RNAi screen reveals synthetic lethality between cyclin G-associated kinase and FBXW7 by inducing aberrant mitoses.

BACKGROUND: F-box and WD40 repeat domain-containing 7 (FBXW7) is an E3 ubiquitin ligase involved in the ubiquitination and degradation of multiple oncogenic substrates. The tumour suppressor function is frequently lost in multiple cancers through genetic deletion and mutations in a broad range of tumours. Loss of FBXW7 functionality results in the stabilisation of multiple major oncoproteins, culminating in increased cellular proliferation and pro-survival pathways, cell cycle deregulation, chromosomal instability and altered metabolism. Currently, there is no therapy to specifically target FBXW7-deficient tumours. METHODS: We performed a siRNA kinome screen to identify synthetically lethal hits to FBXW7 deficiency. RESULTS: We identified and validated cyclin G-associated kinase (GAK) as a potential new therapeutic target. Combined loss of FBXW7 and GAK caused cell cycle defects, formation of multipolar mitoses and the induction of apoptosis. The synthetic lethal mechanism appears to be independent of clathrin-mediated receptor endocytosis function of GAK. CONCLUSIONS: These data suggest a putative therapeutic strategy for a large number of different types of human cancers with FBXW7 loss, many of which have a paucity of molecular abnormalities and treatment options.

Cediranib in patients with relapsed platinum-sensitive ovarian cancer (ICON6): a randomised, double-blind, placebo-controlled phase 3 trial.

BACKGROUND: Angiogenesis is a validated clinical target in advanced epithelial ovarian cancer. Cediranib is an oral antiangiogenic vascular endothelial growth factor receptor 1-3 inhibitor that has shown antitumour activity in recurrent ovarian cancer. We assessed efficacy and safety of cediranib in combination with platinum-based chemotherapy and as continued maintenance treatment in patients with first relapse of platinum-sensitive ovarian cancer. METHODS: In this randomised, three-arm, double-blind, placebo-controlled phase 3 trial, we randomly assigned patients aged 18 years or older with relapsed platinum-sensitive ovarian cancer at 63 centres in Australia, Canada, New Zealand, Spain, and the UK. Participants received up to six cycles of platinum-based chemotherapy (once every 3 weeks) then entered a maintenance phase. Participants were randomly allocated (2:3:3), with five stratification factors and in alternating blocks, to receive placebo alongside chemotherapy and then placebo only maintenance (arm A; reference), cediranib 20 mg once-daily alongside chemotherapy then placebo only maintenance (arm B; concurrent), or cediranib 20 mg once-daily alongside chemotherapy then cediranib 20 mg once-daily maintenance (arm C; maintenance). Patients continued treatment to progression or excessive toxic effects. The primary efficacy endpoint was progression-free survival between arms A and C. Efficacy analysis was by intention to treat. Safety was assessed in all patients who received the allocated study drug. This trial is registered with ClinicalTrials.gov, number NCT00532194; the ISRCTN registry, number ISRCTN68510403; and ANZ Clinical Trials Registry, number ACTRN1261000016003. FINDINGS: We randomly assigned 486 [corrected] women between Nov 13, 2007, and Dec 23, 2011; results presented are for 456 patients randomly assigned subsequent to the 30mg safety phase. During a median of 19·5 months (IQR 14-26) follow-up, 113 (96%) of 118 women assigned to arm A and 141 (86%) of 164 assigned to arm C had disease progression. Median progression-free survival was 11·0 months (95% CI 10·4-11·7) in arm C and 8·7 months (7·7-9·4) in arm A (hazard ratio 0·56, 0·44-0·72, p<0·0001). 156 (90%) of 174 patients in arm B had disease progression, and median progression-free survival was 9·9 months (95% CI 9·4-10·5). Diarrhoea, neutropenia, hypertension, and voice changes were significantly more common, during chemotherapy with cediranib, and diarrhoea, hypothyroidism and voice changes were more common during maintenance. Poor compliance with cediranib was noted during maintenance treatment with toxic effects being the most common cause for discontinuation. INTERPRETATION: Cediranib, when given orally with chemotherapy and continued as maintenance, yielded a meaningful improvement [corrected] in progression-free survival in women with recurrent platinum-sensitive ovarian cancer, albeit with added toxic effects. The positive results in ICON6 could provide women with a new therapeutic option for recurrent ovarian cancer. Assessment of the secondary endpoint of overall survival will need longer follow-up. FUNDING: Medical Research Council, Cancer Research UK, Canadian Cancer Society Research Institute, Cancer Australia, National Gynecological Cancer Centre, and AstraZeneca.

The role of hormonal therapy in patients with relapsed high-grade ovarian carcinoma: a retrospective series of tamoxifen and letrozole.

BACKGROUND: Hormonal therapy is used as a treatment option in high-grade ovarian carcinoma (HGOC), but the role and choice of treatment remains unclear. Agents used include tamoxifen and aromatase inhibitors. Our aim was to evaluate the efficacy of tamoxifen (T) and letrozole (L) in HGOC in clinical practice and investigate factors influencing clinical outcome. METHODS: A retrospective review of patients with relapsed HGOC treated with either tamoxifen or letrozole at the Royal Marsden Hospital between 2007 and 2012 was performed. The primary endpoint of the study was objective response rate (ORR). Secondary endpoints included CA125 response, clinical benefit rate (CBR) and duration of response. Platinum-sensitivity and ER-status were evaluated as predictors of treatment response. RESULTS: 97 patients were included (43 T, 54 L); median age 63 years (20-92); 91% high-grade serous; median number of lines of prior chemotherapy 3 (1-8); 60% platinum-resistant, 40% platinum-sensitive; 52% ER + ve, 1% ER-ve, 47% unknown. 14 patients (6 T, 8 L) achieved a partial response, with ORR (RECIST) of 14% (T) and 15% (L). The CBR for ≥3 months was 65% (22/43) for tamoxifen and 56% (22/54) for letrozole. There was no significant difference in ORR (p = 0.99) or CBR (p = 0.14) between tamoxifen and letrozole. 22 patients (23%) had a CA-125 response with hormonal therapy (10 T - 23% and 12 L - 22%). ORR did not differ by platinum sensitivity (p = 0.42); or ER-status (positive vs unknown, p = 0.12). Responders to letrozole had longer durations of response than responders to tamoxifen (26 vs 11.5 months, p = 0.03), but equivalent disease stability duration (9.6 vs 7.2 months respectively, p = 0.11). CONCLUSIONS: Within the constraints of a retrospective study, we identified that patients treated with letrozole had a significantly longer duration of response than those treated with tamoxifen. Treatment with either tamoxifen or letrozole is a rational treatment option for patients with ER + ve HGOC, with equivalent ORR, CBR and disease stability.

A study of motivations and expectations of patients seen in phase 1 oncology clinics.

BACKGROUND: To better inform clinical practice, this study was aimed at capturing patients' motivations for enrolling in phase 1 trials and at quantifying their expectations of the benefits, risks, and commitment associated with clinical trials and the impact of the initial consultation on their expectations. METHODS: This was a single-center, prospective, quantitative study of newly referred adult patients considering their first phase 1 oncology trial. Participants completed questionnaires before they were seen and an abbreviated follow-up version after their consultation. RESULTS: Questionnaires were completed by 396 (99%) and 301 (76%) before and after the clinic, respectively. Participants ranked the possibility of tumor shrinkage (84%) as the most important motivation for considering a phase 1 trial; this was followed by no alternative treatments (56%), their physician's recommendation (44%), and the fact that the research might benefit others (38%). When they were asked about the potential personal benefit, 43% predicted tumor shrinkage initially. After the consultation, this increased to 47%. Fourteen percent of patients expected a cure. When asked about risks, 71% of the participants expected moderate side effects. When asked about expectations of time commitments, a majority of patients did not anticipate weekly visits, although this was understood by 93% of patients after the consultation. Overall, patients were keen to consider trials and when asked before and after the consultation 72% and 84% were willing to enroll in studies, respectively. CONCLUSIONS: This study reports that more than 80% of patients enroll in early-phase clinical oncology trials motivated by the potential of a clinical benefit, with approximately half expecting tumor shrinkage and approximately a tenth anticipating a cure. The typical phase 1 response rate is 4% to 20%, and this discrepancy exemplifies the challenges faced by patients and healthcare professionals during their interactions for phase 1 studies. Cancer 2016;122:3501-3508. © 2016 American Cancer Society.

A first in man, dose-finding study of the mTORC1/mTORC2 inhibitor OSI-027 in patients with advanced solid malignancies.

BACKGROUND: The kinase activity of mTOR involves 2 multiprotein complexes, (mTORC1-mTORC2). Targeting mTORC1 with rapalogues induces compensatory feedback loops resulting in AKT/ERK activation, which may be abrogated by mTORC2 inhibition. A first-in-human trial evaluating tolerability, pharmacokinetics and pharmacodynamics of the dual TORC1/TORC2 inhibitor OSI-027 was conducted. METHODS: Dose escalation was pursued for three schedules of administration (three consecutive days per week (S1), once a week (S2) and daily dosing (S3)), until dose-limiting toxicities (DLT) were identified. Expansion cohorts with paired tumour biopsies were initiated based on tolerability and pharmacodynamics. RESULTS: One hundred and twenty eight patients with advanced cancer were enrolled. DLT consisted predominantly of fatigue, renal function disturbances and cardiac events. OSI-027 exposure was dose proportional, with Tmax within 4 h and a half-life of ∼14 h. Expansion cohorts were initiated for S1 and S2, as MTD for S3 was overall considered suboptimal. Target modulation in peripheral blood mononuclear cells were observed from 30 mg, but in tumour biopsies 120 mg QD were needed, which was a non-tolerable dose due to renal toxicity. No RECIST responses were recorded, with stable disease >6 months in six (5%) patients. CONCLUSIONS: OSI-027 inhibits mTORC1/2 in patients with advanced tumour s in a dose-dependent manner but doses above the tolerable levels in S1 and S3 are required for a sustained biological effect in tumour biopsies.

Outcomes and endpoints in cancer trials: bridging the divide.

Cancer is not one disease. Outcomes and endpoints in trials should incorporate the therapeutic modality and cancer type because these factors affect clinician and patient expectations. In this Review, we discuss how to: define the importance of endpoints; make endpoints understandable to patients; improve the use of patient-reported outcomes; advance endpoints to parallel changes in trial design and therapeutic interventions; and integrate these improvements into trials and practice. Endpoints need to reflect benefit to patients, and show that changes in tumour size either in absolute terms (response and progression) or relative to control (progression) are clinically relevant. Improvements in trial design should be accompanied by improvements in available endpoints. Stakeholders need to come together to determine the best approach for research that ensures accountability and optimises the use of available resources.

Poor performance status (PS) is an indication for an aggressive approach to neoadjuvant chemotherapy in patients with advanced epithelial ovarian cancer (EOC).

BACKGROUND: Some guidelines suggest that poor performance status (PS) is a contraindication to 1st line chemotherapy. Poor PS is a known adverse prognostic factor in advanced epithelial ovarian cancer (EOC). We show in this retrospective analysis that 1st line chemotherapy in this patient group is not only safe but is associated with good outcomes. PATIENTS AND METHODS: A retrospective review of 114 patients with stage III/IV EOC, who presented with a PS ≥3 at diagnosis and treated as inpatients with upfront platinum-based chemotherapy between 2000 and 2013, at the Royal Marsden Hospital, was conducted. The association between clinical parameters and the likelihood of completion of chemotherapy and overall survival (OS) was assessed. RESULTS: 66% of patients completed ≥6cycles of platinum-based chemotherapy. Prognostic factors for completion of chemotherapy were improvement of PS during hospital stay (p<0.001) and doublet-chemotherapy with carboplatin/paclitaxel compared to single-agent carboplatin (p=0.004). A negative trend for completion of treatment was seen for patients with low albumin (<25g/l) and low CA125 levels at baseline. The median OS for all patients was 13.1months (95% CI: 10.4-15.8) and 21.2months (95% CI: 16.5-25.8) for those who completed 6cycles of chemotherapy. CONCLUSION: Upfront platinum-based chemotherapy is feasible, beneficial and tolerable for the majority of patients with advanced EOC and poor PS. Guidelines suggesting that best supportive care is the preferred option for poor PS patients with solid tumours should be revised to exclude those with advanced EOC. An aggressive approach utilising neoadjuvant carboplatin plus paclitaxel should be regarded as standard of care.

Phase I trials in patients with relapsed, advanced upper gastrointestinal carcinomas: experience in a specialist unit.

BACKGROUND: Conventional therapeutic options for patients with advanced upper gastrointestinal cancers (UGIC) are limited. Following first-line treatments, some patients are offered experimental therapies, including participation in Phase I trials. This study aims to describe the experience of UGIC patients treated in a dedicated Phase I unit. METHODS: Patient, tumour and treatment characteristics, and clinical outcomes of UGIC patients treated consecutively at the Drug Development Unit, Royal Marsden Hospital, between 2005 and 2009, were recorded. RESULTS: Ninety-six patients who previously received a median of 2 (range 1-4) lines of chemotherapies were treated in 30 Phase I trials. Of 81 evaluable patients, 9 achieved RECIST-objective response (11 %) with a 6-month clinical benefit rate of 14 %. Median progression free and overall survival were 7.7 weeks [95 %CI 7.7 (6.4-9.0)] and 19.1 weeks (95 %CI 17.5-20.8), respectively. Grade 3 or 4 toxicities were observed in 37 patients (39 %) and led to trial discontinuation in 9 (9 %); no toxicity-related death was recorded. In the multivariate analysis, serum albumin (<35 g/dl, HR2.0, p = 0.002) and lactate dehydrogenase (>192 µmol/l, HR1.7, p = 0.016) were prognostic of overall survival. CONCLUSION: Phase I clinical trials can be considered a reasonable option in selected patients with relapsed UGIC. The use of objective prognosticators may improve selection and risk/benefit profile of patients.

Secondary mutations in BRCA2 associated with clinical resistance to a PARP inhibitor.

PARP inhibitors (PARPi) for the treatment of BRCA1 or BRCA2 deficient tumours are currently the focus of seminal clinical trials exploiting the concept of synthetic lethality. Although clinical resistance to PARPi has been described, the mechanism underlying this has not been elucidated. Here, we investigate tumour material from patients who had developed resistance to the PARPi olaparib, subsequent to showing an initial clinical response. Massively parallel DNA sequencing of treatment-naive and post-olaparib treatment biopsies identified tumour-specific BRCA2 secondary mutations in olaparib-resistant metastases. These secondary mutations restored full-length BRCA2 protein, and most likely cause olaparib resistance by re-establishing BRCA2 function in the tumour cells.

The poly(ADP-ribose) polymerase inhibitor niraparib (MK4827) in BRCA mutation carriers and patients with sporadic cancer: a phase 1 dose-escalation trial.

BACKGROUND: Poly(ADP-ribose) polymerase (PARP) is implicated in DNA repair and transcription regulation. Niraparib (MK4827) is an oral potent, selective PARP-1 and PARP-2 inhibitor that induces synthetic lethality in preclinical tumour models with loss of BRCA and PTEN function. We investigated the safety, tolerability, maximum tolerated dose, pharmacokinetic and pharmacodynamic profiles, and preliminary antitumour activity of niraparib. METHODS: In a phase 1 dose-escalation study, we enrolled patients with advanced solid tumours at one site in the UK and two sites in the USA. Eligible patients were aged at least 18 years; had a life expectancy of at least 12 weeks; had an Eastern Cooperative Oncology Group performance status of 2 or less; had assessable disease; were not suitable to receive any established treatments; had adequate organ function; and had discontinued any previous anticancer treatments at least 4 weeks previously. In part A, cohorts of three to six patients, enriched for BRCA1 and BRCA2 mutation carriers, received niraparib daily at ten escalating doses from 30 mg to 400 mg in a 21-day cycle to establish the maximum tolerated dose. Dose expansion at the maximum tolerated dose was pursued in 15 patients to confirm tolerability. In part B, we further investigated the maximum tolerated dose in patients with sporadic platinum-resistant high-grade serous ovarian cancer and sporadic prostate cancer. We obtained blood, circulating tumour cells, and optional paired tumour biopsies for pharmacokinetic and pharmacodynamic assessments. Toxic effects were assessed by common toxicity criteria and tumour responses ascribed by Response Evaluation Criteria in Solid Tumors (RECIST). Circulating tumour cells and archival tumour tissue in prostate patients were analysed for exploratory putative predictive biomarkers, such as loss of PTEN expression and ETS rearrangements. This trial is registered with ClinicalTrials.gov, NCT00749502. FINDINGS: Between Sept 15, 2008, and Jan 14, 2011, we enrolled 100 patients: 60 in part A and 40 in part B. 300 mg/day was established as the maximum tolerated dose. Dose-limiting toxic effects reported in the first cycle were grade 3 fatigue (one patient given 30 mg/day), grade 3 pneumonitis (one given 60 mg/day), and grade 4 thrombocytopenia (two given 400 mg/day). Common treatment-related toxic effects were anaemia (48 patients [48%]), nausea (42 [42%]), fatigue (42 [42%]), thrombocytopenia (35 [35%]), anorexia (26 [26%]), neutropenia (24 [24%]), constipation (23 [23%]), and vomiting (20 [20%]), and were predominantly grade 1 or 2. Pharmacokinetics were dose proportional and the mean terminal elimination half-life was 36·4 h (range 32·8-46·0). Pharmacodynamic analyses confirmed PARP inhibition exceeded 50% at doses greater than 80 mg/day and antitumour activity was documented beyond doses of 60 mg/day. Eight (40% [95% CI 19-64]) of 20 BRCA1 or BRCA2 mutation carriers with ovarian cancer had RECIST partial responses, as did two (50% [7-93]) of four mutation carriers with breast cancer. Antitumour activity was also reported in sporadic high-grade serous ovarian cancer, non-small-cell lung cancer, and prostate cancer. We recorded no correlation between loss of PTEN expression or ETS rearrangements and measures of antitumour activity in patients with prostate cancer. INTERPRETATION: A recommended phase 2 dose of 300 mg/day niraparib is well tolerated. Niraparib should be further assessed in inherited and sporadic cancers with homologous recombination DNA repair defects and to target PARP-mediated transcription in cancer. FUNDING: Merck Sharp and Dohme.

Ovarian cancer: strategies for overcoming resistance to chemotherapy.

Ovarian cancer is responsible for 4% of deaths from cancer in women. Treatment comprises a combination of surgery and chemotherapy, but patients typically experience disease relapse within 2 years of the initial treatment. Further treatment can extend survival, although relapse eventually occurs again. A better understanding of the mechanisms that underlie this drug resistance should allow treatment to be optimized, so that substantial improvements in the outlook for women with this disease can be achieved.

Inhibition of poly(ADP-ribose) polymerase in tumors from BRCA mutation carriers.

BACKGROUND: The inhibition of poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) is a potential synthetic lethal therapeutic strategy for the treatment of cancers with specific DNA-repair defects, including those arising in carriers of a BRCA1 or BRCA2 mutation. We conducted a clinical evaluation in humans of olaparib (AZD2281), a novel, potent, orally active PARP inhibitor. METHODS: This was a phase 1 trial that included the analysis of pharmacokinetic and pharmacodynamic characteristics of olaparib. Selection was aimed at having a study population enriched in carriers of a BRCA1 or BRCA2 mutation. RESULTS: We enrolled and treated 60 patients; 22 were carriers of a BRCA1 or BRCA2 mutation and 1 had a strong family history of BRCA-associated cancer but declined to undergo mutational testing. The olaparib dose and schedule were increased from 10 mg daily for 2 of every 3 weeks to 600 mg twice daily continuously. Reversible dose-limiting toxicity was seen in one of eight patients receiving 400 mg twice daily (grade 3 mood alteration and fatigue) and two of five patients receiving 600 mg twice daily (grade 4 thrombocytopenia and grade 3 somnolence). This led us to enroll another cohort, consisting only of carriers of a BRCA1 or BRCA2 mutation, to receive olaparib at a dose of 200 mg twice daily. Other adverse effects included mild gastrointestinal symptoms. There was no obvious increase in adverse effects seen in the mutation carriers. Pharmacokinetic data indicated rapid absorption and elimination; pharmacodynamic studies confirmed PARP inhibition in surrogate samples (of peripheral-blood mononuclear cells and plucked eyebrow-hair follicles) and tumor tissue. Objective antitumor activity was reported only in mutation carriers, all of whom had ovarian, breast, or prostate cancer and had received multiple treatment regimens. CONCLUSIONS: Olaparib has few of the adverse effects of conventional chemotherapy, inhibits PARP, and has antitumor activity in cancer associated with the BRCA1 or BRCA2 mutation. (ClinicalTrials.gov number, NCT00516373.)

Advanced solid tumors treated with cediranib: comparison of dynamic contrast-enhanced MR imaging and CT as markers of vascular activity.

PURPOSE: To assess baseline reproducibility and compare performance of dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging versus DCE computed tomographic (CT) measures of early vascular response in the same patients treated with cediranib (30 or 45 mg daily). MATERIALS AND METHODS: After institutional review board approval, written informed consent was obtained from 29 patients with advanced solid tumors who had lesions 3 cm or larger and in whom simultaneous imaging of an adjacent artery was possible. Two baseline DCE MR acquisitions and two baseline DCE CT acquisitions 7 days or fewer apart (within 14 days of starting treatment) and two posttreatment acquisitions with each modality at day 7 and 28 (±3 days) were obtained. Nonmodeled and modeled parameters were derived (measured arterial input function [AIF] for CT, population-based AIF for MR imaging; temporal sampling rate of 0.5 second for CT, 3-6 seconds for MR imaging). Baseline variability was assessed by using intra- and intersubject analysis of variance and Bland-Altman analysis; a paired t test assessed change from baseline to after treatment. RESULTS: The most reproducible parameters were DCE MR imaging enhancement fraction (baseline intrapatient coefficient of variation [CV]=8.6%), volume transfer constant (CV=13.9%), and integrated area under the contrast agent uptake curve at 60 seconds (CV=15.5%) and DCE CT positive enhancement integral (CV=16.0%). Blood plasma volume was highly variable and the only parameter with CV greater than 30%. Average reductions (percentage change) from baseline were consistently observed for all DCE MR imaging and DCE CT parameters at day 7 and 28 for both starting-dose groups (45 and 30 mg), except for DCE CT mean transit time. Percentage change from baseline for parameters reflecting blood flow and permeability were comparable, and reductions from baseline at day 7 were maintained at day 28. CONCLUSION: DCE MR imaging and DCE CT can depict vascular response to antiangiogenic agents with response evident at day 7. Improved reproducibility with MR imaging favors its use in trials with small patient numbers.

Phase I clinical and pharmacokinetic study of trabectedin and carboplatin in patients with advanced solid tumors.

PURPOSE: This study intended to determine the maximum tolerated dose (MTD) and the recommended phase II dose (RD) of trabectedin combined with carboplatin in patients with advanced solid tumors. PATIENTS AND METHODS: Carboplatin-pretreated patients received carboplatin AUC 4 (Group 1), whereas carboplatin-naïve patients received carboplatin AUC 5 (Group 2) as a 1-h i.v. infusion followed by trabectedin at dose range from 0.5-1.2 mg/m(2) in the schedule of 3-h/every-3-weeks. Pharmacokinetic (PK) sampling was performed in the first 2 cycles. RESULTS: Forty-four patients were treated and evaluable for safety and dose-limiting toxicities (DLTs). In Group 1, at trabectedin 1.0 mg/m(2), cumulative hematological toxicity was found in all patients and 1/10 patients had DLTs. The RD was considered trabectedin 0.8 mg/m(2) combined with carboplatin AUC 4. Although no DLT occurred at this dose level, frequent dose delays (28.6%) and the 4-week cycle re-scheduling (66.7%) were required. In Group 2, DLTs occurred at trabectedin 0.8 mg/m(2) (3/8 patients), 1.0 mg/m(2) (3/10 patients) and 1.2 mg/m(2) (2/2 patients) with cumulative hematological toxicity associated with an important number of transfusions. In this group, neither the MTD nor the RD were established. Promising antitumor activity was found for this carboplatin/trabectedin combination; especially in patients with advanced ovarian cancer and soft tissue sarcoma. No significant PK drug-drug interaction occurred. CONCLUSIONS: This study established a trabectedin dose of 0.8 mg/m(2) combined with carboplatin AUC 4 and given every 4 weeks as the most feasible schedule in carboplatin-pretreated patients. Dose and cycle recommendations for carboplatin-naïve patients warrant further evaluation.

A radiomics-based decision support tool improves lung cancer diagnosis in combination with the Herder score in large lung nodules.

BACKGROUND: Large lung nodules (≥15 mm) have the highest risk of malignancy, and may exhibit important differences in phenotypic or clinical characteristics to their smaller counterparts. Existing risk models do not stratify large nodules well. We aimed to develop and validate an integrated segmentation and classification pipeline, incorporating deep-learning and traditional radiomics, to classify large lung nodules according to cancer risk. METHODS: 502 patients from five U.K. centres were recruited to the large-nodule arm of the retrospective LIBRA study between July 2020 and April 2022. 838 CT scans were used for model development, split into training and test sets (70% and 30% respectively). An nnUNet model was trained to automate lung nodule segmentation. A radiomics signature was developed to classify nodules according to malignancy risk. Performance of the radiomics model, termed the large-nodule radiomics predictive vector (LN-RPV), was compared to three radiologists and the Brock and Herder scores. FINDINGS: 499 patients had technically evaluable scans (mean age 69 ± 11, 257 men, 242 women). In the test set of 252 scans, the nnUNet achieved a DICE score of 0.86, and the LN-RPV achieved an AUC of 0.83 (95% CI 0.77-0.88) for malignancy classification. Performance was higher than the median radiologist (AUC 0.75 [95% CI 0.70-0.81], DeLong p = 0.03). LN-RPV was robust to auto-segmentation (ICC 0.94). For baseline solid nodules in the test set (117 patients), LN-RPV had an AUC of 0.87 (95% CI 0.80-0.93) compared to 0.67 (95% CI 0.55-0.76, DeLong p = 0.002) for the Brock score and 0.83 (95% CI 0.75-0.90, DeLong p = 0.4) for the Herder score. In the international external test set (n = 151), LN-RPV maintained an AUC of 0.75 (95% CI 0.63-0.85). 18 out of 22 (82%) malignant nodules in the Herder 10-70% category in the test set were identified as high risk by the decision-support tool, and may have been referred for earlier intervention. INTERPRETATION: The model accurately segments and classifies large lung nodules, and may improve upon existing clinical models. FUNDING: This project represents independent research funded by: 1) Royal Marsden Partners Cancer Alliance, 2) the Royal Marsden Cancer Charity, 3) the National Institute for Health Research (NIHR) Biomedical Research Centre at the Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, London, 4) the National Institute for Health Research (NIHR) Biomedical Research Centre at Imperial College London, 5) Cancer Research UK (C309/A31316).

Metastatic ovarian and primary peritoneal cancer: assessing chemotherapy response with diffusion-weighted MR imaging--value of histogram analysis of apparent diffusion coefficients.

PURPOSE: To prospectively evaluate apparent diffusion coefficient (ADC) histograms in the prediction of chemotherapy response in patients with metastatic ovarian or primary peritoneal cancer. MATERIALS AND METHODS: Research ethics committee approval and patient written informed consent were obtained. Diffusion-weighted (DW) magnetic resonance (MR) imaging was performed through the abdomen and pelvis before and after one and three cycles of chemotherapy in 42 women (mean age, 63.0 years ± 11.4 [standard deviation]) with newly diagnosed or recurrent disease. Reproducibility and intra- and interobserver agreement of ADC calculations were assessed. Per-patient weighted ADC histograms were generated at each time point from pixel ADCs from five or fewer target lesions. Mean ADC, percentiles (10th, 25th, 50th, 75th, 90th), skew, kurtosis, and their change were analyzed according to histologic grade, primary versus recurrent disease status, and response, determined with integrated biochemical and morphologic criteria, with a linear mixed model. Areas under receiver operating characteristic curve (AUCs) for combinations of parameters were calculated with linear discriminant analysis. RESULTS: Coefficients of variation for repeat measurements and for within and between observers were 4.8%, 11.4%, and 13.7%, respectively. Grade and disease status did not significantly affect histogram parameters. Pretreatment ADCs were not predictive of response. In responders, all ADCs increased after the first and third cycle (P < .001), while skew and kurtosis decreased after the third (P < .001 and P = .006, respectively); however, in nonresponders, no parameter changed significantly. Percentage change of the 25th percentile performed best in identifying response (AUC = 0.82 and 0.83 after first and third cycle, respectively), whereas combination of parameters did not improve accuracy. CONCLUSION: An early increase of ADCs and later decrease of skew and kurtosis characterize chemotherapy response. Quantitative DW MR imaging can aid in early monitoring of treatment efficacy in patients with advanced ovarian cancer.

PARP inhibitors in BRCA gene-mutated ovarian cancer and beyond.

Poly(ADP-ribose)polymerase (PARP) inhibitors are showing considerable promise for the treatment of BRCA mutation-associated ovarian and breast cancer. This approach exploits a synthetic lethal strategy to target the specific DNA repair pathway in cancers that harbor mutations in the BRCA1 or BRCA2 genes. Accumulating evidence suggests that PARP inhibitors may have a wider application in the treatment of sporadic, high-grade serous ovarian cancers and other cancers including endometrial cancer. In this review, we discuss the clinical development of PARP inhibitors in ovarian cancer and explore challenges that need to be addressed if the full potential of these agents is to be realized.

Role of molecular agents and targeted therapy in clinical trials for women with ovarian cancer.

There is now a greater understanding of the molecular pathways in ovarian cancer, and using this knowledge, a large number of new therapeutic agents can be tested. The success of these drugs will depend on selecting drugs that target known key dysfunctional molecular pathways. To make best use of these compounds, prognostic and predictive biomarkers need to be identified. Novel methods of assessment such as functional imaging need to be developed as additional biological end points to evaluate these therapies. Promising antitumor activity has been observed with some drugs, and careful consideration is needed to determine in what circumstances new agents, such as antiangiogenic compounds, could be considered as a standard therapy. These areas were discussed at the 4th Ovarian Cancer Consensus Conference.

Quantitative imaging of RAD51 expression as a marker of platinum resistance in ovarian cancer.

Early relapse after platinum chemotherapy in epithelial ovarian cancer (EOC) portends poor survival. A-priori identification of platinum resistance is therefore crucial to improve on standard first-line carboplatin-paclitaxel treatment. The DNA repair pathway homologous recombination (HR) repairs platinum-induced damage, and the HR recombinase RAD51 is overexpressed in cancer. We therefore designed a REMARK-compliant study of pre-treatment RAD51 expression in EOC, using fluorescent quantitative immunohistochemistry (qIHC) to overcome challenges in quantitation of protein expression in situ. In a discovery cohort (n = 284), RAD51-High tumours had shorter progression-free and overall survival compared to RAD51-Low cases in univariate and multivariate analyses. The association of RAD51 with relapse/survival was validated in a carboplatin monotherapy SCOTROC4 clinical trial cohort (n = 264) and was predominantly noted in HR-proficient cancers (Myriad HRDscore < 42). Interestingly, overexpression of RAD51 modified expression of immune-regulatory pathways in vitro, while RAD51-High tumours showed exclusion of cytotoxic T cells in situ. Our findings highlight RAD51 expression as a determinant of platinum resistance and suggest possible roles for therapy to overcome immune exclusion in RAD51-High EOC. The qIHC approach is generalizable to other proteins with a continuum instead of discrete/bimodal expression.