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Kenneth R Hess

Publications and source records attributed to Kenneth R Hess.

49 records · Page 3Linked to original sources
PubMed2003

Automated quantification of apoptosis after neoadjuvant chemotherapy for breast cancer: early assessment predicts clinical response.

PURPOSE: A large body of evidence implicates apoptosis in the effects of cancer chemotherapeutic agents on tumor cells in vitro and tumor xenografts in vivo, but the predictive value of apoptosis as an early marker for clinical response in cancer patients remains unclear. EXPERIMENTAL DESIGN: We developed an automated, laser scanning cytometer-based method to quantify the percentage of tumor cells containing DNA fragmentation characteristic of apoptosis in tumor sections. We measured levels of apoptosis in a panel of 15 matched, 18-gauge core breast cancer biopsies obtained before and 48 h after neoadjuvant therapy with docetaxel plus doxorubicin or paclitaxel as part of two prospective clinical trials. RESULTS: The results revealed a strongly significant (P = 0.0023) association between chemotherapy-induced apoptosis and pathological response. CONCLUSIONS: If the results can be validated in a larger patient cohort, the method could be used to "tailor" therapy to optimize benefit in a patient-specific fashion.

Apoptosis↗
PubMed2003

Phase III randomized study of postradiotherapy chemotherapy with combination alpha-difluoromethylornithine-PCV versus PCV for anaplastic gliomas.

PURPOSE: In the current study, we sought to determine whether the addition of DFMO (alpha-difluoromethyl ornithine; eflornithine), an inhibitor of ornithine decarboxylase, to a nitrosourea-based therapy procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, vincristine (PCV) would be more effective as a postirradiation adjuvant therapy for anaplastic gliomas (AG) than PCV alone. PATIENTS AND METHODS: After conventional radiation therapy, 249 AG patients were randomized to receive either DFMO-PCV (125 patients) or PCV alone (124 patients), with survival being the primary endpoint and progression-free survival being an important secondary endpoint. The starting dosage of DFMO was 3 grams/m(2) p.o. q. 8 h for 14 days before and 4 weeks after 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea; PCV was administered as described previously (1). Clinical and radiological (gadolinium-enhanced magnetic resonance imaging) follow-ups were nominally at the end of each 6- or 8-week cycle (PCV at 6 weeks; DFMO-PCV at 8 weeks). Laboratory evaluations for hematological and other adverse effects were at 2-week intervals. RESULTS: In the DFMO-PCV arm, there were 114 evaluable patients with 78.1% anaplastic astrocytoma (AA), 3.5% anaplastic oligoastrocytoma (AOA), 14% anaplastic oligodendroglioma (AO), and 4.4% other malignant gliomas. These histological groupings were comparable with those of the 114 patients in the PCV arm: (a) 69.3% AA; (b) 7% AOA; (c) 21.1% AO; and (d) 2.6% malignant gliomas. Although improved survival estimates for the DFMO-PCV treatment group persisted over the course of the study, analysis of survival differences over the entire follow-up period did not yield significance (P = 0.11). However, careful analysis of the corresponding hazard and hazard ratio functions indicated that the real treatment difference was limited to the first 24 months of follow-up (P = 0.02). The median progression-free survival for the two treatment groups, as measured from postradiotherapy registration, was 71.1 months for the DFMO-PCV arm and 37.5 months for the PCV-only arm. Median survival, measured from registration, was 75.8 and 61.1 months, respectively, for the DFMO-PCV and PCV arms. The treatment effect persisted when the AA histology was separated from AO and AOA histologies. This effect persisted even after adjusting for the covariates of age, Karnofsky performance status, and extent of surgery. There was a statistically significant increase in grade 3 adverse events for diarrhea and anemia associated with DFMO-PCV. Grade 3 or 4 adverse events of nausea, ototoxicity, and thrombocytopenia were not significantly increased among groups. CONCLUSIONS: The addition of DFMO to the nitrosourea-based PCV regimen in this Phase III study demonstrated a sustained benefit in survival probabilities for AG patients but not in the corresponding hazard rates. Survival analysis from registration found a DFMO-PCV median survival of 6.3 years (49 of 114 events), whereas that for PCV alone was 5.1 years (55 of 114 events). The hazard function demonstrated a difference over the first 2 years of study (hazard ratio 0.53, P = 0.02) but not after 2 years (hazard ratio 1.06, P = 0.84), supporting the conclusion that DFMO adds to the survival advantage of PCV chemotherapy for AG patients by direct temporal interaction with PCV.

Adolescent↗
PubMed2002

Development of biologic markers of response and assessment of antiangiogenic activity in a clinical trial of human recombinant endostatin.

PURPOSE: Angiogenesis is a target for the treatment of cancer and other diseases, and its complex biology suggests that establishing the appropriate dose and schedule for antiangiogenic treatment will require extensive study. We present the initial results of a dose-finding clinical trial of recombinant human endostatin (rh-Endo) that examined potential surrogates for response to antiangiogenic therapy. PATIENTS AND METHODS: Twenty-five patients were treated with escalating doses of rh-Endo. Positron emission tomography (PET) was used to assess tumor blood flow (with [15O]H2O) and metabolism (with [18F]fluorodeoxyglucose) before the start of therapy and then every 4 weeks. To directly assess the effects of rh-Endo on endothelial cells within the tumors, biopsy specimens of tumor tissue were obtained before therapy and again at 8 weeks and evaluated for endothelial cell and tumor cell apoptosis. RESULTS: Tumor blood flow and metabolism as measured by PET scans generally decreased with increasing doses of rh-Endo; however, the effects were complex and in some analyses nonlinear. Tumor biopsy analysis revealed a significant increase in tumor cell apoptosis (P =.027) and endothelial cell apoptosis (P =.027) after 8 weeks of therapy. However, there was no statistically significant relationship between rh-Endo dose and induction of tumor cell or endothelial cell apoptosis. CONCLUSION: These initial data suggest that rh-Endo has measurable effects on tumor blood flow and metabolism and induces endothelial and tumor cell apoptosis even in the absence of demonstrable anticancer effects. Further study and validation of these biomarkers in the context of antiangiogenic therapy will be required.

Adenocarcinoma↗
PubMed2002

Phase I study of recombinant human endostatin in patients with advanced solid tumors.

PURPOSE: Endostatin, a 20-kd fragment of collagen XVIII, is a potent inhibitor of angiogenesis. We evaluated recombinant human endostatin (rh-Endo) in a phase I trial designed to assess safety, pharmacokinetics, and serum markers of angiogenesis in patients with solid tumors. PATIENTS AND METHODS: Twenty-six patients were enrolled onto a dose-finding trial of rh-Endo administered as an intravenous bolus over a 20-minute period once daily. Three patients each were treated at dose levels of 15, 30, 60, 120, 180, and 600 mg/m(2)/d, and seven patients were treated at 300 mg/m(2)/d. Treatment consisted of a minimum of two 28-day cycles. Evaluations included noninvasive imaging, pharmacokinetics, and serum biomarkers. RESULTS: Twenty-five patients were treated with rh-Endo. Treatment was well tolerated; there were no dose-limiting toxic effects. Bacteremia from frequent central line access was the most common problem. The pharmacokinetic disposition of rh-Endo was linear and best described using a two-compartmental open model. The overall mean half-life was 10.7 +/- 4.1 hours. A dose of 300 mg/m(2) achieved an area under the concentration-time curve associated with activity in preclinical models. In two patients, there was evidence of antitumor activity, but no responses were seen. Serum markers of angiogenic activity did not provide insight into rh-Endo's activity. Serum antibodies were observed against both rh-Endo and the Pichia pastoris vector, but no allergic reactions were observed. CONCLUSION: rh-Endo was safe and well tolerated. rh-Endo pharmacokinetic profiles achieved area under the concentration-time curves associated with activity in preclinical models. Evidence of minor antitumor activity was observed and further studies are indicated.

Adenocarcinoma↗
PubMed2002

Radiographic response to neoadjuvant chemotherapy is a predictor of local control and survival in soft tissue sarcomas.

BACKGROUND: Downstaging of large soft tissue sarcomas can be accomplished by the use of neoadjuvant chemotherapy (NeoCT). The authors tested the hypothesis that radiographic response to NeoCT predicts improved local control and survival. METHODS: The authors reviewed the medical records of 65 patients with Stage II or III soft tissue sarcoma (42 extremity, 23 retroperitoneal) who were treated with doxorubicin or ifosfamide-based NeoCT from January 1991 to December 1996. Radiographic response and impact on surgical therapy were determined retrospectively by comparing imaging studies obtained before and after chemotherapy. RESULTS: The radiographic responses observed were partial response (PR; 22 patients [34%]); minor response (MR; 6 patients [9%]); stable disease (20 patients [31%]); and progressive disease (17 patients [26%]). Downstaging sufficient to decrease the scope of the operation occurred in 13% of the patients, 78% had no change, and 9% had disease progression sufficient to increase the scope of the operation. Patients having any radiographic response (PR or MR) had a higher margin-negative resection rate, a better local recurrence-free survival rate, and a better overall survival rate than did nonresponders. CONCLUSIONS: The NeoCT regimens used in this study resulted in tumor shrinkage sufficient to impact surgical therapy in a few patients. However, radiographic response predicted improved local control and overall survival rate.

Adolescent↗
PubMed2002

Tumor specific gene expression profiles in human leiomyosarcoma: an evaluation of intratumor heterogeneity.

Leiomyosarcomas are malignant smooth muscle tumors characterized by a spectrum of histopathologic features and clinical behavior. Gene expression profiling of leiomyosarcomas may identify differential gene signatures that may allow for the clinical stratification of the tumors. Typically, surgical specimens from these tumors are large and manifest a variegated macroscopic appearance. Because of their large size at the time of diagnosis, sufficient tissue is available for regional and clonal heterogeneity assessment. However, if the gene expression profiles of samples taken from different locations in the tumors are drastically different, biologic classification on the basis of random sample analysis may not be adequate. Therefore, to assess intertumor and intratumor heterogeneity, the authors performed a gene expression study using leiomyosarcoma specimens from three excised sarcomas from an equal number of different patients. Comparisons between tumor and normal samples from the three patients as well as between carefully mapped peripheral and core specimens from the same tumor (excised from one of the patients), were performed. Analysis of the expression profiles demonstrated minimal intratumor variations compared with intertissue variations, indicating homogeneous tumor specific gene expression profiles. The authors also identified genes that are expressed differentially in tumor and normal tissue.

Biomarkers, Tumor↗
PubMed2002

Phase II trial of temozolomide plus the matrix metalloproteinase inhibitor, marimastat, in recurrent and progressive glioblastoma multiforme.

PURPOSE: Novel therapies are needed for patients with recurrent glioblastoma multiforme (GBM). Because there is evidence that temozolomide (TMZ) has some activity in GBM and is well tolerated, and because of laboratory evidence that metalloproteinases are important in glioma cell invasion, the combination of TMZ and the matrix metalloproteinase inhibitor marimastat (MRM) in patients with recurrent GBM was studied. PATIENTS AND METHODS: Forty-four patients with recurrent GBM after standard radiotherapy were enrolled. For 19 patients, this therapy was their first chemotherapy after tumor progression after irradiation; 25 others had received chemotherapy previously. TMZ 150 to 200 mg/m(2) days 1 to 5 and MRM 50 mg days 8 to 28 was administered at 28-day intervals for two cycles; then patients were reevaluated. Treatment continued until progression of tumor or toxicity developed. RESULTS: Joint and tendon pain was the major therapy-related toxicity and was reported in 47% of patients. Five patients (11%) were removed from the study because of intolerable joint pain. For all patients, the progression-free survival (PFS) at 6 months was 39%. Median PFS was 17 weeks, median overall survival was 45 weeks, and 12-month PFS was 16%. CONCLUSION: The combination of TMZ and MRM resulted in a PFS at 6 months that exceeded the literature target by 29%. This drug combination met phase II study criteria; further study in recurrent patients with GBM might be warranted. Further study of therapy-induced joint pain is necessary.

Adult↗
PubMed2002

Spinal cord protection during aortic cross clamping: retrograde venous spinal cord perfusion, distal aortic perfusion, and cerebrospinal fluid drainage.

OBJECTIVE: We investigated retrograde venous spinal cord perfusion (RVP), with the established adjuncts cerebrospinal fluid drainage (CSFD), and distal aortic perfusion (DAP) in the canine model. We then examined the clinical feasibility of RVP, DAP, and CSFD. DESIGN: Canine study: Twenty dogs were randomized to four treatment groups. All animals underwent 60 min of complete aortic cross-clamp. Group 1 was the control and received only aortic cross-clamp; group 2 DAP and CSFD; group 3 DAP, CSFD, and RVP; and group 4 CSFD plus RVP. Human study: Five patients underwent aortic graft replacement of the descending or thoracoabdominal aorta, while receiving CSFD, DAP, and RVP. RESULTS: Canine study: All animals in groups 1 and 4 awoke paralyzed. One animal each in groups 2 and 3 were paraparetic, with the remaining dogs neurologically intact. Groups 2 and 3 differed from groups 1 and 4 at p < 0.0001. Human study: No mortality or permanent complications were observed in this group. CONCLUSION: While RVP did not reduce neurologic injury, neither did it increase morbidity. In humans the method is technically feasible and free from major problems. Further animal studies and randomized trials are underway at our center.

Aged↗
PubMed2002

Molecular classification of human diffuse gliomas by multidimensional scaling analysis of gene expression profiles parallels morphology-based classification, correlates with survival, and reveals clinically-relevant novel glioma subsets.

There are several currently employed classification systems for diffuse gliomas that sort tumors based on histological features. Contemporary molecular techniques, however, offer the promise of improved tumor classification and resultant patient stratification for treatment and prognosis. In particular, gene expression profiling has shown exceptional promise for providing an alternative and more objective molecular approach to glioma classification. In this study, we used cDNA array technology to profile the gene expression of 30 primary human glioma tissue samples comprising 4 different glioma subtypes as defined by current World Health Organization (WHO 2000) criteria: glioblastoma (GM, WHO grade IV), anaplastic astrocytoma (AA, WHO grade III), anaplastic oligodendroglioma (AO, WHO grade III), and oligodendroglioma (OL, WHO grade II). Gene expression data alone were used to group the tumors using multidimensional scaling, which is an unsupervised statistical method. Results show that impressive separation of the 4 glioma subtypes can be achieved solely on the basis of molecular data. In addition, a subcluster of 3 glioblastomas was identified as distinct from other GMs and from the oligodendroglial tumors. These 3 patients have shown extended survival compared to other GMs in the study. Survival analysis of the full data set revealed a good correlation with the molecular classification. Results of this proof-of-principle study demonstrate that molecular profiling alone can recapitulate conventional histologic classification and grading with high fidelity. In addition, results show that the molecular approach to tumor classification can generate clinically meaningful patient stratification, and, more importantly, is an efficient class-discovery tool for human gliomas, permitting the identification of previously unrecognized, clinically relevant tumor subsets.

Algorithms↗
PubMed2002

Expression of metastasis-related genes in human epithelial ovarian tumors.

We examined the expression level of several genes that regulate distinct steps of metastasis in 55 formalin-fixed, paraffin-embedded, archival specimens of primary human ovarian carcinoma from patients undergoing curative surgery. The expression of vascular endothelial growth factor/vascular permeability factor (VEGF/VPF), basic fibroblast growth factor (bFGF), E-cadherin, type IV collagenase, matrix metalloproteinase (MMP-2 and MMP-9), and interleukin 8 (IL-8) was examined by a colorimetric in situ mRNA hybridization technique. The expression level of E-cadherin, MMP-2, MMP-9, VEGF, and IL-8 mRNA correlated with disease stages. The ratio of type IV collagenase expression (mean of the expression of MMP-2 and MMP-9) to E-cadherin expression (MMP:E-cadherin ratio) increased with increasing stage of disease (p<0.0001). Death rates significantly increased with high MMP:E-cadherin ratio (p=0.0005). Multivariate analysis of overall survival showed that the MMP:E-cadherin ratio was a significant independent prognostic factor, even after adjustment for known prognostic factors, such as histology, stage, and age.

Adult↗
PubMed2002

Identification of combination gene sets for glioma classification.

One goal for the gene expression profiling of cancer tissues is to identify signature genes that robustly distinguish different types or grades of tumors. Such signature genes would ideally provide a molecular basis for classification and also yield insight into the molecular events underlying different cancer phenotypes. This study applies a recently developed algorithm to identify not only single classifier genes but also gene sets (combinations) for use as glioma classifiers. Classifier genes identified by this algorithm are shown to be strong features by conservatively and collectively considering the misclassification errors of the feature sets. Applying this approach to a test set of 25 patients, we have identified the best single genes and two- to three-gene combinations for distinguishing four types of glioma: (a) oligodendroglioma; (b) anaplastic oligodendroglioma; (c) anaplastic astrocytoma; and (d) glioblastoma multiforme. Some of the identified genes, such as insulin-like growth factor-binding protein 2, have been confirmed to be associated with one of the tumor types. Using combinations of genes, the classification error rate can be significantly lowered. In many instances, neither of the individual genes of a two-gene set performs well as an accurate classifier, but the combination of the two genes forms a robust classifier with a small error rate. Two-gene and three-gene combinations thus provide robust classifiers possessing the potential to translate expression microarray results into diagnostic histopathological assays for clinical utilization.

Algorithms↗
PubMedDate not supplied

Global gene expression changes during neoadjuvant chemotherapy for human breast cancer.

PURPOSE: The purpose of this study was to analyze global gene expression changes in serial tumor core biopsy specimens taken during neoadjuvant chemotherapy for primary breast cancer. PATIENTS AND METHODS: Core biopsy specimens from tumors were obtained before treatment and 24 and/or 48 hours after treatment from 21 women who were beginning chemotherapy for breast cancer. RNA was extracted, and radiolabeled complementary DNA was synthesized. The complementary DNA probes were hybridized to high-density microarray membranes that contained more than 25,000 human sequence clones. Hierarchical cluster analysis was used to compare the degree of similarity between expression profiles. RESULTS: Twenty-five (45%) of the 56 available core specimens yielded sufficient quantity and quality RNA for microarray analysis. Microarray profiles were performed only on samples from patients with pretreatment and posttreatment specimens, resulting in serial data sets for five patients (14 specimens). The serial samples from individual patients clustered more closely than the samples taken from different patients. Analyses of the variance of individual gene expression showed that there were significantly fewer genes with fivefold differences in expression in an individual tumor at different times (average, 359 genes) versus pretreatment samples of different tumors (average, 732 genes). Patients with a good pathological response to treatment had gene patterns that clustered distinctly from those of poor responders. Significant transcriptional response occurred in all patients during therapy. Surprisingly, all patients had different genes change after chemotherapy, with no single gene having a significant expression change in all five patients. DISCUSSION: This is the first report to show global gene expression changes during chemotherapy in a human solid tumor. Comprehensive gene expression profiles of more than 25,000 genes can be obtained from core biopsy specimens. A remarkable diversity in transcriptional response was observed for individual cases. Further data are needed to determine whether gene profiling can predict response to chemotherapy.

Analysis of Variance↗