Characterization of mismatch-repair/microsatellite instability-discordant endometrial cancers.

BACKGROUND: Mismatch-repair (MMR)/microsatellite instability (MSI) status has therapeutic implications in endometrial cancer (EC). The authors evaluated the concordance of testing and factors contributing to MMR expression heterogeneity. METHODS: Six hundred sixty-six ECs were characterized using immunohistochemistry (IHC), MSI testing, and mut-L homolog 1 (MLH1) methylation. Select samples underwent whole-transcriptome analysis and next-generation sequencing. MMR expression of metastatic/recurrent sites was evaluated. RESULTS: MSI testing identified 27.3% of cases as MSI-high (n = 182), MMR IHC identified 25.1% cases as MMR-deficient (n = 167), and 3.8% of cases (n = 25) demonstrated discordant results. A review of IHC staining explained discordant results in 18 cases, revealing subclonal loss of MLH1/Pms 1 homolog 2 (PMS2) (n = 10) and heterogeneous MMR IHC (mut-S homolog 6 [MSH6], n = 7; MLH1/PMS2, n = 1). MSH6-associated Lynch syndrome was diagnosed in three of six cases with heterogeneous expression. Subclonal or heterogeneous cases had a 38.9% recurrence rate (compared with 16.7% in complete MMR-deficient cases and 9% in MMR-proficient cases) and had abnormal MMR IHC results in all metastatic recurrent sites (n = 7). Tumors with subclonal MLH1/PMS2 demonstrated 74 differentially expressed genes (determined using digital spatial transcriptomics) when stratified by MLH1 expression, including many associated with epithelial-mesenchymal transition. CONCLUSIONS: Subclonal/heterogeneous MMR IHC cases showed epigenetic loss in 66.7%, germline mutations in 16.7%, and somatic mutations in 16.7%. MMR IHC reported as intact/deficient missed 21% of cases of Lynch syndrome. EC with subclonal/heterogeneous MMR expression demonstrated a high recurrence rate, and metastatic/recurrent sites were MMR-deficient. Transcriptional analysis indicated an increased risk for migration/metastasis, suggesting that clonal MMR deficiency may be a driver for tumor aggressiveness. Reporting MMR IHC only as intact/deficient, without reporting subclonal and heterogeneous staining, misses opportunities for biomarker-directed therapy. PLAIN LANGUAGE SUMMARY: Endometrial cancer is the most common gynecologic cancer, and 20%-40% of tumors have a defect in DNA proofreading known as mismatch-repair (MMR) deficiency. These results can be used to guide therapy. Tests for this defect can yield differing results, revealing heterogeneous (mixed) proofreading capabilities. Tumors with discordant testing results and mixed MMR findings can have germline or somatic defects in MMR genes. Cells with deficient DNA proofreading in tumors with mixed MMR findings have DNA expression profiles linked to more aggressive characteristics and cancer spread. These MMR-deficient cells may drive tumor behavior and the risk of spreading cancer.

Intraluminal tumor cells and prognostic accuracy of endometrial cancer stage criteria: A multi-institution study.

OBJECTIVE: Endometrial cancer stage is a strong prognostic factor; however, the current stage classification does not incorporate transtubal spread as determined by intraluminal tumor cells (ILTCs). We examined relationships between ILTCs and survival outcomes according to histological subtype and stage and examined whether identification of ILTCs improves prognostic accuracy of endometrial cancer staging. METHODS: We conducted a retrospective cohort study of women diagnosed with endometrial cancer at five academic hospitals between 2007 and 2012. Pathologists determined ILTC presence (no vs. yes) and location (free in lumen vs. attached to epithelial surface) based on pathology review of hematoxylin and eosin-stained sections of fallopian tubes. Associations between ILTCs with time to recurrence (TTR) and overall survival (OS) were examined with Cox proportional hazards models adjusted for other prognostic factors. Model discrimination metrics were used to assess the addition of ILTCs to stage for prediction of 5-year TTR and OS. RESULTS: In the overall study population (N = 1303), ILTCs were not independently associated with TTR (HR = 0.95, 95% CI = 0.69-1.32) or OS (HR = 0.97, 95% CI = 0.72-1.31). Among 805 women with stage I disease, ILTCs were independently associated with worse TTR (HR = 2.31, 95% CI = 1.06-5.05) and OS (HR = 2.16, 95% CI = 1.14-4.11). Upstaging early-stage cases with ILTCs present did not increase model discrimination. CONCLUSION: While our data do not suggest that endometrial cancer staging guidelines should be revised to include ILTCs, associations between ILTCs and reduced survival observed among stage I cases suggest this tumor feature holds clinical relevance for subgroups of endometrial cancer patients.

Tissue factor as a novel diagnostic target for early detection of ovarian cancer using ultrasound microbubbles.

INTRODUCTION: Ovarian cancer (OC) is the deadliest gynecologic malignancy, with an overall 5-year survival rate of less than 30%. The existing paradigm for OC detection involves a serum marker, CA125, and ultrasound examination, neither of which is sufficiently specific for OC. This study addresses this deficiency through the use of a targeted ultrasound microbubble directed against tissue factor (TF). METHODS: TF expression was examined in both OC cell lines and patient-derived tumor samples via western blotting and IHC. In vivo microbubble ultrasound imaging was analyzed using high grade serous ovarian carcinoma orthotopic mouse models. RESULTS: While TF expression has previously been described on angiogenic, tumor-associated vascular endothelial cells (VECs) of several tumor types, this is first study to show TF expression on both murine and patient-derived ovarian tumor-associated VECs. Biotinylated anti-TF antibody was conjugated to streptavidin-coated microbubbles and in vitro binding assays were performed to assess the binding efficacy of these agents. TF-targeted microbubbles successfully bound to TF-expressing OC cells, as well as an in vitro model of angiogenic endothelium. In vivo, these microbubbles bound to the tumor-associated VECs of a clinically relevant orthotopic OC mouse model. CONCLUSION: Development of a TF-targeted microbubble capable of successfully detecting ovarian tumor neovasculature could have significant implications towards increasing the number of early-stage OC diagnoses. This preclinical study shows potential for translation to clinical use, which could ultimately help increase the number of early OC detections and decrease the mortality associated with this disease.

Glassy cell carcinoma of the cervix: Findings from a combined National Cancer Database analysis and single institution review of treatment patterns and outcomes.

OBJECTIVES: To describe stage, treatment patterns, and survival for glassy cell carcinoma of the cervix (GCCC), a poorly understood rare tumor. METHODS: Clinical data and survival were compared between GCCC and more common histologic types using the National Cancer Database (NCDB) from 2004 to 2017. A retrospective review of GCCC cases at our institution from 2012 to 2020 was simultaneously performed with staging updated according to 2018 FIGO staging. Descriptive statistics and survival analyses were performed, and outcomes compared to historical references. RESULTS: 143/89,001 (0.16%) NCDB cervical cancer cases were GCCC. Compared to other histologies, GCCC cases were younger, with 74.8% diagnosed before age 50. Stage distribution was similar. Stage I cases were less commonly treated with surgery alone (19/69, 27%). 79.4% of locally advanced (stage II-IVA) cases were treated with definitive chemoradiation. GCCC demonstrated worse OS for early-stage and locally-advanced disease. No survival differences were observed for patients with stage IVB disease. Our institutional review identified 14 GCCC cases. Median age at diagnosis was 34 years. All nine early-stage cases underwent radical hysterectomy. Adjuvant radiation was given for cases meeting Sedlis criteria (4/9, 44%). All five advanced stage cases were stage IIIC and received definitive chemoradiation. Recurrence rate was 0% (0/9) for early-stage and 60% (3/5) for advanced-stage cases. 3-year PFS was 100% for early-stage and 40% for advanced-stage. 3-year OS was 100% for early-stage and 60% for advanced-stage GCCC. CONCLUSIONS: GCCC presents at earlier ages than other cervical cancer histologic types. Although NCDB showed worse OS, our more contemporary institutional review, which incorporates updated staging and newer treatment modalities found outcomes more similar to historical references of more common histologic subtypes.

Determinants of Surgical Approach and Survival Among Women with Endometrial Carcinoma.

STUDY OBJECTIVE: To investigate determinants of surgical approach among women with endometrial carcinoma (EC) and associations between surgical approach and overall survival (OS). DESIGN: Retrospective cohort. SETTING: The National Cancer Database, 2010 to 2015. PATIENTS: A total of 140 470 patients with histologically confirmed EC who underwent hysterectomy. INTERVENTIONS: Patients were grouped according to surgical approach. MEASUREMENTS AND MAIN RESULTS: A total of 140 470 patients with EC were included. Robotic-assisted laparoscopy (RAL) was the most common surgical approach (48.8%), followed by laparotomy (33.6%) and traditional laparoscopy (17.6%). Use of RAL increased over the study period, and the percentages of cases managed by laparotomy decreased. Older women, those with insurance, residing in ZIP codes with lower proportions of individuals who did not graduate from high school, and those treated at noncommunity cancer programs were less likely to undergo laparotomy than RAL, and non-white women, those diagnosed with high-grade histology, and those with advanced-stage EC were more likely to undergo laparotomy than RAL. Compared with RAL, all other surgical approaches were associated with worse OS (laparotomy: hazard ratio 1.21; 95% confidence interval, 1.18-1.25; traditional laparoscopy: hazard ratio 1.06; 95% confidence interval, 1.02-1.09). Significant effect modification of the surgical approach and OS relationship according to age, race, histology, stage, and adjuvant treatment was observed. CONCLUSION: RAL increased in frequency over the study period and was associated with improved OS, supporting the continued use of RAL for EC management.

Endometrial Cancer: Who Lives, Who Dies, Can We Improve Their Story?

BACKGROUND: Endometrial cancer (EC) is the most common gynecologic cancer in the U.S. The objective of this cohort study was to characterize the clinical and pathologic features that are associated with endometrial cancer-specific death for women cared for at a single National Cancer Institute-designated comprehensive cancer center. PATIENTS, MATERIALS, AND METHODS: This is a retrospective cohort from 2014 to 2017 including all women who had a hysterectomy for EC. Charts were reviewed for clinical and pathologic data, focusing on survival outcomes. RESULTS: Seven hundred seventy-one patients with EC underwent hysterectomy with 760 informative for outcomes. Seventy-six (10%) deaths were related to their EC; 62 women died from recurrent EC. Nonendometrioid histology and advanced stage were predictors of recurrence and EC death. Among patients with endometrioid ECs, mismatch repair status was significantly associated with EC-specific survival (relative risk = 4.8; 95% confidence interval, 2.3-10.3; p < .0001). Most patients with EC who recurred died of their disease 62/83 (74.7%). Nearly half of the patients that recurred (27/62) had no additional therapy at the time of recurrence. Overall survival was significantly longer for those women who had additional treatment at the time of recurrence; however, the improvement in overall survival with therapy at recurrence was largely attributable to effects in those women who were adjuvant therapy naïve. CONCLUSION: Although there is benefit of treatment at the time of recurrence for treatment-naïve women; only approximately half of patients were able to receive therapy. There is an urgent need for continued efforts for more effective EC therapy in both the front-line and recurrent setting as well as early identification of cancer diagnosis and recurrence. IMPLICATIONS FOR PRACTICE: Approximately 10% of patients died of their endometrial cancer. Most deaths were from recurrent disease; however, almost 20% of endometrial cancer deaths were within 120 days of surgery. Although treatment at the time of recurrence improves overall survival, only approximately half of patients will receive therapy at the time of recurrence. Traditional prognostic features like histology and stage remain important to predict risk of recurrence, and newer biomarkers, such as mismatch repair status, may improve risk stratification and targeted therapy. There remains an urgent need for improved therapy and early detection of diagnosis and recurrence.

Double somatic mismatch repair gene pathogenic variants as common as Lynch syndrome among endometrial cancer patients.

OBJECTIVE: Lynch syndrome is the most common cause of inherited endometrial cancer, attributable to germline pathogenic variants (PV) in mismatch repair (MMR) genes. Tumor microsatellite instability (MSI-high) and MMR IHC abnormalities are characteristics of Lynch syndrome. Double somatic MMR gene PV also cause MSI-high endometrial cancers. The aim of this study was to determine the relative frequency of Lynch syndrome and double somatic MMR PV. METHODS: 341 endometrial cancer patients enrolled in the Ohio Colorectal Cancer Prevention Initiative at The Ohio State University Comprehensive Cancer Center from 1/1/13-12/31/16. All tumors underwent immunohistochemical (IHC) staining for the four MMR proteins, MSI testing, and MLH1 methylation testing if the tumor was MMR-deficient (dMMR). Germline genetic testing for Lynch syndrome was undertaken for all cases with dMMR tumors lacking MLH1 methylation. Tumor sequencing followed if a germline MMR gene PV was not identified. RESULTS: Twenty-seven percent (91/341) of tumors were either MSI-high or had abnormal IHC indicating dMMR. As expected, most dMMR tumors had MLH1 methylation; (69, 75.8% of the dMMR cases; 20.2% of total). Among the 22 (6.5%) cases with dMMR not explained by methylation, 10 (2.9% of total) were found to have Lynch syndrome (6 MSH6, 3 MSH2, 1 PMS2). Double somatic MMR PV accounted for the remaining 12 dMMR cases (3.5% of total). CONCLUSIONS: Since double somatic MMR gene PV are as common as Lynch syndrome among endometrial cancer patients, paired tumor and germline testing for patients with non-methylated dMMR tumor may be the most efficient approach for LS screening.

Pathologic chemotherapy response score in epithelial ovarian cancer: Surgical, genetic, and survival considerations.

OBJECTIVE: A pathologic chemotherapy response score (CRS) is used to grade ovarian cancer response to neoadjuvant chemotherapy (NACT). We evaluated the prognostic significance of the CRS in a single institution cohort. METHODS: A retrospective review of all consecutive epithelial ovarian cancer patients undergoing interval debulking surgery (IDS) after NACT from 2016 to 2017 were included. Clinical, pathologic, surgical, outcomes, and genetic data were abstracted from medical records. CRS was assigned by pathology based on a section of omentum as follows: 1 = minimal response, 2 = moderate response, and 3 = near complete response. RESULTS: Among the 50 subjects, 14 (28%) were classified as CRS1, 29 (58%) as CRS2, and 7 (14%) as CRS3. The majority of patients were diagnosed with high grade serous histology (94%). Most women in this cohort underwent either an optimal or complete cytoreduction to no gross residual disease (96%). Women in the CRS2 group were most likely to have a pathogenic variant (51.7%) while those in the CRS1 were least likely (7.1%). Most women recurred regardless of CRS. CRS was not associated with progression-free survival (log-rank p = 0.82) or overall survival (log-rank p = 0.30). CONCLUSIONS: Though previous data support the use of CRS as a prognostic indicator, we failed to show a correlation between CRS and survival in our continuous single institution cohort. The high rate of optimal debulking across all CRS groups in this study may mitigate the prognostic significance of the scoring system. Nevertheless, tumors that respond poorly to traditional chemotherapy should remain of avid interest for potential novel therapies.

Intentional weight loss, weight cycling, and endometrial cancer risk: a systematic review and meta-analysis.

PURPOSE: Weight cycling, defined as intentional weight loss followed by unintentional weight regain, may attenuate the benefit of intentional weight loss on endometrial cancer risk. We summarized the literature on intentional weight loss, weight cycling after intentional weight loss, bariatric surgery, and endometrial cancer risk. METHODS: A systematic search was conducted using MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases published between January 2000 and November 2018. We followed Preferred Reporting Items of Systematic Reviews and Meta-analysis (PRISMA) guidelines. We qualitatively summarized studies related to intentional weight loss and weight cycling due to the inconsistent definition, and quantitatively summarized studies when bariatric surgery was the mechanism of intentional weight loss. RESULTS: A total of 127 full-text articles were reviewed, and 13 were included (bariatric surgery n=7, self-reported intentional weight loss n=2, self-reported weight cycling n=4). Qualitative synthesis suggested that, compared with stable weight, self-reported intentional weight loss was associated with lower endometrial cancer risk (RR range 0.61-0.96), whereas self-reported weight cycling was associated with higher endometrial cancer risk (OR range 1.07-2.33). The meta-analysis yielded a 59% lower risk of endometrial cancer following bariatric surgery (OR 0.41, 95% CI 0.22 to 0.74). CONCLUSIONS: Our findings support the notion that intentional weight loss and maintenance of a stable, healthy weight can lower endometrial cancer risk. Strategies to improve awareness and maintenance of weight loss among women with obesity are needed to reduce endometrial cancer risk.

Prospective clinical trial of robotic sentinel lymph node assessment with isosulfane blue (ISB) and indocyanine green (ICG) in endometrial cancer and the impact of ultrastaging (NCT01818739).

OBJECTIVES: To assess the performance sentinel lymph node (SLN) biopsy and effect of ultrastaging in clinically early stage endometrial cancer. METHODS: Patients with endometrial cancer prospectively enrolled after informed consent was obtained. The cervix was injected superficially with 1 mL of ISB and 1 mL of ICG (diluted 1:25) at 3 and 9 o'clock each. SLN biopsy was followed by complete pelvic lymphadenectomy (aortic lymphadenectomy at the discretion of the surgeon). Lymph nodes (LNs) were analyzed by standard sectioning with H&E; ultrastaging of SLN was done retrospectively and blinded to treating physicians. RESULTS: 204 patients received dye injections. In 184 (90.2%) patients at least one SLN was identified. Of all patients, 138 (68%) had bilateral mapping. In the patients with successful mapping of a hemipelvis, ICG detected SLNs in 83% and ISB in 64% of cases (p < 0.0001). Median BMI (kg/m2) for patients with successful mapping was 35.7 compared to 40.1 for those who did not map (p = 0.01). Twenty-three (11.3%) patients had positive LNs. Applying the SLN algorithm, positive nodes were detected in 21/23 (91.3%). The negative predictive value (NPV) was 98.9% (95% CI: 96.01% to 99.71%). Eleven patients had positive SLN with isolated tumor cells (ITCs) or micrometastases detected on ultrastaging. Including these patients, 34 (17%) had positive LNs, increasing the NPV to 99% and sensitivity to 94%. There were no recurrences in patients with ITCs only. CONCLUSIONS: SLN assessment in endometrial cancer is feasible and safe with high NPV (99%). ICG was more effective in detecting SLN compared to ISB. Although ultrastaging detected additional positive LNs, treatment based on standard sectioning appears reasonable but further research is needed.

Ovarian insufficiency and CTNNB1 mutations drive malignant transformation of endometrial hyperplasia with altered PTEN/PI3K activities.

Endometrioid endometrial carcinomas (EECs) carry multiple driver mutations even when they are low grade. However, the biological significance of these concurrent mutations is unknown. We explored the interactions among three signature EEC mutations: loss-of-function (LOF) mutations in PTEN, gain-of-function (GOF) mutations of phosphoinositide 3-kinase (PI3K), and CTNNB1 exon 3 mutations, utilizing in vivo mutagenesis of the mouse uterine epithelium. While epithelial cells with a monoallelic mutation in any one of three genes failed to propagate in the endometrium, any combination of two or more mutant alleles promoted the growth of epithelium, causing simple hyperplasia, in a dose-dependent manner. Notably, Ctnnb1 exon 3 deletion significantly increased the size of hyperplastic lesions by promoting the growth of PTEN LOF and/or PI3K GOF mutant cells through the activation of neoadenogenesis pathways. Although these three mutations were insufficient to cause EEC in intact female mice, castration triggered malignant transformation, leading to myometrial invasion and serosal metastasis. Treatment of castrated mice with progesterone or estradiol attenuated the neoplastic transformation. This study demonstrates that multiple driver mutations are required for premalignant cells to break the growth-repressing field effect of normal endometrium maintained by ovarian steroids and that CTNNB1 exon 3 mutations play critical roles in the growth of preneoplastic cells within the endometrium of premenopausal women and in the myometrial invasion of EECs in menopausal women.

Clinicopathologic characteristics, tumor infiltrating lymphocytes and programed cell death ligand-1 expression in 162 endometrial carcinomas with deficient mismatch repair function.

OBJECTIVE: Endometrial carcinoma (EC) with deficient mismatch repair (dMMR) protein has been reported to have increased tumor infiltrating lymphocytes (TILs) and programed cell death ligand-1 (PD-L1) expression. TILs and PD-L1 expression are compared between two main types of dMMR ECs (epigenetic dMMR due to MLH1 promoter methylation vs mutated dMMR due to genetic mutation). METHODS: Immunohistochemistry for PD-L1 was performed in triplicate on tissue microarray sections. TILs were semi-quantitatively evaluated on whole-slide images of whole histologic sections. The clinicopathologic characteristics together with PD-L1 expression and TILs were analyzed between mutated and epigenetic dMMR ECs. RESULTS: Of the 162 dMMR ECs identified, 126 had epigenetic dMMR and 36 had mutated dMMR. Univariate analysis demonstrated mutated dMMR ECs showed younger age, less myometrium invasion of >50%, less lymphovascular invasion, and more TILs than epigenetic dMMR ECs. Multivariate analysis demonstrated significantly younger age and more TILs in mutated dMMR ECs than in epigenetic ECs. PD-L1 expression did not show any significant difference between these two groups. Seventeen (13.5%) patients with epigenetic dMMR EC had recurrence and 13 (10.3%) patients died of disease. In contrast, only one patient with mutated dMMR EC had recurrence (3%) and died of disease (3%). CONCLUSION: ECs with mutated dMMR demonstrated significantly increased TILs than ECs with epigenetic dMMR, suggesting a stronger immune reaction and potential response to immunotherapy in these tumors.

Radiation-associated Angiosarcoma Mimicking Fallopian Tube High-grade Serous Carcinoma in a Woman With De Novo Li-Fraumeni Syndrome.

We present a case study of a woman with history of rectal adenocarcinoma, and a new diagnosis of radiation-associated angiosarcoma mimicking fallopian tube high-grade serous carcinoma who was subsequently found to have de novo Li-Fraumeni syndrome. Our objective is to highlight angiosarcoma as a potential pitfall in the diagnosis of high-grade serous carcinoma.

Postmenopausal Squamous Atypia: Cytologic Features, Hybrid Capture 2 Tests and Contribution to the ASCUS Pool.

OBJECTIVE: Postmenopausal squamous atypia (PSA) mimics squamous intraepithelial lesion (SIL). We investigate the PSA contribution to the atypical squamous cells of undetermined significance (ASCUS) pool, its cytologic features and Hybrid Capture 2 (HC2) relative light unit/cutoff (RLU/CO) values. STUDY DESIGN: 658 ASCUS Pap tests in women ≥55 years were reviewed to select those with koilocyte-like cells and/or atypical parakeratosis. Follow-up was positive when a biopsy showed SIL or carcinoma or a later HC2 test was positive. RESULTS: Sixty-nine cases (10.5%) were selected. Forty-two (60.9%) were HC2 negative, and 27 (39.1%) were HC2 positive. Follow-up was available for 23 (54.7%) HC2-negative and 19 (70.3%) HC2-positive cases. No HC2-negative (0%) and 8 HC2-positive (42.1%) cases were positive on follow-up. Within cases negative on follow-up, 3 were PSA on biopsy. PSA was characterized by perinuclear halos, mild nuclear enlargement, smooth nuclear contours, and smooth chromatin. PSA-associated RLU/CO values were 0.25-2.95. Cases with SIL or carcinoma had RLU/CO values from 3.78 to 1,241.59. CONCLUSIONS: PSA contributes 0.5-2.3% to the ASCUS pool in women ≥55 years old. HC2 testing with RLU/CO of ≥1 may result in PSA occasionally testing positive. A different cutoff is not recommended but awareness of this caveat is important.

Detection of endometrial cancer cells in the fallopian tube lumen is associated with adverse prognostic factors and reduced survival.

OBJECTIVE: Stage is a critical determinant of prognosis and treatment for endometrial cancer (EC) patients. Women who have had a tubal ligation for sterilization have improved EC survival, secondary to lower stage at presentation, suggesting that transtubal spread may represent an important route of metastasis. We evaluated detection of intraluminal tumor cells (ILTCs) in relation to tumor characteristics and survival. METHODS: One pathologist retrospectively evaluated hematoxylin and eosin sections of routinely collected fallopian tubes for ILTCs from 295 EC patients, masked to outcome. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between demographic (age, race) and clinical [FIGO 2009 stage, lymphovascular space invasion (LVSI), histological subtype] characteristics and ILTCs. Cox regression was used to estimate hazard ratios (HRs) and 95% CIs for associations between ILTCs and recurrence-free survival (RFS) and EC-specific survival, overall and stratified by histological subtype or stage. RESULTS: In univariable logistic regression models, age (55-64 vs. ≥65: OR = 3.41, 95% CI = 1.48-7.84), stage (stage IV vs. stage I OR = 14.58, 95% CI = 5.27-40.35), LVSI (OR = 2.93, 95% CI = 1.42-6.04), and histological subtype (serous vs. low-grade endometrioid OR = 3.21, 95% CI = 1.08-9.58), were associated with ILTCs. Only age and stage remained significantly associated with ILTCs in adjusted models. ILTCs were significantly associated with lower EC-specific survival among women with serous EC or stage I disease; however, adjustment for age, stage, and histology attenuated these associations. CONCLUSION: Our findings suggest that ILTCs are associated with adverse EC prognostic features and reduced survival in cases of early stage or serous histology.

Hypoxia-induced exosomes contribute to a more aggressive and chemoresistant ovarian cancer phenotype: a novel mechanism linking STAT3/Rab proteins.

Hypoxia-mediated tumor progression, metastasis, and drug resistance are major clinical challenges in ovarian cancer. Exosomes released in the hypoxic tumor microenvironment may contribute to these challenges by transferring signaling proteins between cancer cells and normal cells. We observed that ovarian cancer cells exposed to hypoxia significantly increased their exosome release by upregulating Rab27a, downregulating Rab7, LAMP1/2, NEU-1, and also by promoting a more secretory lysosomal phenotype. STAT3 knockdown in ovarian cancer cells reduced exosome release by altering the Rab family proteins Rab7 and Rab27a under hypoxic conditions. We also found that exosomes from patient-derived ascites ovarian cancer cell lines cultured under hypoxic conditions carried more potent oncogenic proteins-STAT3 and FAS that are capable of significantly increasing cell migration/invasion and chemo-resistance in vitro and tumor progression/metastasis in vivo. Hypoxic ovarian cancer cells derived exosomes (HEx) are proficient in re-programming the immortalized fallopian tube secretory epithelial cells (FT) to become pro-tumorigenic in mouse fallopian tubes. In addition, cisplatin efflux via exosomes was significantly increased in ovarian cancer cells under hypoxic conditions. Co-culture of HEx with tumor cells led to significantly decreased dsDNA damage and increased cell survival in response to cisplatin treatment. Blocking exosome release by known inhibitor Amiloride or STAT3 inhibitor and treating with cisplatin resulted in a significant increase in apoptosis, decreased colony formation, and proliferation. Our results demonstrate that HEx are more potent in augmenting metastasis/chemotherapy resistance in ovarian cancer and may serve as a novel mechanism for tumor metastasis, chemo-resistance, and a point of intervention for improving clinical outcomes.

STAT3/PIAS3 Levels Serve as "Early Signature" Genes in the Development of High-Grade Serous Carcinoma from the Fallopian Tube.

The initial molecular events that lead to malignant transformation of the fimbria of the fallopian tube (FT) through high-grade serous ovarian carcinoma (HGSC) remain poorly understood. In this study, we report that increased expression of signal transducer and activator of transcription 3 (pSTAT3 Tyr705) and suppression or loss of protein inhibitor of activated STAT3 (PIAS3) in FT likely drive HGSC. We evaluated human tissues-benign normal FT, tubal-peritoneal junction (TPJ), p53 signature FT tissue, tubal intraepithelial lesion in transition (TILT), serous tubal intraepithelial carcinoma (STIC) without ovarian cancer, and HGSC for expression of STAT3/PIAS3 (compared with their known TP53 signature) and their target proliferation genes. We observed constitutive activation of STAT3 and low levels or loss of PIAS3 in the TPJ, p53 signature, TILT, and STIC through advanced stage IV (HGSC) tissues. Elevated expression of pSTAT3 Tyr705 and decreased levels of PIAS3 appeared as early as TPJ and the trend continued until very advanced stage HGSC (compared with high PIAS3 and low pSTAT3 expression in normal benign FT). Exogenous expression of STAT3 in FT cells mediated translocation of pSTAT3 and c-Myc into the nucleus. In vivo experiments demonstrated that overexpression of STAT3 in FT secretory epithelial cells promoted tumor progression and metastasis, mimicking the clinical disease observed in patients with HGSC. Thus, we conclude that the STAT3 pathway plays a role in the development and progression of HGSC from its earliest premalignant states.Significance: Concomitant gain of pSTAT3 Tyr705 and loss of PIAS3 appear critical for initiation and development of high-grade serous carcinoma. Cancer Res; 78(7); 1739-50. ©2018 AACR.

An NRG Oncology/GOG study of molecular classification for risk prediction in endometrioid endometrial cancer.

OBJECTIVES: The purpose of this study was to assess the prognostic significance of a simplified, clinically accessible classification system for endometrioid endometrial cancers combining Lynch syndrome screening and molecular risk stratification. METHODS: Tumors from NRG/GOG GOG210 were evaluated for mismatch repair defects (MSI, MMR IHC, and MLH1 methylation), POLE mutations, and loss of heterozygosity. TP53 was evaluated in a subset of cases. Tumors were assigned to four molecular classes. Relationships between molecular classes and clinicopathologic variables were assessed using contingency tests and Cox proportional methods. RESULTS: Molecular classification was successful for 982 tumors. Based on the NCI consensus MSI panel assessing MSI and loss of heterozygosity combined with POLE testing, 49% of tumors were classified copy number stable (CNS), 39% MMR deficient, 8% copy number altered (CNA) and 4% POLE mutant. Cancer-specific mortality occurred in 5% of patients with CNS tumors; 2.6% with POLE tumors; 7.6% with MMR deficient tumors and 19% with CNA tumors. The CNA group had worse progression-free (HR 2.31, 95%CI 1.53-3.49) and cancer-specific survival (HR 3.95; 95%CI 2.10-7.44). The POLE group had improved outcomes, but the differences were not statistically significant. CNA class remained significant for cancer-specific survival (HR 2.11; 95%CI 1.04-4.26) in multivariable analysis. The CNA molecular class was associated with TP53 mutation and expression status. CONCLUSIONS: A simple molecular classification for endometrioid endometrial cancers that can be easily combined with Lynch syndrome screening provides important prognostic information. These findings support prospective clinical validation and further studies on the predictive value of a simplified molecular classification system.

Programmed Death Ligand 1 Expression Among 700 Consecutive Endometrial Cancers: Strong Association With Mismatch Repair Protein Deficiency.

OBJECTIVE: This study aims to determine the prevalence of programmed death ligand 1 (PD-L1) expression in endometrial carcinoma (EC) and determine clinical and pathological associations. METHODS: Immunohistochemistry for PD-L1 was performed on sections of a triple-core tissue microarray of 700 ECs. Positive PD-L1 expression, defined as 1% of cells staining positive, was evaluated in tumor and stromal compartments. Using age-adjusted logistic regression, we estimated odds ratios and 95% confidence intervals for associations between PD-L1 expression (overall and by staining compartment) with clinical and tumor characteristics. Kaplan-Meier plots and log-rank tests were used to evaluate associations between PD-L1 expression and EC-specific survival. RESULTS: PD-L1 expression was observed in 100 cases (14.3%), including 27 (3.9%) with expression in tumor cells only, 35 (5.0%) with expression in both tumor cells and stroma, and 38 (5.4%) with expression in stroma only. Expression was observed in ECs of different histologic types. Tumors characterized by loss of mismatch repair proteins were significantly associated with tumoral PD-L1 expression (P < 0.0001), but not with stromal PD-L1 expression. Both tumoral and stromal PD-L1 expressions were associated with high-grade endometrioid histology, nonendometrioid histology, and lymphovascular space invasion. We observed no significant associations between PD-L1 expression and EC-specific survival. CONCLUSIONS: PD-L1 is expressed in a significant proportion of EC and is associated with mismatch repair deficiency, potentially representing a mechanism of tumor immune evasion and a therapeutic target in EC.