Rebecca C. Arend

Multiomic Characterization of Pre- and Post-Neoadjuvant Chemotherapy–Treated Ovarian Cancer Reveals Mediators of Tumorigenesis and Chemotherapy Response

Abstract High-grade serous ovarian cancer (HGSC) accounts for more than 200,000 deaths each year. Despite recent advances in treating HGSC with neoadjuvant chemotherapy, the majority of patients ultimately develop chemotherapy resistance. HGSC is characterized by TP53 mutations and widespread copy-number alterations and occurs frequently in the setting of deleterious germline BRCA1/2 variations, but many cases lack putative driver mutations. In this study, we performed whole-exome, whole-genome, and whole-transcriptome sequencing along with mass spectrometry to characterize the molecular landscape of HGSC in 22 paired samples obtained before and after neoadjuvant chemotherapy. Responsiveness to chemotherapy was determined for each patient. Evidence at the DNA, RNA, and protein level revealed numerous defects in cell–cell and cell–matrix interactions, as well as disruption of cell polarity and cytoskeletal regulation in HGSC, indicating that defects in epithelial integrity were present in the majority of patients with HGSC. Nonresponsive HGSC harbored subclones with putative survival mutations. Additionally, ineffective nonsense-mediated decay resulted in the persistence of transcripts with frameshift mutations that were translated into aberrant proteins detectable in HGSC samples. Together, these findings suggest that HGSC may arise through defects in the maintenance of epithelial integrity that lead to the shedding of malignant cells throughout the peritoneum, and the presence of resistant subclones prior to chemotherapy may decrease the chemosensitivity of patients. Significance: Comprehensive longitudinal characterization of ovarian cancer identifies pathways that promote tumorigenesis and provides insights into regulators of chemotherapy response, which could help develop strategies to improve outcomes for patients.

Genomic alterations, molecularly targeted therapy, and survival: a real-world Endometrial Cancer Molecularly Targeted Therapy Consortium cohort study

Next-generation sequencing and tumor testing to direct therapy in advanced/recurrent endometrial cancer are frequently used, but the impact of this approach is unclear. We sought to confirm the proportion of patients with at least 1 actionable alteration and whether the use of molecularly targeted therapy was associated with improved survival in metastatic endometrial cancer. A multidisciplinary consortium was formed to study tumor testing and treatment with targeted therapies in advanced/recurrent endometrial cancer. Tumor testing and therapeutic decisions were physician's recommendations. The abstracted data included age, stage, grade, histology, race, ethnicity, treatment, genomic alterations, protein expression for Her2, p53, mismatch repair, estrogen and progesterone receptors, and survival. Statistical analyses were performed using SAS v9.4. A total of 967 patients from 12 centers were included. The median age was 64 years (range; 22-93 years). Of the participants, 68.5% were White, 24.0% were Black, 2.0% were Asian, and 92.7% were non-Hispanic. A total of 656 (67.8%) patients had recurrent/persistent disease and received a median of two (range; 0-9) therapies. 902 (93.3%) underwent tumor testing. Overall, 576 (94.0%) patients with next-generation sequencing testing had at least 1 genomic alteration in 11 pre-specified genes. The most frequent alterations were PI3K (35.8%), TP53 (34.7%), and PTEN (26.5%) mutations, respectively. A subset of 233 patients received 292 matched biologic therapies, and the median follow-up was 29.7 months, while the median progression-free survival and overall survival were 6.9 and 20.5 months, respectively. The consortium facilitated the development of real-world data on the patterns of genomic testing and molecularly targeted therapy used in a racially and geographically diverse patient cohort with advanced/recurrent endometrial cancer. Survival improved for those receiving matched biologic therapies compared to chemotherapy.

Pilot Study of Daily Exemestane in Women with Endometrial Intraepithelial Neoplasia or Low-Grade Endometrial Cancer

Abstract Purpose: To evaluate exemestane, an aromatase inhibitor, as a preventive intervention for endometrial cancer. Experimental Design: This is a multicenter, single-arm, “window of opportunity” pilot study of exemestane (25 mg daily for 21–42 days) in postmenopausal individuals undergoing hysterectomy for endometrial intraepithelial neoplasia (EIN) or low-grade endometrial cancer. The primary objective is to determine the change in proliferation, measured by Ki-67 expression, in pre- and posttreatment endometrial tissue specimens. Secondary outcomes include measurement of circulating serum estradiol and progesterone levels, pathologic response, tissue biomarkers, safety, and adverse effects. Results: Forty participants were accrued to the study. The mean body mass index was 40.3 (range, 22.8–60.5, SD = 9.8). Preoperative diagnoses included EIN (n = 11, 27.5%), grade 1 endometrial cancer (n = 26, 65%), and grade 2 endometrial cancer (n = 3, 7.5%). Median Ki-67 score decreased from 40.7% [IQR (33.9, 50.3)] at baseline to 18.1% [IQR (8.8, 31.8)] at surgery, representing a median absolute change from baseline of 20.4% [IQR (−29.9, −6.7), P < 0.001]. In a matched historic control cohort, participants also had a decrease in Ki-67 score with a median absolute change from baseline of −6.7% [IQR (−12.7, −1.3), P< 0.001]. However, the decrease in Ki-67 was greater in the study participants than the historic controls, with a median difference between the groups of −13.4% [IQR (−23.3, 6.9), P ≤ 0.01]. Both tissue estrogen receptor and progesterone receptor expression declined significantly with exemestane treatment (P < 0.001). However, serum estradiol levels did not change between baseline and after treatment (P = 0.16). Conclusions: In this pilot study, exemestane demonstrated antiproliferative effects in EIN and low-grade endometrial cancer. This agent warrants further evaluation for the prevention of endometrial cancer.

State-Specific Incidence of Endometrial Cancer in the United States by Histologic Subtype Corrected for Hysterectomy Prevalence from 2010 to 2019

Abstract Background: Accurate reporting of state-specific endometrial cancer incidence is important for informing cancer control efforts and may lead to new hypotheses about environmental and/or geographic risk factors. Previous studies have demonstrated the importance of accounting for hysterectomy prevalence when estimating state-level endometrial cancer incidence rates as hysterectomy prevalence varies by geographic region. Methods: We used the Cancer in North America Public Use Dataset produced by the North American Association of Central Cancer Registries to identify incident endometrial cancer cases among women ≥20 years of age diagnosed from 2010 to 2019. We estimated state-specific hysterectomy-corrected, age-adjusted incidence rates overall and by histology. State-specific hysterectomy prevalence data were obtained from the Behavioral Risk Factor Surveillance System. Results: Hysterectomy prevalence was highest in Southern and Midwestern states and lowest in the Northeast. Although uncorrected endometrial cancer incidence rates were highest in the Northeast, hysterectomy-corrected rates were highest in states within the Midwest and Appalachia. Geographic patterns of the hysterectomy-corrected incidence of endometrioid cancer resembled those of endometrial cancer overall. In contrast, corrected rates of non-endometrioid cancer were highest in the South and in certain states within the Northeast and Midwest. There was no overlap in the top 10 states with the highest rates of endometrioid and non-endometrioid cancers, respectively. Conclusions: State-specific, hysterectomy-corrected incidence rates of endometrial cancer vary by histology, suggesting potential differences in behavioral, sociodemographic, and/or environmental exposures at the state level. Impact: This study presents an accurate assessment of US endometrial cancer rates and emphasizes the importance of hysterectomy correction for geographic comparisons.

Bridging the Gap from Bench to Bedside: A Call for In Vivo Preclinical Models to Advance Endometrial Cancer and Cervical Cancer Immuno-oncology Research

Abstract Advanced-stage endometrial and cervical cancers are associated with poor outcomes despite contemporary advances in surgical techniques and therapeutics. Recent clinical trial results have led to a shift in the treatment paradigm for both malignancies, in which immunotherapy is now incorporated as the standard of care up front for most patients with advanced endometrial and cervical cancers as the standard of care. Impressive response rates have been observed, but unfortunately, a subset of patients do not benefit from immunotherapy, and survival remains poor. Continued preclinical research and clinical trial development are crucial for our understanding of resistance mechanisms to immunotherapy and maximization of therapeutic efficacy. In this setting, syngeneic models are preferred over xenograft models as they allow for the evaluation of the tumor–immune interaction in an immunocompetent host, most closely mimicking the tumor–immune interaction in patients with cancer. Unfortunately, significant disparities exist about syngeneic models in gynecologic malignancy, in which queries from multiple large bioscience companies confirm no commercial availability of endometrial or cervical cancer syngeneic cell lines. Published data exist about the recent development of several endometrial and cervical cancer syngeneic cell lines, warranting further investigation. Closing the disparity gap for preclinical models in endometrial and cervical cancers will support physician scientists, basic and translational researchers, and clinical trialists who are dedicated to improving outcomes for our patients with advanced disease and poor prognosis.

Contemporary Status and Frontiers of Cervical Cancer Screening in the United States

Abstract Cervical cancer screening and its implementation have evolved tremendously since the first method, cytology using the Papanicolaou stain, was introduced in the 1950s. New screening methods, such as human papillomavirus testing, have been discovered, and evidence-based changes have been made to official screening guidelines set forth by various US organizations. With the advent of a human papillomavirus vaccine in 2006 and with more recent research into populations carrying disparate burdens of cervical disease, the effectiveness of current cervical cancer screening programs is being called into question as the disease incidence has not decreased as expected in the past 20 years. This review highlights where cervical cancer screening in the United States started, the current clinical methods, and promising developments on the frontiers of screening research to introduce new screening options or improve current screening programs and outcomes. We also highlight certain population factors that hinder effective screening in high-risk groups, based on research aimed at ensuring that population-wide screening continues to be an effective strategy for reducing cervical cancer incidence and mortality.

Class I histone deacetylase inhibition promotes CD8 T cell activation in ovarian cancer

AbstractObjectivePatients with epithelial ovarian cancer (EOC) typically present with late‐stage disease, posing a significant challenge to treatment. Although taxane and platinum‐based chemotherapy plus surgical debulking are initially effective, EOC is marked by frequent recurrence with resistant disease. Immunotherapy represents an appealing treatment paradigm given the ability of immune cells to engage metastatic sites and impede recurrence; however, response rates to checkpoint blockade in ovarian cancer have been disappointing. Here, we tested whether class I HDAC inhibition can promote anti‐tumor T cell responses in a spontaneous and nonspontaneous murine model of EOC.MethodsWe used the spontaneous Tg‐MISIIR‐Tag and nonspontaneous ID8 models of murine ovarian cancer to test this hypothesis. Whole tumor transcriptional changes were assessed using the nCounter PanCancer Mouse Immune Profiling Panel. Changes in select protein expression of regulatory and effector T cells were measured by flow cytometry.ResultsWe found that treatment with the class I HDAC inhibitor entinostat upregulated pathways and genes associated with CD8 T cell cytotoxic function, while downregulating myeloid derived suppressor cell chemoattractants. Suppressive capacity of regulatory T cells within tumors and associated ascites was significantly reduced, reversing the CD8‐Treg ratio.ConclusionsOur findings suggest class I HDAC inhibition can promote activation of intratumoral CD8 T cells, potentially by compromising suppressive networks within the EOC tumor microenvironment. In this manner, class I HDAC inhibition might render advanced‐stage EOC susceptible to immunotherapeutic treatment modalities.

Neutralization of TGFβ Improves Tumor Immunity and Reduces Tumor Progression in Ovarian Carcinoma

AbstractThe immunosuppressive effects of TGFβ promotes tumor progression and diminishes response to therapy. In this study, we used ID8-p53−/− tumors as a murine model of high-grade serous ovarian cancer. An mAb targeting all three TGFβ ligands was used to neutralize TGFβ. Ascites and omentum were collected and changes in T-cell response were measured using flow. Treatment with anti-TGFβ therapy every other day following injection of tumor cells resulted in decreased ascites volume (4.1 mL vs. 0.7 mL; P < 0.001) and improved the CD8:Treg ratio (0.37 vs. 2.5; P = 0.02) compared with untreated mice. A single dose of therapy prior to tumor challenge resulted in a similar reduction of ascites volume (2.7 vs. 0.67 mL; P = 0.002) and increased CD8:Tregs ratio (0.36 vs. 1.49; P = 0.007), while also significantly reducing omental weight (114.9 mg vs. 93.4 mg; P = 0.017). Beginning treatment before inoculation with tumor cells and continuing for 6 weeks, we observe similar changes and prolonged overall survival (median 70 days vs. 57.5 days). TGFβ neutralization results in favorable changes to the T-cell response within the tumor microenvironment, leading to decreased tumor progression in ovarian cancer. The utilization of anti-TGFβ therapy may be an option for management in patients with ovarian cancer to improve clinical outcomes and warrants further investigation.