Phosphodiesterase 10A (PDE10A) as a novel target to suppress β-catenin and RAS signaling in epithelial ovarian cancer

A leading theory for ovarian carcinogenesis proposes that inflammation associated with incessant ovulation is a driver of oncogenesis. Consistent with this theory, nonsteroidal anti-inflammatory drugs (NSAIDs) exert promising chemopreventive activity for ovarian cancer. Unfortunately, toxicity is associated with long-term use of NSAIDs due to their cyclooxygenase (COX) inhibitory activity. Previous studies suggest the antineoplastic activity of NSAIDs is COX independent, and rather may be exerted through phosphodiesterase (PDE) inhibition. PDEs represent a unique chemopreventive target for ovarian cancer given that ovulation is regulated by cyclic nucleotide signaling. Here we evaluate PDE10A as a novel therapeutic target for ovarian cancer. Analysis of The Cancer Genome Atlas (TCGA) ovarian tumors revealed PDE10A overexpression was associated with significantly worse overall survival for patients. PDE10A expression also positively correlated with the upregulation of oncogenic and inflammatory signaling pathways. Using small molecule inhibitors, Pf-2545920 and a novel NSAID-derived PDE10A inhibitor, MCI-030, we show that PDE10A inhibition leads to decreased ovarian cancer cell growth and induces cell cycle arrest and apoptosis. We demonstrate these pro-apoptotic properties occur through PKA and PKG signaling by using specific inhibitors to block their activity. PDE10A genetic knockout in ovarian cancer cells through CRISP/Cas9 editing lead to decreased cell proliferation, colony formation, migration and invasion, and in vivo tumor growth. We also demonstrate that PDE10A inhibition leads to decreased Wnt-induced β-catenin nuclear translocation, as well as decreased EGF-mediated activation of RAS/MAPK and AKT pathways in ovarian cancer cells. These findings implicate PDE10A as novel target for ovarian cancer chemoprevention and treatment.

HER2 in Uterine Serous Carcinoma: Testing platforms and implications for targeted therapy

OBJECTIVE

HER2 is an important prognostic and therapeutic target in uterine serous carcinoma (USC). Optimal HER2 testing platforms have not been defined and guidelines for testing have changed over time. Our objective is to assess the concordance of HER2 positivity based on chromogenic in situ hybridization (CISH), immunohistochemistry (IHC), and next generation sequencing (NGS) and to determine the rate of downstream mutations that may affect response to HER2 directed therapy.

METHODS

Utilizing the Caris tumor registry, 2192 USC tumors were identified and analyzed using NGS (NextSeq, 592 Genes and WES, NovaSEQ), IHC, and CISH. PD-L1 expression was tested by IHC. Microsatellite instability was tested by fragment analysis, IHC, and NGS. Tumor mutational burden (TMB) was measured by totaling somatic mutations per tumor. HER2 positivity through IHC and CISH was determined based on 2007 and 2018 ASCO/CAP HER2 breast cancer guidelines.

RESULTS

There was a higher rate of HER2 positivity by IHC when using the 2018 guidelines compared to the 2007 guidelines (16.3% vs 12.3%). Concordance between IHC and CISH was 98.9%. ERBB2 amplification was identified by NGS in 10.5% of tumors. Compared to CISH results, this corresponds to a concordance rate of 91.6% and a positive predictive value (PPV) of 60.3%. Single gene alterations in HER2 amplified tumors that may implicate HER2 therapy resistance included PI3K (33.1%), KRAS (2.5%), and PTEN (1.3%).

CONCLUSIONS

There was high concordance between HER2 positivity based on CISH and IHC. Rate of HER2 positivity is the lowest by NGS. Ultimately these testing platforms need to be validated by response to targeted therapy.

Molecular profiles of endometrial cancer tumors among Black patients

OBJECTIVES

Disparate outcomes exist between Black and White patients with endometrial cancer (EC). One contributing factor is the disproportionately low representation of Black patients in clinical trials and in tumor molecular profiling studies. Our objective was to investigate molecular profiles of ECs in a cohort with a high proportion of tumors from Black patients.

METHODS

A total of 248 EC samples and self-reported race data were collected from 6 institutions. Comprehensive tumor profiling and analyses were performed by Caris Life Sciences.

RESULTS

Tumors from 105 (42%) Black and 143 (58%) White patients were included. Serous histology (58% vs 36%) and carcinosarcoma (25% vs 16%), was more common among Black patients, and endometrioid was less common (17% vs 48%) (p < 0.01). Differences in gene mutations between cohorts corresponded to observed histologic differences between races. Specifically, TP53 mutations were predominant in serous tumors. In endometrioid tumors, mutations in ARID1A were the most common, and high rates of MSI-H, MMRd, and TMB-H were observed. In carcinosarcoma tumors, hormone receptor expression was high in tumors of Black patients (PR 23.4%, ER 30.8%). When stratified by histology, there were no significant differences between tumors from Black and White women.

CONCLUSIONS

This cohort had a high proportion of tumors from Black women. Distinct molecular profiles were driven primarily by more aggressive histologic subtypes among Black women. Continued effort is needed to include Black women and other populations under-represented in EC molecular profiling studies as targeted therapies and personalized medicine become mainstream.

Perivascular epithelioid cell tumor (PEComa) of the uterus: Challenges of pregnancy in determining prognosis and optimal treatment

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PEComas are rare mesenchymal neoplasms with malignant potential.

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Diagnosis is difficult to make by imaging or symptoms alone.

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Diagnosis should prompt referral to a gynecologic oncologist to determine appropriate treatment strategy.

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Biopsy is warranted when abnormal findings are encountered during a surgery.

Background

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal neoplasm that exhibits immunohistochemical evidence of smooth muscle and melanocytic differentiation.

Case: We report a case of uterine PEComa in a 21 year-old primigravida, presenting at time of c-section as a small subserosal lesion that expressed soft tan-brown tissue fragments. Microscopically the cells were epithelioid, staining positive for TFE3 and HMB45. Significant cytologic atypia and mitotic activity were concerning for malignancy. The patient was treated post-partum with total robotic hysterectomy and right salpingo-oopherectomy, and is currently without evidence of disease.

Conclusion

This case of PEComa diagnosed during pregnancy highlights the importance of intra-operative biopsy and the difficulty of predicting malignant potential of PEComa in the setting of a gravid uterus with a dynamic smooth muscle architecture.

A novel proteomic-based screening method for ovarian cancer using cervicovaginal fluids: A window into the abdomen

OBJECTIVE

Our objective is to develop a site-specific proteomic-based screening test for ovarian cancer(OC) using the mucus of the cervix and vagina and evaluate a potential means for home testing.

METHODS

Cervicovaginal fluid samples were obtained from ovarian cancer and normal control patients for LC-mass spectrometry(MS) proteomic evaluation. Statistical modeling determined the protein panel with the highest penetrance across ovarian cancer samples. A subcohort of patients consented to provide self-collected vaginal samples at home with questionnaire on feasibility. Cohen's kappa methodology was utilized to determine agreement between physician-collected and patient-collected samples.

RESULTS

A total of 83 consecutive patient samples were collected prospectively (33 ovarian cancer & 50 controls). Thirty patients consented for self-collection. Using LC-MS, 30 peptides demonstrated independent statistical significance for detecting ovarian cancer. Using statistical modeling, the protein panel that determined the best predictor for detecting OC formed a "fingerprint" consisting of 5 proteins: serine proteinase inhibitor A1; periplakin; profilin1; apolipoprotein A1; and thymosin beta4-like protein. These peptides demonstrated a significant increase probability of detecting ovarian cancer with the ROC curve having an AUC of 0.86 (p = 0.00001). Physician-collected and patient-collected specimens demonstrated moderate agreement with kappa average of 0.6 with upper bound of 0.75.

CONCLUSIONS

Using novel site-specific collection methods, we identified an OC "fingerprint" with adequate sensitivity and specificity to warrant further evaluation in a larger cohort. Agreement of physician-collected and patient-collected samples were encouraging and could improve access to screening with a home self-collection if this screening test is validated in future studies.

HER2 in uterine serous carcinoma: Testing platforms and implications for targeted therapy

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Background: HER2 is an emerging prognostic and therapeutic target in uterine serous carcinoma (USC). Testing algorithms and platforms in breast and gastric cancers are well studied and validated, but optimal HER2 testing in uterine cancer is not yet established. We aimed to assess the concordance of chromogenic in situ hybridization (CISH), immunohistochemistry (IHC), and next generation sequencing (NGS) platforms to aid in the development of USC specific testing guidelines. We also evaluated the rate of downstream mutations that may affect response to HER2 directed therapy. Methods: A total of 2,192 USC tumors were analyzed using NGS (NextSeq, 592 Genes and WES, NovaSEQ), a subset of 1,423 tumors were also tested by IHC and CISH (Caris Life Sciences, Phoenix, AZ). HER2 positivity through IHC (4B5, Ventana) and CISH (INFORM DUAL HER2 ISH Assay, Ventana) was determined based on 2007 and 2018 ASCO/CAP HER2 breast cancer guidelines. PD-L1 expression was tested by IHC using SP142 (Spring Biosciences) (positive cut-off >1%). Microsatellite instability (MSI) was tested by fragment analysis (FA), IHC and NGS. Tumor mutational burden (TMB) was measured by totaling somatic mutations per tumor (TMB-high cut-off > 10 mutations per Mb). Statistical significance was determined using chi-square. Results: Rates of HER2 positivity were comparable using the 2018 and 2007 breast cancer guidelines (19.5% vs 17.5%; p=0.25). Based on 2018 guidelines, the concordance between IHC and CISH was 98.9%. Specifically, 229/1423 patients (16%) were IHC+/CISH+, 5 patients (0.4%) were IHC+/CISH- and 11 patients (0.8%) were IHC-/CISH+ (Table). Common pathway alterations in HER2+ USC include TP53, RTK RAS, PI3K, NOTCH, chromatin remodeling and cell cycle genes. Single gene alterations in HER2+ tumors that may implicate HER2 therapy resistance (based on pathway analyses in other tumor types) included PI3K (36%), KRAS (2.6%), and PTEN (2.1%). HER2+ tumors had low immunotherapy biomarker profiles (0.3% MSI-H, 0.8% TMB, 17.1% PD-L1). Conclusions: High concordance rates were observed between CISH and IHC. Ultimately these testing platforms need to be validated by response to HER2 targeted therapies in order to develop USC specific HER2 testing guidelines.[Table: see text]

Molecular determinants of response to immune-oncology therapy in uterine carcinosarcoma

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Background: Uterine carcinosarcoma (UCS) is subtype of endometrial cancer (EC) with aggressive behavior and poor prognosis. UCS has not traditionally been included in EC clinical trials and treatment options are limited. Immune-oncology (IO) therapy has shown promise UCS, but it is unknown which patients benefit most. We sought to identify immunogenic markers in UCS and explore treatment response to IO therapy. Methods: Tumor samples were analyzed using Nex-Gen sequencing of the DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ).PD-L1 IHC used SP-142 (cut-off >1%). MSI was tested by FA, IHC and NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined patient cohorts. Statistical significance was determined using chi-square and Wilcoxon rank sum test and p values adjusted for multiple comparisons (q) to be <0.05. Results: A total of 1,144 UCS tumors underwent comprehensive tumor profiling. 68.4% of samples were obtained from primary tumors and 31.6% from metastatic sites. 21.6% of tumors expressed PD-L1, 8.5% were TMB-H and 6.8% were MSI-H/MMRd. UCS patients treated with IO had longer median overall survival than those not treated with IO (months: 31.2 vs 19.4; HR(95% CI): 0.39 (0.17-0.76) p=0.005). Median OS was also increased for dMMR/MSI-H (OS not yet reached vs 18.9 months); HR(95% CI): 0.56 (0.36-0.92) p=0.019) and TMB-H (OS not yet reached vs 18.9 months); HR(95% CI): 0.62 (0.38-0.99) p=0.047). More patients are needed to determine if these markers predict response to IO therapy. The most common mutations in UCS led to pathway dysregulation in the PI3K, RAS, chromatin remodeling, HR, and WNT pathways. dMMR/MSI-H tumors have distinct molecular profiles compared to MSS tumors (table). Additionally, dMMR/MSI-H tumors had higher TMB (96.9% vs 2.2%, q<0.01) and increased frequency of PDL-1 (23.6% vs 13.8%; q=0.04). Immune checkpoint genes were more often expressed in MSI-H tumors, though this was non-significant except for IFNG (4.66-fold increase; q=0.01). Conclusions: IO therapy is associated with improved survival in USC. MSI and TMB are markers of improved OS in patients with UCS. MSI tumors have a distinct molecular profile compared to MSS tumors, and they appear to be more immunogenic, which could contribute to the improved survival seen in patients who received IO therapy.[Table: see text]

Exploring molecular profiles of uterine carcinosarcoma with alterations in the chromatin remodeling pathway

5587

Background: In a preliminary data analysis to identify prognostic molecular biomarkers in uterine carcinosarcoma (UCS), we found that alterations in KMT2C, a gene involved in the chromatin remodeling pathway, correlated with improved survival. We sought to explore relevant biomarkers of KMT2C-mutated (KMT2C-mut) tumors compared to wildtype (KMT2C-wt) tumors. Methods: Tumor samples were analyzed using next generation sequencing (NGS) of the DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ).PD-L1 IHC used SP-142 (cut-off >1%). Microsatelite instability (MSI) was tested by FA, IHC and NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined patient cohorts. Statistical significance was determined using chi-square and Wilcoxon rank sum test and p values adjusted for multiple comparisons (q) to be <0.05. Results: Molecular analysis was performed on 1,144 UCS tumors. 7.7% were found to be KMT2C-mut. Patients with pathogenic alterations in KMT2C had longer median OS than patients without (OS not yet reached vs 19.0 months HR(95% CI): 0.37(0.19-0.72) p< 0.01). The most common mutations in KMT2C-mut tumors are shown in Table and resulted in more frequent dysregulation in the following pathways compared to KMT2C-wt tumors: chromatin remodeling (100% vs 28%; q<0.01), WNT (39% vs 12%; q=0.01), base/nucleotide excision repair (29% vs 5%; q<0.01), homologous recombination (26% vs 6%; q=0.02), DNA damage sensors (23% vs 4%; q=0.02) and Fanconi anemia (13% vs 1%; q=0.04). KMT2C-mut tumors were more frequently MSI-H (32% vs 6%; q<0.01) and TMB-H (42% vs 5%; q<0.01). Among MSS tumors, KMT2C-mut tumors had increased mutations in JAK1 and POLE (q<0.01) and higher frequency of TMB-H (24% vs 1%; q<0.01) than KMT2C-wt tumors. Additionally, MSS patients with KMT2C-mut had longer OS than patients with KMT2C-wt tumors (OS not yet reached vs 18.9 months; HR(95% CI): 0.33(0.15-0.75) p< 0.01). Conclusions: Mutations in KMT2C correlate with improved OS in UCS. KMT2C-mut tumors have distinct molecular profiles from wild type tumors. They exhibit greater immunogenicity, including more frequent MSI-H and TMB-H. This suggests a potential role for Immune-oncology (IO) therapy. Further study of the impact of IO therapies in the cohort is warranted as this may contribute to the improved survival of these patients.[Table: see text]

Immune-response markers and actual response to immune-oncology therapy in uterine serous carcinoma

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Background: Uterine serous carcinoma (USC) is an aggressive subtype of endometrial cancer with poor prognosis and limited treatment options. Immune-oncology (IO) agents have shown promise USC, however data is limited regarding which patients benefit most from IO therapy. In other malignancies, PD-L1, MSI-H status and high TMB have been predictive of IO response. We sought to characterize the immune profiles of USC and investigate treatment response to IO therapy. Methods: Tumor samples were analyzed using Nex-Gen sequencing of the DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ).PD-L1 IHC used SP-142 (cut-off >1%). MSI was tested by FA, IHC and NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Real-world overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined patient cohorts. Statistical significance was determined using chi-square and Wilcoxon rank sum test and p values adjusted for multiple comparisons (q) to be < 0.05. Results: Molecular analysis was performed on 2,806 USC tumors. The median age was 67 years. 65.3% were from primary tumors, 34.7% from metastatic sites. In total, 92 patients were treated with IO therapy and had a significantly longer median survival than those not treated with IO (months: 59.6 vs 31.2; HR(95% CI): 0.38(0.24-0.61) p < 0.001), resulting in a survival advantage of 867 days. PD-L1 expression was present in 19.1% of cases, but only 2.3% of tumors were MSI-H and 4.2% were TMB-H. Patients with these markers trended toward a better median survival, but this was not significant; PD-L1 (months: 34.4 vs 31.2; HR(95% CI): 0.90 (0.74-1.1), MSI-H (OS not yet reached vs 31.6 months; HR(95% CI): 0.69(0.38-1.25) and TMB-H (months: 36.4 vs 31.6; HR(95% CI): 0.84(0.50-1.39). Regarding the immune microenvironment, the most common infiltrating immune cells were M2 Macrophages (5.35%), B cells (4.71%), myeloid dendritic cells (3.45%), NK cells (2.94%) and regulatory T cells (1.59%). There were few CD8 T cells and non-regulatory CD4 T cells. Conclusions: IO therapy was associated with a median survival benefit of more than 2 years in USC. We did not identify any prognostic markers of IO-therapy response. MSI-H and TMB-H are rare in USC, but PD-L1 is present in nearly 20% of cases. Notably these markers did predict a significant survival benefit, which has important clinical implications. Further study is warranted.

Association of the presence of estrogen and progesterone receptors in uterine carcinosarcoma with improved survival and increased immunogenicity

5588

Background: Recent data has shed light on molecular profiles of uterine carcinosarcoma (UCS), but few have correlated molecular profiles with prognosis. In a preliminary data analysis, we found that hormone receptors (HR)—estrogen receptor (ER) and progesterone receptor (PR)—expression was associated with improved OS. Here, we investigate the molecular profile differences between ER+/- and PR +/- tumors. Methods: Tumor samples were analyzed using Next-Generation sequencing of DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) at the Caris Life Sciences Laboratory (Phoenix, AZ).ER and PR tested by IHC on whole tumor (cut-off: +1, 10%). PD-L1 IHC used SP-142 (cut-off >1%). MSI was tested by FA, IHC an NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined cohorts. Statistical significance was determined by chi-square and Wilcoxon rank sum test and p-values adjusted for multiple comparisons (q) to be <0.05. Results: 1,144 UCS tumors were included. (ER+, n=261; PR+, n=197; HR+ (ER+ and PR+), n=168). Median OS for patients with hormone receptor (HR)+ tumors was significantly longer than for patients with HR- tumors (months: 34.8 vs 17.4; HR(95% CI): 0.67 (0.53-0.84), p<0.01). This remained significant for ER (29.4 vs 17.3) and PR (25.3 vs 18.7) individually. ER+ tumors had fewer alterations in the TP53 pathway (71.4% vs 82.1%) in the WNT (19.5% vs 5.8%) pathway than ER- tumors (q<0.05). PR+ tumors had similar findings in the TP53 and WNT pathways, and also more alterations in the DNA damage sensor pathway. Both ER+ and PR+ UCS tumors had significantly increased MSI-H (ER: 10.9% vs 5.5%, PR: 12.9% vs 5.5%) and TMB-H (ER: 16.8% vs 6.0%; PR: 19.5% vs 6.1%) (all q<0.05) compared to ER- and PR- tumors. They also had increased T-reg cells in their immune micro-environment and increased expression of the immune checkpoint gene IDO1 (q<0.05; Table). Conclusions: HR+ tumors have distinct molecular profiles from HR- tumors. ER+ and PR+ UCS tumors appear more immunogenic with more frequent MSI-H status, TMB-H, increased infiltrating regulatory T-cells and IDO1 expression, suggesting possible benefit with immune-oncology (IO) therapy. This may contribute to the observed improved OS, but more data are needed to determine if HR status is a marker of response to IO therapy.[Table: see text]

Exploring molecular profiles and survival in hormone receptor-positive uterine serous carcinoma

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Background: Hormone receptor (HR) positivity has been reported as a good prognostic indicator in endometrial cancer. This study investigated estrogen receptor (ER) and progesterone receptor (PR) positivity as indicators of platinum response and improved survival in uterine serous carcinoma (USC), and determined differences in molecular profiles between these tumors and hormone receptor negative tumors. Methods: Tumor profiling was done with immunohistochemistry (IHC), next generation sequencing (NGS), and whole transcriptome sequencing (WTS). PD-L1 expression was determined by IHC using SP-142 (cut-off >1%). Microsatellite instability (MSI) status was evaluated with IHC and NGS, and tumor mutational burden (TMB) by totaling somatic mutations per tumor (high if > 10 mutations/ MB). Immune-cell fraction was determined with QuantiSeq. We used insurance claims data to calculate Kaplan-Meier estimates for overall survival (OS). Statistical significance was determined with chi-square and Wilcoxon rank sum test and adjusted for multiple comparisons. Results: 2806 USC tumors were available for molecular profiling with 717 HR+/966 HR-, 1559 ER+/1059 ER- and 805 PR+/1809 PR-. Median OS for HR+ patients was longer than patients who were HR- regardless of treatment (1152 v 797 days; hazard ratio 0.68, 95% CI 0.58-0.80, p < 0.01). This OS benefit of HR positivity remained for patients receiving platinum therapy (1134 v 889 days; hazard ratio 0.75, 95% CI 0.58-0.98, p < 0.01). HR+ status trended towards improved OS in those treated with hormone therapy (407 vs 771 days, hazard ratio 0.78, 95% CI 0.59-1.02, p = 0.07). In addition to increased androgen receptor expression (54.2 vs 6.2%, p = < 0.001), PTEN mutations were more common in the HR+ group (10.3 vs 5.1%, p = 0.016). This resulted in in more frequent alterations of the PI3K pathway when compared to HR- tumors 64.5 vs 52.2%, p = < 0.001). PD-L1, TMB, and MSI status were similar between the two cohorts. Checkpoint inhibitor gene expression was notable for higher IDO expression in the HR+ group, but lower CD80, CD86, HAVCR2, IFNG, and PDC1 expression. The immune micro-environment was notable for less B-cells and M1 macrophages, but more M2 macrophages. Breaking the ER and PR positive cohort down to individual expression of each gene resulted in similar OS and molecular findings. Conclusions: HR positivity is associated with improved survival in allcomers with USC and those treated with platinum therapy, and there was a trend to improved OS with hormone therapy. More data is needed to determine if HR status is a prognostic marker for IO treatment response. This cohort had a distinct molecular profile compared to HR- tumors.