Updates in therapy for uterine serous carcinoma

Immunotherapy in endometrial cancer: rationale, practice and perspectives

Tumor immunotherapy has attracted more and more attention nowadays, and multiple clinical trials have confirmed its effect in a variety of solid tumors. Immune checkpoint inhibitors (ICIs), cancer vaccines, adoptive cell transfer (ACT), and lymphocyte-promoting cytokines are the main immunotherapy methods. Endometrial cancer (EC) is one of the most frequent tumors in women and the prognosis of recurrent or metastatic EC is poor. Since molecular classification has been applied to EC, immunotherapy for different EC subtypes (especially POLE and MSI-H) has gradually attracted attention. In this review, we focus on the expression and molecular basis of the main biomarkers in the immunotherapy of EC firstly, as well as their clinical application significance and limitations. Blocking tumor immune checkpoints is one of the most effective strategies for cancer treatment in recent years, and has now become the focus in the field of tumor research and treatment. We summarized clinical date of planned and ongoing clinical trials and introduced other common immunotherapy methods in EC, such as cancer vaccine and ACT. Hormone aberrations, metabolic syndrome (MetS) and p53 mutant and that affect the immunotherapy of endometrial cancer will also be discussed in this review.

Ubiquitin Carboxyl-Terminal Hydrolase L1 (UCHL1) Promotes Uterine Serous Cancer Cell Proliferation and Cell Cycle Progression

Uterine serous carcinoma (USC) is the most aggressive form of endometrial cancer, with poor survival rates and high recurrence risk. Therefore, the purpose of this study was to identify therapeutic targets that could aid in the management of USC. By analyzing endometrial cancer samples from The Cancer Genome Atlas (TCGA), we found Ubiquitin Carboxyl-Terminal Hydrolase L1 (UCHL1) to be highly expressed in USC and to correlate with poorer overall survival. UCHL1 silencing reduced cell proliferation in vitro and in vivo, cyclin B1 protein levels and cell cycle progression. Further studies showed that UCHL1 interacts with cyclin B1 and increases cyclin B1 protein stability by deubiquitination. Treatment of USC-bearing mice with the UCHL1-specific inhibitor reduced tumor growth and improved overall survival. Our findings suggest that cyclin B1 is a novel target of UCHL1 and targeting UCHL1 is a potential therapeutic strategy for USC.

Moving forward with actionable therapeutic targets and opportunities in endometrial cancer: A NCI clinical trials planning meeting report

The incidence of endometrial cancer (EC) in the U.S. has been rising, from an estimated annual incidence of 49,560 in 2013 to 61,380 in 2017. Meanwhile, the SEER-based relative survival of women with EC in the U.S. has remained flat [82.3% from 1987 to 1989, 82.8% from 2007 to 2013] and our recent increased understanding of EC biology and subtypes has not been translated into therapeutic advances. The U.S. National Cancer Institute (NCI) therefore convened a Uterine Clinical Trials Planning Meeting in January 2016 to initiate and accelerate design of molecularly-targeted EC trials. Prior to the meeting a group of experts in this field summarized available data, emphasizing data on human samples, to identify potentially actionable alterations in EC, and the results of their work has been separately published. The Clinical Trials Meeting planners focused on discussion of (1) novel trial designs, including window-of opportunity trials and appropriate control groups for randomized trials, (2) targets specific to serous carcinoma and promises and pitfalls of separate trials for women with tumors of this histology (3) specific recommendations for future randomized trials.

Risk, risk reduction and management of occult malignancy diagnosed after uterine morcellation: a commentary

Minimally invasive surgical techniques compared with laparotomy offer the advantages of less intraoperative blood loss, shorter hospitalization, fewer wound complications and faster return to baseline activity for both hysterectomy and myomectomy. While morcellation allows for the laparoscopic removal of large specimens, it may result in intraperitoneal dissemination of benign disease or upstaging of occult malignancy leading to compromised survival. There has been heightened scrutiny over appropriate patient selection and preoperative assessment in light of recent warnings against power morcellation issued by the US FDA. This commentary therefore summarizes the magnitude of such risks associated with uterine morcellation, current national regulatory statements and potential merits of risk-reducing approaches such as contained morcellation. The importance of patient counseling is underscored.

Adjuvant carboplatin, paclitaxel, and vaginal cuff brachytherapy for stage III endometrial cancer: analysis of outcomes and patterns of recurrence based on pathologic characteristics

OBJECTIVE

The aim of this study was to evaluate outcomes of patients with stage III endometrial adenocarcinoma treated with surgery followed by adjuvant chemotherapy and vaginal cuff brachytherapy.

METHODS

We retrospectively identified 83 patients treated for 1988 International Federation of Gynecology and Obstetrics (FIGO) stage III endometrial adenocarcinoma at our institution between 2003 and 2010. All patients underwent comprehensive surgical staging. Adjuvant therapy was carboplatin and paclitaxel for 6 cycles and vaginal cuff brachytherapy. For analysis, patients were grouped into type I (FIGO grade 1-2 endometrioid histology, n = 41) or type II (FIGO grade 3, clear cell or papillary serous histology, n = 42) disease. Forty-three patients (52%) had node-positive disease, with similar node-positive rates for type I (n = 21, 51.2%) and type II (n = 22, 52.4%).

RESULTS

The median follow-up was 38.6 months. There were no isolated vaginal failures. The estimated 3-year disease-free survival (DFS) and overall survival (OS) for type I versus type II were 92.4% versus 58.0% (P = 0.001) and 97.2% versus 65.8% (P = 0.002), respectively. The 3-year DFS and OS for node negative versus node positive were 85.0% versus 63.6% (P = 0.02) and 84.2% versus 78.0% (P = 0.02), respectively. Associations between type I histology and node-negative disease with improved DFS and OS persisted on multivariate analysis.

CONCLUSIONS

Our institutional approach of adjuvant chemotherapy and vaginal cuff brachytherapy for stage III endometrial cancer seemed acceptable for patients with low-risk histology or node-negative disease. In contrast, higher rates of failure among those with high-risk histology and/or node-positive disease support intensification of therapy in these subsets.

HER2 over-expressing high grade endometrial cancer expresses high levels of p95HER2 variant

BACKGROUND

Subsets of high grade endometrial cancer (EnCa) over-express HER2 (ERBB2), yet clinical trials have failed to demonstrate any anti-tumor activity utilizing trastuzumab, an approved platform for HER2 positive breast cancer (BrCa). A truncated p95HER2 variant lacking the trastuzumab binding site may confer resistance. The objective of this investigation was to characterize the expression of the p95HER2 truncated variant in EnCa.

MATERIALS AND METHODS

With institutional approval, 86 high grade EnCa tumors were identified with tumor specimens from surgeries performed between 2000 and 2011. Clinical data were collected and all specimens underwent tumor genotyping, HER2 immunohistochemistry (IHC, HercepTest®), HER2 fluorescent in situ hybridization (FISH), along with total HER2 (H2T) and p95HER2 assessment with VeraTag® testing. Regression models were used to compare a cohort of 86 breast tumors selected for equivalent HER2 protein expression.

RESULTS

We identified 44 high grade endometrioid and 42 uterine serous carcinomas (USC). IHC identified high HER2 expression (2+ or 3+) in 59% of the tumors. HER2 gene amplification was observed in 16 tumors (12 USC, 4 endometrioid). Both HER2 gene amplification and protein expression correlated with H2T values. High p95HER2 expression above 2.8RF/mm2 was observed in 53% (n=54) with significant correlation with H2T levels. When matched to a cohort of 107 breast tumors based on HercepTest HER2 expression, high grade EnCa presented with higher p95 levels (p<0.001).

CONCLUSIONS

These data demonstrate that compared to BrCa, high grade EnCa expresses higher levels of p95HER2 possibly providing rationale for the trastuzumab resistance observed in EnCa.

Effect of mTOR inhibitors in nude mice with endometrial carcinoma and variable PTEN expression status

Background

The aim of this study was to investigate the sensitivity to rapamycin of endometrial cancer cells with different phosphatase and tensin homologue (PTEN) expression to understand the mechanism of resistance to mammalian target of rapamycin (mTOR) inhibitors in the treatment of endometrial cancer.

Material/Methods

Twenty specific pathogen-free female BALB/c mice received transplants of either HEC-1A (PTEN-positive) or Ishikawa (PTEN-negative) cells. Mice in the treatment group were injected intraperitoneally once a week for 4 consecutive weeks. The control group was injected weekly with phosphate buffer saline (PBS) for 4 consecutive weeks. Tumor volume, tumor mass, growth curves, and inhibition rate were measured, after which the mice were killed.

Results

Both tumor growth rate and size were slower in the treatment group than in the control group for all mice that received transplants of either HEC-1A or Ishikawa cells. The tumor inhibition rates in the treatment group were 48.1% and 67.1% in mice transplanted with HEC-1A and Ishikawa cells, respectively.

Conclusions

The inhibitory effects of rapamycin were enhanced in PTEN-negative Ishikawa tumor cells compared with PTEN-positive HEC-1A cells, which could explain the reduced effect of rapalogues in some endometrial cancer patients and help to understand the mechanism of resistance to this drug.

βIII-Tubulin: biomarker of taxane resistance or drug target?

INTRODUCTION

βIII-Tubulin (TUBB3) is predominantly expressed in neurons of the central and peripheral nervous systems, while in normal non-neoplastic tissues it is barely detectable. By contrast, this cytoskeletal protein is abundant in a wide range of tumors. βIII-Tubulin is linked to dynamic instability of microtubules (MTs), weakening the effects of agents interfering with MT polymerization. Based on this principle, early studies introduced the classical theory linking βIII-tubulin with a mechanism of counteracting taxane activity and accordingly, prompted its investigation as a predictive biomarker of taxane resistance.

AREAS COVERED

We reviewed 59 translational studies, including cohorts from lung, ovarian, breast, gastric, colorectal and various miscellaneous cancers subject to different chemotherapy regimens.

EXPERT OPINION

βIII-Tubulin functions more as a prognostic factor than as a predictor of response to chemotherapy. We believe this view can be explained by βIII-tubulin's association with prosurvival pathways in the early steps of the metastatic process. Its prognostic response increases if combined with additional biomarkers that regulate its expression, since βIII-tubulin can be expressed in conditions, such as estrogen exposure, unrelated to survival mechanisms and without any predictive activity. Additional avenues for therapeutic intervention could emerge if drugs are designed to directly target βIII-tubulin and its mechanism of regulation.