Context-dependent environmental associations with endometrial cancer histotype and genotype.

OBJECTIVE: MLH1 loss due to MLH1 methylation, detected during Lynch syndrome screening, is one of the most common molecular changes in endometrial cancer. It is well established that environmental influences such as nutritional state can impact gene methylation, both in the germline and in a tumor. In colorectal cancer and other cancer types, aging is associated with changes in gene methylation. The objective of this study was to determine if there was an association between aging or body mass index on MLH1 methylation in sporadic endometrial cancer. METHODS: A retrospective review of patients with endometrial cancer was performed. Tumors were screened for Lynch syndrome via immunohistochemistry, with MLH1 methylation analysis performed when there was loss of MLH1 expression. Clinical information was abstracted from the medical record. RESULTS: There were 114 patients with mismatch repair deficient tumors associated with MLH1 methylation, and 349 with mismatch repair proficient tumors. Patients with mismatch repair deficient tumors were older than those whose tumors were proficient. Mismatch repair deficient tumors had a higher incidence of lymphatic/vascular space invasion. When stratified by endometrioid grade, associations with body mass index and age became apparent. Patients with endometrioid grades 1 and 2 tumors and somatic mismatch repair deficiency were significantly older, but body mass index was comparable with that of the mismatch repair intact group. For endometrioid grade 3, patient age did not significantly vary between the somatic mismatch repair deficient group and the mismatch repair intact group. In contrast, body mass index was significantly higher in the patients with grade 3 tumors with somatic mismatch repair deficiency. CONCLUSION: The relationship of MLH1 methylated endometrial cancer with age and body mass index is complex and somewhat dependent on tumor grade. As body mass index is modifiable, it is possible that weight loss induces a 'molecular switch' to alter the histologic characteristics of an endometrial cancer.

Differences in the microbial profiles of early stage endometrial cancers between Black and White women.

OBJECTIVE: Black women suffer a higher mortality from endometrial cancer (EC) than White women. Potential biological causes for this disparity include a higher prevalence of obesity and more lethal histologic/molecular subtypes. We hypothesize that another biological factor driving this racial disparity could be the EC microbiome. METHODS: Banked tumor specimens of postmenopausal, Black and White women undergoing hysterectomy for early stage endometrioid EC were identified. The microbiota of the tumors were characterized by bacterial 16S rRNA sequencing. The microbial component of endometrioid ECs in The Cancer Genome Atlas (TCGA) database were assessed for comparison. RESULTS: 95 early stage ECs were evaluated: 23 Black (24%) and 72 White (76%). Microbial diversity was increased (p < 0.001), and Firmicutes, Cyanobacteria and OD1 phyla abundance was higher in tumors from Black versus White women (p < 0.001). Genus level abundance of Dietzia and Geobacillus were found to be lower in tumors of obese Black versus obese White women (p < 0.001). Analysis of early stage ECs in TCGA found that microbial diversity was higher in ECs from Black versus White women (p < 0.05). When comparing ECs from obese Black versus obese White women, 5 bacteria distributions were distinct, with higher abundance of Lactobacillus acidophilus in ECs from Black women being the most striking difference. Similarly in TCGA, Dietzia and Geobacillus were more common in ECs from White women compared to Black. CONCLUSION: Increased microbial diversity and the distinct microbial profiles between ECs of obese Black versus obese White women suggests that intra-tumoral bacteria may contribute to EC disparities and pathogenesis.

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.

Comparison of immune infiltrates in melanoma and pancreatic cancer highlights VISTA as a potential target in pancreatic cancer.

Immune checkpoint therapy (ICT) has transformed cancer treatment in recent years; however, treatment response is not uniform across tumor types. The tumor immune microenvironment plays a critical role in determining response to ICT; therefore, understanding the differential immune infiltration between ICT-sensitive and ICT-resistant tumor types will help to develop effective treatment strategies. We performed a comprehensive analysis of the immune tumor microenvironment of an ICT-sensitive tumor (melanoma, n = 44) and an ICT-resistant tumor (pancreatic cancer, n = 67). We found that a pancreatic tumor has minimal to moderate infiltration of CD3, CD4, and CD8 T cells; however, the immune infiltrates are predominantly present in the stromal area of the tumor and are excluded from tumoral area compared with melanoma, where the immune infiltrates are primarily present in the tumoral area. Metastatic pancreatic ductal adenocarcinomas (PDACs) had a lower infiltration of total T cells compared with resectable primary PDACs, suggesting that metastatic PDACs have poor immunogenicity. Further, a significantly higher number of CD68+ macrophages and VISTA+ cells (also known as V-domain immunoglobulin suppressor of T cell activation) were found in the pancreatic stromal area compared with melanoma. We identified VISTA as a potent inhibitory checkpoint that is predominantly expressed on CD68+ macrophages on PDACs. These data suggest that VISTA may be a relevant immunotherapy target for effective treatment of patients with pancreatic cancer.

MIG-6 Is Critical for Progesterone Responsiveness in Human Complex Atypical Hyperplasia and Early-Stage Endometrial Cancer.

Women with complex atypical hyperplasia (CAH) or early-stage endometrioid endometrial cancer (EEC) are candidates for fertility preservation. The most common approach is progesterone (P4) therapy and deferral of hysterectomy until after completion of childbearing. However, P4 therapy response rates vary, and molecular mechanisms behind P4 resistance are poorly understood. One potential molecular cause of P4 resistance is a loss or attenuation of PGR expression. Mitogen-inducible gene 6 (MIG-6) is critical for P4 responsiveness. MIG-6 protein expression in the endometrial epithelial and stromal cells from women with CAH and EEC was significantly lower compared to women without CAH or EEC. The P4-responsive women (10/15) exhibited an increase of MIG-6 expression in epithelial and stromal cells compared to P4-resistant women (5/15). In addition, immunohistochemical analysis for PGR results showed that stromal PGR levels are significantly higher in P4-responsive women compared to P4-resistant women, whereas epithelial PGR expression was not different. A reverse correlation of MIG-6 and pAKT levels was observed in early-stage EEC patients. Studies strongly suggest that loss of MIG-6 and PGR and activation of pAKT lead to P4 resistance in CAH and EEC. These results will help to elucidate the molecular mechanism leading to P4 resistance in CAH and EEC.

Clinical significance of homologous recombination deficiency score testing in endometrial Cancer.

BACKGROUND: Homologous recombination deficiency (HRD) score is related to chemotherapy response in some cancers, but its role in endometrial cancer in not known. We determined frequency and clinical significance of alterations in the HR pathway in endometrial cancer. METHODS: 253 endometrioid endometrial adenocarcinoma (EEA) samples from two independent cohorts (discovery and replication) were tested for HRD score using the Myriad HRD assay, microsatellite instability (MSI) and tumor mutation burden (TMB) using a next generation sequencing assay. HRD scores were also generated on endometrial cancer cell lines and in vivo response to olaparib was assessed. RESULTS: ROC curves were employed to determine optimal cutoffs of HRD in relation to survival impact in endometrial cancer and a cutoff of HRD ≥ 4 was suggested for DFS using the discovery cohort. Patients from two independent cohorts with HRD score ≥ 4 trended toward worse survival as compared to those with HRD score < 4. Both cohorts were further separated into four groups according to molecular subtypes (TMB positive; MSI positive; HRD positive; all others). When grouped by molecular subtype, there was a significant difference between groups using an HRD ≥4 cutoff in the initial (p = 0.0024) and replication (p = 0.042) cohorts. The Hec1a model (HRD score = 19) was highly sensitive to olaparib in in vitro and in vivo experiments. CONCLUSIONS: High HRD score was associated with worse DFS in our patient cohort. These findings suggest that HRD score may have clinical utility in patients with advanced or recurrent endometrial cancer.

Endometrial biomarkers in premenopausal women with obesity: an at-risk cohort.

BACKGROUND: Obesity is a well-known risk factor for endometrial cancer, but the mechanisms of obesity-related carcinogenesis are not well defined, particularly for premenopausal women. With the continuing obesity epidemic, increases in the incidence of endometrial cancer and a younger age of diagnosis are often attributed to a hyperestrogenic state created by hormone production in adipose tissue, but significant knowledge gaps remain. The balance of estrogen-responsive signals has not been defined in the endometrium of premenopausal women with obesity, where obesity may not create hyperestrogenism in the context of ovaries being the primary source of estrogen production. Obesity is associated with a state of low-grade, chronic inflammation that can promote tumorigenesis, and it is also known that hormonal changes alter the immune microenvironment of the endometrium. However, limited research has been conducted on endometrial immune-response changes in women who have an increased risk for cancer due to obesity. OBJECTIVE: Endometrial estrogen-regulated biomarkers, previously shown to be dysregulated in endometrial cancer, were evaluated in a cohort of premenopausal women to determine if obesity is associated with differences in the biomarker expression levels, which might reflect an altered risk of developing cancer. The expression of a multiplexed panel of immune-related genes was also evaluated for expression differences related to obesity. STUDY DESIGN: Premenopausal women with a body mass index of ≥30 kg/m2 (n=97) or a body mass index of ≤25 kg/m2 (n=33) were prospectively enrolled in this cross-sectional study, which included the assessment of serum metabolic markers and a timed endometrial biopsy for pathologic evaluation, hormone-regulated biomarker analysis, and immune response gene expression analysis. Medical and gynecologic histories were obtained. Endometrial gene expression markers were also compared across the body mass index groups in a previous cohort of premenopausal women with an inherited cancer risk (Lynch syndrome). RESULTS: In addition to known systemic metabolic differences, histologically normal endometria from women with obesity showed a decrease in gene expression of progesterone receptor (P=.0027) and the estrogen-induced genes retinaldehyde dehydrogenase 2 (P=.008), insulin-like growth factor 1 (P=.016), and survivin (P=.042) when compared with women without obesity. The endometrial biomarkers insulin-like growth factor 1, survivin, and progesterone receptor remained statistically significant in multivariate linear regression models. In contrast, women with obesity and Lynch syndrome had an increased expression of insulin-like growth factor 1 (P=.017). There were no differences in endometrial proliferation, and limited endometrial immune differences were observed. CONCLUSION: When comparing premenopausal women with and without obesity in the absence of endometrial pathology or an inherited cancer risk, the expression of the endometrial biomarkers does not reflect a local hyperestrogenic environment, but it instead reflects a decreased cancer risk profile that may be indicative of a compensated state. In describing premenopausal endometrial cancer risk, it may be insufficient to attribute a high-risk state to obesity alone; further studies are warranted to evaluate individualized biomarker profiles for differences in the hormone-responsive signals or immune response. In patients with Lynch syndrome, the endometrial biomarker profile suggests that obesity further increases the risk of developing cancer.

Prospective phase II trial of levonorgestrel intrauterine device: nonsurgical approach for complex atypical hyperplasia and early-stage endometrial cancer.

BACKGROUND: The incidence of complex atypical hyperplasia and early-stage endometrioid endometrial cancer is increasing, in part owing to the epidemic of obesity, which is a risk factor tightly linked to the development of endometrial hyperplasia and cancer. The standard upfront treatment for complex atypical hyperplasia and early-stage endometrial cancer is hysterectomy. However, nonsurgical treatment of early-stage endometrial neoplasia may be necessary owing to medical comorbidities precluding surgery or desired future fertility. OBJECTIVE: This study aimed to evaluate the efficacy of the levonorgestrel intrauterine device to treat complex atypical hyperplasia and grade 1 endometrioid endometrial carcinoma. STUDY DESIGN: A single-institution, single-arm, phase II study of the levonorgestrel intrauterine device (52 mg levonorgestrel, Mirena) was conducted in patients with complex atypical hyperplasia or grade 1 endometrioid endometrial cancer. The primary endpoint was pathologic response rate at 12 months, including complete or partial response. Quality of life and toxicity were assessed. Molecular analyses for proliferation markers, hormone-regulated genes, and wingless-related integration site pathway activation were performed at baseline and 3 months. RESULTS: A total of 57 patients were treated (21 endometrial cancer, 36 complex atypical hyperplasia). The median age was 48.0 years, and the median body mass index was 45.5 kg/m2. Of the 47 evaluable patients, 12-month response rate was 83% (90% credible interval, 72.7-90.3)-37 were complete responders (8 endometrial cancer; 29 complex atypical hyperplasia), 2 were partial responders (2 endometrial cancer), 3 had stable disease (2 endometrial cancer; 1 complex atypical hyperplasia), and 5 had progressive disease (3 endometrial cancer; 2 complex atypical hyperplasia). After stratification for histology, the response rate was 90.6% for complex atypical hyperplasia and 66.7% for grade 1 endometrioid endometrial cancer. Notably, 4 patients (9.5%) experienced relapse after the initial response. Adverse events were mild, primarily irregular bleeding and cramping. Quality of life was not negatively affected. At 3 months, exogenous progesterone effect was present in 96.9% of responders (31 of 32) vs 25% of nonresponders (2 of 8) (P=.001). Nonresponders had higher baseline proliferation (Ki67) and lower dickkopf homolog 3 gene expression than responders (P=.023 and P=.030). Nonresponders had significantly different changes in secreted frizzled-related protein 1, frizzled class receptor 8, and retinaldehyde dehydrogenase 2 compared with responders. CONCLUSION: The levonorgestrel intrauterine device has a substantial activity in complex atypical hyperplasia and grade 1 endometrioid endometrial cancer, with a modest proportion demonstrating upfront progesterone resistance. Potential biomarkers were identified that may correlate with resistance to therapy; further exploration is warranted.

Pathologic distribution at the time of interval tumor reductive surgery informs personalized surgery for high-grade ovarian cancer.

INTRODUCTION: The surgical approach for interval debulking surgery after neoadjuvant chemotherapy has been extrapolated from primary tumor reductive surgery for high-grade ovarian cancer. The study objective was to compare pathologic distribution of malignancy at interval debulking surgery versus primary tumor reductive surgery. METHODS: Patients with a diagnosis of high-grade serous or mixed, non-mucinous, epithelial ovarian, fallopian tube or primary peritoneal cancer who underwent neoadjuvant chemotherapy or primary tumor reductive surgery and had at least 6 months of follow-up were identified through tumor registry at a single institution from January 1995 to April 2016. Pathologic involvement of organs was categorized as macroscopic, microscopic, or no tumor. Statistical analyses included Mann-Whitney and Fisher's exact tests. RESULTS: Of 918 patients identified, 366 (39.9%) patients underwent interval debulking surgery and 552 (60.1%) patients underwent primary tumor reductive surgery. Median age was 62.3 years (range 25.3-92.5). The majority of patients in the interval debulking surgery group were unstaged (261, 71.5%). In the patients who had a primary tumor reductive surgery, 406 (74.6%) had stage III disease. In both groups, the majority of patients had serous histology: 325 (90%) and 435 (78.8%) in the interval debulking and primary tumor reductive surgery groups, respectively. There was a statistically significant difference between disease distribution on the uterus between the groups; 31.4% of the patients undergoing interval debulking surgery had no evidence of uterine disease compared with 22.1% of primary tumor reductive surgery specimens (p<0.001). In the adnexa, there was macroscopic disease present in 253 (69.2%) and 482 (87.4%) of cases in the interval vs primary surgery groups, respectively (p<0.001). Within the omentum, no tumor was present in the omentum in 52 (14.2%) in the interval surgery group versus 91 (16.5%) in the primary surgery group (p<0.001). In the interval surgery group, there was no tumor involving the small and large bowel in 49 (13.4%) and 28 (7.7%) pathologic specimens, respectively. This was statistically significantly different from the small and large bowel in the primary surgery group, of which there was no tumor in 20 (3.6%, p<0.001) and 16 (2.9%, p<0.001) of cases, respectively. CONCLUSION: In patients undergoing interval debulking surgery, there was less macroscopic involvement of tumor in the uterus, adnexa and bowel compared with patients undergoing primary cytoreductive surgery.

MLH1-rheMac hereditary nonpolyposis colorectal cancer syndrome in rhesus macaques.

Over the past two decades, 33 cases of colonic adenocarcinomas have been diagnosed in rhesus macaques (Macaca mulatta) at the nonhuman primate colony of the Keeling Center for Comparative Medicine and Research at The University of Texas MD Anderson Cancer Center. The distinctive feature in these cases, based on PET/computed tomography (CT) imaging, was the presence of two or three tumor lesions in different locations, including proximal to the ileocecal juncture, proximal to the hepatic flexure, and/or in the sigmoid colon. These colon carcinoma lesions selectively accumulated [18F]fluorodeoxyglucose ([18F]FDG) and [18F]fluoroacetate ([18F]FACE) at high levels, reflecting elevated carbohydrate and fatty acid metabolism in these tumors. In contrast, the accumulation of [18F]fluorothymidine ([18F]FLT) was less significant, reflecting slow proliferative activity in these tumors. The diagnoses of colon carcinomas were confirmed by endoscopy. The expression of MLH1, MSH2, and MSH6 proteins and the degree of microsatellite instability (MSI) was assessed in colon carcinomas. The loss of MLH1 protein expression was observed in all tumors and was associated with a deletion mutation in the MLH1 promoter region and/or multiple single-nucleotide polymorphism (SNP) mutations in the MLH1 gene. All tumors exhibited various degrees of MSI. The pedigree analysis of this rhesus macaque population revealed several clusters of affected animals related to each other over several generations, suggesting an autosomal dominant transmission of susceptibility for colon cancer. The newly discovered hereditary nonpolyposis colorectal cancer syndrome in rhesus macaques, termed MLH1-rheMac, may serve as a model for development of novel approaches to diagnosis and therapy of Lynch syndrome in humans.

Phase II, 2-stage, 2-arm, PIK3CA mutation stratified trial of MK-2206 in recurrent endometrial cancer.

Endometrial cancers have high rates of phosphoinositide 3-kinase (PI3K) pathway alterations. MK-2206 is an allosteric inhibitor of AKT, an effector kinase of PI3K signals. We hypothesized patients with tumors harboring PIK3CA mutations would be more likely to benefit from MK-2206 than those without PIK3CA mutation. A Phase II study was performed in patients with recurrent endometrial cancer; all histologies except carcinosarcoma were eligible. Up to two prior chemotherapy lines were permitted, excluding prior treatment with PI3K pathway inhibitors. The first 18 patients were treated with MK-2206 200 mg weekly. Due to unacceptable toxicity, dose was reduced to 135 mg. Co-primary endpoints were objective response rate (ORR) and progression-free survival at 6 months (6moPFS). Thirty-seven patients were enrolled (one ineligible). By somatic PIK3CA mutation analysis, nine patients were mutant (MT) [one with partial response (PR)/6moPFS, two with 6moPFS]. Twenty-seven patients were wild-type (WT) (one PR and four 6moPFS). Most common toxicities were rash (44%), fatigue (41%), nausea (42%) and hyperglycemia (31%). Grade 3 and 4 toxicities occurred in 25 and 17% of patients, respectively. Exploratory analysis found serous histology had greater 6moPFS as compared to all other histologies (5/8 vs. 2/28, p = 0.003). PTEN expression was associated with median time to progression (p = 0.04). No other significant associations with PI3K pathway alterations were identified. There is limited single agent activity of MK-2206 in PIK3CA MT and PIK3CA WT endometrial cancer populations. Activity was detected in patients with serous histology and due to their poor outcomes warrants further study (NCT01307631).

PPARD and Interferon Gamma Promote Transformation of Gastric Progenitor Cells and Tumorigenesis in Mice.

BACKGROUND & AIMS: The peroxisome proliferator-activated receptor delta (PPARD) regulates cell metabolism, proliferation, and inflammation and has been associated with gastric and other cancers. Villin-positive epithelial cells are a small population of quiescent gastric progenitor cells. We expressed PPARD from a villin promoter to investigate the role of these cells and PPARD in development of gastric cancer. METHODS: We analyzed gastric tissues from mice that express the Ppard (PPARD1 and PPARD2 mice) from a villin promoter, and mice that did not carry this transgene (controls), by histology and immunohistochemistry. We performed cell lineage-tracing experiments and analyzed the microbiomes, chemokine and cytokine production, and immune cells and transcriptomes of stomachs of these mice. We also performed immunohistochemical analysis of PPARD levels in 2 sets of human gastric tissue microarrays. RESULTS: Thirty-eight percent of PPARD mice developed spontaneous, invasive gastric adenocarcinomas, with severe chronic inflammation. Levels of PPARD were increased in human gastric cancer tissues, compared with nontumor tissues, and associated with gastric cancer stage and grade. We found an inverse correlation between level of PPARD in tumor tissue and patient survival time. Gastric microbiomes from PPARD and control mice did not differ significantly. Lineage-tracing experiments identified villin-expressing gastric progenitor cells (VGPCs) as the origin of gastric tumors in PPARD mice. In these mice, PPARD up-regulated CCL20 and CXCL1, which increased infiltration of the gastric mucosa by immune cells. Immune cell production of inflammatory cytokines promoted chronic gastric inflammation and expansion and transformation of VGPCs, leading to tumorigenesis. We identified a positive-feedback loop between PPARD and interferon gamma signaling that sustained gastric inflammation to induce VGPC transformation and gastric carcinogenesis. CONCLUSIONS: We found PPARD overexpression in VPGCs to result in inflammation, dysplasia, and tumor formation. PPARD and VGPCs might be therapeutic targets for stomach cancer.

Variable Expression of MSH6 in Endometrial Carcinomas With Intact Mismatch Repair and With MLH1 Loss Due to MLH1 Methylation.

Immunohistochemistry for mismatch repair proteins MLH1, MSH2, MSH6, and PMS2 is an effective screen to detect individuals at risk for Lynch syndrome. College of American Pathologists guidelines stipulate that protein expression should be reported as present versus absent, as most patients with germline mutations in a mismatch repair gene have complete loss of protein expression in tumor cells. A similar approach is employed to screen for cancer patients eligible for immune checkpoint blockade. This "all or none" interpretive approach ignores substantial evidence that mismatch repair may be more finely regulated by other mechanisms. We have observed clinically that MSH6 expression is variable, even in carcinomas that are overall considered positive for MSH6 expression. A proof-of-principle study was therefore designed to more rigorously quantify the protein expression of MSH6 and its binding partner, MSH2, using image analysis applied to age-matched endometrioid grade 2 subsets that were either mismatch repair intact or MLH1-deficient due to MLH1 gene methylation. In both endometrioid groups, MSH6 expression was significantly lower than MSH2 expression. MSH6 expression increased in higher grade, mismatch repair intact serous carcinomas, but it was still significantly lower than that for MSH2. MSH2 expression was consistently high across the 3 different tumor groups. These results suggest that MSH6 expression is subject to wide fluctuations in expression, even when overall its expression is considered intact. While such fluctuations are likely not relevant for Lynch syndrome screening, they may be more impactful when considering patients eligible for immune checkpoint blockade.

The ERM family member Merlin is required for endometrial gland morphogenesis.

Disruption of endometrial gland formation or function can cause female infertility. Formation of endometrial glands via tubulogenesis of luminal epithelial cells requires the establishment and maintenance of cell polarity and cell adhesion. The FERM domain-containing protein Merlin coordinates epithelial cell polarity and cell adhesion and is critical for epithelial tissue function in the skin and kidney. We now demonstrate a requirement for Merlin in endometrial gland development. Conditional deletion of Merlin in the endometrium results in female infertility caused by the absence of gland formation. Interestingly, we observed glandular epithelial markers within discrete groups of cells in the Merlin-deficient luminal epithelium. Wnt signaling, a pathway necessary for endometrial gland development is maintained in Merlin-deficient endometrium, suggesting the glandular fate program is active. Instead, we observe increased levels of apical actin and markers indicative of high membrane tension on the basal surface of the Merlin-deficient luminal epithelium. These findings suggest that the structural integrity of the luminal epithelium during gland formation is required for appropriate endometrial tubulogenesis and tissue function. Moreover, our work implicates Merlin-dependent regulation of mechanical tension in the proper formation of endometrial gland architecture and function.

Clinical and molecular characterization of early-onset colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) incidence is increasing in adults younger than 50 years. This study evaluated clinical and molecular features to identify those features unique to early-onset CRC that differentiate these patients from patients 50 years old or older. METHODS: Baseline characteristics were evaluated according to the CRC onset age with 3 independent cohorts. A fourth cohort was used to describe the impact of age on the consensus molecular subtype (CMS) prevalence. RESULTS: This retrospective review of more than 36,000 patients with CRC showed that early-onset patients were more likely to have microsatellite instability (P = .038), synchronous metastatic disease (P = .009), primary tumors in the distal colon or rectum (P < .0001), and fewer BRAF V600 mutations (P < .001) in comparison with patients 50 years old or older. Patients aged 18 to 29 years had fewer adenomatous polyposis coli (APC) mutations (odds ratio [OR], 0.56; 95% confidence interval [CI], 0.35-0.90; P = .015) and an increased prevalence of signet ring histology (OR, 4.89; 95% CI, 3.23-7.39; P < .0001) in comparison with other patients younger than 50 years. In patients younger than 40 years, CMS1 was the most common subtype, whereas CMS3 and CMS4 were uncommon (P = .003). CMS2 was relatively stable across age groups. Early-onset patients with inflammatory bowel disease were more likely to have mucinous or signet ring histology (OR, 5.54; 95% CI, 2.24-13.74; P = .0004) and less likely to have APC mutations (OR, 0.24; 95% CI, 0.07-0.75; P = .019) in comparison with early-onset patients without predisposing conditions. CONCLUSIONS: Early-onset CRC is not only distinct from traditional CRC: special consideration should be given to and further investigations should be performed for both very young patients with CRC (18-29 years) and those with predisposing conditions. The etiology of the high rate of CMS1 in patients younger than 40 years deserves further exploration.

Identification of a subset of microsatellite-stable endometrial carcinoma with high PD-L1 and CD8+ lymphocytes.

Immune checkpoint blockade has emerged as an effective therapeutic strategy for patients with advanced cancer. Identification of biomarkers associated with treatment efficacy will help to select patients more likely to respond to this approach. High levels of microsatellite instability, tumor expression of PD-L1, high tumor mutation burden, and increased tumor-infiltrating lymphocytes have all been associated with response to checkpoint inhibitor blockade. The purpose of this study was to determine if a subset of microsatellite-stable endometrioid endometrial carcinomas have higher immune cell infiltrates and/or expression of PD-L1. PD-L1 expression and characterization of immune cell infiltrates were analyzed in 132 microsatellite stable, FIGO grade 2 endometrioid carcinomas. PD-L1 was positive in 48% (63/132) of the tumors. Tumor cell expression of PD-L1 was significantly associated with lymphatic/vascular invasion and deep myometrial invasion. PD-L1 expression was especially prominent at the invasive front and in foci of tumor-associated squamous metaplasia. Twenty-one cases (16% of the total) with more diffuse and/or especially strong PD-L1 expression were identified. This PD-L1 high subset was associated with significantly higher numbers of tumor-associated CD3+ and CD8+ lymphocytes. Only one tumor in the PD-L1 high subset harbored a POLE mutation. PTEN immunohistochemical loss, a common event in endometrioid-type endometrial carcinoma and associated with local immune suppression in melanoma, was not associated with PD-L1 expression or lymphocyte/macrophage infiltration of the tumor. These results suggest that a subset of microsatellite-stable endometrial cancers has higher expression of PD-L1 and increased tumor-associated CD3+ and CD8+ lymphocytes, characteristics more commonly associated with endometrial cancers with high levels of microsatellite instability. These results suggest that screening strategies to select only microsatellite instability-high advanced endometrial cancers for checkpoint inhibitor therapy might exclude patients who could potentially benefit from this therapeutic approach.

Targeted next-generation sequencing of endometrial cancer and matched circulating tumor DNA: identification of plasma-based, tumor-associated mutations in early stage patients.

There is currently no blood-based marker in routine use for endometrial cancer patients. Such a marker could potentially be used for early detection, but it could also help to track tumor recurrence following hysterectomy. This is important, as extra-vaginal recurrence of endometrial endometrioid adenocarcinoma is usually incurable. This proof-of-principle study was designed to determine if tumor-associated mutations could be detected in cell-free DNA from the peripheral blood of early and late stage endometrial endometrioid carcinoma patients. Approximately 90% of endometrioid carcinomas have at least one mutation in the genes CTNNB1, KRAS, PTEN, or PIK3CA. Using a custom panel targeting 30 hotspot amplicons in these four genes, next-generation sequencing was performed on cell-free DNA extracted from plasma obtained from a peripheral blood draw at the time of hysterectomy and the matching tumor DNA from 48 patients with endometrioid endometrial carcinomas. At least one mutation in the tumor was detected in 45/48 (94%) of patients. Fifteen of 45 patients (33%) had a mutation in the plasma that matched a mutation in the tumor. These same mutations were not detected in the matched negative control buffy coat. Presence of a plasma mutation was significantly associated with advanced stage at hysterectomy, deep myometrial invasion, lymphatic/vascular invasion, and primary tumor size. Detecting a plasma-based mutation was independent of the amount of cell-free DNA isolated from the plasma. Overall, 18% of early stage patients had a mutation detected in the plasma. These results demonstrate that mutations in genes relevant to endometrial cancer can be identified in the peripheral blood of patients at the time of surgery. Future studies can help to determine the post-operative time course of mutation clearance from the peripheral blood and if mutation re-emergence is predictive of recurrence.

G-protein coupled receptor 64 (GPR64) acts as a tumor suppressor in endometrial cancer.

BACKGROUND: Endometrial cancer is the most common gynecological cancer. G-protein coupled receptor 64 (GPR64) belongs to a family of adhesion GPCRs and plays an important role in male fertility. However, the function of GPR64 has not been studied in endometrial cancer. Our objective is to investigate the role of GPR64 in endometrial cancer. METHODS: We examined the levels of GPR64 in human endometrioid endometrial carcinoma by immunohistochemistry analysis. To determine a tumor suppressor role of GPR64 in endometrial cancer, we used a siRNA loss of function approach in human endometrial adenocarcinoma cell lines. RESULTS: GPR64 levels were remarkably lower in 10 of 21 (47.62%) of endometrial carcinoma samples compared to control. Depletion of GPR64 by siRNA transfection revealed an increase of colony formation ability, cell proliferation, cell migration, and invasion activity in Ishikawa and HEC1A cells. The expression of Connexin 43 (Cx43), a member of the large family of gap junction proteins, was reduced through activation of AMP-activated protein kinase (AMPK) in Ishikawa cells with GPR64-deficicy. CONCLUSIONS: These results suggest that GPR64 plays an important tumor suppressor role in endometrial cancer.

Adjuvant combined-modality therapy for stage IIIC endometrioid and non-endometrioid endometrial cancer.

OBJECTIVE: To identify the optimal adjuvant treatment regimen for patients with endometrioid and non-endometrioid node-positive endometrial cancer. METHODS: We retrospectively identified 249 women with FIGO 2009 stage IIIC endometrial cancer at our institution who underwent surgical staging from 1985 to 2015 followed by external beam radiotherapy (RT), chemotherapy (CT), or a combination of CT + RT. Survival rates were calculated using the Kaplan-Meier method. RESULTS: The 5-year disease-specific survival (DSS) rate for all patients was 65%. Adjuvant CT + RT conferred higher rates of 5-year DSS as compared to CT alone in patients with grade 3 endometrioid and non-endometrioid tumors (61% vs. 27%, P = 0.04 and 67% vs. 38%, P = 0.02, respectively). Among patients with non-endometrioid tumors, treatment with concurrent chemoradiotherapy followed by additional sequential chemotherapy had higher 5-year DSS rates than with concurrent chemoradiotherapy alone (74% vs. 50%, P = 0.02). The 3-year pelvic recurrence rate was 5% with RT ±â€¯CT and 35% with CT alone (P < 0.001) for all patients. No paraaortic nodal failures were observed following extended-field RT, but 14% of patients who received pelvic-only RT or CT alone developed recurrences in the paraaortic nodes (P < 0.001). CONCLUSIONS: Combined-modality therapy including adjuvant external beam pelvic radiotherapy yields excellent outcomes for patients with all subtypes of node-positive endometrial cancer. The most pronounced DSS advantage from adjuvant chemoradiotherapy was evident in women with non-endometrioid endometrial cancer.