancer types, no targeted therapy is approved for use in endometrial cancer. The recent identification of activating mutations in fibroblast growth factor receptor 2 (FGFR2) in endometrial tumors has generated a new avenue for the development of targeted therapeutic agents. The majority of the mutations identified are identical to germline mutations in FGFR2 and FGFR3 that cause craniosynostosis and hypochondroplasia syndromes and result in both ligand-independent and ligand-dependent receptor activation. Mutations that predominantly occur in the endometrioid subtype of endometrial cancer, are mutually exclusive with KRAS mutation, but occur in the presence of PTEN abrogation. In vitro studies have shown that endometrial cancer cell lines with activating FGFR2 mutations are selectively sensitive to a pan-FGFR inhibitor, PD173074. Several agents with activity against FGFRs are currently in clinical trials. Investigation of these agents in endometrial cancer patients with activating FGFR2 mutations is warranted.

Gonadotropin-releasing hormone receptor expression in endometrial cancer

Several studies have previously reported the expression of the gonadotropin-releasing hormone receptor (GnRHr) in cases of endometrial cancer. However, the relationship between GnRHr expression and a variety of clinicopathologic parameters remains unclear. This study was conducted with 141 endometrial cancer patients, all of whom had undergone operations between 1993 and 2002. Paraffin-embedded tissue blocks were sectioned and immunostained with monoclonal anti-GnRHr antibody. Clinicopathologic variables were also evaluated, with 10% cutoff values for GnRHr positivity. Seventy specimens (49.6%) stained as GnRHr-positive. Mean parity was higher in the patients with GnRHr-positive tumors than those with GnRHr-negative tumors (2.50+/-1.92 versus 1.82+/-1.37, P=0.016). Body mass indices were also higher in the patients with GnRHr-positive tumors (26.6+/-4.6 versus 24.7+/-4.2, P=0.010). However, GnRHr positivity was not determined to be statistically significantly associated with any other clinicopathologic characteristics, including age, menopausal status, histotype, disease stage, tumor differentiation, lymph node metastasis, and myometrial invasion. The results of this study, although they may require further investigation, suggested that obese and multiparous women with endometrial cancer might be greatly influenced by endogenous gonadotropin-releasing hormone and/or exogenous gonadotropin-releasing hormone analogs.

Proteomics identification of cyclophilin a as a potential prognostic factor and therapeutic target in endometrial carcinoma

Endometrial carcinoma is one of the most common malignancies of the female genital tract, and there is an urgent need for discovery of novel factors for prognostic assessment and therapeutic targets to endometrial carcinoma. Herein a two-dimensional gel electrophoresis and MALDI-Q-TOF MS/MS-based proteomics approach was used to identify differentially expressed proteins in endometrial carcinoma. Of the 99 proteins identified, cyclophilin A was one of the most significantly altered proteins, and its overexpression was confirmed using RT-PCR and Western blot analyses. Immunohistochemistry suggested a link between cyclophilin A expression and poor differentiation and decreased survival (p < 0.01). Knockdown of cyclophilin A expression by RNA interference led to the significant suppression of the cell growth and the induction of apoptosis in endometrial carcinoma HEC-1-B cells in vitro (p < 0.01) and the inhibition of tumor growth in vivo (p < 0.01). These data suggest that cyclophilin A may serve as a novel prognostic factor and possibly an attractive therapeutic target for endometrial carcinoma.

Biological roles of estrogen and progesterone in human endometrial carcinoma--new developments in potential endocrine therapy for endometrial cancer

Endometrial carcinoma is one of the most common female pelvic malignancies. It is well known that uterine endometrial cell proliferation is under the control of both estrogen and progesterone. In this review, results of the recent studies on the biosynthesis and action of estrogen and progestin in normal endometrium and its disorders will be summarized and the new aspects of hormonal therapies in the patients with endometrial carcinoma will be discussed including its future prospectives. We reported that the enzymes responsible for intratumoral estrogen metabolism and biosynthesis are markedly different between human breast and endometrial carcinoma, although both of them are considered "estrogen-dependent malignancies". In addition, the biological significance of Progesterone receptor (PR) isoforms is considered to differ between endometrial and breast carcinomas. Clinical data concerning Hormone replacement therapy (HRT) and estrogen-dependent cancer risk also support these findings. These basic and clinical findings help to understand the biology and provide the new knowledge for prevention, diagnosis and treatment of human endomerial carcinoma. Specific endocrine treatment of endometrial carcinoma should be explored in future, although aromatase inhibitors are the most effective endocrine treatments of estrogen-responsive breast carcinoma. Retinoid, metabolities of vitamin A, and synthetic peroxisome proliferator-activated receptor (PPAR) gamma ligands, which have been used for the treatment of insulin resistance in type II diabetes mellitus, may be the important candidates as drugs not only for prevention but also for possible endocrine treatment of endometrial carcinoma.

Microsatellite Instability and Epigenetic Inactivation of MLH1 and Outcome of Patients With Endometrial Carcinomas of the Endometrioid Type

Purpose

Most studies of microsatellite instability (MSI) and outcomes in endometrial cancer patients have included varied histologic subtypes. Nonetheless, MSI occurs almost exclusively in endometrioid tumors. The impact of MSI on outcomes in patients with endometrial cancer is controversial. We sought to determine whether MSI and MLH1 methylation are associated with clinicopathologic variables and survival outcomes in a large series of patients with endometrial carcinomas of the endometrioid type.

Patients and Methods

Tumor samples, blood, and clinicopathologic data were prospectively collected and analyzed for 446 patients with endometrioid carcinomas. MSI was determined using five National Cancer Institute (NCI) consensus panel markers, and the methylation status of the MLH1 promoter was determined by combined bisulfite restriction analysis (COBRA). Associations with clinicopathologic variables and survival outcomes were evaluated.

Results

MSI was identified in 147 cases (33%). MSI was associated with higher International Federation of Gynecology and Obstetrics (FIGO) grade (P < .0001). MSI+ tumors without MLH1 methylation were associated with younger age (P < .001). MSI was not associated with overall survival (OS; hazard ratio [HR], 1.011; 95% CI, 0.688 to 1.484; P = .96) or disease-free survival (DFS; HR 0.951; 95% CI, 0.554 to 1.635; P = .86). The combined MSI/MLH1 methylation status (treating MSI− as the reference) did not predict OS (MSI+/MLH1-U: HR, 0.62; 95% CI, 0.27 to 1.44; P = .26; MSI+/MLH1-M: HR, 0.95; 95% CI, 0.62 to 1.46; P = .82) or DFS (MSI+/MLH1-U: HR, 0.51; 95% CI, 0.22 to 1.19; P = .12; MSI+/MLH1-M: HR, 0.93; 95% CI, 0.62 to 1.40; P = .72).

Conclusion

MSI is not associated with survival in patients with endometrioid endometrial cancer.

Effect of ATM, CHEK2 and ERBB2 TAGSNPs and haplotypes on endometrial cancer risk

Family history of endometrial cancer increases the risk of developing the disease, but it is still largely unknown which germ-line genetic factors are involved in the aetiology of endometrial cancer. In a Swedish population-based case-control study including 705 cases and 1565 controls, we examined common variation in the ATM, CHEK2 and ERBB2 genes in relation to endometrial cancer risk overall, restricted to tumours of certain characteristics or stratified by various endometrial cancer risk factors. We genotyped a large number of single-nucleotide polymorphisms (SNPs) in the genes and selected seven haplotype-tagging SNPs (tagSNPs) in ATM, six tagSNPs in CHEK2 and seven tagSNPs in ERBB2 that could predict common variants and haplotypes (frequency > or =0.03) in each gene with R(2) > or = 0.8. We included the tagSNPs or their haplotypes as explanatory variables in unconditional logistic regression models adjusted for age. Our results indicated an increased risk of developing endometroid endometrial cancer for homozygous carriers of the rare allele (AA) of a tagSNP (rs4987886) in CHEK2 (P = 0.005) when contrasted with GG carriers. We also found a decreased endometrial cancer risk among non-smoking carriers of a haplotype in ATM (P = 0.0007) and among carriers of a haplotype in CHEK2, who had experienced menopause below 49 years of age (P = 0.0009) compared with non-carriers of these haplotypes. We found no effect of genetic variation in ERBB2 on endometrial cancer risk. In conclusion, it is possible that common variants in the ATM and CHEK2 genes, in interaction with oestrogen-related exposures, are involved in endometrial cancer aetiology.