Choosing wisely: Selecting PARP inhibitor combinations to promote anti-tumor immune responses beyond BRCA mutations.

PARP inhibitors have transformed the management of advanced high-grade serous ovarian cancer. Despite the overwhelming success of PARP inhibition, particularly in BRCA-mutated ovarian cancer, several limitations and unanswered questions remain. With PARP inhibitors now being used in earlier treatment settings, the issue of both de novo and acquired resistance mechanisms and appropriate post-PARP management are pressing concerns. In addition, the population appropriate to target with PARP inhibitors and their use in patients without BRCA mutations is controversial and evolving. In this review we will discuss exciting PARP combinations and biologic rationale for the development and selection of PARP inhibitor combinations.

Contemporary management of ovarian germ cell tumors and remaining controversies.

Ovarian germ cell tumors (GCTs) are rare in adults, but are more common in adolescents and young adults. Contemporary management of ovarian GCTs is evolving as collaboration among pediatric, medical, and gynecologic oncologists increases, and studies increasingly incorporate female adult patients. Despite an improved understanding of ovarian GCT, many questions remain. Areas of continued controversy include which stage I ovarian GCTs and immature teratomas can be observed without adjuvant therapy, appropriate risk classification for ovarian GCT, surveillance strategies, and optimal therapy for recurrence. These topics as well as active areas of clinical investigation are discussed.

Diagnosis and management of a recurrent polymerase-epsilon (POLE)-mutated endometrial cancer.

Polymerase-epsilon (POLE)-mutated carcinomas are a rare, but well-known subtype of endometrial cancer. While typically associated with good prognosis, recurrences are documented. Here we present a case of recurrent POLE-mutated endometrial cancer, discuss pathologic features, current methods of molecular classification, and explore therapeutic implications for the POLE-mutation phenotype.

Glucocorticoid receptor expression is associated with inferior overall survival independent of BRCA mutation status in ovarian cancer.

OBJECTIVE: High glucocorticoid receptor (GR) protein expression is associated with decreased progression-free survival in ovarian cancer patients and decreased sensitivity to chemotherapy in preclinical models. Prior studies suggest wild type BRCA1 promotes GR activation. The objective of this study was to characterize the relationship of tumor GR gene expression to outcome in ovarian cancer, and to evaluate the relationship of GR expression with BRCA status. METHODS: Whole exome and whole genome sequencing, gene expression, and clinical data were obtained for high-grade serous ovarian cancers in The Cancer Genome Atlas. Cases with pathogenic somatic or germline BRCA1 or BRCA2 mutations were identified and classified as BRCA mutated. High or low glucocorticoid receptor expression was defined as expression above or below median of the GR/nuclear receptor subfamily 3 C1 (NR3C1) gene level. Overall survival was estimated by the Kaplan-Meier method and compared by Cox regression analysis. RESULTS: Combined germline DNA sequencing and tumor microarray expression data were available for 222 high-grade serous ovarian cancer cases. Among these, 47 had a deleterious germline and/or somatic mutation in BRCA1 or BRCA2. In multivariate analysis, high glucocorticoid receptor gene expression was associated with decreased overall survival among ovarian cancer patients, independently of BRCA mutation status. No correlation of GR/NR3C1 gene expression with BRCA mutation status or BRCA1 or BRCA2 mRNA level was observed. CONCLUSIONS: Increased GR gene expression is associated with decreased overall survival in ovarian cancer patients, independently of BRCA mutation status. High-grade serous ovarian cancers with high GR expression and wild type BRCA have a particularly poor outcome.

Expression of glucocorticoid receptor is associated with aggressive primary endometrial cancer and increases from primary to metastatic lesions.

BACKGROUND: Glucocorticoid receptor (GR) has emerged as an important steroid nuclear receptor in hormone dependent cancers, however few data are available regarding a potential role of GR in endometrial cancer. The aim of this study was to investigate expression of GR in primary and metastatic endometrial cancer lesions, and to assess the relationship between GR expression and clinical and histopathological variables and survival. METHODS: Expression of GR was investigated by IHC in 724 primary tumors and 289 metastatic lesions (from 135 patients), and correlations with clinical and histopathological data and survival were explored. RESULTS: Expression of GR was significantly increased in non-endometrioid tumors compared to endometrioid tumors, and was associated with markers of aggressive disease and poor survival both in univariate and multivariate analysis after correcting for age, FIGO stage and histologic grade. Within the subgroups of hormone receptor negative tumors (loss of androgen receptor, estrogen receptor or progesterone receptor) expression of GR was highly significantly associated with poor disease specific survival. There was an overall increase in GR expression from primary to metastatic lesions, and the majority of metastases expressed GR. CONCLUSION: GR expression in primary endometrial cancer is associated with aggressive disease and poor survival. The majority of metastatic endometrial cancer lesions express GR; therefore GR may represent a therapeutic target in the adjuvant therapy of poor prognosis early-stage as well as metastatic endometrial cancer.

High glucocorticoid receptor expression predicts short progression-free survival in ovarian cancer.

OBJECTIVE: To investigate the association of tumor glucocorticoid receptor (GR) expression and patient outcome in ovarian cancer. METHODS: GR expression was evaluated by immunohistochemistry using tissue microarrays of specimens from 481 patients with ovarian cancer and 4 patients with benign conditions. Low GR expression was defined as an intensity of 0 or 1+ and high GR as 2+ or 3+ in >1% of tumor cells. Analyses were performed to evaluate the relationship of GR expression with clinical characteristics, progression-free survival (PFS) and overall survival (OS). RESULTS: GR protein was highly expressed in 133 of 341 (39.0%) tumors from patients who underwent upfront cytoreduction surgery followed by adjuvant chemotherapy. High GR expression was more common in serous tumors (p<0.001), high grade tumors (p<0.001), and advanced stage tumors (p=0.037). Median PFS was significantly decreased in cases with high GR (20.4months) compared to those with low GR (36.0months, HR=1.66, 95% CI 1.29-2.14, p<0.001). GR remained an independent prognostic factor for PFS in multivariate analysis. OS was not associated with GR status. CONCLUSIONS: These data suggest that high GR expression correlates with poor prognosis and support the hypothesis that modulating GR activity in combination with chemotherapy may improve outcomes.

Time-dependent transcriptional profiling links gene expression to mitogen-activated protein kinase kinase 4 (MKK4)-mediated suppression of omental metastatic colonization.

Although metastasis is the most lethal attribute of cancer, critical gaps in our knowledge of how cancer cells effectively colonize distant sites remain. For example, little is known about the cellular and molecular events that occur during the timecourse of metastatic colonization. To address this we are using the mitogen-activated protein kinase kinase 4 (MKK4) metastasis suppressor as a tool to identify these events. Specifically, we report a microarray expression-based strategy to identify genes whose transcription is altered in SKOV3ip.1 human ovarian cancer cells that express ectopic MKK4 throughout the course of in vivo metastatic colonization. The majority of genes identified fell into the categories of cytokinesis, cytoskeleton remodeling, and cell adhesion, and their expression was repressed in MKK4-expressing cells relative to vector controls. The greatest transcriptional divergence was concomitant with impaired proliferation at 14 days post injection (dpi). Specifically, 763 genes were differentially expressed (FDR < 0.05) between lesions that expressed ectopic MKK4 and paired controls. In contrast, only seven genes were differentially expressed at the experimental endpoint, when MKK4-expressing and control cells had formed macroscopic metastases. Application of our cohort of differentially expressed genes to three independent clinical datasets demonstrated a strong correlation between our findings and metastatic phenotypes in patient samples. Our results highlight the dynamic nature of metastatic colonization and reinforce the importance of examining both molecular and cellular phenotypes over time when studying metastasis formation.