Integrated mutational landscape analysis of poorly differentiated high-grade neuroendocrine carcinoma of the uterine cervix.

High-grade neuroendocrine cervical cancers (NETc) are exceedingly rare, highly aggressive tumors. We analyzed 64 NETc tumor samples by whole-exome sequencing (WES). Human papillomavirus DNA was detected in 65.6% (42/64) of the tumors. Recurrent mutations were identified in PIK3CA, KMT2D/MLL2, K-RAS, ARID1A, NOTCH2, and RPL10. The top mutated genes included RB1, ARID1A, PTEN, KMT2D/MLL2, and WDFY3, a gene not yet implicated in NETc. Somatic CNV analysis identified two copy number gains (3q27.1 and 19q13.12) and five copy number losses (1p36.21/5q31.3/6p22.2/9q21.11/11p15.5). Also, gene fusions affecting the ACLY-CRHR1 and PVT1-MYC genes were identified in one of the eight samples subjected to RNA sequencing. To resolve evolutionary history, multiregion WES in NETc admixed with adenocarcinoma cells was performed (i.e., mixed-NETc). Phylogenetic analysis of mixed-NETc demonstrated that adenocarcinoma and neuroendocrine elements derive from a common precursor with mutations typical of adenocarcinomas. Over one-third (22/64) of NETc demonstrated a mutator phenotype of C > T at CpG consistent with deficiencies in MBD4, a member of the base excision repair (BER) pathway. Mutations in the PI3K/AMPK pathways were identified in 49/64 samples. We used two patient-derived-xenografts (PDX) (i.e., NET19 and NET21) to evaluate the activity of pan-HER (afatinib), PIK3CA (copanlisib), and ATR (elimusertib) inhibitors, alone and in combination. PDXs harboring alterations in the ERBB2/PI3K/AKT/mTOR/ATR pathway were sensitive to afatinib, copanlisib, and elimusertib (P < 0.001 vs. controls). However, combinations of copanlisib/afatinib and copanlisib/elimusertib were significantly more effective in controlling NETc tumor growth. These findings define the genetic landscape of NETc and suggest that a large subset of these highly lethal malignancies might benefit from existing targeted therapies.

Black-White differences in uterine cancer symptomatology and stage at diagnosis.

OBJECTIVE: To examine whether uterine cancer symptoms differ between Black and White patients and how this may influence their stage at diagnosis. METHODS: Using the Surveillance, Epidemiology and End Results-Medicare database, we identified 2328 Black and 21,774 White patients with uterine cancer in 2008-2017. Their symptoms in the 18 months before diagnosis were categorized as postmenopausal bleeding (PMB) alone, PMB together with other symptoms (e.g., abdominal/pelvic pain, bloating), non-PMB symptoms alone, or no symptoms. Stage at diagnosis was dichotomized as advanced (i.e., regional/distant) versus localized. The association between race and stage was analyzed using regression models incrementally adjusting for symptoms and other patient characteristics. RESULTS: A larger proportion of Black than White patients experienced PMB together with other symptoms (63.1% versus 58.0%) or experienced non-PMB symptoms alone (13.1% versus 9.4%) (p < 0.001). Black patients had a higher risk of advanced-stage diagnosis than White patients (45.0% versus 30.3%, unadjusted RR = 1.52, 95% CI: 1.44-1.59). Adjusting for Black-White differences in symptoms attenuated the RR to 1.46 (95% CI: 1.39-1.53). Compared to PMB symptoms alone, having additional non-PMB symptoms (RR = 1.21, 95% CI: 1.15-1.26) and having non-PMB symptoms alone (RR = 1.99, 95% CI: 1.88-2.10) were associated with increased risk of advanced-stage diagnosis. Further adjusting for histology and other patient characteristics reduced Black-White disparity in advanced-stage diagnosis to 1.08 (95% CI: 1.03-1.14) but symptoms remained significantly associated with stage at diagnosis. CONCLUSIONS: Having non-PMB symptoms was associated with more advanced stage at diagnosis. Non-PMB symptoms were more common among Black than White patients, which might hinder symptom recognition/evaluation.

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.

Hyperthermic Intraperitoneal Chemotherapy in Ovarian Cancer.

Hyperthermic intraperitoneal chemotherapy (HIPEC) is a treatment modality that aims to target the main site of tumor dissemination in ovarian cancer, the peritoneum, by combining the benefits of intraperitoneal chemotherapy with the synergistic effects of hyperthermia all during a single administration at the time of cytoreductive surgery. High-quality evidence currently only supports the use of HIPEC with cisplatin at the time of interval cytoreduction after neoadjuvant chemotherapy for stage III epithelial ovarian cancer. Many questions remain, including HIPEC's role at other timepoints in ovarian cancer treatment, who are optimal candidates, and specifics of HIPEC protocols. This article reviews the history of normothermic and hyperthermic intraperitoneal chemotherapy in ovarian cancer and evidence regarding HIPEC implementation and patient outcomes. Additionally, this review explores details of HIPEC technique and perioperative care, cost considerations, complication and quality of life data, disparities in HIPEC use, and unresolved issues.

Trastuzumab deruxtecan (DS-8201a), a HER2-targeting antibody-drug conjugate with topoisomerase I inhibitor payload, shows antitumor activity in uterine and ovarian carcinosarcoma with HER2/neu expression.

OBJECTIVES: Carcinosarcomas are highly aggressive gynecologic malignancies containing both carcinomatous and sarcomatous elements with heterogeneous HER2/neu expression and limited therapeutic options. We compared the efficacy of trastuzumab deruxtecan (DS-8201a), a novel HER2/neu-targeting antibody-drug conjugate (ADC) to an ADC isotype control (MAAA-9199) against primary uterine and ovarian carcinosarcomas in vitro and in vivo. METHODS: Twelve primary carcinosarcoma (CS) cell lines were evaluated for HER2/neu surface expression by immunohistochemistry (IHC) and by flow cytometry, and gene amplification by fluorescence in situ hybridization (FISH) assays. The in vitro experiments included cytotoxicity and bystander killing effect assays on three cell lines of variable HER2/neu expression. In vivo activity was studied in a mouse CS xenograft model of 3+ HER2/neu uterine CS. RESULTS: In vitro studies showed that DS-8201a was highly effective against uterine and ovarian CS cell lines demonstrating 3+ HER2/neu expression compared to MAAA-9199 control; there was no significant improvement in the 0 HER2/neu CS cell line. However, DS-8201a induced efficient bystander killing of 0 HER2/neu tumor cells when admixed with 3+ HER2/neu cells. In vivo studies confirmed that DS-8201a was more effective than MAAA-9199 in 3+ HER2/neu-expressing CS xenografts. CONCLUSION: DS-8201a may represent a novel and highly effective ADC against HER2/neu-expressing CS.

Elimusertib (BAY1895344), a novel ATR inhibitor, demonstrates in vivo activity in ATRX mutated models of uterine leiomyosarcoma.

INTRODUCTION: Uterine leiomyosarcoma (uLMS) is a rare, highly aggressive malignancy. Recent data suggest 50% of uLMS may harbor alterations in the ATRX gene and such mutations may confer sensitivity to ataxia-telangiectasia-and-Rad3-related (ATR) kinase inhibitors. We sought to investigate the in vivo activity of Elimusertib (BAY1895344), a novel ATR-inhibitor, against ATRX-mutated uLMS patient-derived xenografts (PDXs). METHODS: Two fully characterized uLMS (i.e., LEY-11 and LEY-16) were grafted into female CB-17/SCID mice. Treatments with control vehicle or BAY1895344 (20 mg/kg dosed twice daily 3 days on 4 days off) were given via oral gavage and tumor measurements as well as weights obtained twice weekly. Tumor volume differences were calculated with a two-way ANOVA. Mechanistic studies were performed ex vivo using BAY1895344 treated uLMS tumor samples by western blot analysis. RESULTS: Both PDX LEY-11 and PDX LEY-16 harboring ATRX gene mutations demonstrated an aggressive behavior in vivo (i.e., control mice were euthanized on average at day 12.5 for PDX LEY-11 and at day 33 for PDX LEY-16). In both tumor models BAY1895344 20 mg/kg dosed with an intermittent oral schedule was able to induce significant growth inhibition compared to vehicle control treatment (p < 0.001 for both LEY-11 and LEY-16) and prolong median overall survival [PDX LEY-11 (12.5 vs. 42 days, p < 0.001) and PDX LEY-16 (33 vs. 60 days, p < 0.001)]. There were not significant changes in weight between treatment and controls. By western blot assays BAY1895344 exposure decreased phosphorylated-ATR and increased expression of apoptotic molecules in LMS PDXs. CONCLUSIONS: BAY1895344 demonstrates promising in vivo activity against biologically aggressive PDX models of uLMS harboring ATRX mutations, with no significant toxicity. Clinical trials of BAY1895344 in uLMS patients are warranted.

The Poly (ADP-ribose) polymerase inhibitor olaparib and pan-ErbB inhibitor neratinib are highly synergistic in HER2 overexpressing epithelial ovarian carcinoma in vitro and in vivo.

INTRODUCTION: Ovarian cancer (OC) is associated with the highest gynecologic cancer mortality. The development of novel, effective combinations of targeted therapeutics remains an unmet medical need. We evaluated the preclinical efficacy of the Poly (ADP-ribose) polymerase (PARP) inhibitor (olaparib) and the pan-ErbB inhibitor (neratinib) as single agents and in combination in ovarian cancer cell lines and xenografts with variable HER2 expression. METHODS: In vitro cell viability with olaparib, neratinib, and their combination was assessed using flow-cytometry based assays against a panel of OC primary cell lines with variable HER2 expression. Immunoblotting experiments were performed to elucidate the mechanism of activity and synergism. The in vivo antitumor activity of the olaparib/neratinib combination versus single agents was tested in HER2 positive xenograft OC models. RESULTS: HER2 + OC cell lines demonstrated higher sensitivity to olaparib and neratinib when compared to HER2 negative tumors (i.e., IC50: 2.06 ± 0.33 µM vs. 39.28 ± 30.51 µM, p = 0.0035 for olaparib and 19.42 ± 2.63 nM vs. 235.0 ± 165.0 nM, p = 0.0035 for neratinib). The combination of olaparib with neratinib was more potent when compared to single-agent olaparib or neratinib both in vitro and in vivo, and demonstrated synergy in all primary HER2 + OC models. Western blot experiments showed neratinib decreased pHER2/neu while increased Poly(ADP-ribose) (PAR) enzymatic activity; olaparib increased pHER2/Neu expression and blocked PAR activatio. Olaparib/neratinib in combination decreased both pHER2/Neu as well as PAR activation. CONCLUSION: The combination of olaparib and neratinib is synergistic and endowed with remarkable preclinical activity against HER2+ ovarian cancers. This combination may represent a novel therapeutic option for ovarian cancer patients with HER2+, homologous recombination-proficient tumors resistant to chemotherapy.

Ovarian and uterine carcinosarcomas are sensitive in vitro and in vivo to elimusertib, a novel ataxia-telangiectasia and Rad3-related (ATR) kinase inhibitor.

BACKGROUND: Carcinosarcoma of the ovary (OCS) and uterus (UCS) are rare highly aggressive malignancies. Ataxia-telangiectasia-and-Rad3-related (ATR) kinase and homologous recombination play a pivotal role in DNA damage repair. Homologous recombination deficiency (HRD) has been demonstrated in >30% of OCS/UCS. We investigated the preclinical activity of elimusertib, a selective ATR kinase inhibitor, against carcinosarcoma (CS) cell lines and xenografts. METHODS: Sensitivity to elimusertib was evaluated in vitro against nine whole exome-sequenced (WES) primary CS cell lines and in vivo against HRD CS xenografts. Western blots were performed to determine baseline ATR and p-ATR protein expression in CS, and ATR pathway downstream effectors and apoptosis markers in CS HRD cell lines after Elimusertib treatment. RESULTS: Out of the 9 CS cell lines, 3 harbored HRD and 6 homologous recombination proficient (HRP) features. Most of CS (i.e., 7/9 = 85%) were found to be sensitive to Elimusertib in vitro. Among the 5 primary CS cell lines with a high-grade pure serous epithelial component, HRD cell lines were more sensitive to elimusertib than HRP tumors (mean IC50 ± SEM HRD CS = 61.3 nM ±15.2 vs HRP = 361.6 nM ±24.4 (p = 0.01)). Baseline ATR and p-ATR protein expression was higher in HRD CS cell lines. Elimusertib showed tumor growth inhibition in HRD CS xenografts (p < 0.0001) and increased overall animal survival (p < 0.0001). Western blot demonstrated dose-dependent inhibition of ATR, p-ATR and its downstream effector p-CHK1, and a dose-dependent increase in caspase-3 expression. CONCLUSIONS: Elimusertib is preclinically active in vitro and in vivo against primary CS cell lines and xenografts, respectively. CS models harboring HRD or with pure/mixed endometrioid histology demonstrated higher sensitivity to ATR inhibition. Clinical trials with elimusertib in CS patients are warranted.

Uterine leiomyosarcomas harboring MAP2K4 gene amplification are sensitive in vivo to PLX8725, a novel MAP2K4 inhibitor.

INTRODUCTION: Uterine leiomyosarcomas (uLMS) are rare, highly aggressive tumors. Up to 30% of uLMS may harbor gain of function (GOF) in the MAP2K4 gene, important for tumor cell proliferation, differentiation and metastasis. We investigated the in vivo activity of a novel MAP2K4 inhibitor, PLX8725, against uLMS harboring MAP2K4 gene-amplification. METHODS: Two fully characterized uLMS (i.e., LEY-11 and LEY-16) were grafted into female CB-17/SCID mice. Treatments with control vehicle or PLX8725 (50 mg/kg) were given via oral gavage daily on weekdays for up to 60 days. Tumor volume differences were calculated with two-way ANOVA. Pharmacokinetic (PK) and mechanistic studies of PLX8725 in uLMS PDX models were also performed. RESULTS: Both uLMS tumors evaluated demonstrated GOF in MAP2K4 (i.e., 3 CNV in both LEY-11 and LEY-16). Tumor growth inhibition was significantly greater in both PDX LEY-11 and PDX LEY-16 treated with PLX8725 when compared to controls (p < 0.001). Median overall survival was also significantly longer in both PDX LEY-11 (p = 0.0047) and PDX LEY-16 (p = 0.0058) treatment cohorts when compared to controls. PLX8725 oral treatment was well tolerated, and PK studies demonstrated that oral PLX8725 gives extended exposure in mice. Ex vivo tumor samples after PLX8725 exposure decreased phosphorylated-ATR, JNK and p38, and increased expression of apoptotic molecules on western blot. CONCLUSION: PLX8725 demonstrates promising in vivo activity against PDX models of uLMS harboring GOF alterations in the MAP2K4 gene with tolerable toxicity. Phase I trials of PLX8725 in advanced, recurrent, chemotherapy-resistant uLMS patients are warranted.

Changes to same day discharge after minimally invasive hysterectomy throughout COVID-19 pandemic.

BACKGROUND: Minimally invasive hysterectomy is a common gynecologic procedure. Numerous studies have found that a same day discharge (SDD) is safe following this procedure. Research has found that SDDs decrease resource strain, nosocomial infections, and financial burden for both the patient and healthcare system. Due to the recent COVID-19 pandemic, the safety of hospital admissions and elective surgeries was called into question. OBJECTIVE: To assess the rates of SDD among patients who underwent a minimally invasive hysterectomy before and during the COVID-19 pandemic. STUDY DESIGN: A retrospective chart review was performed from September 2018 to December 2020 on 521 patients, who met inclusion criteria. Descriptive analysis, chi-square tests of association, and multivariable logistic regression were used for analysis. RESULTS: There was a significant difference between rate of SDDs pre-COVID-19 (12.5%) versus during the COVID-19 period (28.6%) (p < 0.001). Surgical complexity was predictive of not being discharged the same day of surgery (odds ratio [OR] = 4.4, 95% confidence interval [CI] = 2.2-8.8), as was surgical completion time after 4 p.m. (OR = 5.2, 95% CI = 1.1-25.2). There was no difference in readmissions (p = 0.209) and emergency department (ED) visits (p = 0.973) between SDD and overnight stay. CONCLUSION: Rates of SDD for patients undergoing minimally invasive hysterectomy were significantly increased during the COVID-19 pandemic. SDDs are safe; the number of readmissions and ED visits did not increase among patients who were discharged on the same day.

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.

Validation of the KELIM score as a predictor of response to neoadjuvant treatment in patients with advanced high grade serous ovarian cancer.

OBJECTIVE: The objective of this study is to externally validate the KELIM (rate of elimination of CA-125 elimation) score in patients with high grade serous ovarian cancer(HGSC)undergoing NACT and determine its relation to outcome of cytoreduction, platinum sensitivity, progression free(PFS) and overall survival(OS). METHODS: This is a retrospective cohort study of patients with Stage III-IV HGSC diagnosed between January 1, 2010 and December 31, 2019 and treated with NACT. KELIM score was calculated using at least 3 CA-125 values within the first 100 days of chemotherapy. Demographic parameters were collected and Kaplan Meier survival analyses were performed for PFS and OS. This study was approved by local ethics board. RESULTS: 217 patients met inclusion criteria. Median follow-up was 28.93 months(range 2.86-135.06). There was no significant difference in stage, functional status, cytoreductive outcome or BRCA status(germline or somatic) between patients with a KELIM ≥ 1 and <1. Patients with a KELIM<1 had a lower median PFS (13.58 vs 19.69, p < 0.001), median platinum free interval(PFI) (7.66 vs 13.64, p < 0.001) and 5-year OS (57% vs 72%, p = 0.0140) compared to patients with KELIM≥1 . After adjusting for stage, treatment delays, bevacizumab or poly adenosine diphosphate-ribose polymerase(parp)-inhibitor use, and BRCA status, patients with KELIM<1 had a high risk of disease progression(HR = 1.57 (95% CI 1.08-2.28) and death(HR = 1.99 (95% CI 1.01-3.95) compared to KELIM≥1. BRCA status was independently associated to an increase on KELIM score (OR = 1.917, 95% CI 1.046-3.512, p = 0.035). CONCLUSION: Patients with advanced HGSC undergoing NACT with a KELIM <1 were more likely to have platinum-resistant disease, worse PFS and worse OS when compared to patients with KELIM≥1. The KELIM score can be a helpful tool to predict chemo-response and aid in treatment decision making.

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.

Endometrial Carcinoma as the Presenting Malignancy in a Teenager With a Pathogenic TP53 Germline Mutation: A Case Report and Literature Review.

Patients with germline TP53 mutations are characterized by the occurrence of multiple early-onset malignancies. The characteristic syndrome is Li-Fraumeni syndrome (OMIM # 151623), an autosomal dominant disorder typified by premenopausal breast carcinoma, adrenal cortical tumors, bone and soft tissue sarcomas, leukemias, and tumors of the brain and spinal cord. Gynecologic malignancies are uncommonly reported in families harboring TP53 mutations, and the predominant tumor type reported is ovarian. Uterine carcinoma has been reported only a handful of times in patients with germline TP53 mutations, none as a presenting tumor in a teenager. We report on an 18-year-old patient who presented with grade 3, high-stage endometrioid endometrial carcinoma. Sequencing detected a single-nucleotide substitution in the TP53 gene (NM_000546.6:c.818G>A), encoding the missense substitution p.Arg273His (R273H) in both the tumor and normal tissue, consistent with a germline mutation. We discuss the biology of the TP53 gene and p53 protein, with emphasis on the R273H mutation. We also review the literature on endometrial carcinoma in patients with germline TP53 mutations.

Hormone maintenance therapy for women with low-grade serous ovarian cancer in the front-line setting: A systematic review.

OBJECTIVE: Low-grade serous ovarian cancer (LGSOC) is a rare form of ovarian cancer that accounts for 5-10% of epithelial ovarian cancers. LGSOCs are difficult to treat as they respond poorly to traditional chemotherapy treatments. This systematic review aims to appraise the literature describing the efficacy of hormone maintenance therapy (HMT) in patients with LGSOC given after cytoreductive surgery. METHODS: Medline, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews were searched from inception to November 2020. No language restrictions were applied. Publications describing HMT in the primary setting following cytoreductive surgery with or without chemotherapy in women with LGSOC were included. Publications describing HMT in recurrence, non-LGSOC carcinomas, and in-vitro or animal studies were excluded along with case reports, case series, and conference proceedings. We summarized oncologic outcomes, HMT used, and hormone receptor status where reported. Studies were assessed for risk of bias and quality of evidence. RESULTS: The literature search identified 14,799 records. Four cohort studies met eligibility criteria. A total of 558 patients were included, of which 127 were treated with HMT. There was significant heterogeneity between studies demonstrated by differences in HMT regimens used, dosing, and study population, leading to various outcomes following treatment with HMT. CONCLUSIONS: Treatment of LGSOC remains a challenge. One retrospective study demonstrated improved progression-free survival following HMT for LGSOC, while two others failed to show significant improvements. However, there is limited data available in the literature which restricts the generalizability of these results. Therefore, well-designed, prospective, and randomized trials are needed to confirm the benefit of HMT in patients with this rare subgroup of ovarian cancer.

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.

Does Radical Hysterectomy for Clinically Apparent Stage II Endometrial Cancer Affect Risk of Local Recurrence?

OBJECTIVE: Compare recurrence-free survival (RFS) and morbidity between radical hysterectomy (RH) and simple hysterectomy (SH) for clinically diagnosed stage II endometrial cancer. METHODS: A multicentre, retrospective study, from 2000 to 2015, involving patients with endometrial cancer with cervical involvement preoperatively and stromal invasion on final pathology. Wilcoxon rank-sum test, Fisher exact test, Kaplan-Meier survival functions, and Cox proportional hazards models were used for analysis. RESULTS: Ninety of 1613 patients had clinical stage II endometrial cancer; 57 underwent RH and 33 underwent SH, with no difference in adjuvant treatment or morbidity. About half of patients (51%) had pathologic stage III-IV disease. Mean follow-up was 3.3 and 3.8 years for SH and RH, respectively. Thirty-three percent of patients with RH and SH experienced a recurrence. Most recurrences were distant: 90% with SH and 79% with RH. There was no difference in RFS between groups (2-year: SH 65% vs. RH 75%; 5-year: SH 54% vs. RH 63%; P = 0.72). Controlling for stage, adjuvant treatment, and margin status, RH was not associated with RFS (HR 0.62; 95% CI 0.28-1.35). Among 44 patients with pathologic stage II disease, 7 had a recurrence (4 SH and 3 RH); 6 of 7 had distant recurrences. CONCLUSIONS: Fifty-one percent of patients with clinical stage II endometrial cancer had advanced disease on final pathology, highlighting the importance of surgical staging. RH was not associated with RFS or reduced morbidity. Most recurrences were distant. Although RH could be performed to achieve negative surgical margins, SH may be sufficient for central, small tumours given the high risk of advanced disease and distant recurrence. Research efforts should further elucidate the ideal management of these patients.