Ovarian cancer p53 mutation is associated with tumor microvessel density

Paclitaxel With and Without Pazopanib for Persistent or Recurrent Ovarian Cancer: A Randomized Clinical Trial

Importance

Ovarian cancer is the leading cause of gynecologic cancer deaths in the United States. Pazopanib is an oral, multitarget kinase inhibitor of vascular endothelial growth factor receptors 1, 2, and 3; platelet-derived growth factor receptors α and β; and proto-oncogene receptor tyrosine kinase (c-KIT).

Objective

To estimate the progression-free survival (PFS) hazard ratio (HR) of weekly paclitaxel and pazopanib compared with weekly paclitaxel and placebo in women with recurrent ovarian cancer. Secondary objectives included frequency and severity of adverse events, proportion responding, and overall survival (OS) in each arm. Translational research objectives included exploring the association between possible biomarkers and single-nucleotide polymorphisms in vascular endothelial growth factor A, interleukin 8, and hypoxia-inducible factor 1α; and PFS, OS, and proportion responding.

Design, Setting, and Participants

A randomized, placebo-controlled, double-blind phase 2 study was conducted at 26 participating institutions. Patients were enrolled between December 12, 2011, and April 22, 2013. Data were frozen on August 11, 2014. Participants were patients with persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma with 1 to 3 prior regimens and performance status of 0 to 2. One hundred six patients enrolled; 100 were evaluable for toxic effects.

Interventions

All patients received paclitaxel 80 mg/m2 intravenously on days 1, 8, and 15 every 28 days and were randomized 1:1 to pazopanib 800 mg orally daily or placebo.

Main Outcomes and Measures

The primary end point was PFS. The study was designed to detect a 37.5% reduction in the hazard with 80% power (α = 10%).

Results

A total of 106 women (median age [range], 61 [35-87] years; 88 [83%] white) were enrolled. Study arms were well balanced for age, performance status, measurable disease, and prior bevacizumab. Proportion responding was 14 of 44 (31.8%) vs 10 of 44 (22.7%) for pazopanib plus paclitaxel vs paclitaxel alone. Median PFS was 7.5 vs 6.2 months for pazopanib plus paclitaxel vs paclitaxel alone, respectively (HR, 0.84; 90% CI, 0.57-1.22; P = .20). Median OS was 20.7 vs 23.3 months for pazopanib plus paclitaxel vs paclitaxel alone (HR, 1.04; 90% CI, 0.60-1.79; P = .90). Severe hypertension was more common on the pazopanib plus paclitaxel arm (relative risk, 12.0; 95% CI, 1.62-88.84). More patients discontinued treatment on the paclitaxel arm for disease progression (34 of 52 [65.4%] vs 17 of 54 [31.5%]), and more on the pazopanib plus paclitaxel arm for adverse events (20 of 54 [37%] vs 5 of 52 [9.6%]). No association was found between single-nucleotide polymorphisms (interleukin 8 and hypoxia-inducible factor 1α) and OS and proportion responding. Patients with VEGFA CC genotype may be more resistant to weekly paclitaxel than those with the AC or AA genotype, with 1 of 14 (7%), 3 of 15 (20%), and 4 of 8 (50%) responding, respectively.

Conclusions and Relevance

The combination of pazopanib plus paclitaxel is not superior to paclitaxel in women with recurrent ovarian cancer.

Trial Registration

clinicaltrials.gov Identifier: NCT01468909.

DNA damage response and repair in ovarian cancer: Potential targets for therapeutic strategies

Ovarian cancer is among the most lethal gynecologic malignancies with a poor survival prognosis. The current therapeutic strategies involve surgery and chemotherapy. Research is now focused on novel agents especially those targeting DNA damage response (DDR) pathways. Understanding the DDR process in ovarian cancer necessitates having a detailed knowledge on a series of signaling mediators at the cellular and molecular levels. The complexity of the DDR process in ovarian cancer and how this process works in metastatic conditions is comprehensively reviewed. For evaluating the efficacy of therapeutic agents targeting DNA damage in ovarian cancer, we will discuss the components of this system including DDR sensors, DDR transducers, DDR mediators, and DDR effectors. The constituent pathways include DNA repair machinery, cell cycle checkpoints, and apoptotic pathways. We also will assess the potential of active mediators involved in the DDR process such as therapeutic and prognostic candidates that may facilitate future studies.

Characterisation of tumour microvessel density during progression of high-grade serous ovarian cancer: clinico-pathological impact (an OCTIPS Consortium study)

BACKGROUND

High-grade serous ovarian cancer (HGSOC) intratumoural vasculature evolution remains unknown. The study investigated changes in tumour microvessel density (MVD) in a large cohort of paired primary and recurrent HGSOC tissue samples and its impact on patients' clinico-pathological outcome.

METHODS

A total of 222 primary (pOC) and recurrent (rOC) intra-patient paired HGSOC were assessed for immunohistochemical expression of angiogenesis-associated biomarkers (CD31, to evaluate MVD, and VEGF-A). Expression profiles were compared between pOCs and rOCs and correlated with patients' data.

RESULTS

High intratumoural MVD and VEGF-A expression were observed in 75.7% (84/111) and 20.7% (23/111) pOCs, respectively. MVD^high and VEGF⁽⁺⁾ samples were detected in 51.4% (57/111) and 20.7% (23/111) rOCs, respectively. MVD^high/VEGF⁽⁺⁾ co-expression was found in 19.8% (22/111) and 8.1% (9/111) of pOCs and rOCs, respectively (p = 0.02). Pairwise analysis showed no significant change in MVD (p = 0.935) and VEGF-A (p = 0.121) levels from pOCs to rOCs. MVD^high pOCs were associated with higher CD3⁽⁺⁾ (p = 0.029) and CD8⁽⁺⁾ (p = 0.013) intratumoural effector TILs, while VEGF⁽⁺⁾ samples were most frequently encountered among BRCA-mutated tumours (p = 0.019). Multivariate analysis showed VEGF and MVD were not independent prognostic factors for OS.

CONCLUSIONS

HGSOC intratumoural vasculature did not undergo significant changes during disease progression. High concentration of CD31⁽⁺⁾ vessels seems to promote recruitment of effector TILs. The study also provides preliminary evidence of the correlation between VEGF-positivity and BRCA status.

Paclitaxel With and Without Pazopanib for Persistent or Recurrent Ovarian Cancer: A Randomized Clinical Trial

Importance

Ovarian cancer is the leading cause of gynecologic cancer deaths in the United States. Pazopanib is an oral, multitarget kinase inhibitor of vascular endothelial growth factor receptors 1, 2, and 3; platelet-derived growth factor receptors α and β; and proto-oncogene receptor tyrosine kinase (c-KIT).

Objective

To estimate the progression-free survival (PFS) hazard ratio (HR) of weekly paclitaxel and pazopanib compared with weekly paclitaxel and placebo in women with recurrent ovarian cancer. Secondary objectives included frequency and severity of adverse events, proportion responding, and overall survival (OS) in each arm. Translational research objectives included exploring the association between possible biomarkers and single-nucleotide polymorphisms in vascular endothelial growth factor A, interleukin 8, and hypoxia-inducible factor 1α; and PFS, OS, and proportion responding.

Design, Setting, and Participants

A randomized, placebo-controlled, double-blind phase 2 study was conducted at 26 participating institutions. Patients were enrolled between December 12, 2011, and April 22, 2013. Data were frozen on August 11, 2014. Participants were patients with persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma with 1 to 3 prior regimens and performance status of 0 to 2. One hundred six patients enrolled; 100 were evaluable for toxic effects.

Interventions

All patients received paclitaxel 80 mg/m2 intravenously on days 1, 8, and 15 every 28 days and were randomized 1:1 to pazopanib 800 mg orally daily or placebo.

Main Outcomes and Measures

The primary end point was PFS. The study was designed to detect a 37.5% reduction in the hazard with 80% power (α = 10%).

Results

A total of 106 women (median age [range], 61 [35-87] years; 88 [83%] white) were enrolled. Study arms were well balanced for age, performance status, measurable disease, and prior bevacizumab. Proportion responding was 14 of 44 (31.8%) vs 10 of 44 (22.7%) for pazopanib plus paclitaxel vs paclitaxel alone. Median PFS was 7.5 vs 6.2 months for pazopanib plus paclitaxel vs paclitaxel alone, respectively (HR, 0.84; 90% CI, 0.57-1.22; P = .20). Median OS was 20.7 vs 23.3 months for pazopanib plus paclitaxel vs paclitaxel alone (HR, 1.04; 90% CI, 0.60-1.79; P = .90). Severe hypertension was more common on the pazopanib plus paclitaxel arm (relative risk, 12.0; 95% CI, 1.62-88.84). More patients discontinued treatment on the paclitaxel arm for disease progression (34 of 52 [65.4%] vs 17 of 54 [31.5%]), and more on the pazopanib plus paclitaxel arm for adverse events (20 of 54 [37%] vs 5 of 52 [9.6%]). No association was found between single-nucleotide polymorphisms (interleukin 8 and hypoxia-inducible factor 1α) and OS and proportion responding. Patients with VEGFA CC genotype may be more resistant to weekly paclitaxel than those with the AC or AA genotype, with 1 of 14 (7%), 3 of 15 (20%), and 4 of 8 (50%) responding, respectively.

Conclusions and Relevance

The combination of pazopanib plus paclitaxel is not superior to paclitaxel in women with recurrent ovarian cancer.

Trial Registration

clinicaltrials.gov Identifier: NCT01468909.

CT and MRI findings of type I and type II epithelial ovarian cancer

OBJECTIVE

To assess whether types I and II epithelial ovarian cancer (EOC) differ in CT and MRI imaging features.

METHODS

For this retrospective study, we enrolled 65 patients with 68 ovarian lesions that have been pathologically proven to be EOC. Of these patients, 38 cases underwent MR examinations only, 15 cases underwent CT examinations only, and 12 cases completed both examinations. The clinical information [age, CA-125, menopausal status, and Ki-67] and imaging findings were compared between two types of EOCs. The diagnostic performance of image findings were assessed by receiver-operating characteristic curve(ROC) analysis. The association between EOC type and imaging features was assessed by multivariate logistic regression analysis. The random forest approach was used to build a classifier in differential diagnosis between two types of EOCs.

RESULTS

Of the 68 EOC lesions, 24 lesions were categorized as types I and other 44 lesions as type II based on the immunohistochemical results, respectively. Patients in type I EOCs were more likely to involve menopausal women and showed lower CA-125 and Ki-67 values (Ki-67<30%) than patients in type II EOCs. The imaging characteristics of type II EOCs frequently demonstrated a solid or predominantly solid mass (38.6% vs. 12.5%, P<0.05), smaller lesions (diameter <6cm; 27.3% vs. 4.2%, P<0.05), absence of mural nodules (65.9% vs. 25.9%, P=0.001), and mild enhancement (84.1% vs. 54.2%, P<0.05) compared to type I EOCs. Combination of tumor size, morphology, mural nodule, enhancement degrees (AUC=0.808) has a higher specificity (87.50%) and positive predictive value (90.0%) than any single image finding alone in differential diagnosis between two types of EOCs. The multivariate logistic regression analysis showed that enhancement degrees(OR 0.200, P<0.05),mural nodule(OR 0.158, P<0.05) significantly influence EOC classification. Random forests model identified both as the most important discriminating variables. The diagnostic accuracy of the classifier was 73.53%.

CONCLUSIONS

Differences in imaging characteristics existed between two types of EOCs. Combination of several image findings improved the preoperative diagnostic performance, which is helpful for the clinical treatment and prognosis evaluation.

ERG is a novel and reliable marker for endothelial cells in central nervous system tumors

ETS-related gene (ERG) is a transcription factor that has been linked to angiogenesis. Very little research has been done to assess ERG expression in central nervous system (CNS) tumors. We evaluated 57 CNS tumors, including glioblastomas (GBMs) and hemangioblastomas (HBs), as well as two arteriovenous malformations and four samples of normal brain tissue with immunohistochemistry using a specific ERG rabbit monoclonal antibody. In addition, immunostains for CD31, CD34, and α-smooth muscle actin (α-SMA) were performed on all samples. CD31 demonstrated variable and sometimes weak immunoreactivity for endothelial cells. Furthermore, in 1 case of a GBM, CD34 stained not only endothelial cells, but also tumor cells. In contrast, we observed that ERG was only expressed in the nuclei of endothelial cells, for example, in the hyperplastic vascular complexes that comprise the glomeruloid microvascular proliferation seen in GBMs. Conversely, α-SMA immunoreactivity was identified in the abluminal cells of these hyperplastic vessels. Quantitative evaluation with automated methodology and custom Matlab 2008b software was used to calculate percent staining of ERG in each case. We observed significantly higher quantitative expression of ERG in HBs than in other CNS tumors. Our results show that ERG is a novel, reliable, and specific marker for endothelial cells within CNS tumors that can be used to better study the process of neovascularization.

CECs and IL-8 Have Prognostic and Predictive Utility in Patients with Recurrent Platinum-Sensitive Ovarian Cancer: Biomarker Correlates from the Randomized Phase-2 Trial of Olaparib and Cediranib Compared with Olaparib in Recurrent Platinum-Sensitive Ovarian Cancer

OBJECTIVE

Olaparib (O), a polyADPribose polymerase (PARP) inhibitor, and cediranib (C), a VEGF receptor (VEGFR)1-3 inhibitor together had greater activity than O alone in women with recurrent platinum-sensitive ovarian cancer (OvCa). The objective of this study is to identify potential lead biomarker candidates for response to O + C in the setting of a multi-institutional phase II study of O with and without C in recurrent platinum-sensitive OvCa.

METHODS

A self-selected group of patients participated in a prospectively planned exploratory biomarker substudy of the randomized phase II study of O versus O + C. Whole blood for peripheral blood mononuclear cell (PBMC) and plasma isolation was collected prior to and on day 3 of treatment. Quantitation of circulating endothelial cells (CEC), IL-6, IL-8, VEGF, and soluble VEGFR-2 plasma concentrations, and polyADPribose (PAR) incorporation were performed. Single nucleotide polymorphism analysis of XRCC1 280H, R194W, and Q399R was done. Dynamic contrast-enhanced-magnetic resonance imaging (DCE-MRI) was performed at baseline and day 3 of treatment. Parameter changes were compared between the two arms using an exact Wilcoxon rank sum test. Kaplan-Meier and log-rank tests were used to examine survival outcome.

RESULTS

Thirteen patients elected to participate in the translational substudy, seven patients on O and six patients on O + C. Patients on O + C had a greater decrease in IL-8 concentration and larger CEC fold increase compared with those on O alone (p = 0.026, p = 0.032). The fold increase in CEC on day 3 was associated with duration of progression-free survival (PFS) (R (2) = 0.77, 95% CI 0.55-0.97, p < 0.001). IL-8 post-pretreatment changes correlate with PFS (p = 0.028). XRCC1 DNA polymorphisms were not related to PFS. All patients had reduction in PAR incorporation, and all except one had reduction in vascular flow on DCE-MRI.

CONCLUSION

Our exploratory correlative studies indicate that CEC and IL-8 changes may be predictive for response to O + C and prognostic in recurrent platinum-sensitive OvCa, requiring prospective validation.

Flt-1 in colorectal cancer cells is required for the tumor invasive effect of placental growth factor through a p38-MMP9 pathway

Background

Placenta growth factor (PlGF), a dimeric glycoprotein with 53% homology to VEGF, binds to VEGF receptor-1 (Flt-1), but not to VEGF receptor-2 (Flk-1), and may function by modulating VEGF activity. We previously have showed that PlGF displays prognostic value in colorectal cancer (CRC) but the mechanism remains elucidated.

Results

Overexpression of PlGF increased the invasive/migration ability and decreased apoptosis in CRC cells showing Flt-1 expression. Increased migration was associated with increasing MMP9 via p38 MAPK activation. Tumors grew faster, larger; with higher vascularity from PlGF over-expression cells in xenograft assay. In two independent human CRC tissue cohorts, PlGF, MMP9, and Flt-1 expressions were higher in the advanced than the localized disease group. PlGF expression correlated with MMP9, and Flt-1 expression. CRC patients with high PlGF and high Flt-1 expression in tissue had poor prognosis.

Conclusion

PlGF/Flt-1 signaling plays an important role in CRC progression, blocking PlGF/Flt-1 signaling maybe an alternative therapy for CRC.

Microvessel density and p53 mutations in advanced-stage epithelial ovarian cancer

We planned to determine the relationship between angiogenesis and p53 mutational status in advanced-stage epithelial ovarian cancer. Using 190 tumor samples from patients with stage III and IV ovarian cancer we performed p53 sequencing, immunohistochemistry, and CD31 microvessel density (MVD) determination. MVD was elevated in tumors with p53 null mutations compared to p53 missense mutation or no mutation. Disease recurrence was increased with higher MVD in both unadjusted and adjusted analyses. In adjusted analysis, p53 null mutation was associated with increased recurrence and worse overall survival. Worse overall survival and increased recurrence risk were also associated with the combination of CD31 MVD values >25 vessels/HPF and any p53 mutation. P53 mutation status and MVD may have prognostic significance in patients with advanced-stage ovarian cancer. Tumors with p53 null mutations are likely to be more vascular, contributing to decreased survival and increased recurrence probability.

Angiogenesis and molecular markers in advanced epithelial ovarian cancer: a retrospective study

OBJECTIVE

The role of molecular markers in ovarian cancer is still a matter of debate. Angiogenesis is a necessary condition for tumor growth. Hypoxia induces angiogenesis, and cyclooxygenase-2 (COX-2), p53 and HER2 are involved in cancer proliferation and angiogenesis regulation. The aims of this study were to evaluate the relationship between intratumoral microvessel density (IMD) and the expression of molecular markers that affect angiogenesis (COX-2, p53 and HER2) in advanced epithelial ovarian cancer (EOC), to analyze their prognostic and predictive value and their association with clinicopathological features, such as serum hemoglobin level at diagnosis (Hb).

METHODS

Immunohistochemical staining with CD34 (for IMD), COX-2, p53 and HER2 antibodies was performed in 113 patients with advanced EOC who had undergone primary surgery. Clinicopathological data were collected and statistical analyses were performed.

RESULTS

Neither IMD, COX-2 nor HER2 had any predictive or prognostic value in EOC. A relationship that approached statistical significance was found between p53 expression and a complete response to treatment (p=0.05). p53 expression and tumor grade were inversely associated (p=0.012). Hb<12g/dl had predictive value (p=0.02).

CONCLUSIONS

In our series IMD, COX-2 and HER2 had neither prognostic nor predictive value in advanced EOC. p53 and Hb may be predictive factors. The results and clinical usefulness of immunohistochemistry are controversial. Further evaluations are required to determine whether the serum levels of molecular markers correlate with the results of immunohistochemical assays and whether they offer any prognostic and/or predictive value. Targeted therapy remains the ultimate goal of these studies.

Antiangiogenic Therapies in Epithelial Ovarian Cancer

Background

Angiogenesis is a critical component of tumor development and proliferation, and increased angiogenesis has been associated with a worse clinical outcome in a number of solid tumors, including ovarian cancer. Therefore, agents that target the angiogenic process are of considerable interest in the treatment of ovarian cancer.

Methods

Studies evaluating the efficacy of antiangiogenic agents in ovarian cancer are reported. Antiangiogenic agents examined include vascular endothelial growth factor (VEGF) pathway inhibitors, including monoclonal antibodies, tyrosine kinase inhibitors (TKIs), and a soluble receptor decoy, as well as inhibitors of other angiogenic factors and vascular disrupting agents.

Results

The VEGF inhibitor bevacizumab has been shown to have efficacy in ovarian cancer in phase II trials and a progression-free survival advantage in one phase III trial. TKIs block the VEGF receptors and secondary angiogenic pathways and have shown activity in phase I and II trials. Alternative angiogenesis inhibitors include EphA2 inhibitors and a selective angiopoietin 1/2-neutralizing peptibody. Another strategy is to destroy the existing tumor vasculature, and a number of vascular disrupting agents are being studied in preclinical and phase I trials. Antiangiogenic agents have a unique side effect profile, likely due to inhibition of normal physiologic angiogenesis.

Conclusions

Phase II and early phase III trials have demonstrated that antiangiogenic therapies have significant activity in ovarian cancer. The results of phase III trials in the front-line and recurrent settings will determine the extent of clinical benefit of antiangiogenic therapies in combination with chemotherapy. Antiangiogenic agents have a distinct side effect profile, and further studies are necessary to evaluate how to minimize the incidence of these events and to identify women most likely to benefit from these therapies.

Predictive and prognostic angiogenic markers in a gynecologic oncology group phase II trial of bevacizumab in recurrent and persistent ovarian or peritoneal cancer

OBJECTIVE

Potential predictive/prognostic angiogenic markers were prospectively examined in a phase II trial of bevacizumab in epithelial ovarian cancer (EOC)/primary peritoneal cancer (PPC).

METHODS

Recurrent/persistent EOC/PPC patients were treated with bevacizumab (15 mg/kg IV q21days) until disease progression. Validated-immunohistochemistry (IHC) assays were performed on pre-cycle 1/4 tumor biopsies for CD31-microvessel density (MVD), VEGF-histoscore (HS), p53-HS, and TSP1 image analysis score (IA). Pre-cycle 1/4 serum and plasma VEGF were quantified using a validated-ELISA.

RESULTS

CD31-MVD and serum VEGF, evaluated pre-cycle 1 in 41/61 and 51/61 eligible patients, respectively, did not appear to be correlated. High CD31-MVD, categorized at the median, appeared to be associated with tumor response, a 13-month shorter median survival, and an increased risk of death (unadjusted hazard ratio [HR] = 2.2, 95% confidence interval [CI] = 1.067-4.467). In addition, each standard deviation (SD) increase in CD31-MVD appeared to be associated with worse survival in unadjusted and adjusted analyses. IHC and plasma biomarkers did not change with bevacizumab treatment except for serum VEGF, which appeared to decrease during bevacizumab treatment. This decrease was not associated with response. High pre-cycle 1 serum VEGF, categorized at the median, was associated with 22-month shorter median survival and an increased risk of death (unadjusted HR = 2.7, 95% CI = 1.369-5.191). Categorized p53 appeared to be associated with unadjusted survival and each SD increase in TSP1-IA appeared to be associated with a decreased risk of progression in unadjusted and adjusted analyses.

CONCLUSIONS

Despite the limitations in sample size and exploratory nature of the study, angiogenic markers in tumor and serum may provide prognostic value in recurrent/persistent EOC/PPC, and are being prospectively evaluated in the GOG phase III trial of carboplatin, paclitaxel and bevacizumab/placebo in previously untreated EOC/PPC.

Predictive and prognostic angiogenic markers in a gynecologic oncology group phase II trial of bevacizumab in recurrent and persistent ovarian or peritoneal cancer

OBJECTIVE

Potential predictive/prognostic angiogenic markers were prospectively examined in a phase II trial of bevacizumab in epithelial ovarian cancer (EOC)/primary peritoneal cancer (PPC).

METHODS

Recurrent/persistent EOC/PPC patients were treated with bevacizumab (15 mg/kg IV q21days) until disease progression. Validated-immunohistochemistry (IHC) assays were performed on pre-cycle 1/4 tumor biopsies for CD31-microvessel density (MVD), VEGF-histoscore (HS), p53-HS, and TSP1 image analysis score (IA). Pre-cycle 1/4 serum and plasma VEGF were quantified using a validated-ELISA.

RESULTS

CD31-MVD and serum VEGF, evaluated pre-cycle 1 in 41/61 and 51/61 eligible patients, respectively, did not appear to be correlated. High CD31-MVD, categorized at the median, appeared to be associated with tumor response, a 13-month shorter median survival, and an increased risk of death (unadjusted hazard ratio [HR] = 2.2, 95% confidence interval [CI] = 1.067-4.467). In addition, each standard deviation (SD) increase in CD31-MVD appeared to be associated with worse survival in unadjusted and adjusted analyses. IHC and plasma biomarkers did not change with bevacizumab treatment except for serum VEGF, which appeared to decrease during bevacizumab treatment. This decrease was not associated with response. High pre-cycle 1 serum VEGF, categorized at the median, was associated with 22-month shorter median survival and an increased risk of death (unadjusted HR = 2.7, 95% CI = 1.369-5.191). Categorized p53 appeared to be associated with unadjusted survival and each SD increase in TSP1-IA appeared to be associated with a decreased risk of progression in unadjusted and adjusted analyses.

CONCLUSIONS

Despite the limitations in sample size and exploratory nature of the study, angiogenic markers in tumor and serum may provide prognostic value in recurrent/persistent EOC/PPC, and are being prospectively evaluated in the GOG phase III trial of carboplatin, paclitaxel and bevacizumab/placebo in previously untreated EOC/PPC.

Predictive and prognostic angiogenic markers in a gynecologic oncology group phase II trial of bevacizumab in recurrent and persistent ovarian or peritoneal cancer

OBJECTIVE

Potential predictive/prognostic angiogenic markers were prospectively examined in a phase II trial of bevacizumab in epithelial ovarian cancer (EOC)/primary peritoneal cancer (PPC).

METHODS

Recurrent/persistent EOC/PPC patients were treated with bevacizumab (15 mg/kg IV q21days) until disease progression. Validated-immunohistochemistry (IHC) assays were performed on pre-cycle 1/4 tumor biopsies for CD31-microvessel density (MVD), VEGF-histoscore (HS), p53-HS, and TSP1 image analysis score (IA). Pre-cycle 1/4 serum and plasma VEGF were quantified using a validated-ELISA.

RESULTS

CD31-MVD and serum VEGF, evaluated pre-cycle 1 in 41/61 and 51/61 eligible patients, respectively, did not appear to be correlated. High CD31-MVD, categorized at the median, appeared to be associated with tumor response, a 13-month shorter median survival, and an increased risk of death (unadjusted hazard ratio [HR] = 2.2, 95% confidence interval [CI] = 1.067-4.467). In addition, each standard deviation (SD) increase in CD31-MVD appeared to be associated with worse survival in unadjusted and adjusted analyses. IHC and plasma biomarkers did not change with bevacizumab treatment except for serum VEGF, which appeared to decrease during bevacizumab treatment. This decrease was not associated with response. High pre-cycle 1 serum VEGF, categorized at the median, was associated with 22-month shorter median survival and an increased risk of death (unadjusted HR = 2.7, 95% CI = 1.369-5.191). Categorized p53 appeared to be associated with unadjusted survival and each SD increase in TSP1-IA appeared to be associated with a decreased risk of progression in unadjusted and adjusted analyses.

CONCLUSIONS

Despite the limitations in sample size and exploratory nature of the study, angiogenic markers in tumor and serum may provide prognostic value in recurrent/persistent EOC/PPC, and are being prospectively evaluated in the GOG phase III trial of carboplatin, paclitaxel and bevacizumab/placebo in previously untreated EOC/PPC.

Predictive and prognostic protein biomarkers in epithelial ovarian cancer: recommendation for future studies

Epithelial ovarian cancer is the most lethal gynecological malignancy. Due to its lack of symptoms, this disease is diagnosed at an advanced stage when the cancer has already spread to secondary sites. While initial rates of response to first treatment is >80%, the overall survival rate of patients is extremely low, mainly due to development of drug resistance. To date, there are no reliable clinical factors that can properly stratify patients for suitable chemotherapy strategies. Clinical parameters such as disease stage, tumor grade and residual disease, although helpful in the management of patients after their initial surgery to establish the first line of treatment, are not efficient enough. Accordingly, reliable markers that are independent and complementary to clinical parameters are needed for a better management of these patients. For several years, efforts to identify prognostic factors have focused on molecular markers, with a large number having been investigated. This review aims to present a summary of the recent advances in the identification of molecular biomarkers in ovarian cancer patient tissues, as well as an overview of the need and importance of molecular markers for personalized medicine in ovarian cancer.

Activation of checkpoint kinase 2 by 3,3'-diindolylmethane is required for causing G2/M cell cycle arrest in human ovarian cancer cells

We evaluated the effect of 3,3'-diindolylmethane (DIM) in ovarian cancer cells. DIM treatment inhibited the growth of SKOV-3, TOV-21G, and OVCAR-3 ovarian cancer cells in both a dose- and time-dependent manner with effective concentrations ranging from 40 to 100 muM. Growth-inhibitory effects of DIM were mediated by cell cycle arrest in G(2)/M phase in all the three cell lines. G(2)/M arrest was associated with DNA damage as indicated by phosphorylation of H(2)A.X at Ser139 and activation of checkpoint kinase 2 (Chk2) in all the three cell lines. Other G(2)/M regulatory molecules such as Cdc25C, Cdk1, cyclin B1 were down-regulated by DIM. Cycloheximide or Chk2 inhibitor pretreatment abrogated not only activation of Chk2 but also G(2)/M arrest and apoptosis mediated by DIM. To further establish the involvement of Chk2 in DIM-mediated G(2)/M arrest, cells were transfected with dominant-negative Chk2 (DN-Chk2). Blocking Chk2 activation by DN-Chk2 completely protected cells from DIM-mediated G(2)/M arrest. These results were further confirmed in Chk2 knockout DT40 lymphoma cells, in which DIM failed to cause cell cycle arrest. These results clearly indicate the requirement of Chk2 activation to cause G(2)/M arrest by DIM in ovarian cancer cells. Moreover, blocking Chk2 activation also abrogates the apoptosis-inducing effects of DIM. Furthermore, our results show that DIM treatment cause ROS generation. Blocking ROS generation by N-acetyl cysteine protects the cells from DIM-mediated G(2)/M arrest and apoptosis. Our results establish Chk2 as a potent molecular target of DIM in ovarian cancer cells and provide the rationale for further clinical investigation of DIM.

Angiogenesis and ovarian cancer

Ovarian carcinoma is the most important cause of gynaecological cancer-related mortality in Western societies. The age at diagnosis, extent of disease (as expressed by FIGO state), success of primary surgery and the histopathological features of the tumour are important prognostic markers. The majority of patients with ovarian cancer present with advanced disease (FIGO stage III/IV) and in this group of patients the median survival is only three years. New treatment approaches are therefore required to improve outcome in this disease. Angiogenesis, the development of a neovascular blood supply, is a critical step in the propagation of malignant tumour growth and metastasis and represents a promising target. This review will focus on angiogenesis, VEGF biology and the potential value of angiogenic factors with prognostic value in ovarian cancer.

VEGF-A and i-NOS expression are prognostic factors in serous epithelial ovarian carcinomas after complete surgical resection

AIMS

Clinical stage at the time of diagnosis and achievement of complete macroscopic resection during initial surgery are key factors determining the outcome of ovarian cancer. However, prediction of outcome lacks accuracy and more reliable prognostic factors are required. Therefore, an analysis and evaluation of key angiogenic factors was carried out to determine their diagnostic and prognostic value in serous ovarian cancer.

METHODS

Expression levels of vascular endothelial growth factor (VEGF)-A, hypoxia-inducible factor (HIF)1-alpha and inducible nitric oxide synthase (i-NOS) were analysed by immunohistochemistry in a homogenous group of 112 patients with serous adenocarcinoma of the ovary. Vascular density as an indicator of angiogenesis was assessed using the Chalkley eyepiece method after staining for CD34. The correlation of these data with survival and established prognostic factors such as histological grade, Federation of Gynecology and Obstetrics (FIGO) stage, and residual tumour after surgery, was evaluated. Survival analyses, multivariate analyses and correlation tests were performed.

RESULTS

In the patient group with macroscopic complete tumour resection (R0) there was a significant correlation between VEGF-A and i-NOS expression. Kaplan-Meier analysis further revealed improved progression-free survival for R0 patients with VEGF-A-positive and i-NOS-negative tumours. The predictive relevance of VEGF-A regarding progression-free survival was sustained in multivariate analysis using FIGO stage, grading and resection status as fixed variables.

CONCLUSION

VEGF-A and i-NOS are prognostic markers for clinical outcome in serous ovarian cancer patients with macroscopic complete tumour resection (R0). Hence, pre-therapeutic assessment of VEGF-A as predictive factor for an antiangiogenic therapy might be of clinical value.

p53 hot-spot mutants increase tumor vascularization via ROS-mediated activation of the HIF1/VEGF-A pathway

The function of p53 tumor suppressor is often altered in various human tumors predominantly through missense-mutations resulting in accumulation of mutant proteins. We revealed that expression of p53 proteins with amino-acid substitutions at codons 175 (R175H), 248 (R248W), and 273 (R273H), representing the hot-spots of mutations in various human tumors, increased the number of vessels in HCT116 human colon carcinoma xenografts and, as a result, accelerated their growth. Stimulation of tumor angiogenesis was connected with about 2-fold increase in intracellular level of reactive oxygen species (ROS). Antioxidant N-acetyl-l-aspartate (NAC) decreased vessels number in tumors formed by cells with inactivated p53 and inhibited their growth. Effect of ROS on angiogenesis in tumors expressing hot-spot p53 mutants was correlated with their ability to increase a content of HIF1 transcriptional factor responsible for up-regulation of VEGF-A mRNAs.

Prognostic Value of Measurements of Angiogenesis in Serous Carcinoma of the Ovary

The study objective was to determine whether tumor vascularity correlates with patient survival, to compare newer semiautomated methods of angiogenesis assessment to older methods, and to determine if advanced image analysis methods can offer useful patient outcome data in serous ovarian cancer. Using the specific endothelial marker CD34, microvessel determinations were quantified in 132 serous ovarian tumors by manual counting at final magnifications of x 200 and x 400 in the most highly vascular areas. Computer-assisted image analysis microvessel counts, endothelial area estimates, and minimum spanning tree (MST) analysis of capillary architecture, which involves assessment of intercapillary distances, were correlated with traditional manual techniques.Manual, semiautomated, and advanced image analysis methods were found to be highly reproducible and express strong correlation with one another. Univariate cyclooxygenase analysis revealed angiogenesis parameters to be highly significant predictors for overall survival (OS) and disease-free survival. Multivariate cyclooxygenase analysis revealed maximum MST (P = 0.009), length MST (P = 0.005), 1 nearest neighbor (P <or= 0.01) and mean microvessel density (x 400) (P = 0.0001) to be significant predictors for OS, and mean endothelial area (P <or= 0.01) and stage (P = 0.001) significant predictors for disease-free survival. Despite showing prognostic significance on univariate analysis, most clinicopathologic parameters did not retain independent significance on multivariate analysis. Microvessel determination is an independent prognostic indicator for survival in patients with serous ovarian carcinoma. Computer-assisted image analysis is a highly reproducible method of assessment capable of accurately evaluating tumor vascularity. Minimum spanning tree analysis of capillary architecture was found to be the strongest prognosticator for OS, suggesting this to be a promising marker.

Co-expression of angiogenic markers and associations with prognosis in advanced epithelial ovarian cancer: a Gynecologic Oncology Group study

OBJECTIVES

The aim of this study was to explore the co-expression and prognostic relevance of thrombospondin-1 (THBS-1), basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF) and VEGF receptor 1 (VEGFR-1) in epithelial ovarian cancer (EOC).

METHODS

Frozen tumor specimens with defined p53 status were obtained from 67 patients with previously untreated advanced-stage EOC who participated in a Gynecologic Oncology Group specimen-banking protocol and a phase III treatment protocol. Relative expression of the angiogenic markers was quantified by immunoblot analysis and categorized at the median angiogenic marker/actin ratio. p-values are provided as an indication of confidence in the results and to prioritize further testing.

RESULTS

An association was observed between categorized VEGF and p53 overexpression (p=0.022), and between VEGFR-1 and race (p=0.027) or histologic subtype (p=0.007). Unadjusted Cox regression analyses indicated that high compared with low THBS-1, but not VEGF or VEGFR-1, was associated with an increased risk of disease progression (hazard ratio [HR]=2.19; 95% confidence interval [CI]=1.29-3.71; p=0.004) and death (HR=1.93; 95% CI=1.12-3.32; p=0.018) whereas bFGF was associated with a reduced risk of disease progression (HR=0.60; 95% CI=0.36-0.99; p=0.046) and death (HR=0.54; 95% CI=0.32-0.93; p=0.026). After adjusting for prognostic factors including clinical characteristics and p53 overexpression, THBS-1 but not bFGF, VEGF or VEGFR-1 was associated with progression-free and overall survival.

CONCLUSIONS

These data suggest that high THBS-1 is an independent predictor of worse progression-free and overall survival in women with advanced-stage EOC. A larger prospective study is warranted for validation of these findings.

Quantification of angiogenesis by the Chalkley method and its prognostic significance in epithelial ovarian cancer

AIM

The aim of the present study was to clarify prognostic role of angiogenesis in epithelial ovarian cancer.

METHODS

Quantification of angiogenesis was performed by the Chalkley method after immunostaining of 175 epithelial ovarian cancer specimens with an antibody against CD34.

RESULTS

The Chalkley count was categorised into two groups according to the median value: low <8 or high > or =8. The low Chalkley count correlated significantly with serous and clear cell histological subtype of the tumour (p<0.0005), whereas there existed no association with FIGO (International Federation of Gynecology and Obstetrics) stage, histological grade, presence of primary residual tumour, age at diagnosis, or chemotherapy response. In univariate analysis, the high Chalkley count predicted poor overall survival in the subgroup of patients with FIGO stages III-IV tumours (p=0.007) but not in the entire study cohort. However, in multivariate analysis, the Chalkley count was found to be an independent predictor of death from ovarian cancer in the entire study cohort (p=0.044, RR=1.50, 95% CI 1.01-2.21) as well as in the subgroup of FIGO stages III-IV tumours (p=0.046, RR=1.58, 95% CI 1.01-2.46) together with the presence of primary residual tumour (p<0.0005, RR=5.10, 95% CI 3.02-8.62, and p=0.002, RR=4.28, 95% CI 1.34-13.73, respectively).

CONCLUSIONS

The Chalkley count seems to be suitable for evaluation of angiogenesis and to have prognostic significance in ovarian cancer.

EphA2 overexpression is associated with angiogenesis in ovarian cancer

BACKGROUND

EphA2 is overexpressed in the majority of ovarian cancers and predicts poor clinical outcome. Based on EphA2's emerging role in angiogenesis, we hypothesized that tumors overexpressing EphA2 demonstrate greater microvessel density (MVD) and matrix metalloproteinase (MMP) expression.

METHODS

After Institutional Review Board (IRB) approval, 77 invasive epithelial ovarian tumors were analyzed for CD31, EphA2, MMP-2, MMP-9, and MT1-MMP expression.

RESULTS

The median age of the patients was 59 years (range, 34-83). EphA2 was overexpressed in 76% of tumors and was associated with advanced-stage disease (P < .001) and high-grade histology (P = .04). MVD was stratified into high (>12.7 vessels/high-power field [HPF]) versus low (<or=12.7 vessels/HPF) counts. High MVD was significantly associated with advanced stage (P < .001), presence of ascites (P < .001), and suboptimal surgical cytoreduction (P = .01). MMP expression was scored separately in the stromal (percentage of tumors with high expression: MMP-2 = 43%; MMP-9 = 74%; MT1-MMP = 40%) and epithelial (percentage of tumors with high expression: MMP-2 = 52%; MMP-9 = 61%; MT1-MMP = 44%) compartments. Endothelial cell EphA2 overexpression correlated with epithelial MMP-9 (P = .02), whereas EphA2 overexpression in tumor cells was significantly associated with high MVD (P = .002), as well as strong stromal and epithelial MMP-9 (P = .01 and P = .04, respectively), epithelial MMP-2 (P = .006), and epithelial MT1-MMP (P = .01) expression.

CONCLUSIONS

EphA2 overexpression in endothelial and ovarian cancer cells was strongly associated with critical factors involved in angiogenesis and invasion. These findings may explain the poor clinical outcome of patients with EphA2 overexpression.

The prognostic value of endoglin (CD105) expression in ovarian carcinoma

Intratumoral angiogenesis has become an important issue after the identification of antiangiogenic therapeutics. The purpose of this study was to investigate the prognostic value of CD105 in patients with ovarian cancer and also to compare with CD31. Fifty-eight patients were included to this study. All the paraffin blocks were reviewed, and angiogenesis was determined by immunohistochemical staining, using anti-CD105 and anti-CD31 monoclonal antibodies. The mean microvessel density (MVD) with CD105 and CD31 were 28.78 +/- 22.20 and 28.69 +/- 18.57, respectively (P = 0.97). With respect to prognostic factors, CD31 was only significant for suboptimal cytoreduction (P = 0.02), and CD105 was significant for both advanced stage and suboptimal cytoreduction (P = 0.02 and P = 0.05, respectively). For survival analysis, patients were divided into three groups by quartiles for each marker (group 1, <25%; group 2, 25-75%; and group 3, >75%). By CD31, only significant difference was noted between group 1 and group 2 (P = 0.03). In analysis with CD105, the survival rate of patients with group 3 was significantly worse than group 1 and group 2 (P = 0.01 for both). In multivariate analysis, cytoreduction and MVD determined by CD105 remained significant. In this study, endoglin was found to be an independent predictor of poor survival. Therefore, it could be used for antiangiogenic therapies.

Clinicopathologic study of vascular endothelial growth factor, thrombospondin-1, and microvessel density assessed by CD34 in patients with stage III ovarian carcinoma

The aim of the study was to investigate angiogenesis in patients with advanced-stage ovarian carcinoma. We used paraffin-embedded tumor tissues from 33 patients diagnosed with FIGO III ovarian cancer who had optimal surgery and received platinum-based chemotherapy. The tissue expression of CD34, vascular endothelial growth factor (VEGF), and thrombospondin-1 (TSP-1) was assessed immunohistochemically. CD34 stained hot spot areas were used to evaluate tumor microvessel density (MVD). VEGF and TSP-1 were assessed by semiquantitative methods. The studied molecules were investigated for relationship with standard clinicopathologic parameters. MVD count was high: median value of 39, range 12-143 microvessels/mm2. VEGF was present in all cases and stained strong in 91%. Stroma staining for TSP-1 was weak in 79% of the cases, strong in 6%, and absent in five (15%). We did not find correlations between the three studied markers and histologic type or tumor grade. MVD score did not relate to VEGF or TSP-1. We only observed a trend toward a longer survival in patients with tumors expressing high TSP-1 (60 vs. 36 months, P= 0.1). Proangiogenetic factor VEGF is highly expressed in advanced-stage ovarian carcinomas. The findings of this study may offer support for considering VEGF-targeted therapeutics in ovarian cancer treatment research.

The Relationship of Molecular Markers of p53 Function and Angiogenesis to Prognosis of Stage I Epithelial Ovarian Cancer

PURPOSE

Multiple angiogenic factors may influence tumor progression and metastasis. Several are modified by the p53 gene. We sought to identify molecular markers for high-risk stage I epithelial ovarian cancers.

EXPERIMENTAL DESIGN

Seventy-seven consecutive stage I epithelial ovarian cancers were evaluated for p53, CD31 microvessel density, thrombospondin-1, vascular endothelial growth factor (VEGF), p21 immunohistochemical staining, and p53 gene mutations. Molecular marker impact upon disease-specific survival, disease recurrence, and distant recurrence was evaluated with Cox regression.

RESULTS

There were 12 deaths from disease. Twelve of the 77 tumors contained p53 mutations-10 missense and 3 null (one tumor had two mutations). Fesddration Internationale des Gynaecologistes et Obstetristes substage (IA/IB versus IC; P < 0.001) and VEGF staining (P = 0.02) were significant in bivariate models with relationship to disease-specific survival. Stage (P = 0.0004), grade (P = 0.008), histology (P = 0.0025), p53 dysfunction (positive stain and/or mutation; P = 0.048), and microvessel density (P = 0.04) were significant in bivariate models with relationship to time to recurrence. In multivariate analyses among stage IC patients, failure to receive chemotherapy and microvessel density were associated with disease-specific survival, time to recurrence, and time to distant recurrence with hazard ratios of 4.8 to 44.1.

CONCLUSIONS

The p53-dependent molecular markers of angiogenesis are of limited utility in developing a clinical strategy for postoperative management of stage I ovarian carcinoma. Microvessel density impacts survival and metastasis for high-risk stage IC disease. Adjuvant chemotherapy is necessary, but not sufficient, for cure of high-risk stage I epithelial ovarian cancers.

Endothelial cells co-cultured with wild-type and dominant/negative p53-transfected glioblastoma cells exhibit differential sensitivity to radiation-induced apoptosis

We performed expressional profiling of isogenic glioblastoma cell lines U87-Lux8 and U87-175.4. These cell lines differ in that U87-Lux8 expresses wild-type p53 and U87-175.4 expresses a dominant-negative p53 (175(His) mutation). DNA array analysis and real-time PCR measurements demonstrated that basal expression and response to irradiation were different in these isogenic glioblastoma cell lines. These differences included genes involved in growth regulation and genes associated with cell-to-cell and cell/ECM communications. Co-cultivation of U87-175.4 and U87-Lux8 with HUVE cells demonstrated that U87-175.4 cells suppress the angiogenic phenotype of HUVEC and increase their sensitivity to radiation-induced apoptosis compared to co-culture of U87-Lux8/HUVEC. These data suggest that blockade of p53 function may alter the communication between tumor cells and endothelial cells such that endothelial cells exhibit an increase in radiosensitivity. These findings may have important implications for the treatment of glioblastoma tumors and other human cancers.

The influence of microvessel density on ovarian carcinogenesis

OBJECTIVE

Tumor microvessel density, measured by CD31 immunohistochemistry, correlates with survival in patients with ovarian cancer. CA 125 is secreted by most ovarian cancers, and we have previously shown that the rate of decline of CA 125 is also predictive of ovarian cancer survival. Because increased tumor vascularity may allow metastases on one hand, while facilitating the delivery of chemotherapy on the other, we investigated the relationship of tumor microvessel density to preoperative CA 125, residual disease, and the initial response to treatment.

METHODS

FIGO stage, grade, age, residual disease, and CD31 microvessel density count were correlated with consecutive patients (n = 202) diagnosed with epithelial ovarian cancer who met entry criteria. The relationship of CD31 staining to preoperative CA 125, and the rate of decline in CA 125 (slope) as a measure of initial response to therapy, was also evaluated based on complete CA 125 data. Spearman correlation and the Wilcoxon rank sum test were used for bivariate analyses. Linear and logistic regression was used for multivariate analysis.

RESULTS

There were 21 stage I, 14 stage II, 125 stage III, and 42 stage IV patients diagnosed with epithelial ovarian cancer included in the study. More than half (N = 126) of the patients were optimally cytoreduced. Elevated microvessel density was associated with advanced stage of disease (P = 0.0453), grade (P = 0.0002), and an increased amount of residual disease (P = 0.0144). CA 125 values were higher in patients with residual disease versus patients without residual disease (P = 0.0357), and the decline in the CA 125 (slope) was less steep in patients without residual disease versus patients with residual disease (P = 0.0003). However, the initial response to chemotherapy was unrelated to the microvessel density count as measured by CD31 antibody staining (P = 0.7911). In multivariate analyses, CD31 counts remained significant in relationship to grade. Nonideal slopes, indicating decreased response, were associated with increasing age (P = 0.0008) and residual disease (P = 0.0035).

CONCLUSION

Elevated ovarian cancer microvessel density count is related to advanced stage and grade of disease, and compromised potential for cytoreduction. Residual disease is associated with higher CA 125 levels and faster CA 125 decline rates. The rate of decline of CA 125 during the initial response to treatment cannot be predicted based on CD31 counts, confirming a complex relationship between tumor vascularity, metastasis, and response to treatment.

Clinical importance of molecular determinations in gynecologic patients with multiple tumors

BACKGROUND

The prognosis and treatment of patients with multiple tumors may depend on the correlation between tumors: multiple primary tumors, or recurrent tumors, and metastatic disease. The authors investigated whether the detection of molecular aberrations in multiple gynecologic tumors in individual patients provided clinically useful information on the correlation between the tumors.

METHODS

Between 1999 and 2001, molecular analyses were performed on tissue from 15 gynecologic patients, all with multiple tumors. The molecular analyses included loss of heterozygosity determinations at eight DNA loci and mutation analyses of p53 exons 5-8 using the single-strand conformation polymorphism method. Previously, it was not possible to use routine diagnostic histopathology to determine accurately the correlation between multiple lesions in patients with gynecologic malignancies, information that may have an impact on clinical decision-making and prognosis.

RESULTS

Molecular results were obtained from all tumors from each of the 15 patients. The DNA alterations detected provided evidence that two patients had second primary tumors, nine patients had a single tumor with metastases, and four patients had two independent primary tumors as well as metastatic disease. The results provided additional diagnostic information and contributed to clinical decision-making.

CONCLUSIONS

The authors demonstrated that, by comparing DNA alterations in multiple tumors within an individual patient, evidence about correlations between the tumors can be obtained. These investigations can be performed on routinely processed tissues, and the results may be of clinical importance in helping to determine the management or prognosis of patients with gynecologic malignancies.