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Evidence that the phosphoinositide 3-kinase (PI3K) pathway is deregulated in ovarian cancer is largely based on the analysis of surgical specimens sampled at diagnosis and may not reflect the biology of advanced ovarian cancer. We aimed to investigate PI3K signaling in cancer cells isolated from patients with advanced ovarian cancer. Ascites samples were analyzed from 88 patients, of whom 61 received further treatment. Cancer cells were immunomagnetically separated from ascites, and the signaling output of the PI3K pathway was studied by quantifying p-AKT, p-p70S6K, and p-GSK3β by ELISA. Relevant oncogenes, such as PIK3CA and AKT, were sequenced by PCR-amplified mass spectroscopy detection methods. In addition, PIK3CA and AKT2 amplifications and PTEN deletions were analyzed by FISH. p-p70S6K levels were significantly higher in cells from 37 of 61 patients who did not respond to subsequent chemotherapy (0.7184 vs. 0.3496; P = 0.0100), and this difference was greater in patients who had not received previous chemotherapy. PIK3CA and AKT mutations were present in 5% and 0% of samples, respectively. Amplification of PIK3CA and AKT2 and deletion of PTEN was seen in 10%, 10%, and 27% of samples, respectively. Mutations of PIK3CA and amplification of PIK3CA/AKT2 or deletion of PTEN did not correlate with levels of p-AKT, p-p70S6K, and p-GSK3β. In patients with advanced ovarian cancer, there is an association between levels of p-p70S6K and response to subsequent chemotherapy. There is no clear evidence that this is driven specifically by PIK3CA or AKT mutations or by amplifications or deletion of PTEN. Mol Cancer Ther; 11(7); 1609–17. ©2012 AACR.

Platinum-based chemotherapy, with cytoreductive surgery, is the cornerstone of treatment of advanced ovarian cancer; however, acquired drug resistance is a major clinical obstacle. It has been proposed that subpopulations of tumor cells with stem cell–like properties, such as so-called side populations (SP) that overexpress ABC drug transporters, can sustain the growth of drug-resistant tumor cells, leading to tumor recurrence following chemotherapy. The histone methyltransferase EZH2 is a key component of the polycomb-repressive complex 2 required for maintenance of a stem cell state, and overexpression has been implicated in drug resistance and shorter survival of ovarian cancer patients. We observed higher percentage SP in ascites from patients that have relapsed following chemotherapy compared with chemonaive patients, consistent with selection for this subpopulation during platinum-based chemotherapy. Furthermore, ABCB1 (P-glycoprotein) and EZH2 are consistently overexpressed in SP compared with non-SP from patients' tumor cells. The siRNA knockdown of EZH2 leads to loss of SP in ovarian tumor models, reduced anchorage-independent growth, and reduced tumor growth in vivo. Together, these data support a key role for EZH2 in the maintenance of a drug-resistant, tumor-sustaining subpopulation of cells in ovarian cancers undergoing chemotherapy. As such, EZH2 is an important target for anticancer drug development. Mol Cancer Ther; 10(2); 325–35. ©2010 AACR.

BackgroundPrevious studies investigating the effect of increased dose intensity and chemotherapy-induced neutropenia in patients with advanced non-small cell lung cancer (NSCLC) have not consistently shown significant survival benefits.MethodsThis retrospective analysis reviewed the outcome of patients receiving palliative chemotherapy for advanced NSCLC (stages III–IV) at the Royal Marsden Hospital. Regimens included cisplatin or carboplatin with either vinorelbine or gemcitabine on days 1 and 8, every 21 days. Patients who received at least four cycles of chemotherapy were classified into groups based on dose intensity, dose reductions, and worst grade of neutropenia for a landmark analysis. Comparisons between these groups for time to progression and overall survival were made by standard univariate and multivariate methods.ResultsOne hundred sixty-nine of a total of 190 patients who received more than four cycles of chemotherapy during the period between November 1998 and December 2008 were included. One hundred twenty-five (73.9%) patients received four chemotherapy cycles with the remaining receiving up to six cycles. The median relative dose intensity for platinum was 93.9% (62.1–102%) and for vinorelbine/gemcitabine was 91.7% (37.8–105%). Dose reductions were recorded in 64 patients (37.8%), and 65 patients (38.5%) had grades 3 to 4 neutropenia. There were no statistically significant differences in time to progression and overall survival between any of the subgroups.ConclusionsThis retrospective analysis demonstrates no significant relationship between survival and dose intensity (

Purpose of review Ovarian cancer remains the gynaecological malignancy with the highest mortality in the Western world. The strategy of identifying biologically distinct subgroups of ovarian cancer by means of clinical characteristics, histology and molecular profiling is an exciting prospect in personalizing and improving therapy for ovarian cancer. Recent findings Preclinical recognition that BRCA1 and BRCA2-associated tumours are very sensitive to inhibition of poly-ADP ribose polymerase (PARP), a key molecule in DNA repair, led to ovarian cancer patients with germline BRCA1 and BRCA2 mutations being treated with the PARP inhibitor olaparib (AZD2281, KU-0059436; KuDOS/Astra-Zeneca). The initial trials of olaparib in this patient population demonstrated an impressive rate of clinical benefit. Furthermore, tumours from patients with sporadic ovarian cancer have been found to commonly have somatic BRCA1 and BRCA2 mutations or other defects in DNA repair, with the implication that PARP inhibition may also have a role in treating these patients. Summary In this review, we discuss DNA repair mechanisms and strategies used to target them in oncology, our current experience with PARP inhibition in BRCA1 and BRCA2-mutation associated and sporadic ovarian cancer, as well as current issues in the clinical development of these agents.

Hormone-driven expression of the ERG oncogene after fusion with TMPRSS2 occurs in 30% to 70% of therapy-naive prostate cancers. Its relevance in castration-resistant prostate cancer (CRPC) remains controversial as ERG is not expressed in some TMPRSS2-ERG androgen-independent xenograft models. However, unlike these models, CRPC patients have an increasing prostate-specific antigen, indicating active androgen receptor signaling. Here, we collected blood every month from 89 patients (54 chemotherapy-naive patients and 35 docetaxel-treated patients) treated in phase I/phase II clinical trials of an orally available, highly specific CYP17 inhibitor, abiraterone acetate, that ablates the synthesis of androgens and estrogens that drive TMPRSS2-ERG fusions. We isolated circulating tumor cells (CTC) by anti–epithelial cell adhesion molecule immunomagnetic selection followed by cytokeratin and CD45 immunofluorescence and 4′,6-diamidino-2-phenylindole staining. We used multicolor fluorescence in situ hybridization to show that CRPC CTCs, metastases, and prostate tissue invariably had the same ERG gene status as therapy-naive tumors (n = 31). We then used quantitative reverse transcription–PCR to show that ERG expression was maintained in CRPC. We also observed homogeneity in ERG gene rearrangement status in CTCs (n = 48) in contrast to significant heterogeneity of AR copy number gain and PTEN loss, suggesting that rearrangement of ERG may be an earlier event in prostate carcinogenesis. We finally report a significant association between ERG rearrangements in therapy-naive tumors, CRPCs, and CTCs and magnitude of prostate-specific antigen decline (P = 0.007) in CRPC patients treated with abiraterone acetate. These data confirm that CTCs are malignant in origin and indicate that hormone-regulated expression of ERG persists in CRPC. [Cancer Res 2009;69(7):2912–8]

Ovarian cancer is the leading cause of death from gynaecological malignancies in the Western world. Despite the evolution of surgical techniques and meticulously designed chemotherapy regimens, relapse remains almost inevitable in patients with advanced disease. In an age when great advances have been made in understanding the genetics and molecular biology of this heterogeneous disease, it is likely that the introduction of novel targeted therapies will have a major impact on the management of ovarian cancer. Importantly, such strategies might allow selection of treatments based on the molecular characteristics of tumours and bring us closer to an era of personalized medicine.

Summary Since the inception of phase I clinical trials in cancer, patients with symptomatic brain metastases have commonly been excluded from participation because of a poor outlook. However, patients with asymptomatic brain metastases pose an increasingly frequent challenge for clinicians: more sensitive brain imaging can identify clinically silent brain metastases; frequency of detection might have increased because of changes in the natural history of many tumour types as a result of more effective systemic treatment; and routine brain imaging as a screening procedure before entry into a clinical trial can show lesions which are of questionable clinical importance, but which frequently preclude trial enrolment. Evidence suggests that delaying whole-brain radiotherapy until symptomatic progression has no adverse effect on prognosis. Safety and efficacy data are accumulating for targeted agents to treat brain metastases. We think that a subset of patients with asymptomatic brain metastases might be appropriately entered into phase I trials, and we present our approach for their stratification. As a consequence, patients might have increased access to experimental treatments and thus effective interventions for brain metastases might be developed more promptly.

Vascular endothelial growth factor (VEGF) is a key mediator of physiological and pathological angiogenesis. All solid tumors are dependent on pathological angiogenesis, and anti-VEGF therapy has demonstrated clinical benefit in breast, colorectal, non-small-cell lung, and renal carcinomas. Central nervous system metastases are common in many of these tumor types. An increased risk of bleeding has been reported with anti-VEGF therapy, but the risk of intracranial bleeding is unknown with this type of therapy. We reviewed the available data to investigate the risk of intracranial bleeding with anti-VEGF therapy in the presence and absence of CNS metastases. The PubMed and Medline databases and the Proceedings of the American Society of Clinical Oncology (ASCO) annual meetings were searched for articles, abstracts, and presentations of clinical trials. We identified 57 trials examining the safety and efficacy of anti-VEGF therapy in a total of 10,598 patients. Four trials examined the use of anti-VEGF therapy in treating patients with brain metastases. The presence of CNS metastases was a stated exclusion criterion in 76% of trials. The rate of intra cranial bleeding was negligible. We conclude that there is no trial evidence that anti-VEGF therapy confers an increased risk of intracranial bleeding, even in the presence of CNS metastases. Future trials of anti-VEGF therapy should not exclude patients with controlled CNS metastases at enrollment.

Purpose Clinical trials are critical to improving patient outcomes, but participation in cancer clinical trials is low. Patient understanding of clinical trial process is also limited. Patients are increasingly using the Internet as a source of information. It is critical that such Internet-based information is relevant, current, balanced, and easy to access and navigate. We critically reviewed seven international online resources that provide information for patients/consumers regarding cancer clinical trials. Methods Seven international websites from North America, Europe and Australia were selected based on profile/usage. Sites were evaluated with respect to their content, readability and appropriateness using a suite of standard assessment tools. Results No sites performed well in terms of all assessment criteria. There was substantial variation between sites regarding information provided, content, design and readability. All sites required high literacy levels and assessment using the Standard Assessment of Means tool showed consistent deficiencies. Conclusion Although there are numerous websites providing information about cancer clinical trials to patients/consumers, all evaluated sites have several shortcomings. Attention to the content of information, its presentation and the design of Internet resources has an ethical imperative, and is likely to lead to improved patient satisfaction.

Compared with conventional chemotherapy, rationally designed molecularly targeted agents may be more likely to have antitumor activity in selected tumor subgroups driven by the oncogenic signals targeted by these compounds and a different side-effect profile. The use of biomarkers in the early clinical trials of these new anticancer agents has the potential to increase study participants' benefit from early clinical trials, accelerate the drug development process, maximize the ability to generate important biological information about human cancer, and decrease the risk of late and costly drug attrition.

Purpose: The vascular disrupting agent (VDA) combretastatin A4 phosphate (CA4P) induces significant tumor necrosis as a single agent. Preclinical models have shown that the addition of an anti-VEGF antibody to a VDA attenuates the revascularization of the surviving tumor rim and thus significantly increases antitumor activity. Experimental Design: Patients with advanced solid malignancies received CA4P at 45, 54, or 63 mg/m2 on day 1, day 8, and then every 14 days. Bevacizumab 10 mg/kg was given on day 8 and at subsequent cycles four hours after CA4P. Functional imaging with dynamic contrast enhanced-MRI (DCE-MRI) was conducted at baseline, after CA4P alone, and after cycle 1 CA4P + bevacizumab. Results: A total of 63 mg/m2 CA4P + 10 mg/kg bevacizumab q14 is the recommended phase II dose. A total of 15 patients were enrolled. Dose-limiting toxicities were grade III asymptomatic atrial fibrillation and grade IV liver hemorrhage in a patient with a history of hemorrhage. Most common toxicities were hypertension, headache, lymphopenia, pruritus, and pyrexia. Asymptomatic electrocardiographic changes were seen in five patients. Nine of 14 patients experienced disease stabilization. A patient with ovarian cancer had a CA125 response lasting for more than a year. DCE-MRI showed statistically significant reductions in tumor perfusion/vascular permeability, which reversed after CA4P alone but which were sustained following bevacizumab. Circulating CD34+ and CD133+ bone marrow progenitors increased following CA4P as did VEGF and granulocyte colony-stimulating factor levels. Conclusions: CA4P in combination with bevacizumab appears safe and well tolerated in this dosing schedule. CA4P induced profound vascular changes, which were maintained by the presence of bevacizumab. Clin Cancer Res; 18(12); 3428–39. ©2012 AACR.

Poly(ADP-ribose) polymerase (PARP) is an attractive antitumor target because of its vital role in DNA repair. The homologous recombination (HR) DNA repair pathway is critical for the repair of DNA double-strand breaks and HR deficiency leads to a dependency on error-prone DNA repair mechanisms, with consequent genomic instability and oncogenesis. Tumor-specific HR defects may be exploited through a synthetic lethal approach for the application of anticancer therapeutics, including PARP inhibitors. This theory proposes that targeting genetically defective tumor cells with a specific molecular therapy that inhibits its synthetic lethal gene partner should result in selective tumor cell killing. The demonstration of single-agent antitumor activity and the wide therapeutic index of PARP inhibitors in BRCA1 and BRCA2 mutation carriers with advanced cancers provide strong evidence for the clinical application of this approach. Emerging data also indicate that PARP inhibitors may be effective in sporadic cancers bearing HR defects, supporting a substantially wider role for PARP inhibitors. Drugs targeting this enzyme are now in pivotal clinical trials in patients with sporadic cancers. In this article, the evidence supporting this antitumor synthetic lethal strategy with PARP inhibitors is reviewed, evolving resistance mechanisms and potential molecular predictive biomarker assays are discussed, and the future development of these agents is envisioned.

Purpose Selective tumor cell cytotoxicity can be achieved through a synthetic lethal strategy using poly(ADP)-ribose polymerase (PARP) inhibitor therapy in BRCA1/2 mutation carriers in whom tumor cells have defective homologous recombination (HR) DNA repair. Platinum-based chemotherapy responses correlate with HR DNA repair capacity. Olaparib is a potent, oral PARP inhibitor that is well tolerated, with antitumor activity in BRCA1/2 mutation carriers. Patients and Methods Patients with BRCA1/2-mutated ovarian cancer were treated with olaparib within a dose-escalation and single-stage expansion of a phase I trial. Antitumor activity was subsequently correlated with platinum sensitivity. Results Fifty patients were treated: 48 had germline BRCA1/2 mutations; one had a BRCA2 germline sequence change of unknown significance, and another had a strong family history of BRCA1/2-associated cancers who declined mutation testing. Of the 50 patients, 13 had platinum-sensitive disease, 24 had platinum-resistant disease, and 13 had platinum-refractory disease (according to platinum-free interval). Twenty (40%; 95% CI, 26% to 55%) achieved Response Evaluation Criteria in Solid Tumors (RECIST) complete or partial responses and/or tumor marker (CA125) responses, and three (6.0%) maintained RECIST disease stabilization for more than 4 months, giving an overall clinical benefit rate of 46% (95% CI, 32% to 61%). Median response duration was 28 weeks. There was a significant association between the clinical benefit rate and platinum-free interval across the platinum-sensitive, resistant, and refractory subgroups (69%, 45%, and 23%, respectively). Post hoc analyses indicated associations between platinum sensitivity and extent of olaparib response (radiologic change, P = .001; CA125 change, P = .002). Conclusion Olaparib has antitumor activity in BRCA1/2 mutation ovarian cancer, which is associated with platinum sensitivity.

The development of anticancer drugs remains slow and costly. Use of predictive biomarkers has been postulated to not only accelerate this process but also increase the odds of drug approval ([1][1]). Despite concerns about the validation of the insulin-like growth factor receptor type I (IGF-IR) as

Anticancer drug development remains slow, costly and inefficient. One way of addressing this might be the use of predictive biomarkers to select patients for Phase I/II trials. Such biomarkers, which predict response to molecular-targeted agents, have the potential to enrich these trials with patients more likely to benefit. Doing so could maximize the efficiency of anticancer drug development by facilitating earlier clinical qualification of predictive biomarkers and generating valuable information on cancer biology. In this review, we suggest a new model of early clinical trial design, which incorporates patient selection through predictive molecular biomarkers for selected targeted agents.

Background: The purpose of this study was to evaluate the association of circulating tumour cell (CTC) counts, before and after commencing treatment, with overall survival (OS) in patients with castration-resistant prostate cancer (CRPC). Experimental design: A 7.5 ml of blood was collected before and after treatment in 119 patients with CRPC. CTCs were enumerated using the CellSearch (R) System. Results: Higher CTC counts associated with baseline characteristics portending aggressive disease. Multivariate analyses indicated that a CTC >= 5 was an independent prognostic factor at all time points evaluated. Patients with baseline CTC >= 5 had shorter OS than those with 30 months, hazard ratio (HR) 3.25, P = 0.012]; patients with CTC > 50 had a poorer OS than those with CTCs 5-50 (median OS 6.3 versus 21.1 months, HR 4.1, P = 5 at baseline to < 5 following treatment had a better OS compared with those who did not. CTC counts showed a similar, but earlier and independent, ability to time to disease progression to predict OS. Conclusion: CTC counts predict OS and provide independent prognostic information to time to disease progression; CTC dynamics following therapy need to be evaluated as an intermediate end point of outcome in randomised phase III trials.

There is a growing body of evidence that although medical or surgical castration blocks the generation of gonadal testosterone in prostate cancer, androgens originating from other sources may continue to drive androgen receptor (AR) signaling. Recent studies have demonstrated high intratumoral levels of androgens and continued AR signaling in castration-resistant prostate cancer (CRPC), suggesting that androgens may also be synthesized de novo. Inhibiting the systemic biosynthesis of androgens in CRPC by targeting CYP17 may thus represent a rational therapeutic approach since this enzyme catalyses two key steroid reactions involving 17alpha-hydroxylase and C(17,20)-lyase in the androgen biosynthesis pathway. This review will discuss the rationale for and implications of targeting CYP17 in CRPC and focus on established and novel CYP17 inhibitors, including ketoconazole, abiraterone acetate, and VN/124-1, which are agents currently at different stages of development.