Patient decision aids in mainstreaming genetic testing for women with ovarian cancer: A prospective cohort study

OBJECTIVE

To evaluate patient preference for short (gist) or detailed/extensive decision aids (DA) for genetic testing at ovarian cancer (OC) diagnosis.

DESIGN

Cohort study set within recruitment to the Systematic Genetic Testing for Personalised Ovarian Cancer Therapy (SIGNPOST) study (ISRCTN: 16988857).

SETTING

North-East London Cancer Network (NELCN) population.

POPULATION/SAMPLE

Women with high-grade non-mucinous epithelial OC.

METHODS

A more detailed DA was developed using patient and stakeholder input following the principles/methodology of IPDAS (International Patients Decision Aids Standards). Unselected patients attending oncology clinics evaluated both a pre-existing short and a new long DA version and then underwent mainstreaming genetic testing by a cancer clinician. Appropriate inferential descriptive and regression analyses were undertaken.

MAIN OUTCOME MEASURES

Satisfaction, readability, understanding, emotional well-being and preference for long/short DA.

RESULTS

The mean age of patients was 66 years (interquartile range 11), and 85% were White British ethnicity. Of the participants, 74% found DAs helpful/useful in decision-making. Women reported higher levels of satisfaction (86% versus 58%, p < 0.001), right amount of information provided (76.79% versus49.12%, p < 0.001) and improved understanding (p < 0.001) with the long DA compared with the short DA. There was no statistically significant difference in emotional outcomes (feeling worried/concerned/reassured/upset) between 'short' and 'long' DA; 74% of patients preferred the long DA and 24% the short DA. Patients undergoing treatment (correlation coefficient (coef) = 0.603; 95% CI 0.165-1.041, p = 0.007), those with recurrence (coef = 0.493; 95% CI 0.065-0.92, p = 0.024) and older women (coef = 0.042; 95% CI 0.017-0.066, p = 0.001) preferred the short DA. Ethnicity did not affect outcomes or overall preference for long/short DA.

CONCLUSIONS

A longer DA in OC patients has higher satisfaction without increasing emotional distress. Older women and those undergoing treatment/recurrence prefer less extensive information, whereas those in remission preferred a longer DA.

Seminoma and dysgerminoma: evidence for alignment of clinical trials and de-escalation of systemic chemotherapy

Malignant germ cell tumours are a group of rare cancers whose incidence peaks in late adolescence and early adulthood. Dysgerminomas of the ovary and seminomas of the testis are analogous diseases, but seminomas have a 10-fold higher incidence. The two tumours are morphologically identical and are only differentiated by surrounding organ-specific tissue or testicular germ cell neoplasia in situ. They share genetic features including KIT and RAS mutations, amplification of chromosome 12p, and expression of pluripotency markers (NANOG (Nanog homeobox), OCT3/4 (Octamer-binding transcription factor 3/4), and SAL4 (Spalt-like trascription factor 4)). Both histologies are exquisitely sensitive to platinum chemotherapy, and the combination of bleomycin, etoposide, and cisplatin (BEP) yields survival rates greater than 90%. However, BEP causes significant, lifelong toxicity (cardiovascular, renal, respiratory, and neurological) in these young patients with an expectation of cure. Here, we comprehensively review the biological features of dysgerminoma and seminoma to demonstrate that they are biologically analogous diseases. We present available clinical trial data supporting de-escalation of chemotherapy treatment. Finally, we propose that future trials should enrol men, women, and children to benefit all patients regardless of age or sex.

The Landscape of Adoptive Cellular Therapies in Ovarian Cancer

Ovarian cancers are typically poorly immunogenic and have demonstrated disappointing responses to immune checkpoint inhibitor (ICI) therapy. Adoptive cellular therapy (ACT) offers an alternative method of harnessing the immune system that has shown promise, especially with the success of chimeric antigen receptor T-cell (CAR-T) therapy in haematologic malignancies. So far, ACT has led to modest results in the treatment of solid organ malignancies. This review explores the possibility of ACT as an effective alternative or additional treatment to current standards of care in ovarian cancer. We will highlight the potential of ACTs, such as CAR-T, T-cell receptor therapy (TCR-T), tumour-infiltrating lymphocytes (TILs) and cell-based vaccines, whilst also discussing their challenges. We will present clinical studies for these approaches in the treatment of immunologically 'cold' ovarian cancer and consider the rationale for future research.

The role of PARP inhibitor combination therapy in ovarian cancer

The use of PARP inhibitors (PARPi) has transformed the care of advanced high-grade serous/endometrioid ovarian cancer. PARPi are now available to patients in both the first-line and recurrent platinum-sensitive disease settings; therefore, most patients will receive PARPi at some point in their treatment pathway. The majority of this expanding population of patients eventually acquire resistance to PARPi, in addition to those with primary PARPi resistance. We discuss the rationale behind developing combination therapies, to work synergistically with PARPi and overcome mechanisms of resistance to restore drug sensitivity, and clinical evidence of their efficacy to date.

Disparity in the era of personalized medicine for epithelial ovarian cancer

The treatment of high-grade serous ovarian cancer and high-grade endometrioid ovarian cancer has seen significant improvements in recent years, with BRCA1/2 and homologous recombination status guiding a personalized approach which has resulted in improved patient outcomes. However, for other epithelial ovarian cancer subtypes, first-line treatment remains unchanged from the platinum-paclitaxel trials of the early 2000s. In this review, we explore novel therapeutic approaches being adopted in the treatment of clear cell, mucinous, carcinosarcoma and low-grade serous ovarian cancer and the biological rational behind them. We discuss why such disparities exist, the challenges faced in conducting dedicated trials in these rarer histologies and look towards new approaches being adopted to overcome them.

First-in-human phase I/II, open-label study of the anti-OX40 agonist INCAGN01949 in patients with advanced solid tumors

BACKGROUND

OX40 is a costimulatory receptor upregulated on antigen-activated T cells and constitutively expressed on regulatory T cells (Tregs). INCAGN01949, a fully human immunoglobulin G1κ anti-OX40 agonist monoclonal antibody, was designed to promote tumor-specific immunity by effector T-cell activation and Fcγ receptor-mediated Treg depletion. This first-in-human study was conducted to determine the safety, tolerability, and preliminary efficacy of INCAGN01949.

METHODS

Phase I/II, open-label, non-randomized, dose-escalation and dose-expansion study conducted in patients with advanced or metastatic solid tumors. Patients received INCAGN01949 monotherapy (7-1400 mg) in 14-day cycles while deriving benefit. Safety measures, clinical activity, pharmacokinetics, and pharmacodynamic effects were assessed and summarized with descriptive statistics.

RESULTS

Eighty-seven patients were enrolled; most common tumor types were colorectal (17.2%), ovarian (8.0%), and non-small cell lung (6.9%) cancers. Patients received a median three (range 1-9) prior therapies, including immunotherapy in 24 patients (27.6%). Maximum tolerated dose was not reached; one patient (1.1%) receiving 350 mg dose reported dose-limiting toxicity of grade 3 colitis. Treatment-related adverse events were reported in 45 patients (51.7%), with fatigue (16 (18.4%)), rash (6 (6.9%)), and diarrhea (6 (6.9%)) being most frequent. One patient (1.1%) with metastatic gallbladder cancer achieved a partial response (duration of 6.3 months), and 23 patients (26.4%) achieved stable disease (lasting &gt;6 months in one patient). OX40 receptor occupancy was maintained over 90% among all patients receiving doses of ≥200 mg, while no treatment-emergent antidrug antibodies were detected across all dose levels. Pharmacodynamic results demonstrated that treatment with INCAGN01949 did not enhance proliferation or activation of T cells in peripheral blood or reduce circulating Tregs, and analyses of tumor biopsies did not demonstrate any consistent increase in effector T-cell infiltration or function, or decrease in infiltrating Tregs.

CONCLUSION

No safety concerns were observed with INCAGN01949 monotherapy in patients with metastatic or advanced solid tumors. However, tumor responses and pharmacodynamic effects on T cells in peripheral blood and post-therapy tumor biopsies were limited. Studies evaluating INCAGN01949 in combination with other therapies are needed to further evaluate the potential of OX40 agonism as a therapeutic approach in patients with advanced solid tumors.

TRIAL REGISTRATION NUMBER

NCT02923349.

Ovarian Cancer Therapy: Homologous Recombination Deficiency as a Predictive Biomarker of Response to PARP Inhibitors

Poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors have revolutionised the management of patients with high-grade serous and endometrioid ovarian cancer demonstrating significant improvements in progression-free survival. Whilst the greatest benefit is seen with BRCA1/2 mutant cancers, it is clear that the benefit extends beyond this group. This sensitivity is thought to be due to homologous recombination deficiency (HRD), which is present in up to 50% of the high-grade serous cancers. Several different HRD assays exist, which fall into one of three main categories: homologous recombination repair (HRR)-related gene analysis, genomic “scars” and/or mutational signatures, and real-time HRD functional assessment. We review the emerging data on HRD as a predictive biomarker for PARP inhibitors and discuss the merits and disadvantages of different HRD assays.

PARP inhibitors in ovarian cancer: overcoming resistance with combination strategies

The use of PARP inhibitors (PARPi) in patients with epithelial ovarian cancer is expanding, with the transition from use in recurrent disease to the first-line setting. This is accompanied with an increasing population of patients who develop acquired PARPi resistance. Coupled with those patients with primary PARPi resistance, there is an urgent need to better understand mechanisms of resistance and identify means to overcome this resistance. Combination therapy offers the potential to overcome innate and acquired resistance, by either working synergistically with PARPi or by restoring homologous recombination deficiency, targeting the homologous recombination repair pathway through an alternate strategy. We discuss mechanisms of PARPi resistance and data on novel combinations which may restore PARPi sensitivity.

PARP inhibitors and immunotherapy in ovarian and endometrial cancers

Advanced ovarian and endometrial cancers have historically been associated with poor prognosis and few treatment options, limited to single or doublet chemotherapy regimens. The introduction of novel target therapies has transformed the management of these cancers. In contrast to chemotherapy, which inhibits DNA replication and mitosis, targeted therapies target cancer signalling pathways, stroma, immune-microenvironment and vasculature in tumour tissues. The most notable advances in gynaecological cancers have come from the introduction of PARP inhibitors and immune checkpoint inhibitors for ovarian and endometrial cancer, respectively. Several PARP inhibitors, which target defective DNA repair, have been approved as maintenance therapy for advanced ovarian cancer in both the first line and platinum-sensitive relapsed settings. Immune checkpoint inhibitors such as anti-PD-1/PD-L1 antibodies have proven successful in advanced mismatch repair deficient endometrial cancers with use now being investigated beyond this population. This review will explore the biological rationale and clinical evidence behind the use of PARP inhibitors and immunotherapy in ovarian and endometrial cancers.

Implementation of Multigene Germline and Parallel Somatic Genetic Testing in Epithelial Ovarian Cancer: SIGNPOST Study

We present findings of a cancer multidisciplinary-team (MDT) coordinated mainstreaming pathway of unselected 5-panel germline BRCA1/BRCA2/RAD51C/RAD51D/BRIP1 and parallel somatic BRCA1/BRCA2 testing in all women with epithelial-OC and highlight the discordance between germline and somatic testing strategies across two cancer centres. Patients were counselled and consented by a cancer MDT member. The uptake of parallel multi-gene germline and somatic testing was 97.7%. Counselling by clinical-nurse-specialist more frequently needed >1 consultation (53.6% (30/56)) compared to a medical (15.0% (21/137)) or surgical oncologist (15.3% (17/110)) (p < 0.001). The median age was 54 (IQR = 51-62) years in germline pathogenic-variant (PV) versus 61 (IQR = 51-71) in BRCA wild-type (p = 0.001). There was no significant difference in distribution of PVs by ethnicity, stage, surgery timing or resection status. A total of 15.5% germline and 7.8% somatic BRCA1/BRCA2 PVs were identified. A total of 2.3% patients had RAD51C/RAD51D/BRIP1 PVs. A total of 11% germline PVs were large-genomic-rearrangements and missed by somatic testing. A total of 20% germline PVs are missed by somatic first BRCA-testing approach and 55.6% germline PVs missed by family history ascertainment. The somatic testing failure rate is higher (23%) for patients undergoing diagnostic biopsies. Our findings favour a prospective parallel somatic and germline panel testing approach as a clinically efficient strategy to maximise variant identification. UK Genomics test-directory criteria should be expanded to include a panel of OC genes.

Targeting HPV in gynaecological cancers - Current status, ongoing challenges and future directions

Despite the success of preventive vaccination, the Human Papilloma Virus still accounts for 266,000 deaths annually, as the main causative factor of cervical, vaginal, anal, penile and oropharyngeal cancers. Human Papilloma Virus infects epithelial cells, driving tumourigenesis primarily from incorporation of DNA into the host cellular genome. Translation of two particular Human Papilloma Virus-specific oncoproteins, E6 and E7, are the key drivers of malignancy. If diagnosed early cervical, vaginal and vulval cancers have good prognosis and are treated with curative intent. However, metastatic disease carries a poor prognosis, with first-line systemic treatment providing only modest increase in outcome. Having shown promise in other solid malignancies, immune checkpoint inhibition and therapeutic cancer vaccines have been directed towards Human Papilloma Virus-associated gynaecological cancers, mindful that persistent Human Papilloma Virus infection drives malignancy and is associated with immunosuppression and lack of T-cell immunity. In this review, we discuss novel therapeutic approaches for targeting Human Papilloma Virus-driven gynaecological malignancies including vaccination strategies, use of immunomodulation, immune checkpoint inhibitors and agents targeting Human Papilloma Virus-specific oncoproteins. We also highlight the evolving focus on exciting new treatments including adoptive T-cell therapies.

ESMO recommendations on predictive biomarker testing for homologous recombination deficiency and PARP inhibitor benefit in ovarian cancer

BACKGROUND

Homologous recombination repair deficiency (HRD) is a frequent feature of high-grade serous ovarian, fallopian tube and peritoneal carcinoma (HGSC) and is associated with sensitivity to PARP inhibitor (PARPi) therapy. HRD testing provides an opportunity to optimise PARPi use in HGSC but methodologies are diverse and clinical application remains controversial.

MATERIALS AND METHODS

To define best practice for HRD testing in HGSC the ESMO Translational Research and Precision Medicine Working Group launched a collaborative project that incorporated a systematic review approach. The main aims were to (i) define the term 'HRD test'; (ii) provide an overview of the biological rationale and the level of evidence supporting currently available HRD tests; (iii) provide recommendations on the clinical utility of HRD tests in clinical management of HGSC.

RESULTS

A broad range of repair genes, genomic scars, mutational signatures and functional assays are associated with a history of HRD. Currently, the clinical validity of HRD tests in ovarian cancer is best assessed, not in terms of biological HRD status per se, but in terms of PARPi benefit. Clinical trials evidence supports the use of BRCA mutation testing and two commercially available assays that also incorporate genomic instability for identifying subgroups of HGSCs that derive different magnitudes of benefit from PARPi therapy, albeit with some variation by clinical scenario. These tests can be used to inform treatment selection and scheduling but their use is limited by a failure to consistently identify a subgroup of patients who derive no benefit from PARPis in most studies. Existing tests lack negative predictive value and inadequately address the complex and dynamic nature of the HRD phenotype.

CONCLUSIONS

Currently available HRD tests are useful for predicting likely magnitude of benefit from PARPis but better biomarkers are urgently needed to better identify current homologous recombination proficiency status and stratify HGSC management.

Olaparib maintenance for first-line treatment of ovarian cancer: will SOLO1 reset the standard of care?

Maintenance therapy with PARP inhibitors has heralded a new era in the management of recurrent epithelial ovarian cancer. The greatest effect is seen in women with BRCA1/2 tumors but those without this mutation also benefit. However, in most patients, the drugs eventually fail to prevent progression, so alternative strategies are needed. The SOLO1 trial randomized women with BRCA1/2-mutated advanced ovarian cancer to olaparib or placebo maintenance after first-line chemotherapy. Olaparib significantly improved progression-free survival to a degree that has not been seen in other first-line trials in ovarian cancer. This landmark trial is likely to change practice for this group of women. Here, we focus on the SOLO1 results in the context of the current management of advanced ovarian cancer.

Abstract 2726: Guidance by molecular selection improves the outcome of early phase treatment for gynecological (GYN) cancers

Background: Patients (pts) with advanced gynecological (GYN) cancers have limited therapeutic options and the prognosis is poor. Early phase trials may be a suitable option for pts with good performance status. Increasingly, molecular characterisation guides pt selection for early phase trials. We sought to determine the outcome of GYN pts treated in a phase 1 unit and examined the role of molecular selection to inform therapeutic decision making.

Methods: Medical records of all pts with a GYN malignancy treated within an early phase trial between 2010 and 2016 were reviewed. Data comprising patient and tumor characteristics, prior treatment, trial therapy and outcome were analysed.

Results: 81 pts with a median age of 60 years (range 20-75) with a diagnosis of ovarian (OC, 54), endometrial (EC, 15) or cervical/vulval (CC, 12) cancer were identified. The median number of prior therapies for advanced disease was 3 (OC) and 2 (EC and CC) (overall range 1-6). 9 pts (11%) entered a second and 1 pt a third phase 1 study on disease progression. Next Generation Sequencing (NGS) using a targeted panel was performed in 32 pts (40%) with an actionable mutation identified in 9 including; KRAS (3pts), PIK3CA (2pts) and EGFR (2pts). Germline BRCA (gBRCA) testing was performed in 35 OC pts (65%) with 24 gBRCA mutations identified.

Pts were allocated, in order of priority, where available, to (1) a trial selected on the basis of NGS or gBRCA (‘genomic’ 35%), (2) a ‘tumor specific’ cohort within an early phase trial (15%) or (3) a ‘generic’ study (51%). For the whole cohort there was an overall response rate (ORR) of 18% with 41% stable disease (SD) and median progression free survival (PFS) and overall survival (OS) of 13 and 46 weeks respectively. Outcomes were best for pts in the genomic group. Both PFS and OS were significantly longer with genomic selection (p &lt; 0.01 for both, Mantel-cox test) with median PFS of 29.7, 14.2, 8.0 weeks and OS of 84.1, 69.7, 33.6 weeks for genomics, tumor specific and generic studies respectively. The ORR was also greatest for the genomic cohort (32%) compared to the tumour specific (7%) and generic (11%) groups.

Within the heavily pre-treated EC and CC cohorts there was an OS of 30 and 42 weeks respectively. 24% of EC pts had an ORR with a further 24% with stable disease (SD). There was only 1 response (9%) in the CC cohort, however SD was seen in 64%. The OS for the OC was 55 weeks with an ORR of 20% and 46% SD.

Conclusions: Early phase trials represent a good option for pts with advanced GYN malignancies. Whilst applicable to all GYN cancers, this is particularly relevant for EC and CC pts as standard treatment options are limited. For OC patients (median 3 prior lines of chemotherapy in this cohort) where standard treatment options exist, early access to phase 1 genomic trials may result in improved response rates and allow further standard options to be given subsequently. NGS is feasible in real time and may have a positive impact on outcome.

Citation Format: Rowan E. Miller, Michael John Devlin, Nicholas Brown, Kin Woo, Tami Grunewald, Arran Speirs, Miriam Mitchison, Michelle Lockley, Mary McCormack, Jonathan Ledermann, Martin Forster, Tim Meyer, Rebecca Kristeleit. Guidance by molecular selection improves the outcome of early phase treatment for gynecological (GYN) cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2726. doi:10.1158/1538-7445.AM2017-2726

Gynecologic Cancers: Emerging Novel Strategies for Targeting DNA Repair Deficiency

The presence of a BRCA mutation, somatic or germline, is now established as a standard of care for selecting patients with ovarian cancer for treatment with a PARP inhibitor. During the clinical development of the PARP inhibitor class of agents, a subset of women without BRCA mutations were shown to respond to these drugs (termed "BRCAness"). It was hypothesized that other genetic abnormalities causing a homologous recombinant deficiency (HRD) were sensitizing the BRCA wild-type cancers to PARP inhibition. The molecular basis for these other causes of HRD are being defined. They include individual gene defects (e.g., RAD51 mutation, CHEK2 mutation), homozygous somatic loss, and whole genome properties such as genomic scarring. Testing this knowledge is possible when selecting patients to receive molecular therapy targeting DNA repair, not only for patients with ovarian cancer but also endometrial and cervical cancers. The validity of HRD assays and multiple gene sequencing panels to select a broader population of patients for treatment with PARP inhibitor therapy is under evaluation. Other non-HRD targets for exploiting DNA repair defects in gynecologic cancers include mismatch repair (MMR), checkpoint signaling, and nonhomologous end-joining (NHEJ) DNA repair. This article describes recent evidence supporting strategies in addition to BRCA mutation for selecting patients for treatment with PARP inhibitor therapy. Additionally, the challenges and opportunities of exploiting DNA repair pathways other than homologous recombination for molecular therapy in gynecologic cancers is discussed.

The status of poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors in ovarian cancer, part 2: extending the scope beyond olaparib and BRCA1/2 mutations

Poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors have shown clinical activity in epithelial ovarian cancer, leading both the US Food and Drug Administration (FDA) and the European Medicines Agency to approve olaparib for tumors characterized by BRCA1 and BRCA2 mutations. However, it is becoming increasingly evident that tumors that share molecular features with BRCA-mutant tumors-a concept known as BRCAness-also may exhibit defective homologous recombination DNA repair, and therefore will respond to PARP inhibition. A number of strategies have been proposed to identify BRCAness, including identifying defects in other genes that modulate homologous recombination and characterizing the mutational and transcriptional signatures of BRCAness. In addition to olaparib, a number of other PARP inhibitors are in clinical development. This article reviews the development of PARP inhibitors other than olaparib, and discusses the evidence for PARP inhibitors beyond BRCA1/2-mutant ovarian cancer.

Insurance status and disparities in disease presentation, treatment, and outcomes for men with germ cell tumors

BACKGROUND

People aged 26 to 34 years represent the greatest proportion of the uninsured, and they have the highest incidence of testicular cancers. The aim of this study was to investigate the association between insurance status and cancer outcomes in men diagnosed with germ cell tumors.

METHODS

The Surveillance, Epidemiology, and End Results database was used to identify 10,211 men diagnosed with germ cell gonadal neoplasms from 2007 to 2011. Associations between insurance status and characteristics at diagnosis and receipt of treatment were examined with log-binomial regression. The association between insurance status and mortality was assessed with Cox proportional hazards regression.

RESULTS

Uninsured patients had an increased risk of metastatic disease at diagnosis (relative risk [RR], 1.26; 95% confidence interval [CI], 1.15-1.38) in comparison with insured patients, as did Medicaid patients (RR, 1.62; 95% CI, 1.51-1.74). Among men with metastatic disease, uninsured and Medicaid patients were more likely to be diagnosed with intermediate/poor-risk disease (RR for uninsured patients, 1.22; 95% CI, 1.04-1.44; RR for Medicaid patients, 1.39; 95% CI, 1.23-1.57) and were less likely to undergo lymph node dissection (RR for uninsured patients, 0.74; 95% CI, 0.57-0.94; RR for Medicaid patients, 0.76; 95% CI, 0.63-0.92) in comparison with insured patients. Men without insurance were more likely to die of their disease (hazard ratio [HR], 1.88; 95% CI, 1.29-2.75) in comparison with insured men, as were those with Medicaid (HR, 1.51; 95% CI, 1.08-2.10).

CONCLUSIONS

Patients without insurance and patients with Medicaid have an increased risk of presenting with advanced disease and dying of the disease in comparison with those who have insurance. Future studies should examine whether implementation of the Patient Protection and Affordable Care Act reduces these disparities. Cancer 2016;122:3127-35. © 2016 American Cancer Society.

The status of poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors in ovarian cancer, part 1: olaparib

Poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitors have shown promising clinical activity in epithelial ovarian cancer. Following the observation in vitro that PARP inhibition is synthetically lethal in tumors with BRCA mutations, PARP inhibition has become the first genotype-directed therapy for BRCA1- and BRCA2-associated ovarian cancer. However, it is becoming clear that PARP inhibition also may have clinical utility in cancers associated with defects or aberrations in DNA repair that are unrelated to BRCA mutations. Deficient DNA repair mechanisms are present in approximately 30% to 50% of high-grade serous ovarian cancers, the most common histologic subtype. Olaparib is the best-studied PARP inhibitor to date, and a number of phase 3 trials with this agent are underway. This article reviews the development of olaparib for ovarian cancer and discusses the current evidence for its use, ongoing studies, future research directions, and the challenges ahead.

Synthetic Lethal Targeting of ARID1A-Mutant Ovarian Clear Cell Tumors with Dasatinib

New targeted approaches to ovarian clear cell carcinomas (OCCC) are needed, given the limited treatment options in this disease and the poor response to standard chemotherapy. Using a series of high-throughput cell-based drug screens in OCCC tumor cell models, we have identified a synthetic lethal (SL) interaction between the kinase inhibitor dasatinib and a key driver in OCCC, ARID1A mutation. Imposing ARID1A deficiency upon a variety of human or mouse cells induced dasatinib sensitivity, both in vitro and in vivo, suggesting that this is a robust synthetic lethal interaction. The sensitivity of ARID1A-deficient cells to dasatinib was associated with G1-S cell-cycle arrest and was dependent upon both p21 and Rb. Using focused siRNA screens and kinase profiling, we showed that ARID1A-mutant OCCC tumor cells are addicted to the dasatinib target YES1. This suggests that dasatinib merits investigation for the treatment of patients with ARID1A-mutant OCCC. Mol Cancer Ther; 15(7); 1472-84. ©2016 AACR.

Gynecologic Cancers: Emerging Novel Strategies for Targeting DNA Repair Deficiency

The presence of a BRCA mutation, somatic or germline, is now established as a standard of care for selecting patients with ovarian cancer for treatment with a PARP inhibitor. During the clinical development of the PARP inhibitor class of agents, a subset of women without BRCA mutations were shown to respond to these drugs (termed "BRCAness"). It was hypothesized that other genetic abnormalities causing a homologous recombinant deficiency (HRD) were sensitizing the BRCA wild-type cancers to PARP inhibition. The molecular basis for these other causes of HRD are being defined. They include individual gene defects (e.g., RAD51 mutation, CHEK2 mutation), homozygous somatic loss, and whole genome properties such as genomic scarring. Testing this knowledge is possible when selecting patients to receive molecular therapy targeting DNA repair, not only for patients with ovarian cancer but also endometrial and cervical cancers. The validity of HRD assays and multiple gene sequencing panels to select a broader population of patients for treatment with PARP inhibitor therapy is under evaluation. Other non-HRD targets for exploiting DNA repair defects in gynecologic cancers include mismatch repair (MMR), checkpoint signaling, and nonhomologous end-joining (NHEJ) DNA repair. This article describes recent evidence supporting strategies in addition to BRCA mutation for selecting patients for treatment with PARP inhibitor therapy. Additionally, the challenges and opportunities of exploiting DNA repair pathways other than homologous recombination for molecular therapy in gynecologic cancers is discussed.

Chemotherapy for metastatic castrate-sensitive prostate cancer

BACKGROUND

The role of docetaxel chemotherapy in combination with androgen deprivation therapy for metastatic castrate-sensitive prostate cancer is emerging.

METHODS

We reviewed the results from the pivotal randomized phase III trials in this area: GETUG15, CHAARTED and STAMPEDE.

RESULTS

All three studies demonstrated a benefit in progression-free survival with the use of docetaxel. However, two of the studies demonstrated a clinically meaningful overall survival benefit (CHAARTED and STAMPEDE), whereas the GETUG15 study did not demonstrate a major benefit.

CONCLUSIONS

Docetaxel is an important option to consider for men who are fit for chemotherapy with newly diagnosed metastatic prostate cancer commencing androgen deprivation therapy.

Genome-wide profiling of genetic synthetic lethality identifies CDK12 as a novel determinant of PARP1/2 inhibitor sensitivity

Small-molecule inhibitors of PARP1/2, such as olaparib, have been proposed to serve as a synthetic lethal therapy for cancers that harbor BRCA1 or BRCA2 mutations. Indeed, in clinical trials, PARP1/2 inhibitors elicit sustained antitumor responses in patients with germline BRCA gene mutations. In hypothesizing that additional genetic determinants might direct use of these drugs, we conducted a genome-wide synthetic lethal screen for candidate olaparib sensitivity genes. In support of this hypothesis, the set of identified genes included known determinants of olaparib sensitivity, such as BRCA1, RAD51, and Fanconi's anemia susceptibility genes. In addition, the set included genes implicated in established networks of DNA repair, DNA cohesion, and chromatin remodeling, none of which were known previously to confer sensitivity to PARP1/2 inhibition. Notably, integration of the list of candidate sensitivity genes with data from tumor DNA sequencing studies identified CDK12 deficiency as a clinically relevant biomarker of PARP1/2 inhibitor sensitivity. In models of high-grade serous ovarian cancer (HGS-OVCa), CDK12 attenuation was sufficient to confer sensitivity to PARP1/2 inhibition, suppression of DNA repair via homologous recombination, and reduced expression of BRCA1. As one of only nine genes known to be significantly mutated in HGS-OVCa, CDK12 has properties that should confirm interest in its use as a biomarker, particularly in ongoing clinical trials of PARP1/2 inhibitors and other agents that trigger replication fork arrest.

Lung carcinoma with hypertrophic osteoarthropathy in a teenager

Hypertrophic osteoarthropathy (HOA) characterised by arthralgia, clubbing and periosteal proliferation of long bones, is rarely encountered in children and adolescents. Whereas in adults over 80% of cases are associated with malignancy, in children the majority of cases are due to non-neoplastic causes such as cystic fibrosis, bilary atresia and congenital heart disease. Up to 5% of adults with lung cancer demonstrate signs of HOA. However, lung cancer is extremely uncommon in children and young people. Here we report a case of lung adenocarcinoma in an 18 year old male associated with HOA present both at diagnosis and at subsequent disease progression.

Plant nutrient acquisition and utilisation in a high carbon dioxide world

Producing enough food to meet the needs of an increasing global population is one of the greatest challenges we currently face. The issue of food security is further complicated by impacts of elevated CO2 and climate change. In this viewpoint article, we begin to explore the impacts of elevated CO2 on two specific aspects of plant nutrition and resource allocation that have traditionally been considered separately. First, we focus on arbuscular mycorrhizas, which play a major role in plant nutrient acquisition. We then turn our attention to the allocation of resources (specifically N and C) in planta, with an emphasis on the secondary metabolites involved in plant defence against herbivores. In doing so, we seek to encourage a more integrated approach to investigation of all aspects of plant responses to eCO2.

U.s. Geological survey core drilling on the atlantic shelf

The first broad program of scientific shallow drilling on the U.S. Atlantic continental shelf has delineated rocks of Pleistocene to Late Cretaceous age, including phosphoritic Miocene strata, widespread Eocene carbonate deposits that serve as reflective seismic markers, and several regional unconformities. Two sites, off Maryland and New Jersey, showed light hydrocarbon gases having affinity to mature petroleum. Pore fluid studies showed that relatively fresh to brackish water occurs beneath much of the Atlantic continental shelf, whereas increases in salinity off Georgla and beneath the Florida-Hatteras slope suggest buried evaporitic strata. The sediment cores showed engineering properties that range from good foundation strength to a potential for severe loss of strength through interaction between sediments and man-made structures.

Combination systemic therapy for advanced renal cell carcinoma

Outcomes for patients with advanced renal cell carcinoma (RCC) have improved significantly in recent years with the development of novel noncytotoxic systemic therapies. The multitargeted kinase inhibitors sunitinib and sorafenib have been approved for the treatment of advanced RCC, and bevacizumab, a monoclonal anti-vascular endothelial growth factor antibody, has shown significant clinical activity, both as a single agent and in combination with interferon-alpha. The mammalian target of rapamycin inhibitors temsirolimus and everolimus have led to longer overall survival times in poor-risk patients in the first-line setting and longer progression-free survival times in kinase inhibitor refractory patients in the second-line setting, respectively. Despite these advances, almost all patients develop resistance to treatment and cure is rarely seen. There is therefore a need to overcome resistance, induce longer lasting remissions, and improve survival. A potential approach to this is to combine active agents, and the clinical data for combination therapy with novel targeted agents in advanced RCC are reviewed here.

Variation in defence strategies in two species of the genus Beilschmiedia under differing soil nutrient and rainfall conditions

The relationships between various leaf functional traits that are important in plant growth (e.g., specific leaf area) have been investigated in recent studies; however, research in this context on plants that are highly protected by chemical defences, particularly resource-demanding nitrogen-based defence, is lacking. We collected leaves from cyanogenic (N-defended) Beilschmiedia collina B. Hyland and acyanogenic (C-defended) Beilschmiedia tooram (F. M. Bailey) B. Hyland at high- and low-soil nutrient sites in two consecutive years that varied significantly in rainfall. We then measured the relationships between chemical defence and morphological and functional leaf traits under the different environmental conditions. We found that the two species differed significantly in their resource allocation to defence as well as leaf morphology and function. The N defended species had a higher leaf nitrogen concentration, whereas the C-defended species had higher amounts of C-based chemical defences (i.e., total phenolics and condensed tannins). The C-defended species also tended to have higher force to fracture and increased leaf toughness. In B. collina, cyanogenic glycoside concentration was higher with higher rainfall, but not with higher soil nutrients. Total phenolic concentration was higher at the high soil nutrient site in B. tooram, but lower in B. collina; however, with higher rainfall an increase was found in B. tooram, while phenolics decreased in B. collina. Condensed tannin concentration decreased in both species with rainfall and nutrient availability. We conclude that chemical defence is correlated with leaf functional traits and that variation in environmental resources affects this correlation.

Infrared laser spectroscopy of the CH3–HCN radical complex stabilized in helium nanodroplets

The CH3-HCN and CD3-HCN radical complexes have been formed in helium nanodroplets by sequential pickup of a CH3 (CD3) radical and a HCN molecule and have been studied by high-resolution infrared laser spectroscopy. The complexes have a hydrogen-bonded structure with C3v symmetry, as inferred from the analysis of their rotationally resolved nu = 1 <-- 0 H-CN vibrational bands. The A rotational constants of the complexes are found to change significantly upon vibrational excitation of the C-H stretch of HCN within the complex, DeltaA = A'-A" = -0.04 cm(-1) (for CH3-HCN), whereas the B rotational constants are found to be 2.9 times smaller than that predicted by theory. The reduction in B can be attributed to the effects of helium solvation, whereas the large DeltaA is found to be a sensitive probe of the vibrational averaging dynamics of such weakly bound systems. The complex has a permanent electric dipole moment of 3.1 +/- 0.2 D, as measured by Stark spectroscopy. A vibration-vibration resonance is observed to couple the excited C-H stretching vibration of HCN within the complex to the lower-frequency C-H stretches of the methyl radical. Deuteration of the methyl radical was used to detune these levels from resonance, increasing the lifetime of the complex by a factor of 2. Ab initio calculations for the energies and molecular parameters of the stationary points on the CN+CH4 --> HCN+CH3 potential-energy surface are also presented.

Infrared laser spectroscopy of CH3⋯HF in helium nanodroplets: The exit-channel complex of the F+CH4 reaction

High-resolution infrared laser spectroscopy is used to study the CH3...HF and CD3...HF radical complexes, corresponding to the exit-channel complex in the F + CH4 --> HF + CH3 reaction. The complexes are formed in helium nanodroplets by sequential pickup of a methyl radical and a HF molecule. The rotationally resolved spectra presented here correspond to the fundamental v = 1 <-- 0 H-F vibrational band, the analysis of which reveals a complex with C(3v) symmetry. The vibrational band origin for the CH3...HF complex (3797.00 cm(-1)) is significantly redshifted from that of the HF monomer (3959.19 cm(-1)), consistent with the hydrogen-bonded structure predicted by theory [E. Ya. Misochko et al., J. Am. Chem. Soc. 117, 11997 (1995)] and suggested by previous matrix isolation experiments [M. E. Jacox, Chem. Phys. 42, 133 (1979)]. The permanent electric dipole moment of this complex is experimentally determined by Stark spectroscopy to be 2.4+/-0.3 D. The wide amplitude zero-point bending motion of this complex is revealed by the vibrational dependence of the A rotational constant. A sixfold reduction in the line broadening associated with the H-F vibrational mode is observed in going from CH3...HF to CD3...HF. The results suggest that fast relaxation in the former case results from near-resonant intermolecular vibration-vibration (V-V) energy transfer. Ab initio calculations are also reported (at the MP2 level) for the various stationary points on the F + CH4 surface, including geometry optimizations and vibrational frequency calculations for CH3...HF.

Finite-temperature quasicontinuum: molecular dynamics without all the atoms

Using a combination of statistical mechanics and finite-element interpolation, we develop a coarse-grained (CG) alternative to molecular dynamics (MD) for crystalline solids at constant temperature. The new approach is significantly more efficient than MD and generalizes earlier work on the quasicontinuum method. The method is validated by recovering equilibrium properties of single crystal Ni as a function of temperature. CG dynamical simulations of nano-indentation reveal a strong dependence on temperature of the critical stress to nucleate dislocations under the indenter.

Construction and evaluation of cDNA libraries for large-scale expressed sequence tag sequencing in wheat (Triticum aestivum L.)

A total of 37 original cDNA libraries and 9 derivative libraries enriched for rare sequences were produced from Chinese Spring wheat (Triticum aestivum L.), five other hexaploid wheat genotypes (Cheyenne, Brevor, TAM W101, BH1146, Butte 86), tetraploid durum wheat (T. turgidum L.), diploid wheat (T. monococcum L.), and two other diploid members of the grass tribe Triticeae (Aegilops speltoides Tausch and Secale cereale L.). The emphasis in the choice of plant materials for library construction was reproductive development subjected to environmental factors that ultimately affect grain quality and yield, but roots and other tissues were also included. Partial cDNA expressed sequence tags (ESTs) were examined by various measures to assess the quality of these libraries. All ESTs were processed to remove cloning system sequences and contaminants and then assembled using CAP3. Following these processing steps, this assembly yielded 101,107 sequences derived from 89,043 clones, which defined 16,740 contigs and 33,213 singletons, a total of 49,953 "unigenes." Analysis of the distribution of these unigenes among the libraries led to the conclusion that the enrichment methods were effective in reducing the most abundant unigenes and to the observation that the most diverse libraries were from tissues exposed to environmental stresses including heat, drought, salinity, or low temperature.

Rotational and vibrational dynamics of ethylene in helium nanodroplets

Rotationally resolved infrared spectra are reported for the asymmetric C-H stretching fundamental bands of C(2)H(4) in helium nanodroplets, as well as two weak combination bands. The J=2 rotor levels are strongly shifted from the energies estimated from a rigid rotor calculation and can be accounted for with two centrifugal distortion constants. The excited states of the three bands with B(3u) symmetry are strongly coupled in the gas phase and exhibit lifetimes >100 ps in helium, with the upper member of the polyad exhibiting the shortest lifetime. In contrast, the nu(9) band (B(2u) symmetry) exhibits very broad, homogeneously broadened line profiles (full width at half maximum approximately 0.5 cm(-1)) corresponding to an excited state lifetime of approximately 10 ps. This short lifetime is presumed to be due to an efficient, solvent mediated vibration-to-vibration relaxation process. In addition, the absence of transitions to the 2(21) and 2(20) rotor levels in the nu(9) band suggests they form rotational resonances with the elementary modes of helium, resulting in very short excited state lifetimes of less than 2 ps.

Multiple tautomers of cytosine identified and characterized by infrared laser spectroscopy in helium nanodroplets: probing structure using vibrational transition moment angles

Infrared laser spectroscopy in helium nanodroplets is used to identify and characterize several distinct tautomers of cytosine. The experimentally observed species correspond to the lowest-energy structures obtained from ab initio calculations, also reported here. The assignment of the infrared vibrational bands in the spectra is aided by the measurement of the corresponding vibrational transition moment angles, which are also calculated using ab initio methods. In the present study we confirm the existence of three primary tautomers and provide tentative assignments for even higher-energy forms of cytosine in helium nanodroplets.

The isomers of HF–HCN formed in helium nanodroplets: Infrared spectroscopy and ab initio calculations

Binary complexes containing hydrogen cyanide and hydrogen fluoride are formed in helium nanodroplets, and studied using high-resolution infrared laser spectroscopy. Rotationally resolved spectra are reported for the H-F and C-H stretches of the linear HCN-HF complex, a system that has been thoroughly studied in the gas phase. We report the high-resolution spectra of the higher energy, bent HF-HCN isomer, which is also formed in helium. Stark spectra are reported for both isomers, providing dipole moments of these complexes. The experimental results are compared with ab initio calculations, also reported here. Spectra are reported for several ternary complexes, including (HCN)2-HF, HCN-(HF)2, HF-(HCN)2, and HF-HCN-HF.

Multiple isomers of uracil–water complexes: infrared spectroscopy in helium nanodroplets

Infrared laser spectroscopy is used to show that four structural isomers of the uracil-water binary complex are formed in helium nanodroplets. The assignment of the infrared spectra is aided by measurements of vibrational transition moment angles (VTMAs) for various vibrational modes of these complexes. The experimental results are in excellent agreement with ab initio calculations, which had previously predicated the existence of the same four isomers. The results suggest that the relative abundances of the various isomers formed in helium droplets have more to do with the widths of the valleys in the potential surface that funnel into a particular local minimum than on the associated energetics.

Development of an expressed sequence tag (EST) resource for wheat (Triticum aestivum L.): EST generation, unigene analysis, probe selection and bioinformatics for a 16,000-locus bin-delineated map

This report describes the rationale, approaches, organization, and resource development leading to a large-scale deletion bin map of the hexaploid (2n = 6x = 42) wheat genome (Triticum aestivum L.). Accompanying reports in this issue detail results from chromosome bin-mapping of expressed sequence tags (ESTs) representing genes onto the seven homoeologous chromosome groups and a global analysis of the entire mapped wheat EST data set. Among the resources developed were the first extensive public wheat EST collection (113,220 ESTs). Described are protocols for sequencing, sequence processing, EST nomenclature, and the assembly of ESTs into contigs. These contigs plus singletons (unassembled ESTs) were used for selection of distinct sequence motif unigenes. Selected ESTs were rearrayed, validated by 5' and 3' sequencing, and amplified for probing a series of wheat aneuploid and deletion stocks. Images and data for all Southern hybridizations were deposited in databases and were used by the coordinators for each of the seven homoeologous chromosome groups to validate the mapping results. Results from this project have established the foundation for future developments in wheat genomics.