Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Koen DeGeest is active.

Publication


Featured researches published by Koen DeGeest.


Journal of Clinical Oncology | 2003

Phase III Trial of Carboplatin and Paclitaxel Compared With Cisplatin and Paclitaxel in Patients With Optimally Resected Stage III Ovarian Cancer: A Gynecologic Oncology Group Study

Robert F. Ozols; Brian N. Bundy; Benjamin E. Greer; Jeffrey M. Fowler; Daniel L. Clarke-Pearson; Robert A. Burger; Robert S. Mannel; Koen DeGeest; Ellen M. Hartenbach; Rebecca N. Baergen

PURPOSE In randomized trials the combination of cisplatin and paclitaxel was superior to cisplatin and cyclophosphamide in advanced-stage epithelial ovarian cancer. Although in nonrandomized trials, carboplatin and paclitaxel was a less toxic and highly active combination regimen, there remained concern regarding its efficacy in patients with small-volume, resected, stage III disease. Thus, we conducted a noninferiority trial of cisplatin and paclitaxel versus carboplatin and paclitaxel in this population. PATIENTS AND METHODS Patients with advanced ovarian cancer and no residual mass greater than 1.0 cm after surgery were randomly assigned to receive cisplatin 75 mg/m2 plus a 24-hour infusion of paclitaxel 135 mg/m2 (arm I), or carboplatin area under the curve 7.5 intravenously plus paclitaxel 175 mg/m2 over 3 hours (arm II). RESULTS Seven hundred ninety-two eligible patients were enrolled onto the study. Prognostic factors were similar in the two treatment groups. Gastrointestinal, renal, and metabolic toxicity, as well as grade 4 leukopenia, were significantly more frequent in arm I. Grade 2 or greater thrombocytopenia was more common in arm II. Neurologic toxicity was similar in both regimens. Median progression-free survival and overall survival were 19.4 and 48.7 months, respectively, for arm I compared with 20.7 and 57.4 months, respectively, for arm II. The relative risk (RR) of progression for the carboplatin plus paclitaxel group was 0.88 (95% confidence interval [CI], 0.75 to 1.03) and the RR of death was 0.84 (95% CI, 0.70 to 1.02). CONCLUSION In patients with advanced ovarian cancer, a chemotherapy regimen consisting of carboplatin plus paclitaxel results in less toxicity, is easier to administer, and is not inferior, when compared with cisplatin plus paclitaxel.


The New England Journal of Medicine | 2012

Paraneoplastic Thrombocytosis in Ovarian Cancer

Rebecca L. Stone; Alpa M. Nick; Iain A. McNeish; Frances R. Balkwill; Hee Dong Han; Justin Bottsford-Miller; Rajesha Rupaimoole; Guillermo N. Armaiz-Pena; Chad V. Pecot; Jermaine Coward; Michael T. Deavers; Hernan Vasquez; Diana L. Urbauer; Charles N. Landen; Wei Hu; Hannah Gershenson; Koji Matsuo; Mian M.K. Shahzad; Erin R. King; Ibrahim Tekedereli; Bulent Ozpolat; Edward H. Ahn; Virginia K. Bond; Rui Wang; Angela F. Drew; Francisca C. Gushiken; Donald M. Lamkin; Katherine Collins; Koen DeGeest; Susan K. Lutgendorf

BACKGROUND The mechanisms of paraneoplastic thrombocytosis in ovarian cancer and the role that platelets play in abetting cancer growth are unclear. METHODS We analyzed clinical data on 619 patients with epithelial ovarian cancer to test associations between platelet counts and disease outcome. Human samples and mouse models of epithelial ovarian cancer were used to explore the underlying mechanisms of paraneoplastic thrombocytosis. The effects of platelets on tumor growth and angiogenesis were ascertained. RESULTS Thrombocytosis was significantly associated with advanced disease and shortened survival. Plasma levels of thrombopoietin and interleukin-6 were significantly elevated in patients who had thrombocytosis as compared with those who did not. In mouse models, increased hepatic thrombopoietin synthesis in response to tumor-derived interleukin-6 was an underlying mechanism of paraneoplastic thrombocytosis. Tumor-derived interleukin-6 and hepatic thrombopoietin were also linked to thrombocytosis in patients. Silencing thrombopoietin and interleukin-6 abrogated thrombocytosis in tumor-bearing mice. Anti-interleukin-6 antibody treatment significantly reduced platelet counts in tumor-bearing mice and in patients with epithelial ovarian cancer. In addition, neutralizing interleukin-6 significantly enhanced the therapeutic efficacy of paclitaxel in mouse models of epithelial ovarian cancer. The use of an antiplatelet antibody to halve platelet counts in tumor-bearing mice significantly reduced tumor growth and angiogenesis. CONCLUSIONS These findings support the existence of a paracrine circuit wherein increased production of thrombopoietic cytokines in tumor and host tissue leads to paraneoplastic thrombocytosis, which fuels tumor growth. We speculate that countering paraneoplastic thrombocytosis either directly or indirectly by targeting these cytokines may have therapeutic potential. (Funded by the National Cancer Institute and others.).


Journal of Clinical Investigation | 2010

Adrenergic modulation of focal adhesion kinase protects human ovarian cancer cells from anoikis

Anil K. Sood; Guillermo N. Armaiz-Pena; Jyotsnabaran Halder; Alpa M. Nick; Rebecca L. Stone; Wei Hu; Amy R. Carroll; Whitney A. Spannuth; Michael T. Deavers; Julie K. Allen; Liz Y. Han; Aparna A. Kamat; Mian M.K. Shahzad; Bradley W. McIntyre; Claudia M. Diaz-Montero; Nicholas B. Jennings; Yvonne G. Lin; William M. Merritt; Koen DeGeest; Pablo Vivas-Mejia; Gabriel Lopez-Berestein; Michael D. Schaller; Steven W. Cole; Susan K. Lutgendorf

Chronic stress is associated with hormonal changes that are known to affect multiple systems, including the immune and endocrine systems, but the effects of stress on cancer growth and progression are not fully understood. Here, we demonstrate that human ovarian cancer cells exposed to either norepinephrine or epinephrine exhibit lower levels of anoikis, the process by which cells enter apoptosis when separated from ECM and neighboring cells. In an orthotopic mouse model of human ovarian cancer, restraint stress and the associated increases in norepinephrine and epinephrine protected the tumor cells from anoikis and promoted their growth by activating focal adhesion kinase (FAK). These effects involved phosphorylation of FAKY397, which was itself associated with actin-dependent Src interaction with membrane-associated FAK. Importantly, in human ovarian cancer patients, behavioral states related to greater adrenergic activity were associated with higher levels of pFAKY397, which was in turn linked to substantially accelerated mortality. These data suggest that FAK modulation by stress hormones, especially norepinephrine and epinephrine, can contribute to tumor progression in patients with ovarian cancer and may point to potential new therapeutic targets for cancer management.


Gynecologic Oncology | 2009

A randomized phase III trial in advanced endometrial carcinoma of surgery and volume directed radiation followed by cisplatin and doxorubicin with or without paclitaxel: A Gynecologic Oncology Group study☆ , ☆☆

Howard D. Homesley; Virginia Filiaci; Susan K. Gibbons; Harry J. Long; David Cella; Nick M. Spirtos; Robert T. Morris; Koen DeGeest; Roger B. Lee; Anthony G. Montag

OBJECTIVES After surgical debulking and volume-directed irradiation of the pelvis/para-aortic lymph nodes, treatment was randomized to compare recurrence-free survival (RFS) and toxicity between two chemotherapy regimens for the treatment of women with advanced stage endometrial carcinoma. METHODS Treatment was randomized between 6 cycles of cisplatin [C] (50 mg/m(2)) and doxorubicin [D] (45 mg/m(2)) with or without paclitaxel [P] (160 mg/m(2)). Initially in paclitaxel treated patients and, after May 2002, all patients received granulocyte growth factor with each cycle. RESULTS Of 659 patients enrolled following surgery, 552 eligible patients were randomized to chemotherapy after irradiation. Accrual closed to Stage IV patients in June, 2003. Approximately 80% completed six cycles of chemotherapy. Three deaths resulted from bowel complications and one death was due to renal failure. Hematologic adverse events, sensory neuropathy and myalgia, were more frequent and severe in the paclitaxel arm (p<0.01) which was confirmed by Quality of Life assessments. Percentage of patients alive and recurrence-free at 36 months was 62% for CD vs. 64% for CDP. The hazard of recurrence or death relative to the CD arm stratified by stage is 0.90 (95% CI is 0.69 to 1.17, p=0.21, one-tail). However, in subgroup analysis, CDP was associated with a 50% reduction in the risk of recurrence or death among patients with gross residual disease (95% CI: 0.26 to 0.92). Stage, residual disease, histology/grade, positive para-aortic node and cytology, pelvic metastases and age were significantly associated with RFS. CONCLUSION The addition of paclitaxel to cisplatin and doxorubicin following surgery and radiation was not associated with a significant improvement in RFS but was associated with increased toxicity.


Journal of Clinical Oncology | 2011

Activity of Sorafenib in Recurrent Ovarian Cancer and Primary Peritoneal Carcinomatosis: A Gynecologic Oncology Group Trial

Daniela Matei; Michael W. Sill; Heather A. Lankes; Koen DeGeest; Robert E. Bristow; David G. Mutch; S. Diane Yamada; David E. Cohn; Valerie S. Calvert; John H. Farley; Emanuel F. Petricoin; Michael J. Birrer

PURPOSE Sorafenib is a kinase inhibitor targeting Raf and other kinases (ie, vascular endothelial growth factor receptor [VEGFR], platelet-derived growth factor receptor [PDGFR], Flt3, and c-KIT). This study assessed its activity and tolerability in patients with recurrent ovarian cancer (OC) or primary peritoneal carcinomatosis (PPC). METHODS This open-label, multi-institutional, phase II study used a two-stage design. Eligible patients had persistent or recurrent OC/PPC after one to two prior cytotoxic regimens, and they experienced progression within 12 months of platinum-based therapy. Treatment consisted of sorafenib 400 mg orally twice per day. Primary end points were progression-free survival (PFS) at 6 months and toxicity by National Cancer Institute criteria. Secondary end points were tumor response and duration of PFS and overall survival. Biomarker analyses included measurement of ERK and b-Raf expression in tumors and phosphorylation of ERK (pERK) in peripheral-blood lymphocytes (PBLs) before and after 1 month of treatment. Results Seventy-three patients were enrolled, of which 71 were eligible. Fifty-nine eligible patients (83%) had measurable disease, and 12 (17%) had detectable disease. Significant grade 3 or 4 toxicities included the following: rash (n = 7), hand-foot syndrome (n = 9), metabolic (n = 10), GI (n = 3), cardiovascular (n = 2), and pulmonary (n = 2). Only patients with measurable disease were used to assess efficacy. Fourteen survived progression free for at least 6 months (24%; 90% CI, 15% to 35%). Two patients had partial responses (3.4%; 90% CI, 1% to 10%); 20 had stable disease; 30 had progressive disease; and seven could not have their tumor assessed. ERK and b-Raf were expressed in all tumors. Exploratory analyses indicated that pERK in post-treatment PBL specimens was associated with PFS. CONCLUSION Sorafenib has modest antitumor activity in patients with recurrent OC, but the activity was at the expense of substantial toxicity.


Gynecologic Oncology | 2003

A phase II study of docetaxel in paclitaxel-resistant ovarian and peritoneal carcinoma: A Gynecologic Oncology Group study

Peter G. Rose; Harrison G Ball; James S. Hoffman; David Warshal; Koen DeGeest; David H. Moore

OBJECTIVES Docetaxel is an inhibitor of microtubule depolymerization and has demonstrated activity in paclitaxel-resistant breast cancer and gynecologic cancer. The Gynecologic Oncology Group (GOG) conducted a study of docetaxel in paclitaxel-resistant ovarian and peritoneal carcinoma to determine its activity, and nature and degree of toxicity, in this cohort of patients. METHODS Patients with platinum- and paclitaxel-resistant ovarian or peritoneal carcinoma, defined as progression while on or within 6 months of therapy, were eligible if they had measurable disease and had not received more than one chemotherapy regimen. Docetaxel at a dose of 100 mg/m(2) was administered iv over 1 h every 21 days. A prophylactic regimen of oral dexamethasone 8 mg bid was begun 24 h before docetaxel administration and continued for 48 h thereafter. Hepatic function was strictly monitored. RESULTS Sixty patients were entered and treated with a total of 256 courses, with all 60 evaluable for toxicity and 58 evaluable for response. Responses were observed in 22.4% of patients, with 5.2% achieving complete response and 17.2% achieving partial response (95% CI, 12.5-35.3%). The median duration of response was 2.5 months. The likelihood of observing a response did not appear to be related to the length of the prior paclitaxel-free interval or duration of prior paclitaxel infusions. The principal adverse effect of grade 4 neutropenia occurred in 75% of patients. There was one treatment-related death. Dose reductions were required in 36% of patients. CONCLUSIONS Docetaxel is active in paclitaxel-resistant ovarian and peritoneal cancer but, in view of significant hematologic toxicity, further study is warranted to ascertain its optimal dose and schedule.


Journal of Clinical Oncology | 2008

Interleukin-6, Cortisol, and Depressive Symptoms in Ovarian Cancer Patients

Susan K. Lutgendorf; Aliza Z. Weinrib; Frank J. Penedo; Daniel W. Russell; Koen DeGeest; Erin S. Costanzo; Patrick J. Henderson; Sandra E. Sephton; Nicolas Rohleder; Joseph A. Lucci; Steven W. Cole; Anil K. Sood; David M. Lubaroff

PURPOSE Inflammatory processes have been implicated in the pathogenesis of both depression and cancer. Links between depressive symptoms, interleukin-6 (IL-6), and cortisol dysregulation have been demonstrated in cancer patients, but vegetative versus affective components of depression have been minimally examined. The objective of the current study was to examine associations between IL-6, diurnal cortisol rhythms, and facets of depression in epithelial ovarian cancer patients. PATIENTS AND METHODS Patients awaiting surgery for a pelvic mass suspected for ovarian cancer completed questionnaires, collected salivary samples for 3 days presurgery, and gave a presurgical blood sample. Ascites was obtained during surgery. IL-6 was measured by enzyme-linked immunosorbent assay and cortisol by a chemiluminescence immunoassay. The final sample included 112 invasive ovarian cancer patients (86 advanced stage, 26 early stage) and 25 patients with tumors of low malignant potential (LMP). RESULTS Advanced-stage ovarian cancer patients demonstrated elevations in vegetative and affective depressive symptoms, plasma IL-6, and the cortisol area under the curve (AUC) compared with patients with LMP tumors (all P < .05). Among invasive ovarian cancer patients, greater vegetative depression was related to elevated IL-6 in plasma (P = .008) and ascites (P = .024), but affective depression was unrelated to IL-6. Elevations in total depression (P = .026) and vegetative depression (P = .005) were also related to higher evening cortisol levels. Plasma IL-6 was related to greater afternoon and evening cortisol and cortisol AUC (all P values < .005). CONCLUSION These results demonstrate significant relationships between IL-6, cortisol, and vegetative depression, and may have implications for treatment of depression in ovarian cancer patients.


Obstetrics & Gynecology | 2004

Social and cultural barriers to Papanicolaou test screening in an urban population

Kian Behbakht; Anne M. Lynch; Stephanie B. Teal; Koen DeGeest; Stewart Massad

OBJECTIVE: To define screening behaviors, attitudes, and beliefs regarding cancer and its treatment among women with cervical cancer. METHODS: Between August 2000 and July 2002, 148 consecutive women with invasive cervical cancer were queried about barriers to screening. Women presented to outpatient clinics, emergency departments, or inpatient units of 3 urban hospitals. Two groups of women were identified: those who denied having had a Papanicolaou (Pap) test and those who had recalled having Pap test in the past. Responses were compared using t tests, &khgr;2 tests, and binary logistic regression. RESULTS: The 146 (99%) respondents were predominantly African Americans (50%) or Hispanic (27%). Thirty-six (25%) women reported no prior screening. Women never screened were significantly more likely to be Hispanic (odds ratio [OR] 3.0, 95% confidence interval [CI] 1.4–6.7), recent immigrants (OR 5.7, 95% CI 2.0–16), less educated (OR 3.6, 95% CI 1.6–8.0), and uninsured (OR 3.9, 95% CI 1.6–9.7). They were more likely to lack family support (adjusted OR 3.5, 95% CI 1.1–11) and lack knowledge about their risk for cervical cancer (adjusted OR 2.6, 95% CI 1.1–6.4). Unscreened women displayed fatalistic attitudes, believing cancer is bad luck (adjusted OR 2.6, 95% CI 1.0–6.9) and not wanting to know they had cancer (adjusted OR 3.0, 95% CI 1.0–9.4).. CONCLUSION: We have identified factors and beliefs that are barriers to Pap test screening in urban cervical cancer patients. Further studies should evaluate effects of addressing cultural, cognitive, and financial barriers on Pap test compliance. LEVEL OF EVIDENCE: III


Brain Behavior and Immunity | 2009

Depression, social support, and beta-adrenergic transcription control in human ovarian cancer.

Susan K. Lutgendorf; Koen DeGeest; Caroline Y. Sung; Jesusa M.G. Arevalo; Frank J. Penedo; Joseph A. Lucci; Michael J. Goodheart; David M. Lubaroff; Donna M. Farley; Anil K. Sood; Steve W. Cole

Motivated by previous indications that beta-adrenergic signaling can regulate tumor cell gene expression in model systems, we sought to determine whether similar dynamics occur in primary human ovarian cancer. DNA microarray analyses of 10 ovarian carcinomas identified 266 human transcripts that were differentially expressed in tumors from patients with elevated biobehavioral risk factors (high depressive symptoms and low social support) relative to grade- and stage-matched tumors from low-risk patients. Promoter-based bioinformatic analyses indicated increased activity of several beta-adrenergically-linked transcription control pathways, including CREB/ATF, NF-kappaB/Rel, STAT, and Ets family transcription factors. Consistent with increased beta-adrenergic signaling, high biobehavioral risk patients also showed increased intra-tumor concentrations of norepinephrine (but no difference in plasma norepinephrine). These data show that genome-wide transcriptional profiles are significantly altered in tumors from patients with high behavioral risk profiles, and they identify beta-adrenergic signal transduction as a likely mediator of those effects.


Clinical Cancer Research | 2008

Biobehavioral influences on matrix metalloproteinase expression in ovarian carcinoma

Susan K. Lutgendorf; Donald M. Lamkin; Nicholas B. Jennings; Jesusa M.G. Arevalo; Frank J. Penedo; Koen DeGeest; Robert R. Langley; Joseph A. Lucci; Steve W. Cole; David M. Lubaroff; Anil K. Sood

Purpose: Stromal cells in the tumor microenvironment, such as macrophages, play an active role in tumor growth and angiogenesis. However, little is known about relationships of biobehavioral factors with angiogenic cytokines and matrix metalloproteinases (MMP) produced by stromal cells. This study examined distress, MMPs, and angiogenic cytokines in ovarian cancer patients and in vitro. Experimental Design: Patients suspected of ovarian cancer completed preoperative questionnaires. At surgery, 56 were confirmed to have epithelial ovarian cancer. Tumor samples were analyzed for macrophage (CD68+) and tumor cell levels of MMP-2, MMP-9, and vascular endothelial growth factor. In vitro stimulation of isolated macrophage cells by the stress hormones norepinephrine and cortisol was done to assess effects on MMP-9. Results: Depressed patients showed significant elevations of MMP-9 in CD68+ cells, adjusting for stage (P < 0.0001). Patients with higher levels of current stress (P = 0.01), life stress over the last 6 months (P = 0.004), and general negative affect (P = 0.007) also showed significantly greater MMP-9 in CD68+ cells. In contrast, higher social support was associated with lower levels of MMP-9 (P = 0.023) and vascular endothelial growth factor (P = 0.036) in tumor cells. In vitro analyses showed that macrophage MMP-9 production could be directly enhanced (up to a 2-fold increase) by the stress hormones norepinephrine and cortisol. Conclusions: Ovarian cancer patients with elevated depressive symptoms, chronic stress, and low social support showed elevations in MMP-9 in tumor-associated macrophages. Direct in vitro enhancement of stromal MMP-9 production by stress hormones was also shown. These findings may have implications for patient outcomes in ovarian cancer.

Collaboration


Dive into the Koen DeGeest's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Anil K. Sood

University of Texas MD Anderson Cancer Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Michael J. Goodheart

University of Iowa Hospitals and Clinics

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Edward S. Podczaski

Pennsylvania State University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Rodrigue Mortel

Pennsylvania State University

View shared research outputs
Top Co-Authors

Avatar

Amina Ahmed

University of Iowa Hospitals and Clinics

View shared research outputs
Researchain Logo
Decentralizing Knowledge