Integrated mutational landscape analysis of uterine leiomyosarcomas.

Uterine leiomyosarcomas (uLMS) are aggressive tumors arising from the smooth muscle layer of the uterus. We analyzed 83 uLMS sample genetics, including 56 from Yale and 27 from The Cancer Genome Atlas (TCGA). Among them, a total of 55 Yale samples including two patient-derived xenografts (PDXs) and 27 TCGA samples have whole-exome sequencing (WES) data; 10 Yale and 27 TCGA samples have RNA-sequencing (RNA-Seq) data; and 11 Yale and 10 TCGA samples have whole-genome sequencing (WGS) data. We found recurrent somatic mutations in TP53, MED12, and PTEN genes. Top somatic mutated genes included TP53, ATRX, PTEN, and MEN1 genes. Somatic copy number variation (CNV) analysis identified 8 copy-number gains, including 5p15.33 (TERT), 8q24.21 (C-MYC), and 17p11.2 (MYOCD, MAP2K4) amplifications and 29 copy-number losses. Fusions involving tumor suppressors or oncogenes were deetected, with most fusions disrupting RB1, TP53, and ATRX/DAXX, and one fusion (ACTG2-ALK) being potentially targetable. WGS results demonstrated that 76% (16 of 21) of the samples harbored chromoplexy and/or chromothripsis. Clinically actionable mutational signatures of homologous-recombination DNA-repair deficiency (HRD) and microsatellite instability (MSI) were identified in 25% (12 of 48) and 2% (1 of 48) of fresh frozen uLMS, respectively. Finally, we found olaparib (PARPi; P = 0.002), GS-626510 (C-MYC/BETi; P < 0.000001 and P = 0.0005), and copanlisib (PIK3CAi; P = 0.0001) monotherapy to significantly inhibit uLMS-PDXs harboring derangements in C-MYC and PTEN/PIK3CA/AKT genes (LEY11) and/or HRD signatures (LEY16) compared to vehicle-treated mice. These findings define the genetic landscape of uLMS and suggest that a subset of uLMS may benefit from existing PARP-, PIK3CA-, and C-MYC/BET-targeted drugs.

Advances in antibody-drug conjugates for gynecologic malignancies.

PURPOSE OF REVIEW: Antibody-drug conjugates (ADCs) represent a new class of drugs that combine a surface receptor-targeting antibody linked to a cytotoxic molecule delivering the potent cytotoxic payload directly to tumor cells. This review summarizes the current literature demonstrating their use in the treatment of gynecologic malignancies. RECENT FINDINGS: Tisotumab vedotin is the first U.S. Food and Drug Administration (FDA) approved ADC for the treatment of gynecologic cancers. While in the phase 3 randomized controlled trial in platinum resistant ovarian cancer patients, FORWARD 1, mirvetuximab did not meet its primary endpoint of progression-free survival. But we await more recent data from the two ongoing phase 3 trials of mirvetuximab in recurrent ovarian cancer patients. HER2/neu, Napi2b, mesothelin, and human trophoblast cell-surface marker (Trop-2) overexpression have also been exploited as excellent targets by novel ADCs in multiple tumors including ovarian, endometrial, and cervical cancers. SUMMARY: Current evidence strongly supports the use of ADCs and ongoing clinical trials will provide further information into the potential of making these drugs part of current standard practice allowing patients to be treated with a higher level of personalized cancer care.

A phase 2 evaluation of pembrolizumab for recurrent Lynch-like versus sporadic endometrial cancers with microsatellite instability.

BACKGROUND: Microsatellite instability-high (MSI-H)/mismatch repair deficiency (dMMR) is a biomarker for responses to immune checkpoint inhibitors (ICIs). Whether mechanisms underlying microsatellite instability alter responses to ICIs is unclear. This article reports data from a prospective phase 2 pilot study of pembrolizumab in patients with recurrent MSI-H endometrial cancer (EC) analyzed by whole exome sequencing (WES) and potential mechanisms of primary/secondary ICI resistance (NCT02899793). METHODS: Patients with measurable MSI-H/dMMR EC confirmed by polymerase chain reaction/immunohistochemistry were evaluated by WES and received 200 mg of pembrolizumab every 3 weeks for ≤2 years. The primary end point was the objective response rate (ORR). Secondary end points included progression-free survival (PFS) and overall survival (OS). RESULTS: Twenty-five patients (24 evaluable) were treated. Six patients (25%) harbored Lynch/Lynch-like tumors, whereas 18 (75%) had sporadic EC. The tumor mutation burden was higher in Lynch-like tumors (median, 2939 mutations/megabase [Mut/Mb]; interquartile range [IQR], 867-5108 Mut/Mb) than sporadic tumors (median, 604 Mut/Mb; IQR, 411-798 Mut/Mb; P = .0076). The ORR was 100% in Lynch/Lynch-like patients but only 44% in sporadic patients (P = .024). The 3-year PFS and OS proportions were 100% versus 30% (P = .017) and 100% versus 43% (P = .043), respectively. CONCLUSIONS: This study suggests prognostic significance of Lynch-like cancers versus sporadic MSI-H/dMMR ECs for ORR, PFS, and OS when patients are treated with pembrolizumab. Larger confirmatory studies in ECs and other MSI-H/dMMR tumors are necessary. Defective antigen processing/presentation and deranged induction in interferon responses serve as mechanisms of resistance in sporadic MSI-H ECs. Oligoprogression in MSI-H/dMMR patients appears salvageable with surgical resection and/or local treatment and the continuation of pembrolizumab off study. Clinical studies evaluating separate MSI-H/dMMR EC subtypes treated with ICIs are warranted.

Randomised phase II trial of weekly ixabepilone ± biweekly bevacizumab for platinum-resistant or refractory ovarian/fallopian tube/primary peritoneal cancer.

BACKGROUND: This multi-center RP2 study assessed activity/safety of ixabepilone + bevacizumab compared to ixabepilone in platinum-resistant/refractory ovarian/fallopian tube/primary peritoneal cancer. Additional objectives were to examine the role of prior bevacizumab and taxanes, and explore class III-ß-tubulin (TUBB3) as a predictive biomarker. METHODS: Participants were randomised to receive ixabepilone 20 mg/m2 days 1, 8, 15 with (IXA + BEV) or without (IXA) bevacizumab 10 mg/kg days 1, 15 every 28 days. Patients were stratified by prior BEV. The primary endpoint was PFS. OS, safety, and ORR served as secondary endpoints. RESULTS: Among 76 evaluable patients who received IXA + BEV (n = 39) compared to IXA (n = 37), the ORR was 33% (n = 13) versus 8% (n = 3)(P = 0.004), durable at 6 months in 37% (n = 14) and 3% (n = 1) (P < 0.001). BEV significantly improved PFS (median:5.5 vs 2.2 months, HR = 0.33, 95%CI 0.19-0.55, P < 0.001) and OS (median:10.0 vs 6.0 months, HR = 0.52, 95%CI 0.31-0.87, P = 0.006). Both regimens were well-tolerated. TUBB3 expression did not predict response. Subgroup analyses revealed minimal effect of prior BEV or taxane resistant/refractory status on response to IXA + BEV. CONCLUSIONS: IXA + BEV is a well-tolerated, effective combination for platinum/taxane-resistant ovarian cancer that extends PFS and likely OS relative to IXA monotherapy. Prior receipt of BEV should not preclude the use of IXA + BEV. TUBB3 is not a predictive biomarker. CLINICAL TRIAL REGISTRATION: NCT3093155.

Synergistic activity of neratinib in combination with olaparib in uterine serous carcinoma overexpressing HER2/neu.

INTRODUCTION: Uterine serous carcinoma (USC) is an aggressive variant of endometrial cancer with a poor prognosis. Approximately 30% of USC overexpress HER2/neu, a recognized target for trastuzumab in advanced/recurrent HER2/neu-positive USC. We evaluated the efficacy of the pan-c-erb inhibitor neratinib and the poly (ADP-ribose)-polymerase (PARP) inhibitor olaparib as single agents and in combination against USC cell lines and xenografts. METHODS: In-vitro cell-viability assays with olaparib, neratinib, and olaparib/neratinib were assessed using flow-cytometry based assays against a panel of USC cell lines with high and low HER2/neu expression. Homologous recombination deficiency (HRD) signatures were evaluated as described by Alexandrov et al. (Nature;2020;578:94-101) while downstream signaling affected by neratinib/olaparib exposure was assessed with immunoblotting. Efficacy of single- versus dual-agent inhibition was evaluated in-vivo using two USC-xenografts with 3+ HER2/neu expression. RESULTS: Neratinib was more potent than olaparib in suppression of in-vitro growth of HER2/neu 3+ cell lines (ARK1: p = 0.0047; ARK2: p = 0.0428) while no difference was noted against HER2/neu 1+ tumors (ARK4). Importantly, the combination of olaparib with neratinib synergistically improved tumor suppression compared to either single-agent in vitro. USC cells exposed to olaparib upregulated HER2/neu expression, while neratinib treatment increased PARP activity (ARK1: p < 0.0001; ARK2: p < 0.0001). Single-agent neratinib transiently inhibited in vivo growth of USC xenografts harboring HER2/neu gene amplification (ARK1: p < 0.05; ARK2: p < 0.05). In contrast, the combination of the two inhibitors caused a stronger and durable growth inhibition in both USC xenografts (ARK1: p < 0.05; ARK2: p < 0.05). CONCLUSION: The combination of olaparib and neratinib is active and synergistic against primary HER2/neu + USC. This combination may represent a novel therapeutic option for USC patients with HER2/neu+, homologous recombination-proficient tumors resistant to chemotherapy.

Homologous recombination deficiency (HRD) signature-3 in ovarian and uterine carcinosarcomas correlates with preclinical sensitivity to Olaparib, a poly (adenosine diphosphate [ADP]- ribose) polymerase (PARP) inhibitor.

OBJECTIVES: Carcinosarcoma (CS) of the ovary and uterus are highly aggressive malignancies associated with poor survival. Poly(ADP-ribose)-polymerase inhibitors (PARPi) are targeted agents impairing DNA repair via homologous-recombination-deficiency (HRD) mechanisms. We used whole-exome-sequencing (WES) data from a cohort of fresh tumor samples of ovarian (OCS) and uterine carcinosarcoma (UCS), primary cell lines and xenografts to investigate the role for olaparib in CSs. METHODS: WES data from 73 CS samples (48 UCS and 25 OCS) were analyzed for HRD signatures. Olaparib activity was evaluated using cell-viability, cell-cycle, apoptosis and cytotoxicity assays against primary CS cell lines. Olaparib antitumor activity was tested in vivo against HRD CS xenografts. RESULTS: Signature-3 (i.e. HRD-related signature) was identified in 60% of OCS (15 of 25) vs 25% of UCS (12 of 48) (p = 0.005). CS cell lines harboring Signature-3/HRD (3 OCS/1 UCS) were significantly more sensitive to olaparib when compared to HRP cell lines (5 UCS/1 OCS) [mean IC50 ± SEM = 2.94 µM ± 0.07 vs mean ± SEM = 23.3 µM ± 0.09, (p = 0.02), respectively]. PARPi suppressed CS cell growth through cell cycle arrest in the G2/M phase and caused more apoptosis in HRD vs HRP primary tumors (p < 0.0001). In vivo, olaparib significantly impaired HRD CS xenografts tumor growth (p = 0.0008) and increased overall animal survival (p < 0.0001). CONCLUSIONS: OCS and UCS cell lines harboring HRD signature-3 were significantly more sensitive to olaparib in vitro and in vivo when compared to HRP CS. Clinical studies with PARPi in CS patients with a dominant signature 3 (HRD-related) are warranted.

Targeted Therapies in the Treatment of Uterine Serous Carcinoma.

OPINION STATEMENT: Despite the dismal prognosis of uterine serous carcinoma (USC), recent advances in molecular classification and targeted treatments have demonstrated improvements in survival outcomes for patients both in the upfront and recurrent treatment settings. After appropriate surgical staging and surgical cytoreduction as indicated, correct pathologic and molecular classification of USC is important to provide the most appropriate systemic adjuvant treatment. HER2-targeted agents are one of the most important advances in the treatment of USC in decades. Thus, for HER2-positive tumors, the addition of trastuzumab to conventional chemotherapy is indicated in those with advanced stage and/or recurrent disease. Treatment with pembrolizumab and lenvatinib suggests a 50% response rate in women with recurrent disease which serves as a promising targeted treatment strategy. Overall, emerging targeted therapeutic options with antibody-drug conjugates (i.e. targeting HER2, folic acid receptor alpha, or Trop-2), combinations of immunotherapies and tyrosine kinase inhibitors, PARP inhibitors, WEE1 inhibitors, and AKT inhibitors shed further promise in advancements of effective disease-modifying treatments for this unmet medical need for patients with USC. Several trials evaluating these targeted agents are ongoing, and those results are eagerly awaited. As such, enrollment of patients in clinical trials is highly recommended as it will provide patients with a higher level of personalized cancer care.

Trastuzumab tolerability in the treatment of advanced (stage III-IV) or recurrent uterine serous carcinomas that overexpress HER2/neu.

OBJECTIVE: Due to previously reported trastuzumab safety concerns and the scant data available in endometrial cancer patients, we sought to assess the safety, tolerability and toxicity profile of trastuzumab in patients with advanced/recurrent uterine serous carcinoma (USC) that overexpress HER2/neu in our multicenter randomized phase II trial. METHODS: Patients were randomized 1:1 to receive carboplatin/paclitaxel (C/P) for 6 cycles ± trastuzumab (T) with the experimental arm continuing to receive single agent trastuzumab maintenance treatment until disease progression/toxicity. Progression-free-survival was the primary endpoint; overall-survival and toxicity were secondary endpoints. Adverse events (AEs) were compared between treatment arms. RESULTS: There were 28 patients in the C/P arm and 32 patients in the experimental (C/P + T) arm. Fifty-eight patients (97%) experienced 977 treatment-related AEs of which 875 (89.6%) were low-grade (grade 1-2) and 102 (10.4%) were high-grade (grade 3-5). The mean ± standard deviation of AEs per patient was 15.5 ± 16.3 in the C/P arm and 17.0 ± 16.0 in the C/P + T arm. Gastrointestinal AEs were the most common in both arms (n = 155, 15.7%) of which 94.2% were low-grade (n = 146). Importantly, no significant difference between treatment arms was detected in any system-organ class of AE including cardiac AE. Five (17%) of 29 patients who received prolonged trastuzumab maintenance therapy had no sign of cumulative toxicity after an average (range) of 5.1 (4.2-6.3) years. CONCLUSIONS: Trastuzumab appears to be safe and has a manageable toxicity profile both when used in combination with chemotherapy and when used for single agent maintenance in patients with HER2/neu positive USC. This safety profile is reassuring given the proven efficacy of trastuzumab in advanced/recurrent HER2/neu positive USC.

DHES0815A, a novel antibody-drug conjugate targeting HER2/neu, is highly active against uterine serous carcinomas in vitro and in vivo.

OBJECTIVE: Uterine serous carcinoma (USC) is an aggressive histologic variant of endometrial cancer which portends a poor prognosis. DHES0815A is a novel antibody-drug-conjugate (ADC) which binds specifically to HER2 overexpressing tumors at a distinct epitope from that bound by trastuzumab and pertuzumab after which it delivers the toxic payload, PBD-MA, a DNA mono-alkylating agent. The objective of this study was to evaluate the preclinical activity of DHES0815A against primary USC cell lines and xenografts. METHODS: Twelve primary USC cell lines were assessed by immunohistochemistry (IHC) for HER2 protein expression and for C-erbB2 gene amplification using fluorescent in situ hybridization (FISH) analysis. Cell viability and bystander killing in USC cell lines after exposure to DHES0815A, the non-targeted ADC, and the unconjugated antibody (i.e. MHES0488A) were evaluated using flow cytometry-based-assays. In vivo activity of DHES0815A was tested against HER2/neu overexpressing USC xenografts. RESULTS: High HER2/neu protein expression was seen in 25% (3/12) of the primary USC cell lines. USC cell lines overexpressing HER2/neu were significantly more sensitive to DHES0815A when compared to the non-targeted control ADC (p < 0.001). DHES0815A did not induce significant bystander killing of HER2/neu negative tumors when admixed with HER2/neu positive tumors. DHES0815A caused growth-inhibition and increased survival in USC HER2/neu overexpressing xenografts when compared to controls (p < 0.01). CONCLUSIONS: DHES0815A is both highly selective and toxic to USC tumors overexpressing HER2/neu both in vitro and in vivo. HER2-directed ADCs, alone or in combination with other HER2/neu targeted agents may represent a novel treatment option for patients with tumors harboring HER2/neu overexpression refractory to trastuzumab and traditional chemotherapy.

Immunotherapy in Cervical Cancer.

PURPOSE OF REVIEW: This review aims to summarize the current immunotherapy studies and the potential targeted therapies showing promise in the treatment of cervical cancer. RECENT FINDINGS: There are promising ongoing monotherapy and combination therapy trials using different immune checkpoint inhibitors, poly adenosine diphosphate ribose polymerase inhibitors, tumor angiogenesis inhibitors (i.e., bevacizumab), antibody-drug conjugates, therapeutic vaccines, and tumor-infiltrating T lymphocytes (adoptive immunotherapy). Some of these novel modalities are also being evaluated in combination with standard platinum-based chemotherapy regimen. At this time, pembrolizumab is approved for the treatment of relapsed or metastatic programmed death ligand 1 (PD-L1) positive cervical cancer after frontline chemotherapy treatment. Multiple novel therapeutic modalities are emerging as safe and effective for the treatment of cervical cancer patients. Development and participation in investigative treatments can provide benefit and improve outcomes in cervical cancer.

Novel antibody-drug conjugates: current and future roles in gynecologic oncology.

PURPOSE OF REVIEW: Antibody-drug conjugates (ADCs) represent a new class of drugs that combine a surface receptor-targeting antibody linked to a cytotoxic molecule. This review summarizes the current literature demonstrating their tremendous promise as therapeutic agents in the treatment of aggressive gynecologic malignancies. RECENT FINDINGS: Several antigens have proven to be differentially overexpressed in a variety of gynecologic tumors when compared with normal surrounding tissue and serve as novel targets for ADC therapy. In the last few years HER2/neu, folic acid-alpha (FRα) and Trop-2 overexpression have been exploited as excellent targets by novel ADCs such as Trastuzumab emtansine (T-DM1), SYD985, IMGN853 (Mirvetuximab soravtansine) and Sacituzumab govitecan (SG, IMMU-132) in multiple tumors including ovarian, endometrial and cervical cancers. Although the selectivity of ADCs with noncleavable linkers (i.e. T-DM1) has shown negligible effect on surrounding antigen negative cells, those ADCs with cleavable linkers (i.e. SYD985, IMGN853 and SG) may kill both antigen-positive target cells and surrounding antigen-negative cells via the bystander effect. SUMMARY: Preclinical data strongly supports these ADCs and ongoing clinical trials will shed further light into the potential of making these drugs part of current standard practice and providing our patients with a higher level of personalized cancer care.

Robotic Low Anterior Resection and Partial Bladder Resection for Management of Locoregional Endometrial Cancer Recurrence.

OBJECTIVE: To demonstrate a robotic tumor debulking for management of locoregional endometrial cancer recurrence. DESIGN: Case report. SETTING: Tertiary referral center in New Haven, CT. INTERVENTIONS: A 70-year-old patient with a history of stage IB endometrioid endometrial cancer presented with rectal bleeding 3 years after the completion of treatment. A mass involving the distal sigmoid colon/upper rectum and bilateral distal periureteral masses were visualized on imaging. There was no distant metastatic disease. Colonoscopic biopsies were consistent with endometrial cancer recurrence. Because the patient was symptomatic with rectal bleeding and had no distant metastasis, it was recommended that she undergo surgical resection for management of this locoregional recurrence. The patient was placed in reverse Trendelenburg position with a rightward tilt to mobilize the splenic flexure. Once the cephalad aspect of the descending colon mobilization was completed, the patient was placed in Trendelenburg lithotomy position to expose the pelvis. A robot was docked at this point and the pelvic avascular spaces were delineated. A medial-to-lateral approach was used in mobilization of the sigmoid colon mesentery. The left ureter was identified and the sigmoid branches of inferior mesenteric artery were sealed. The descending/sigmoid colon junction was stapled. After complete mobilization of the sigmoid colon, the tumor-free upper rectum was delineated and stapled. Attention was then turned to the distal peri-ureteral masses. The 2-cm mass on the right, which was densely adherent to the distal right ureter, was completely resected after extensive ureterolysis. The resection of the 4-cm mass on the left which involved both the distal left ureter and the bladder dome required an intentional cystotomy and a partial cystectomy to attain negative margins (Supplemental Figure 1). The procedure was continued with the bowel anastomosis. The anvil was introduced through the vagina and was placed into the proximal limb through an antimesenteric incision. An end-to-end tension-free anastomosis was performed and adequate vascularization was confirmed with intravenous indocyanine green. CONCLUSION: Robotic low anterior resection and partial bladder resection were performed without any complications with negative margins. Robotic tumor debulking should be considered in appropriate patients when managing locoregional recurrence of endometrial cancer [1,2].

Risk factors associated with delayed discharge following robotic assisted surgery for gynecologic malignancy.

BACKGROUND: The risk factors for extended length of stay (LOS) have not been examined in a cohort of patients with complex social and medical barriers who undergo robotic assisted (RA) surgery for gynecologic malignancies. We sought to identify those patients with a LOS > 24 h after robotic surgery and the risk factors associated with delayed discharge. Then we aimed to develop a predictive model for clinical care and identify modifiable pre-operative risk factors. METHODS: After IRB approval, data was abstracted from medical records of all patients with a gynecologic malignancy who underwent a RA laparoscopic surgery from 2010 to 2015. Univariable and multivariable logistic regression was performed to identify independent risk factors associated with delayed discharge defined as LOS > 24 h. A multi-variable logistic regression model was performed using a stepwise backward selection for the final prediction model. All testing was two-sided and a p-value < 0.05 was considered statistically significant. RESULTS: Of the 406 eligible and evaluable patients, 194 (48%) had a LOS > 24 h. Age ≥ 60 years, a higher usage of narcotic medication, a longer surgical time, and a larger estimated blood loss were all associated with LOS > 24 h (p < 0.05). Many of these women had a social work consultation and went home with home care services despite no surgical or post-operative complications. Our prediction model has the potential to correctly classified 75% of the patients discharged within 24 h. CONCLUSIONS: The development of a pre-hospitalization risk stratification and anticipating the possible need for home care services pre-operatively shows promise as a strategy to decrease LOS in patients classified as high-risk. These findings warrant prospective validation through the use of this prediction model in our institution.

Human epidermal growth factor 2 (HER2) in early stage uterine serous carcinoma: A multi-institutional cohort study.

BACKGROUND: Human epidermal growth factor receptor 2 (HER2) has emerged as an important prognostic and therapeutic target in advanced stage and recurrent uterine serous carcinoma (USC). The significance of tumoral HER2 expression in early-stage disease has not been established. METHODS: This multi-center cohort study included women with stage I USC treated from 2000 to 2019. Demographic, treatment, recurrence, and survival data were collected. Immunohistochemistry (IHC) was performed for HER2 and scored 0-3+. Equivocal IHC results (2+) were further tested with fluorescence in-situ hybridization (FISH). HER2 positivity was defined as 3+ IHC or FISH positive. RESULTS: One hundred sixty-nine patients with stage I USC were tested for HER2; 26% were HER2-positive. There were no significant differences in age, race, stage, adjuvant therapy, or follow-up duration between the HER2-positive and negative cohorts. Presence of lymph-vascular space invasion was correlated with HER2-positive tumors (p = .003). After a median follow-up of 50 months, there were 43 (25.4%) recurrences. There were significantly more recurrences in the HER2-positive cohort (50.0% vs 16.8%, p < .001). HER2 positive tumors were associated with worse progression-free (PFS) and overall survival (OS) (p < .001 and p = .024). On multivariate analysis, HER2 positive tumors were associated with inferior PFS (aHR 3.50, 95%CI 1.84-6.67; p < .001) and OS (aHR 2.00, 95%CI 1.04-3.88; p = .039) compared to HER2-negative tumors. CONCLUSIONS: Given its significant association with worse recurrence and survival outcomes, HER2 positivity appears to be a prognostic biomarker in women with stage I uterine serous carcinoma. These data provide support for clinical trials with anti-HER2-directed therapy in early-stage disease.

Derangements in HUWE1/c-MYC pathway confer sensitivity to the BET bromodomain inhibitor GS-626510 in uterine cervical carcinoma.

OBJECTIVE: Whole-exome-sequencing (WES) studies reported c-MYC gene-amplification and HUWE1 gene deletion/mutations in a significant number of cervical-cancer-patients (CC) suggesting HUWE1/c-MYC pathway as potential therapeutic target. We investigated HUWE1/c-MYC expression in fresh-frozen-CC and the activity of the novel BET inhibitor GS-626510 (Gilead-Science-Inc) against primary WES CC-cultures and CC-xenografts. METHODS: HUWE1 and c-MYC expression were evaluated by qRT-PCR in 23 CC including 12 fresh-frozen-tumor-tissues and 11 primary-cell-lines. c-Myc expression was also evaluated by Western-Blot (WB) and fluorescence-in-situ-hybridization (FISH) in all 11 fully sequenced primary-CC-cell-lines. Primary tumors were evaluated for sensitivity to GS-626510 in-vitro using proliferation and viability-assays. siRNA experiments were used to evaluate the effect of HUWE1 silencing on primary-CC-cell-line growth and sensitivity to GS-626510. Finally, the in-vivo activity of GS-626510 was studied in CC-CVX8-mouse-xenografts. RESULTS: Fresh-frozen-CC and primary-CC-cell-lines overexpressed c-MYC when compared to normal tissues (p = .01). FISH demonstrated amplification of c-MYC in 9/11 (82%) of the primary-CC-cell-lines. Cell-lines with derangements in HUWE1/c-MYC pathway were highly sensitive to GS-626510, with a dose-response decrease in cell proliferation and viability. siRNA silencing of HUWE1 significantly increased c-MYC expression and CC cell-proliferation and enhanced the in-vitro sensitivity to GS-626510. Twice-daily oral doses of GS-626510 were well tolerated in-vivo and highly effective in decreasing tumor-growth (p = .004) and increasing survival (p = .004) of CC-CVX8 xenografts. CONCLUSIONS: Downregulation/inactivation of HUWE1 may increase c-MYC expression and proliferation in primary-CC-cell-lines. GS-626510 may represent a novel, potentially highly effective therapeutic agent against CC overexpressing c-MYC and/or harboring HUWE1 mutations. Clinical studies with BET inhibitor in CC-patients harboring radiation/chemotherapy-resistant disease are warranted.

In vitro and in vivo activity of sacituzumab govitecan, an antibody-drug conjugate targeting trophoblast cell-surface antigen 2 (Trop-2) in uterine serous carcinoma.

OBJECTIVE: Uterine serous carcinoma (USC) is an aggressive variant of endometrial cancer with poor prognosis. Sacituzumab govitecan (SG) is a novel antibody-drug-conjugate (ADC) targeting trophoblast cell-surface antigen 2 (Trop-2), a transmembrane-calcium-signal-transducer, to deliver SN-38, the active metabolite of irinotecan. The objective of this study was to evaluate the expression of Trop-2 in USC and the preclinical activity of SG against primary USC cell-lines and xenografts. METHODS: We used immunohistochemistry (IHC) and flow-cytometry-based assays to evaluate Trop-2 expression and cell-viability in USC tissue and primary tumor-cell-lines after exposure to SG, non-targeting control ADC, and naked antibody hRS7-IgG. Antibody-dependent-cell-cytotoxicity (ADCC) against Trop-2+ and Trop-2- USC cell-lines was evaluated in vitro using 4-hr-Chromium-release-assays. In vivo activity of SG was tested against Trop-2+ USC xenografts by intravenous administration of SG, control ADC, and hRS7. RESULTS: Trop-2 expression by IHC was detected in 95.1% of USC samples (99/104). Primary tumor cell-lines overexpressing Trop-2 were significantly more sensitive to SG when compared to control ADC (p <0.05). Both SG and hRS7 mediated ADCC in Trop2+ USC cell-lines while no cytotoxicity was detected against Trop-2- cells. SG induced significant bystander killing of Trop-2- tumors when admixed with Trop-2+ tumors. SG caused growth-inhibition and increased survival in SG treated mice harboring Trop-2+ xenografts when compared to controls (p <0.05). CONCLUSIONS: SG is remarkably active against USC overexpressing Trop-2 in vitro and in vivo. Our results combined with SG clinical responses recently reported against multiple chemotherapy resistant human tumors further support clinical development of SG in USC patients with advanced/recurrent disease.

Unplanned hospitalizations in a racially and ethnically diverse population of women receiving chemotherapy for epithelial ovarian cancer.

OBJECTIVES: Unplanned hospital admission following chemotherapy is a measure of quality cancer care. Large retrospective datasets have shown admission rates of 10-35% for women with ovarian cancer receiving chemotherapy. We sought to evaluate the prevalence and associated risk factors for hospital admission following chemotherapy in our racially diverse urban population. METHODS: After IRB approval, clinicopathologic and treatment data were abstracted from all patients with newly diagnosed epithelial ovarian cancer who received chemotherapy at our institution from 2005 to 2016. Two-sided statistical analyses and Cox regression analysis were performed using Stata. RESULTS: Of 217 evaluable patients, 87 (40%) had unplanned admissions following chemotherapy: adjuvant 64 (74%) and neoadjuvant 23(26%). Thirty (14%) had more than one admission. In total, there were 1314 days of hospitalization. The median readmission duration was 3 days. Body mass index and hypertension were predictive of readmission (p < 0.05). When comparing those readmitted more than once to those admitted once, both race and aspirin use were predictive of readmission (p < 0.05). Of those admitted more than once the self-identified race and ethnicity was 12 (40%) Hispanic, 8 (27%) White, 8 (27%) Black and 2 (7%) other. There was a significant difference in disease free (p = 0.01) and overall survival (p = 0.004) for patients with unplanned admission after chemotherapy as compared to those without admission. CONCLUSIONS: Readmission rates in our racially diverse patient population were higher than previously reported in the literature. Identifying patients at risk of readmission may play a role in chemotherapy decision-making, and resource allocation including patient care navigators.

Comparative Use of Napsin A and Glypican 3 to Distinguish Endometrial Clear Cell from Serous and Endometrioid Carcinomas.

OBJECTIVE: Diagnosis of endometrial clear cell carcinomas is difficult owing to the low reproducibility of histological cell type in high-grade endometrial cancers. Recently, immunoreactivity for napsin A and glypican 3 has been reported in clear cell cancers. We sought to evaluate the use of napsin A and glypican 3 staining to distinguish clear cell carcinoma from other high-grade endometrial cancers. METHODS/MATERIALS: Twenty cases of pure and mixed endometrial clear cell carcinoma were extracted from the 2000-2014 archival material in the Departments of Obstetrics & Gynecology and Pathology at Montefiore Medical Center and compared to serous and grade 3 endometrioid controls. Representative sections were stained with monoclonal antibodies to napsin A and glypican 3. Immunostains were independently reviewed by 2 pathologists to assess frequency and pattern of staining. Charts were reviewed for clinicopathologic and treatment data. RESULTS: Granular cytoplasmic positivity for napsin A was observed in 70% of endometrial clear cell carcinomas; only 25% showed cytoplasmic or membranous glypican 3 positivity. No serous or high-grade endometrioid tumors stained for either marker. No cases of clear cell carcinoma that stained negative for napsin A stained positive for glypican 3. No difference in the immunohistochemical profile was found between pure and mixed clear cell carcinomas and between early- and advanced-stage clear cell carcinomas. CONCLUSIONS: Napsin A is a more sensitive marker for endometrial clear cell carcinoma than glypican 3. In histologically ambiguous cases, napsin A and glypican 3 may help distinguish clear cell carcinoma from other high-grade histologies. Further investigation of endometrial clear cell carcinoma is needed to identify additional diagnostic tools for this rare histology. Correlation of a unique immunohistochemical profile and clinical outcomes is necessary.