Improved risk assessment of endometrial cancer by combined analysis of MSI, PI3K-AKT, Wnt/β-catenin and P53 pathway activation

TP53 mutation and abnormal p53 expression in endometrial cancer: Associations with race and outcomes

OBJECTIVE

This multi-center cohort study assessed associations between race, TP53 mutations, p53 expression, and histology to investigate racial survival disparities in endometrial cancer (EC).

METHODS

Black and White patients with advanced or recurrent EC with Next Generation Sequencing data in the Endometrial Cancer Molecularly Targeted Therapy Consortium database were identified. Clinicopathologic and treatment variables were summarized by race and compared. Overall survival (OS) and progression-free survival (PFS) among all patients were estimated by the Kaplan-Meier method. Cox proportional hazards models estimated the association between race, TP53 status, p53 expression, histology, and survival outcomes.

RESULTS

Black patients were more likely than White patients to have TP53-mutated (N = 727, 71.7% vs 49.7%, p < 0.001) and p53-abnormal (N = 362, 71.1% vs 53.2%, p = 0.003) EC. Patients with TP53-mutated EC had worse PFS (HR 2.73 (95% CI 1.88-3.97)) and OS (HR 2.20 (95% CI 1.77-2.74)) compared to those with TP53-wildtype EC. Patients with p53-abnormal EC had worse PFS (HR 2.01 (95% CI 1.22-3.32)) and OS (HR 1.61 (95% CI 1.18-2.19)) compared to those with p53-wildtype EC. After adjusting for TP53 mutation and p53 expression, race was not associated with survival outcomes. The most frequent TP53 variants were at nucleotide positions R273 (n = 54), R248 (n = 38), and R175 (n = 23), rates of which did not differ by race.

CONCLUSIONS

Black patients are more likely to have TP53-mutated and p53-abnormal EC, which are associated with worse survival outcomes than TP53- and p53-wildtype EC. The higher frequency of these subtypes among Black patients may contribute to survival disparities.

Microsatellite instability as a marker of prognosis: a systematic review and meta-analysis of endometrioid endometrial cancer survival data

INTRODUCTION

To investigate whether microsatellite instability (MSI) is an important prognostic biomarker for endometrioid endometrial cancer (EEC).

METHODS

The PubMed, EMBASE, and the Cochrane Cooperative Library databases were searched from inception to July 2021. Overall survival, disease-free survival, progression-free survival, EEC-specific survival, recurrence-free survival, and the recurrence rate were pooled to analyze the correlation between MSI and EEC. In addition, Egger's regression analysis and Begg's test were used to detect publication bias.

RESULTS

17 studies met the inclusion criteria and were included in our meta-analysis with a sample size of 4723, and the included patients with endometrioid cancer (EC) all were EEC. The pooled hazard ratios (HR) in patients with EEC showed that MSI was significantly associated with shorter overall survival [HR = 1.37, 95% confidence interval (CI) (1.00-1.86), p = 0.048, I2 = 60.6%], shorter disease-free survival [HR = 1.99, 95% CI (1.31-3.01), p = 0.000, I2 = 67.2%], shorter EEC-specific survival [HR = 2.07, 95% CI (1.35-3.18), p = 0.001, I2 = 31.6%] and a higher recurrence rate [Odds ratios (OR) = 2.72, 95% CI (1.56-4.76), p = 0.000, I2 = 0.0%]. In the early-stage EEC subgroup, MSI was significantly associated with shorter overall survival [HR = 1.47, 95% CI (1.11-1.95), p = 0.07], shorter disease-free survival [HR = 4.17, 95% CI (2.37-7.41), p = 0.000], and shorter progression-free survival [HR = 2.41, 95% CI (1.05-5.54), p = 0.039]. No significant heterogeneity was observed in overall survival (I2 = 20.9%), disease-free survival (I2 = 0.0%), or progression-free survival (I2 = 0.0%) in patients with early-stage EEC. Meanwhile, publication bias was not observed, and the p-value for Egger's test of overall survival, disease-free survival, and EEC-specific survival were p = 0.131, p = 0.068, and p = 0.987, respectively.

CONCLUSION

MSI is likely an important biomarker for poor prognosis in patients with EEC, and this correlation is even more certain in patients with early-stage EEC.

Clinicopathologic Evaluation of CTNNB1 Mutations in High-Intermediate Risk Endometrial Endometrioid Carcinoma

CTNNB1 mutations convey increased risk of recurrence in low-risk endometrial endometrioid carcinoma (EEC). Results from previous high-intermediate risk (HIR) cohorts are mixed. The aims of this study were to correlate CTNNB1 mutational status with clinical outcomes and to evaluate the relationship between CTNNB1 mutations and the 4 prognostic subgroups defined by The Cancer Genome Atlas in HIR EEC. CTNNB1 mutational status was determined by Sanger sequencing of exon 3 of the CTNNB1 gene. Mismatch repair, POLE , p53, and L1 cell-adhesion molecule (L1CAM) status were also evaluated. Descriptive statistics and survival analyses were performed. Eighty-eight cases of HIR EEC were identified, of which 22 (25%) were CTNNB1 mutant ( CTNNB1 -mut) and 66 (75%) were wild-type ( CTNNB1 -WT). Median follow-up was 60 mo. Recurrence occurred in 13/88 (15%) patients. Recurrence rates were not significantly different between patients with CTNNB1- mut and CTNNB1- WT tumors (14% vs. 15%, P =0.86). Recurrence-free survival and overall survival were not significantly different (recurrence-free survival hazard ratio: 0.97, 95% confidence interval: 0.27-3.52, P =0.96; overall survival hazard ratio: 0.23, 95% confidence interval: 0.03-1.71, P =0.15). Mismatch repair deficiency was more prevalent in CTNNB1 -WT compared with CTNNB1 -mut tumors (46% vs. 14%, P =0.01); prevalence of POLE mutations and aberrant p53 were not significantly different. In contrast to patients with low-risk EEC, no differences in recurrence or survival were found in patients with HIR EEC with CTNNB1- mut compared with CTNNB1 -WT tumors.

Genomic landscape of endometrial carcinomas of no specific molecular profile

Endometrial carcinomas (ECs) classified by The Cancer Genome Atlas (TCGA) as copy number-low (also referred to as "no specific molecular profile" [NSMP]) have a prognosis intermediate between POLE-mutated and copy number-high ECs. NSMP-ECs are a heterogeneous group, however, comprising both relatively indolent and aggressive ECs. We identified a total of 472 NSMP-ECs among 1,239 ECs that underwent clinical sequencing of 410-468 cancer-related genes. Somatic mutation and copy number alteration data were subjected to unsupervised hierarchical clustering, which identified three genomic clusters. Random sampling with stratification was used to choose ~80 endometrioid ECs from each cluster, resulting in a study size of 240 endometrioid ECs as well as an additional 44 non-endometrioid NSMP-ECs. Cluster 1 (C1, n = 80) consisted primarily of NSMP-ECs with PTEN and PIK3R1 mutations, Cluster 2 (C2, n = 81) of tumors with PTEN and PIK3CA mutations and Cluster 3 (C3, n = 79) of NSMP-ECs with chromosome 1q high-level gain and lack of PTEN mutations. The majority (72.7%) of non-endometrioid NSMP-ECs mapped to C3. NSMP-ECs from C3 were more likely to be FIGO grade 3 (30%), estrogen receptor-negative/weak (54.5%) and FIGO stages III or IV. In multivariate analysis, molecular clusters were associated with worse overall survival outcomes with C3 tumors having the worst (hazard ratio: 4) and C1 tumors having the best outcome. In conclusion, NSMP-ECs are a heterogenous group of tumors and comprise both aggressive and clinically low-risk ECs that can be identified based on mutation and copy number data.

Adjuvant treatment in early-stage endometrial cancer: context-dependent impact of somatic CTNNB1 mutation on recurrence-free survival

OBJECTIVE

The primary objective of this study was to determine whether women whose tumors harbor a somatic CTNNB1 mutation have longer recurrence-free survival if they receive traditional adjuvant therapy strategies compared with those who do not.

METHODS

A retrospective, stage I endometrial cancer cohort from MD Anderson Cancer Center was assessed. Clinical and pathological characteristics and type of adjuvant therapy (cuff brachytherapy, pelvic radiation, chemotherapy) were obtained by review of medical records. CTNNB1 exon 3 sequencing was performed. Summary statistics were calculated, and recurrence-free survival was measured using the Kaplan-Meier product-limit estimator.

RESULTS

The analysis included 253 patients, 245 with information regarding adjuvant therapy. Most patients had tumors of endometrioid histology (210/253, 83%) with superficial myometrial invasion (197/250, 79%) and no lymphatic/vascular space invasion (168/247, 68%). Tumor CTNNB1 mutations were present in 45 (18%) patients. Patients receiving adjuvant therapy were more likely to have higher-grade tumors, non-endometrioid histology, deep myometrial invasion, and lymphatic/vascular invasion. For patients with low-risk features not receiving adjuvant therapy, the presence of CTNNB1 mutation did not significantly impact recurrence-free survival (11.3 years wild-type vs 8.1 years mutant, p=0.65). The cohort was then limited to intermediate-risk tumors, defined as endometrioid histology of any grade with deep myometrial invasion and/or lymphatic/vascular space invasion. When recurrence-free survival was stratified by CTNNB1 mutation status and adjuvant therapy, patients with CTNNB1 mutations and no adjuvant therapy had the shortest recurrence-free survival at 1.6 years, followed by patients with CTNNB1 mutations who received adjuvant therapy (4.0 years), and wild-type CTNNB1 with and without adjuvant therapy (8.5 and 7.2 years, respectively) (comparison for all four groups, p=0.01).

CONCLUSION

In patients with intermediate-risk endometrioid endometrial cancers, the use of adjuvant therapy was associated with an improvement in recurrence-free survival for patients with tumor mutations in CTNNB1.

Long-Term Survival and Clinicopathological Implications of DNA Mismatch Repair Status in Endometrioid Endometrial Cancers in Hong Kong Chinese Women

To investigate the role of DNA mismatch repair status (MMR) in survival of endometrioid endometrial cancer in Hong Kong Chinese women and its correlation to clinical prognostic factors, 238 patients with endometrioid endometrial cancer were included. Tumor MMR status was evaluated by immunohistochemistry. Clinical characteristics and survival were determined. Association of MMR with survival and clinicopathological parameters were assessed. MMR deficiency (dMMR) was found in 43 cases (16.5%). dMMR was associated with poor prognostic factors including older age, higher stage, higher grade, larger tumor size and more radiotherapy usage. Long-term survival was worse in dMMR compared to the MMR proficient group. The dMMR group had more deaths, shorter disease-specific survival (DSS), shorter disease-free survival (DFS), less 10-year DSS, less 10-year DFS, and more recurrence. The 5-year DSS and 5-year DFS in the dMMR group only showed a trend of worse survival but did not reach statistical significance. In conclusion, dMMR is present in a significant number of endometrioid endometrial cancers patients and is associated with poorer clinicopathological factors and survival parameters in the long run. dMMR should be considered in the risk stratification of endometrial cancer to guide adjuvant therapy and individualisation for longer follow up plan.

Recurrence risk factors in stage IA grade 1 endometrial cancer

OBJECTIVES

Patients with early-stage endometrial cancers (EC) with disease recurrences have worse survival outcomes. The purpose of this study was to identify clinical and pathologic factors that predict for all recurrences in stage IA grade 1 (IAG1) EC.

METHODS

Records from patients diagnosed with EC were retrospectively reviewed. Baseline characteristics of 222 patients with IAG1 EC who underwent surgical resection were analyzed. Cox proportional hazard analysis was used to identify univariate and multivariate risk factors that predict for recurrence.

RESULTS

Seventeen (7.65%) patients had recurrences. The 3-year cumulative incidence of recurrence were significantly higher for patients with time from biopsy to surgery ≥6 months (54% vs. 8%, p=0.003), simple hysterectomy with ovarian preservation vs. total hysterectomy and bilateral salpingo-oophorectomy (31% vs. 9%, p=0.032), any myometrial invasion vs. no invasion (18% vs. 2%, p=0.004), and tumor size ≥2 cm (15% vs. 2%, p=0.021). On, multivariate analysis, any myometrial invasion, increasing time from biopsy to surgery, and larger tumor size were independent predictors of any recurrence. Patients with recurrences had worse outcomes than those without (5-year overall survival [OS]=60%; 95% confidence interval [CI]=16%-86% vs. 5-year OS=95%; 95% CI=87%-99%, respectively, p=0.003).

CONCLUSION

Time from biopsy to surgery, larger tumors, and myometrial invasion are the most important predictors of recurrence. Though the recurrence rates are generally low in IAG1 EC, the survival rate for the patients with recurrences was worse than those without. Identification of additional recurrence risk factors can help select patients who may benefit from adjuvant treatment.

Expression of anti-apoptotic protein survivin in human endometrial carcinoma: Clinical and pathological associations as a separate factor and in combination with concomitant PTEN and p53 expression

Endometrial carcinoma is one of the most common types of gynecological cancer. A total of 99 cases of primary endometrial carcinoma were investigated for survivin expression by immunohistochemistry. Furthermore, the association between concomitant survivin, PTEN and p53 expression, and clinicopathological parameters was examined. Immunopositivity for survivin was identified in 88% of cases. Concomitant survivin, PTEN and p53 expression (staining scores and intensity) was observed in 60% of endometrial adenocarcinomas. A significant association was identified between the sum of staining intensity and scores of survivin immunopositive cells, and patient age (P=0.028), histological grade (P<0.001), clinical stage (P=0.018) and fallopian tube and/or ovarian invasion (P=0.039). A negative tendency for correlation was observed between surivin and PTEN immunostaining scores (P=0.062; ρ=−0.238). Specimens with high scores of survivin expression tended to show decreased scores of PTEN immunostaining, and vice versa. However, in circumstances with an increased co-expression of survivin and PTEN, a statistically significant association with histological types was observed (P=0.020). A statistically significant positive correlation was identified between survivin and p53 sum co-expression (P=0.008; ρ=0.300). Furthermore, a significant association was identified between survivin and p53 concomitant sum expression and age of patients (P=0.001), histological type (P=0.020), clinical stage (P=0.037), histological differentiation (P=0.001) and presence of fallopian tube and/or ovarian invasion (P=0.026). The present findings suggested that survivin may be an indicator of unfavorable outcome in older patients with endometrial carcinoma, in specific circumstances that are dependent on different concomitant genetic alterations and different combinations of molecular signaling pathways. Increased expression levels of survivin and PTEN may serve a role in the development of more aggressive endometrial carcinoma during their interaction. In addition, protein expression levels of survivin and p53 are positively correlated and may share a common molecular pathway to promote endometrial carcinogenesis. These findings provided evidence that survivin and p53 combined may be useful markers for the prediction of tumor behavior and prognosis.

Diagnostic accuracy of p53 immunohistochemistry as surrogate of TP53 sequencing in endometrial cancer

Aberrant p53 immunohistochemical expression is used to identify the copy-number-high/TP53-mutant subgroup of endometrial cancer (EC). We aimed to determine the diagnostic accuracy of p53 immunohistochemistry as surrogate for TP53 sequencing through a systematic review and meta-analysis. Electronic databases were searched from their inception to June 2019. All studies assessing p53 expression and TP53 mutations in EC were included. Diagnostic accuracy was assessed based on area under the curve (AUC). Immunohistochemical criteria used to define aberrant p53 expression were "overexpression" and "overexpression or complete absence". Subgroup analysis was based on the sequencing technique adopted (Polymerase Chain Reaction + sequencing, or next generation sequencing, NGS). Thirteen observational studies with 727 endometrial cancers were included. Both "overexpression" and "overexpression or complete absence" showed high diagnostic accuracy (AUC = 0.9088 and 0.9030, respectively). The subgroup with "overexpression" and NGS showed the best results, with very high diagnostic accuracy (AUC = 0.9927). In conclusion, immunohistochemistry for p53 is a highly accurate surrogate of TP53 sequencing. Overexpression of p53 in ≥70-80% showed the best accuracy in predicting TP53 mutations. Further studies in this field should adopt optimized immunohistochemical procedures and take into account less common p53 patterns (e.g. cytoplasmic expression).

Impact of TP53 immunohistochemistry on the histological grading system for endometrial endometrioid carcinoma

Endometrial endometrioid carcinoma is usually divided into three histological subgroups: grade 1 (G1), grade 2 (G2), and grade 3 (G3). Most cases of endometrial endometrioid carcinoma G1/2 have a favorable prognosis, although some can have unfavorable outcomes, especially when they involve elderly patients, with similarities to endometrioid carcinoma G3 and serous carcinoma. This retrospective study evaluated whether TP53 abnormalities in endometrial endometrioid carcinoma could be used to supplement the current grading system and improve its ability to predict clinical outcomes. Immunohistochemical expression of TP53 was analyzed using tissue microarrays from the surgically resected specimens of 475 patients with endometrial endometrioid carcinoma. Weak or moderate expression was defined as TP53-normal expression, while absent or strongly positive expression was defined as TP53-aberrant expression. The endometrial endometrioid carcinomas had originally been diagnosed as G1 (69%), G2 (18%), and G3 (13%). Univariate analyses revealed that TP53-aberrant expression was associated with poor survival in G1 and G2 cases, but not G3 cases. In addition, age (<60 years vs. ≥60 years) was correlated with TP53-aberrant expression in G1 cases (3% vs. 16%, p = 0.001), but not in G2 or G3 cases. Based on immunohistochemical TP53 expression, the endometrial endometrioid carcinomas were reclassified using a prognostic grading system as high-grade (G1 or G2 with TP53- aberrant expression, and G3 with TP53-normal or -aberrant expression) or low-grade (G1 or G2 with TP53-normal expression). The multivariate analyses revealed that the prognostic grading system (using histological grade and TP53 expression) could independently predict poor progression-free survival (hazard ratio: 2.91, p < 0.001) and overall survival (hazard ratio: 3.62, p < 0.001). Therefore, combining immunohistochemical TP53 expression with the traditional histological grading system for endometrial endometrioid carcinoma may help improve its ability to accurately predict the patient's prognosis.

Identification of key genes and pathways between type I and type II endometrial cancer using bioinformatics analysis

Endometrial carcinoma (EC) is a common malignant neoplasm of the female reproductive tract. The malignant degree of type II EC is much greater than that of type I EC, usually presenting with a high recurrence rate and a poor prognosis. Therefore, the present study aimed to examine the principal genes associated with the degree of differentiation in type I and type II EC and reveal their potential mechanisms. Differentially expressed genes (DEGs) were selected from the gene expression profiles derived from The Cancer Genome Atlas. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted. In the present study, the KEGG pathway enrichment analysis revealed that 5,962 upregulated DEGs were significantly enriched in the ‘p53 signaling pathway’ and involved in ‘lysine degradation’. In addition, 3,709 downregulated DEGs were enriched in ‘pathways in cancer’, as well as ‘tight junction regulation’, the ‘cell cycle’ and the ‘Wnt signaling pathway’. The 13 top hub genes MAPK1, PHLPP1, ESR1, MDM2, CDKN2A, CDKN1A, AURKA, BCL2L1, POLQ, PIK3R3, RHOQ, EIF4E and LATS2 were identified via the protein-protein interaction network. Furthermore, the OncoPrint algorithm from cBioPortal declared that 25% of EC cases carried genetic alterations. The altered DEGs (MAPK1, MDM2, AURKA, EIF4E and LATS2) may be involved in tumor differentiation and may be valuable diagnostic biomarkers. In conclusion, a number of principal genes were identified in the present study that may be determinants of poorly differentiated type II EC carcinogenesis, which may contribute to future research into potential molecular mechanisms. In addition, these genes may help identify candidate biomarkers and novel therapeutic targets for type II EC.

A Transcriptionally Distinct CXCL13+CD103+CD8+ T-cell Population Is Associated with B-cell Recruitment and Neoantigen Load in Human Cancer

The chemokine CXCL13 mediates recruitment of B cells to tumors and is essential for the formation of tertiary lymphoid structures (TLSs). TLSs are thought to support antitumor immunity and are associated with improved prognosis. However, it remains unknown whether TLSs are formed in response to the general inflammatory character of the tumor microenvironment, or rather, are induced by (neo)antigen-specific adaptive immunity. We here report on the finding that the TGFβ-dependent CD103⁺CD8⁺ tumor-infiltrating T-cell (TIL) subpopulation expressed and produced CXCL13. Accordingly, CD8⁺ T cells from peripheral blood activated in the presence of TGFβ upregulated CD103 and secreted CXCL13. Conversely, inhibition of TGFβ receptor signaling abrogated CXCL13 production. CXCL13⁺CD103⁺CD8⁺ TILs correlated with B-cell recruitment, TLSs, and neoantigen burden in six cohorts of human tumors. Altogether, our findings indicated that TGFβ plays a noncanonical role in coordinating immune responses against human tumors and suggest a potential role for CXCL13⁺CD103⁺CD8⁺ TILs in mediating B-cell recruitment and TLS formation in human tumors.

Genomic Comparison of Endometrioid Endometrial Carcinoma and Its Precancerous Lesions in Chinese Patients by High-Depth Next Generation Sequencing

Endometrial intraepithelial neoplasia (EIN), also known as endometrial atypical hyperplasia (EAH) is believed to be the precursor lesion of endometrioid endometrial carcinoma (EEC). Many genetic factors play important roles in the process of carcinogenesis, however, the key genetic alterations from dysplasia to endometrial cancer remains poorly understood. Germline mutations in Lynch syndrome genes are associated with hereditary endometrial carcinoma. The role of other cancer susceptibility genes is unclear. The aim of this study was to investigate the genomic alterations of premalignant endometrial lesion and EEC, and to determine the prevalence of cancer predisposition gene mutations in an unselected endometrial carcinoma patient cohort. Here, we applied a comprehensive cancer gene panel (363 cancer-related genes) to capture the exomes of cancer-related genes. Samples were collected from 79 patients with EEC and 36 patients with EIN. Our results demonstrate that EIN harbors most of the driver events reported in EEC and for the first time we reported a high frequency of the amplification of VEGFB gene in endometrial cancer. Moreover, we identified four novel candidate cancer-associated genes (CTCF, ARHGAP35, NF1, and KDR) which may be crucial in the carcinogenesis of EEC. In addition, we identified 2 patients who had a deleterious germline mutation in Lynch syndrome genes (MLH1 and MLH2), and another 8 patients harbored germline mutations of 6 non-Lynch syndrome genes (MUTYH, GALNT12, POLE, MPL, ATM, and ERCC4) which may be associated with endometrial cancer. Larger series will have to be investigated to assess the risks and the proportion of endometrial cancers attributable to other genes.

Expression of p53 and PTEN in human primary endometrial carcinomas: Clinicopathological and immunohistochemical analysis and study of their concomitant expression

Endometrial carcinoma is a common malignancy of the female genital tract. Alterations in the expression levels of various oncogenes and tumor suppressor genes serve important roles in the carcinogenesis and biological behavior of endometrial carcinoma. The aim of the present study was to evaluate the combination and individual expression of p53 and phosphatase and tensin homolog (PTEN) protein in human endometrial carcinoma. In addition, the correlation of these proteins with clinicopathological parameters was also assessed. Retrospective immunohistochemical analysis of the expression of p53 and PTEN tumor suppressor proteins was conducted in 99 women with endometrial carcinoma. The overall rate of p53 and PTEN positivity was 89 and 77%, respectively, according to the sum of stain intensity and scores of immunopositive cells. The sum of p53 positivity correlated strongly with PTEN expression (ρ=0.256; P=0.044). The concomitant sum of p53 and PTEN expression was identified in 45% of patients with endometrial adenocarcinoma. Notably, the sum of the immunohistochemical expression of p53 was significantly correlated with patient age (P=0.037), histologic type (P=0.008), histologic grade (P=0.002) and fallopian and/or ovarian invasion (P=0.014). Furthermore, PTEN expression was associated with myometrial invasion (ρ=−0.377; P=0.002) and clinical stage (P=0.019). In addition, concomitant p53 and PTEN expression was correlated with patient age (P=0.008) and histologic differentiation (P=0.028). The findings indicated a correlation between the expression of p53 and PTEN in endometrial adenocarcinoma, which suggested an intrinsic association between expression levels of these tumor suppressor genes. The study also suggested that concomitant p53 and PTEN expression contributed in characterizing the tumor behavior of endometrial carcinoma. Taken together, the present study suggested the combined expression of p53 and PTEN in the development of high-grade endometrial carcinoma in older patients. In addition, the findings indicated activation of different molecular pathways in the tumor progression between low-grade and high-grade endometrial carcinomas.

Limited impact of intratumour heterogeneity on molecular risk assignment in endometrial cancer

Introduction

Individual prediction of tumour behaviour based on molecular markers may refine adjuvant treatment strategies in endometrial cancer (EC). As these molecular alterations are determined in a small tumour fraction, high intratumour heterogeneity may interfere with correct risk prediction. This study aimed to investigate to which extent intratumour heterogeneity exists for molecular markers and whether it affects the molecular risk assignment in EC.

Methods

Forty-nine ECs (three tumour blocks/case) were selected with alterations in POLE (n=10), CTNNB1 (n=8), p53 (n=10), mismatch repair (n=11), L1CAM (n=10), and ECs without any of these markers (n=9). Nine ECs carried more than one molecular marker. All 147 blocks were analysed for POLE exonuclease domain and CTNNB1 exon 3 mutations, and for p53, mismatch repair and L1CAM protein expression. All blocks were assigned to a favourable, intermediate or unfavourable risk group, based on a molecular risk assignment.

RESULTS

Concordance between the three tumour blocks for POLE and CTNNB1 mutational status, and p53, mismatch repair and L1CAM protein expression was found in 100% (48/48), 95.9% (47/49), 93.9% (46/49), 98.0% (48/49), and 91.8% (45/49) of tumours, respectively. These discordances were found in a total of nine cases (18.4%). The intratumour heterogeneity impacted the risk assignment in five cases (10.2%).

Conclusion

Intratumour heterogeneity of prognostic molecular markers in EC without morphologic heterogeneity is uncommon among three tumour fractions, affecting the molecular risk allocation in a limited number of cases. This low intratumour heterogeneity facilitates the implementation of the molecular risk assignment, advocating its use in clinical decision making.

Combined ASRGL1 and p53 immunohistochemistry as an independent predictor of survival in endometrioid endometrial carcinoma

OBJECTIVE

In clinical practise, prognostication of endometrial cancer is based on clinicopathological risk factors. The use of immunohistochemistry-based markers as prognostic tools is generally not recommended and a systematic analysis of their utility as a panel is lacking. We evaluated whether an immunohistochemical marker panel could reliably assess endometrioid endometrial cancer (EEC) outcome independent of clinicopathological information.

METHODS

A cohort of 306 EEC specimens was profiled using tissue microarray (TMA). Cost- and time-efficient immunohistochemical analysis of well-established tissue biomarkers (ER, PR, HER2, Ki-67, MLH1 and p53) and two new biomarkers (L1CAM and ASRGL1) was carried out. Statistical modelling with embedded variable selection was applied on the staining results to identify minimal prognostic panels with maximal prognostic accuracy without compromising generalizability.

RESULTS

A panel including p53 and ASRGL1 immunohistochemistry was identified as the most accurate predictor of relapse-free and disease-specific survival. Within this panel, patients were allocated into high- (5.9%), intermediate- (29.5%) and low- (64.6%) risk groups where high-risk patients had a 30-fold risk (P<0.001) of dying of EEC compared to the low-risk group.

CONCLUSIONS

P53 and ASRGL1 immunoprofiling stratifies EEC patients into three risk groups with significantly different outcomes. This simple and easily applicable panel could provide a useful tool in EEC risk stratification and guiding the allocation of treatment modalities.

ROR1 and ROR2 play distinct and opposing roles in endometrial cancer

OBJECTIVE

In recent years, the Wnt signalling pathway and the ROR1 and ROR2 receptors have been implicated in a range of gynecological cancers. These receptors have been described as prospective therapeutic targets, and this study investigated such potential in an endometrial cancer context.

METHOD

Immunohistochemistry for ROR1 and ROR2 was performed in a patient cohort, and expression was correlated with clinicopathological parameters including type, stage, grade, myometrial invasion, lymphovascular involvement, patient age and survival. The functional role of these receptors in endometrial cancer was investigated via siRNA knockdown of ROR1 and ROR2 in three cell line models (KLE, RL95-2 and MFE-319). Effects on proliferation, adhesion, migration and invasion were measured.

RESULTS

High ROR1 expression in patient samples correlated with worse overall survival (p = 0.0169) while high ROR2 expression correlated with better overall survival (p = 0.06). ROR1 knockdown in KLE cells significantly decreased proliferation (p = 0.047) and reduced migration and invasion. ROR2 knockdown in RL95-2 cells increased cell migration and invasion (p = 0.011). Double ROR1 and ROR2 knockdown in MFE-319 cells decreased adhesion and significantly increased cell migration (P = 0.008) and invasion (p < 0.001).

CONCLUSION

ROR1 and ROR2 play distinct roles in endometrial cancer. ROR1 may promote tumor progression, similar to its role in ovarian cancer, while ROR2 may act as a tumor suppressor in endometrioid endometrial cancer, similar to its role in colorectal cancer. With several ROR-targeting therapies currently in development and phase I clinical trials for other tumor types, this study supports the potential of these receptors as therapeutic targets for women with endometrial cancer.

KRAS Mutation in Gastric Cancer and Prognostication Associated with Microsatellite Instability Status

Microsatellite instability (MSI) is one of the subgroups based on the new molecular classification of gastric cancer (GC). In this study, we analyzed the role of KRAS status in MSI GC and the impact of MSI status on KRAS mutation. We performed analysis on 595 GC patients. Polymerase chain reaction (PCR) was used for the screening of KRAS mutation (exon 2) and 5 quasi-monomorphic mononucleotide repeats, namely, BAT-26, BAT-25, NR -24, NR-21, and NR-27 were used to determine the MSI status. The KRAS and MSI status were then compared with clinicopathologic data of the GC patients. MSI GC was found in 20.3% of all cases. KRAS mutation was seen in 24 patients; 18 were MSI (75%) and 6 were microsatellite stable (MSS) (25%). MSI GC patients with KRAS mutation were older and mostly female, but MSS presented more advanced T and N stage of the disease, more cardia tumors, and adjuvant treatment. Five-year survival was 72.2% for KRAS mutation patients with MSI and 0% for MSS (p < 0.001). Although KRAS mutations in GC are linked with MSI in the majority of cases, KRAS mutations with MSS status presented with a poor prognosis and a worse outcome. In multivariate analysis, MSI was associated with better survival (p < 0.001) but KRAS was with worse survival (p = 0.304). Our study suggests that KRAS mutations are based on MSI status rather than different codon subtypes of mutation, and such a division could be used to determine the GC patient outcome.

CTNNB1 (beta-catenin) mutation identifies low grade, early stage endometrial cancer patients at increased risk of recurrence

Although the majority of low grade, early stage endometrial cancer patients will have good survival outcomes with surgery alone, those patients who do recur tend to do poorly. Optimal identification of the subset of patients who are at high risk of recurrence and would benefit from adjuvant treatment has been difficult. The purpose of this study was to evaluate the impact of somatic tumor mutation on survival outcomes in this patient population. For this study, low grade was defined as endometrioid FIGO grades 1 or 2, while early stage was defined as endometrioid stages I or II (disease confined to the uterus). Next-generation sequencing was performed using panels comprised of 46-200 genes. Recurrence-free and overall survival was compared across gene mutational status in both univariate and multivariate analyses. In all, 342 patients were identified, 245 of which had endometrioid histology. For grades 1-2, stages I-II endometrioid endometrial cancer patients, age (HR 1.07, 95% CI 1.03-1.10), CTNNB1 mutation (HR 5.97, 95% CI 2.69-13.21), and TP53 mutation (HR 4.07, 95% CI 1.57-10.54) were associated with worse recurrence-free survival on multivariate analysis. When considering endometrioid tumors of all grades and stages, CTNNB1 mutant tumors were associated with significantly higher rates of grades 1-2 disease, lower rates of deep myometrial invasion, and lower rates of lymphatic/vascular space invasion. When both TP53 and CTNNB1 mutations were considered, presence of either TP53 mutation or CTNNB1 mutation remained a statistically significant predictor of recurrence-free survival on multivariate analysis and was associated with a more precise confidence interval (HR 4.69, 95% CI 2.38-9.24). Thus, mutational analysis of a 2 gene panel of CTNNB1 and TP53 can help to identify a subset of low grade, early stage endometrial cancer patients who are at high risk of recurrence.

Differential Expression and Clinical Significance of DNA Methyltransferase 3B (DNMT3B), Phosphatase and Tensin Homolog (PTEN) and Human MutL Homologs 1 (hMLH1) in Endometrial Carcinomas

BACKGROUND The aim of this study was to investigate the expression and the clinicopathologic significance of DNA methyltransferase 3B (DNMT3B), phosphatase and tensin homolog (PTEN) and human MutL homologs 1 (hMLH1) in endometrial carcinomas between Han and Uygur women in Xinjiang. MATERIAL AND METHODS The expression of DNMT3B, PTEN, and hMLH1 in endometrial carcinomas were assessed by immunohistochemistry, followed by an analysis of their relationship to clinical-pathological features and prognosis. RESULTS There were a 61.7% (95/154) overexpression of DNMT3B, 50.0% (77/154) loss of PTEN expression and 18.2% (28/154) loss of hMLH1 expression. The expression of DNMT3B and PTEN in endometrial carcinomas was statistically significantly different between Uygur women and Han women (p=0.001, p=0.010, respectively). DNMT3B expression was statistically significant based on the grade of endometrial carcinomas (p=0.031). PTEN loss was statistically significant between endometrioid carcinomas (ECs) and non endometrioid carcinomas (NECs) (p=0.040). DNMT3B expression was statistically significant in different myometrial invasion groups in Uygur women (p=0.010). Furthermore, the correlation of DNMT3B and PTEN expression was significant in endometrial carcinomas (p=0.021). PTEN expression was statistically significant in the overall survival (OS) rate of women with endometrial cancers (p=0.041). CONCLUSIONS Our findings suggest that PTEN and DNMT3B possess common regulation features as well as certain ethnic differences in expression between Han women and Uygur women. An interaction may exist in the pathogenesis of endometrial carcinoma. DNMT3B was expressed differently in cases of myometrial invasion and PTEN was associated with OS, which suggested that these molecular markers may be useful in the evaluation of the biological behavior of endometrial carcinomas and may be useful indicators of prognosis in women with endometrial carcinomas.

Exploring Morphologic and Molecular Aspects of Endometrial Cancer Under Progesterone Treatment in the Context of Fertility Preservation

OBJECTIVE

The standard treatment of early-stage (FIGO [International Federation of Gynecology and Obstetrics] I) endometrioid endometrial cancer (EEC) is hysterectomy with bilateral salpingo-oophorectomy. An alternative approach for younger women with low-grade EEC who wish to preserve fertility may be hormonal treatment. Previous studies have suggested that progesterone may elicit its antitumor effect in EEC by interacting with the Wingless (Wnt) and/or phosphatidylinositol 3-kinase (PI3K)/Akt pathways. Therefore, we explored whether common activating genetic alterations in Wnt and PI3K/Akt signaling correlated with nonresponsiveness to progesterone therapy for low-grade EEC. In addition, we investigated whether benign morphology under progesterone treatment is accompanied by the absence of genetic changes.

METHODS

We analyzed molecular alterations in the Wnt and PI3K/Akt signaling in 84 serial endometrial samples from 11 premenopausal patients with progesterone receptor-positive low-grade EEC conservatively treated with progesterone and correlated these with histological and clinical follow-up.

RESULTS

There were 6 responders and 5 nonresponders to progesterone treatment. The response rate to progesterone treatment was 55%, and the relapse rate was 83%. All responders had alterations in both the Wnt and PI3K/Akt pathway before treatment. In the nonresponder group, tumors inconsistently showed alterations in none, 1, or both pathways. Normalization of the endometrium morphology under progesterone treatment is accompanied by the absence of the genetic changes found in the specimen before treatment.

CONCLUSIONS

We found that activating molecular alterations in either Wnt or PI3K/Akt signaling pathways did not predict resistance to progesterone treatment. It seems that morphological response goes along with disappearance of the established mutations. This exploratory study suggests that Wnt or PI3K/Akt status is unable to predict response to progesterone treatment in patients with EEC.

Mismatch Repair Deficiency and Response to Immune Checkpoint Blockade

: More than 1.6 million new cases of cancer will be diagnosed in the U.S. in 2016, resulting in more than 500,000 deaths. Although chemotherapy has been the mainstay of treatment in advanced cancers, immunotherapy development, particularly with PD-1 inhibitors, has changed the face of treatment for a number of tumor types. One example is the subset of tumors characterized by mismatch repair deficiency and microsatellite instability that are highly sensitive to PD-1 blockade. Hereditary forms of cancer have been noted for more than a century, but the molecular changes underlying mismatch repair-deficient tumors and subsequent microsatellite unstable tumors was not known until the early 1990s. In this review article, we discuss the history and pathophysiology of mismatch repair, the process of testing for mismatch repair deficiency and microsatellite instability, and the role of immunotherapy in this subset of cancers.

IMPLICATIONS FOR PRACTICE

Mismatch repair deficiency has contributed to our understanding of carcinogenesis for the past 2 decades and now identifies a subgroup of traditionally chemotherapy-insensitive solid tumors as sensitive to PD-1 blockade. This article seeks to educate oncologists regarding the nature of mismatch repair deficiency, its impact in multiple tumor types, and its implications for predicting the responsiveness of solid tumors to immune checkpoint blockade.

Mismatch Repair Deficiency and Response to Immune Checkpoint Blockade

: More than 1.6 million new cases of cancer will be diagnosed in the U.S. in 2016, resulting in more than 500,000 deaths. Although chemotherapy has been the mainstay of treatment in advanced cancers, immunotherapy development, particularly with PD-1 inhibitors, has changed the face of treatment for a number of tumor types. One example is the subset of tumors characterized by mismatch repair deficiency and microsatellite instability that are highly sensitive to PD-1 blockade. Hereditary forms of cancer have been noted for more than a century, but the molecular changes underlying mismatch repair-deficient tumors and subsequent microsatellite unstable tumors was not known until the early 1990s. In this review article, we discuss the history and pathophysiology of mismatch repair, the process of testing for mismatch repair deficiency and microsatellite instability, and the role of immunotherapy in this subset of cancers.

IMPLICATIONS FOR PRACTICE

Mismatch repair deficiency has contributed to our understanding of carcinogenesis for the past 2 decades and now identifies a subgroup of traditionally chemotherapy-insensitive solid tumors as sensitive to PD-1 blockade. This article seeks to educate oncologists regarding the nature of mismatch repair deficiency, its impact in multiple tumor types, and its implications for predicting the responsiveness of solid tumors to immune checkpoint blockade.

Prognostic significance of L1CAM expression and its association with mutant p53 expression in high-risk endometrial cancer

Studies in early-stage, predominantly low- and intermediate-risk endometrial cancer have demonstrated that L1 cell adhesion molecule (L1CAM) overexpression identifies patients at increased risk of recurrence, yet its prognostic significance in high-risk endometrial cancer is unclear. To evaluate this, its frequency, and the relationship of L1CAM with the established endometrial cancer biomarker p53, we analyzed the expression of both markers by immunohistochemistry in a pilot series of 116 endometrial cancers (86 endometrioid, 30 non-endometrioid subtype) with high-risk features (such as high tumor grade and deep myometrial invasion) and correlated results with clinical outcome. We used The Cancer Genome Atlas (TCGA) endometrial cancer series to validate our findings. Using the previously reported cutoff of 10% positive staining, 51/116 (44%) tumors were classified as L1CAM-positive, with no significant association between L1CAM positivity and the rate of distant metastasis (P=0.195). However, increasing the threshold for L1CAM positivity to 50% resulted in a reduction of the frequency of L1CAM-positive tumors to 24% (28/116), and a significant association with the rate of distant metastasis (P=0.018). L1CAM expression was strongly associated with mutant p53 in the high-risk and TCGA series (P<0.001), although a substantial fraction (36% of endometrioid, 10% of non-endometrioid morphology) of p53-mutant endometrial cancers displayed <10% L1CAM positivity. Moreover, 30% of p53-wild-type non-endometrioid endometrial cancers demonstrated diffuse L1CAM staining, suggesting p53-independent mechanisms of L1CAM overexpression. In conclusion, the previously proposed threshold for L1CAM positivity of >10% does not predict prognosis in high-risk endometrial cancer, whereas an alternative threshold (>50%) does. L1CAM expression is strongly, but not universally, associated with mutant p53, and may be strong enough for clinical implementation as prognostic marker in combination with p53. The high frequency of L1CAM expression in high-risk endometrial cancers suggests that it may also be a promising therapeutic target in this tumor subset.

Measuring the biological effect of presurgical metformin treatment in endometrial cancer

Background:

Preclinical studies in endometrial cancer (EC) show that metformin reduces cellular proliferation by PI3K-AKT-mTOR inhibition. We tested the hypothesis that short-term presurgical metformin reduces cellular proliferation in atypical endometrial hyperplasia (AEH) and endometrioid EC, and assessed the feasibility of using phosphorylated PI3K-AKT-mTOR proteins as tissue end points.

Methods:

Women with AEH or EC received metformin 850 mg twice a day or no drug in the presurgical window between diagnosis and hysterectomy. Before and after the window, tissue samples were obtained; serum markers of insulin resistance (e.g. homeostasis model of assessment of insulin resistance index) were determined; and anthropometrics measured (e.g. BMI). Cell proliferation (Ki-67) and PI3K-AKT-mTOR phosphostatus were assessed by immunohistochemistry and scored blinded to treatment.

Results:

Twenty-eight metformin-treated and 12 untreated patients, well matched for age and BMI, completed the study. Metformin treatment (median 20 days, range 7–34) was associated with a 17.2% reduction in tumour Ki-67 (95% CI −27.4, −7.0, P=0.002), in a dose-dependent manner. Tumour PI3K-AKT-mTOR protein phosphostatus varied but the effects were not significant after adjusting for changes in controls.

Conclusions:

Short-term metformin was associated with reduced Ki-67 expression in EC. Changes in tumour PI3K-AKT-mTOR protein phosphostatus were seen in both groups. Future studies should address the variability attributed to different sampling techniques including devascularisation of the uterus at hysterectomy.

Systematic Analysis of Endometrial Cancer-Associated Hub Proteins Based on Text Mining

Objective. The aim of this study was to systematically characterize the expression of endometrial cancer- (EC-) associated genes and to analysis the functions, pathways, and networks of EC-associated hub proteins. Methods. Gene data for EC were extracted from the PubMed (MEDLINE) database using text mining based on NLP. PPI networks and pathways were integrated and obtained from the KEGG and other databases. Proteins that interacted with at least 10 other proteins were identified as the hub proteins of the EC-related genes network. Results. A total of 489 genes were identified as EC-related with P < 0.05, and 32 pathways were identified as significant (P < 0.05, FDR < 0.05). A network of EC-related proteins that included 271 interactions was constructed. The 17 proteins that interact with 10 or more other proteins (P < 0.05, FDR < 0.05) were identified as the hub proteins of this PPI network of EC-related genes. These 17 proteins are EGFR, MET, PDGFRB, CCND1, JUN, FGFR2, MYC, PIK3CA, PIK3R1, PIK3R2, KRAS, MAPK3, CTNNB1, RELA, JAK2, AKT1, and AKT2. Conclusion. Our data may help to reveal the molecular mechanisms of EC development and provide implications for targeted therapy for EC. However, corrections between certain proteins and EC continue to require additional exploration.

Precise Classification of Cervical Carcinomas Combined with Somatic Mutation Profiling Contributes to Predicting Disease Outcome

Introduction

Squamous cell carcinoma (SCC), adenocarcinoma (AC), and adenosquamous carcinoma (ASC) are the most common histological subtypes of cervical cancer. Differences in the somatic mutation profiles of these subtypes have been suggested. We investigated the prevalence of somatic hot-spot mutations in three well-defined cohorts of SCC, AC, and ASC and determined the additional value of mutation profiling in predicting disease outcome relative to well-established prognostic parameters.

Materials and Methods

Clinicopathological data were collected for 301 cervical tumors classified as SCC (n=166), AC (n=55), or ASC (n=80). Mass spectrometry was used to analyze 171 somatic hot-spot mutations in 13 relevant genes.

Results

In 103 (34%) tumors, 123 mutations were detected (36% in SCC, 38% in AC, and 28% in ASC), mostly in PIK3CA (20%) and KRAS (7%). PIK3CA mutations occurred more frequently in SCC than AC (25% vs. 11%, P=0.025), whereas KRAS mutations occurred more frequently in AC than SCC (24% vs. 3%, P<0.001) and ASC (24% vs. 3%, P<0.001). A positive mutation status correlated with worse disease-free survival (HR 1.57, P=0.043). In multivariate analysis, tumor diameter, parametrial infiltration, and lymph node metastasis, but not the presence of a somatic mutation, were independent predictors of survival.

Conclusion

Potentially targetable somatic mutations occurred in 34% of cervical tumors with different distributions among histological subtypes. Precise classification of cervical carcinomas in combination with mutation profiling is valuable for predicting disease outcome and may guide the development and selection of tumor-specific treatment approaches.

POLE Proofreading Mutations Elicit an Antitumor Immune Response in Endometrial Cancer

PURPOSE

Recent studies have shown that 7% to 12% of endometrial cancers are ultramutated due to somatic mutation in the proofreading exonuclease domain of the DNA replicase POLE. Interestingly, these tumors have an excellent prognosis. In view of the emerging data linking mutation burden, immune response, and clinical outcome in cancer, we investigated whether POLE-mutant endometrial cancers showed evidence of increased immunogenicity.

EXPERIMENTAL DESIGN

We examined immune infiltration and activation according to tumor POLE proofreading mutation in a molecularly defined endometrial cancer cohort including 47 POLE-mutant tumors. We sought to confirm our results by analysis of RNAseq data from the TCGA endometrial cancer series and used the same series to examine whether differences in immune infiltration could be explained by an enrichment of immunogenic neoepitopes in POLE-mutant endometrial cancers.

RESULTS

Compared with other endometrial cancers, POLE mutants displayed an enhanced cytotoxic T-cell response, evidenced by increased numbers of CD8(+) tumor-infiltrating lymphocytes and CD8A expression, enrichment for a tumor-infiltrating T-cell gene signature, and strong upregulation of the T-cell cytotoxic differentiation and effector markers T-bet, Eomes, IFNG, PRF, and granzyme B. This was accompanied by upregulation of T-cell exhaustion markers, consistent with chronic antigen exposure. In silico analysis confirmed that POLE-mutant cancers are predicted to display more antigenic neoepitopes than other endometrial cancers, providing a potential explanation for our findings.

CONCLUSIONS

Ultramutated POLE proofreading-mutant endometrial cancers are characterized by a robust intratumoral T-cell response, which correlates with, and may be caused by an enrichment of antigenic neopeptides. Our study provides a plausible mechanism for the excellent prognosis of these cancers.

Dietary phytochemicals alter epigenetic events and signaling pathways for inhibition of metastasis cascade: phytoblockers of metastasis cascade

Cancer metastasis is a multistep process in which a cancer cell spreads from the site of the primary lesion, passes through the circulatory system, and establishes a secondary tumor at a new nonadjacent organ or part. Inhibition of cancer progression by dietary phytochemicals (DPs) offers significant promise for reducing the incidence and mortality of cancer. Consumption of DPs in the diet has been linked to a decrease in the rate of metastatic cancer in a number of preclinical animal models and human epidemiological studies. DPs have been reported to modulate the numerous biological events including epigenetic events (noncoding micro-RNAs, histone modification, and DNA methylation) and multiple signaling transduction pathways (Wnt/β-catenin, Notch, Sonic hedgehog, COX-2, EGFR, MAPK-ERK, JAK-STAT, Akt/PI3K/mTOR, NF-κB, AP-1, etc.), which can play a key role in regulation of metastasis cascade. Extensive studies have also been performed to determine the molecular mechanisms underlying antimetastatic activity of DPs, with results indicating that these DPs have significant inhibitory activity at nearly every step of the metastatic cascade. DPs have anticancer effects by inducing apoptosis and by inhibiting cell growth, migration, invasion, and angiogenesis. Growing evidence has also shown that these natural agents potentiate the efficacy of chemotherapy and radiotherapy through the regulation of multiple signaling pathways. In this review, we discuss the variety of molecular mechanisms by which DPs regulate metastatic cascade and highlight the potentials of these DPs as promising therapeutic inhibitors of cancer.

Refining prognosis and identifying targetable pathways for high-risk endometrial cancer; a TransPORTEC initiative

This study aimed to investigate whether molecular analysis can be used to refine risk assessment, direct adjuvant therapy, and identify actionable alterations in high-risk endometrial cancer. TransPORTEC, an international consortium related to the PORTEC3 trial, was established for translational research in high-risk endometrial cancer. In this explorative study, routine molecular analyses were used to detect prognostic subgroups: p53 immunohistochemistry, microsatellite instability and POLE proofreading mutation. Furthermore, DNA was analyzed for hotspot mutations in 13 additional genes (BRAF, CDKNA2, CTNNB1, FBXW7, FGFR2, FGFR3, FOXL2, HRAS, KRAS, NRAS, PIK3CA, PPP2R1A, and PTEN) and protein expression of ER, PR, PTEN, and ARID1a was analyzed. Rates of distant metastasis, recurrence-free, and overall survival were calculated using the Kaplan-Meier method and log-rank test. In total, samples of 116 high-risk endometrial cancer patients were included: 86 endometrioid; 12 serous; and 18 clear cell. For endometrioid, serous, and clear cell cancers, 5-year recurrence-free survival rates were 68%, 27%, and 50% (P=0.014) and distant metastasis rates 23%, 64%, and 50% (P=0.001), respectively. Four prognostic subgroups were identified: (1) a group of p53-mutant tumors; (2) microsatellite instable tumors; (3) POLE proofreading-mutant tumors; and (4) a group with no specific molecular profile (NSMP). In group 3 (POLE-mutant; n=14) and group 2 (microsatellite instable; n=19) patients, no distant metastasis occurred, compared with 50% distant metastasis rate in group 1 (p53-mutant; n=36) and 39% in group 4 (NSMP; P<0.001). Five-year recurrence-free survival was 93% and 95% for group 3 (POLE-mutant) and group 2 (microsatellite instable) vs 42% (group 1, p53-mutant) and 52% (group 4, NSMP; P<0.001). Targetable FBXW7 and FGFR2 mutations (6%), alterations in the PI3K-AKT pathway (60%) and hormone receptor positivity (45%) were frequently found. In conclusion, molecular analysis of high-risk endometrial cancer identifies four distinct prognostic subgroups, with potential therapeutic implications. High frequencies of targetable alterations were identified and may serve as targets for individualized treatment.

Prognostic significance of POLE proofreading mutations in endometrial cancer

BACKGROUND

Current risk stratification in endometrial cancer (EC) results in frequent over- and underuse of adjuvant therapy, and may be improved by novel biomarkers. We examined whether POLE proofreading mutations, recently reported in about 7% of ECs, predict prognosis.

METHODS

We performed targeted POLE sequencing in ECs from the PORTEC-1 and -2 trials (n = 788), and analyzed clinical outcome according to POLE status. We combined these results with those from three additional series (n = 628) by meta-analysis to generate multivariable-adjusted, pooled hazard ratios (HRs) for recurrence-free survival (RFS) and cancer-specific survival (CSS) of POLE-mutant ECs. All statistical tests were two-sided.

RESULTS

POLE mutations were detected in 48 of 788 (6.1%) ECs from PORTEC-1 and-2 and were associated with high tumor grade (P < .001). Women with POLE-mutant ECs had fewer recurrences (6.2% vs 14.1%) and EC deaths (2.3% vs 9.7%), though, in the total PORTEC cohort, differences in RFS and CSS were not statistically significant (multivariable-adjusted HR = 0.43, 95% CI = 0.13 to 1.37, P = .15; HR = 0.19, 95% CI = 0.03 to 1.44, P = .11 respectively). However, of 109 grade 3 tumors, 0 of 15 POLE-mutant ECs recurred, compared with 29 of 94 (30.9%) POLE wild-type cancers; reflected in statistically significantly greater RFS (multivariable-adjusted HR = 0.11, 95% CI = 0.001 to 0.84, P = .03). In the additional series, there were no EC-related events in any of 33 POLE-mutant ECs, resulting in a multivariable-adjusted, pooled HR of 0.33 for RFS (95% CI = 0.12 to 0.91, P = .03) and 0.26 for CSS (95% CI = 0.06 to 1.08, P = .06).

CONCLUSION

POLE proofreading mutations predict favorable EC prognosis, independently of other clinicopathological variables, with the greatest effect seen in high-grade tumors. This novel biomarker may help to reduce overtreatment in EC.

The impact of microRNA-mediated PI3K/AKT signaling on epithelial-mesenchymal transition and cancer stemness in endometrial cancer

Activation of the PI3K/AKT pathway, a common mechanism in all subtypes of endometrial cancers (endometrioid and non-endometrioid tumors), has important roles in contributing to epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) features. MicroRNAs (miRNAs) are small non-coding RNA molecules that concurrently affect multiple target genes, and regulate a wide range of genes involved in modulating EMT and CSC properties. Here we overview the recent advances revealing the impact of miRNAs on EMT and CSC phenotypes in tumors including endometrial cancer via regulating PI3K/AKT pathway. MiRNAs are crucial mediators of EMT and CSC through targeting PTEN-PI3K-AKT-mTOR axis. In endometrial cancer cells, miRNAs can activate or attenuate EMT and CSC by targeting PTEN and other EMT-associated genes, such as Twist1, ZEB1 and BMI-1. More detailed studies of miRNAs will deepen our understanding of the molecular basis underlying PI3K/AKT-induced endometrial cancer initiation and progression. Targeting key signaling components of PI3K/AKT pathway by restoring or inhibiting miRNA function holds promise as a potential therapeutic approach to suppress EMT and CSC in endometrial cancer.

PI3K/Akt-mediated regulation of p53 in cancer

Mutations activating the PI3K (phosphoinositide 3-kinase)/Akt signalling pathway and inactivating the TP53 tumour-suppressor gene are common mechanisms that cancer cells require to proliferate and escape pre-programmed cell death. In a well-described mechanism, Akt mediates negative control of p53 levels through enhancing MDM2 (murine double minute 2)-mediated targeting of p53 for degradation. Accumulating evidence is beginning to suggest that, in certain circumstances, PTEN (phosphatase and tensin homologue deleted on chromosome 10)/PI3K/Akt also promotes p53 translation and protein stability, suggesting that additional mechanisms may be involved in the Akt-mediated regulation of p53 in tumours. In the present article, we discuss these aspects in the light of clinical PI3K/Akt inhibitors, where information regarding the effect on p53 activity will be a crucial factor that will undoubtedly influence therapeutic efficacy.

Lack of association between deficient mismatch repair expression and outcome in endometrial carcinomas of the endometrioid type

OBJECTIVE

Endometrial carcinomas of the endometrioid type (EEC) are associated with a good prognosis. However, about 20% of them recur and new prognostic markers are needed. Microsatellite instability (MSI), associated with mismatch repair (MMR) deficiency, is a frequent alteration in EECs that has been associated with prognosis. However, its prognostic impact on EECs remains unclear. The aim of the present study was to clarify the relationship between MMR deficiency and outcome in a large cohort of well classified EECs.

METHODS

A total of 212 EEC samples were analyzed by immunohistochemistry for the MMR genes MLH-1, MSH-2, MSH-6 and PMS-2. Kaplan-Meier survival analysis and log-rank tests were performed to study the prognostic significance of dMMR taking into account clinical and pathological parameters.

RESULTS

We observed no association between MMR deficiency and OS or PFS in our 212 EEC patients (p-value=0.6565 and 0.4380, respectively). When we performed the analysis in different FIGO-stage groups, we did not find association between MMR and OS or PFS in stages I, I/II or III/IV. When we analyzed the specific group of patients with lymphatic invasion separately, MMR expression was not associated with OS or PFS either.

CONCLUSIONS

MMR deficiency does not seem to be a good prognostic marker in endometrioid type endometrial carcinomas.

Designing a high-throughput somatic mutation profiling panel specifically for gynaecological cancers

Somatic mutations play a major role in tumour initiation and progression. The mutation status of a tumour may predict prognosis and guide targeted therapies. The majority of techniques to study oncogenic mutations require high quality and quantity DNA or are analytically challenging. Mass-spectrometry based mutation analysis however is a relatively simple and high-throughput method suitable for formalin-fixed, paraffin-embedded (FFPE) tumour material. Targeted gene panels using this technique have been developed for several types of cancer. These current cancer hotspot panels are not focussed on the genes that are most relevant in gynaecological cancers. In this study, we report the design and validation of a novel, mass-spectrometry based panel specifically for gynaecological malignancies and present the frequencies of detected mutations. Using frequency data from the online Catalogue of Somatic Mutations in Cancer, we selected 171 somatic hotspot mutations in the 13 most important genes for gynaecological cancers, being BRAF, CDKN2A, CTNNB1, FBXW7, FGFR2, FGFR3, FOXL2, HRAS, KRAS, NRAS, PIK3CA, PPP2R1A and PTEN. A total of 546 tumours (205 cervical, 227 endometrial, 89 ovarian, and 25 vulvar carcinomas) were used to test and validate our panel, and to study the prevalence and spectrum of somatic mutations in these types of cancer. The results were validated by testing duplicate samples and by allele-specific qPCR. The panel presented here using mass-spectrometry shows to be reproducible and high-throughput, and is usefull in FFPE material of low quality and quantity. It provides new possibilities for studying large numbers of gynaecological tumour samples in daily practice, and could be useful in guided therapy selection.

Does Metformin affect ER, PR, IGF-1R, β-catenin and PAX-2 expression in women with diabetes mellitus and endometrial cancer?

OBJECTIVE

Diabetes mellitus, as a risk factor for endometrial cancer (EC), causes an increase in insulin and IGF-1 concentrations in the blood serum. The increase in insulin and IGF-1 are considered mitogenic factors contributory to cancer development. Studies suggest that metformin has preventive activity, decreasing mortality and the risk of neoplasms. Since estrogen (ER), progesterone (PR) and IGF-1 (IGF-1R) receptor expression and β-catenin and PAX-2 mutations are significant in the development of endometrial cancer, it was decided to study these factors in patients with endometrial cancer and type 2 diabetes mellitus (DM2), and to establish the effects of metformin on their expression.

METHODS

The expression of ER, PR, IGF-1R, β-catenin and PAX-2 have been immunohistochemically investigated in 86 type I endometrial cancer specimens. Patients were grouped according to the presence of DM2 and the type of hypoglycemic treatment administered.

RESULTS

Comparing EC patients with DM2 and normal glycemic status, we found increased IGF-1R expression in women with DM2. A decrease in ER expression was noted in women with EC and DM2 receiving metformin as compared to women treated with insulin (p = 0.004). There was no statistically significant difference in PR, IGF-1R, β-catenin and PAX-2 expression among women receiving metformin and other hypoglycemic treatment.

CONCLUSION

Although epidemiological studies suggest the beneficial role of metformin in many human cancers, there are still few studies confirming its favorable effect on endometrial cancer. Decreased ER expression in patients receiving metformin needs further research to allow evaluation of its clinical significance.

Loss of ARID1A expression and its relationship with PI3K-Akt pathway alterations, TP53 and microsatellite instability in endometrial cancer

The switch/sucrose non-fermentable (SWI/SNF) subunit ARID1A (AT-rich interactive domain 1A gene) has been recently postulated as a novel tumor suppressor of gynecologic cancer and one of the driver genes in endometrial carcinogenesis. However, specific relationships with established molecular alterations in endometrioid endometrial cancer (EEC) are currently unknown. We analyzed the expression of ARID1A in 146 endometrial cancers (130 EECs and 16 non-EECs) in relation to alterations in the PI3K-Akt pathway (PTEN expression/KRAS/PIK3CA mutations), TP53 status (TP53 immunohistochemistry) and microsatellite instability. To discriminate between microsatellite instability due to somatic MLH1 promoter hypermethylation or germline mutations in one of the mismatch repair genes (Lynch syndrome), we included a 'Lynch syndrome set'. This set included 21 cases with confirmed germline mutations and 15 cases that were suspected to have a germline mutation. Loss of ARID1A expression was exclusively found in EECs in 31% (40/130) of the EEC cases. No loss of expression of the other subunits of the SWI/SNF complex, SMARCD3 and SMARCB1, was detected. Alterations in the PI3K-Akt pathway were more frequent when ARID1A expression was lost. Loss of ARID1A and mutant-like TP53 expression was nearly mutually exclusive (P=0.0004). In contrast to Lynch-associated tumors, a strong association between ARID1A loss and sporadic microsatellite instability was found. Only five cases (14%) of the 'Lynch syndrome set' as compared with 24 cases (75%, P<0.0001) of the sporadic microsatellite-unstable tumors showed loss of ARID1A. These observations suggest that ARID1A is a causative gene, instead of a target gene, of microsatellite instability by having a role in epigenetic silencing of the MLH1 gene in endometrial cancer.

Survival of endometrial cancer patients with lymphatic invasion and deficient mismatch repair expression

OBJECTIVE

This study examines patients under the age of 70 with endometrial cancer and lymphatic invasion or lymph node metastases. Survival of patients with loss of tumor mismatch repair expression is compared to survival of patients with normal mismatch repair expression.

METHODS

This is a retrospective review of patients treated from 1998-2009 for carcinoma of the endometrium. All patients with lymphatic invasion, including lymph node metastases, had immunohistochemical staining of the primary tumor for loss of expression of the mismatch repair genes MLH1, PMS2, MSH6, and MSH2. Overall survival and disease specific survival were compared using Kaplan-Meier plots.

RESULTS

Sixty-six patients were identified for inclusion; 26 demonstrated loss of mismatch repair expression and 40 demonstrated normal mismatch repair expression. Overall survival and disease specific survival were significantly better in the group with defective mismatch repair expression. Subgroup analysis of FIGO stage 3C patients also showed significantly better survival in patients with deficient mismatch repair expression.

CONCLUSION

For patients with endometrial cancer and lymphatic invasion, patients demonstrating loss of mismatch repair expression in the primary tumor appear to have a significantly better survival than patients with normal mismatch repair expression. Further investigation appears warranted to examine a possible role of mismatch repair expression as a prognostic marker for high risk patients with endometrial cancer.