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Dive into the research topics where Larry Stitt is active.

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Featured researches published by Larry Stitt.


The Lancet | 2008

Early combined immunosuppression or conventional management in patients with newly diagnosed Crohn's disease: an open randomised trial

Geert R. D'Haens; Filip Baert; Gert Van Assche; Philip Caenepeel; Philippe Vergauwe; Hans Tuynman; Martine De Vos; Sander J. H. van Deventer; Larry Stitt; Allan Donner; Severine Vermeire; Frank J. Van de Mierop; Jean-Charles R Coche; Janneke van der Woude; Thomas Ochsenkühn; Ad A. van Bodegraven; Philippe Van Hootegem; Guy Lambrecht; F. Mana; Paul Rutgeerts; Brian G. Feagan; Daniel W. Hommes

BACKGROUND Most patients who have active Crohns disease are treated initially with corticosteroids. Although this approach usually controls symptoms, many patients become resistant to or dependent on corticosteroids, and long exposure is associated with an increased risk of mortality. We aimed to compare the effectiveness of early use of combined immunosuppression with conventional management in patients with active Crohns disease who had not previously received glucocorticoids, antimetabolites, or infliximab. METHODS We did a 2-year open-label randomised trial at 18 centres in Belgium, Holland, and Germany between May, 2001, and January, 2004. We randomly assigned 133 patients to either early combined immunosuppression or conventional treatment. The 67 patients assigned to combined immunosuppression received three infusions of infliximab (5 mg/kg of bodyweight) at weeks 0, 2, and 6, with azathioprine. We gave additional treatment with infliximab and, if necessary, corticosteroids, to control disease activity. 66 patients assigned to conventional management received corticosteroids, followed, in sequence, by azathioprine and infliximab. The primary outcome measures were remission without corticosteroids and without bowel resection at weeks 26 and 52. Analysis was by modified intention to treat. This trial was registered with ClinicalTrials.gov, number NCT00554710. FINDINGS Four patients (two in each group) did not receive treatment as per protocol. At week 26, 39 (60.0%) of 65 patients in the combined immunosuppression group were in remission without corticosteroids and without surgical resection, compared with 23 (35.9%) of 64 controls, for an absolute difference of 24.1% (95% CI 7.3-40.8, p=0.0062). Corresponding rates at week 52 were 40/65 (61.5%) and 27/64 (42.2%) (absolute difference 19.3%, 95% CI 2.4-36.3, p=0.0278). 20 of the 65 patients (30.8%) in the early combined immunosuppression group had serious adverse events, compared with 19 of 64 (25.3%) controls (p=1.0). INTERPRETATION Combined immunosuppression was more effective than conventional management for induction of remission and reduction of corticosteroid use in patients who had been recently diagnosed with Crohns disease. Initiation of more intensive treatment early in the course of the disease could result in better outcomes.


Journal of Clinical Oncology | 1997

Supratentorial low-grade glioma in adults: an analysis of prognostic factors and timing of radiation.

Christopher Leighton; Barbara Fisher; Glenn Bauman; Steven Depiero; Larry Stitt; David R. Macdonald; Gregory Cairncross

PURPOSE To review the outcomes of patients with low-grade glioma diagnosed by modern imaging and treated at a center where postponing radiotherapy was common practice. METHODS We reviewed the records of patients (age > or = 18 years) with pathologically confirmed supratentorial low-grade fibrillary astrocytoma, oligodendroglioma, and mixed glioma treated at a regional cancer center in Canada between 1979 and 1995. RESULTS Median survival for the entire group (N = 167; mean age 40.6 years) was 10.5 years with 5- and 10-year survival rates of 72% and 50%, respectively. Median progression-free survival was 4.9 years with 5- and 10-year progression-free rates of 50% and 12%, respectively. Overall and progression-free survivals were longer for patients with an oligodendroglioma or mixed glioma than with astrocytoma (median 13 v 7.5 years, P = .003; progression-free 5.6 v 4.4 years, p = .054). Age at diagnosis < or = 40 years, seizures at presentation, minimal residual tumor after surgery, Karnofsky performance status > or = 70, and oligodendroglioma or mixed glioma pathology were associated with significantly longer median survival on univariate and multivariate analyses. Radiotherapy deferred until tumor progression (v immediate radiotherapy) was associated with longer survival on univariate analysis, but an imbalance in other variables accounted for this advantage such that timing of radiotherapy was not an independent (favorable or adverse) prognostic factor on multivariate analysis. CONCLUSION Patients with low-grade glioma diagnosed by modern imaging can be expected to live a long time; timing of radiotherapy may be a less important determinant of survival than nontreatment variables and residual tumor bulk.


Journal of Clinical Oncology | 2000

Chemotherapy in Neuroendocrine/Merkel Cell Carcinoma of the Skin: Case Series and Review of 204 Cases

Patricia Tai; Edward Yu; Eric Winquist; Alex Hammond; Larry Stitt; Jon Tonita; Jim Gilchrist

PURPOSE To study the use of chemotherapy for Merkel cell carcinoma (MCC) of the skin. PATIENTS AND METHODS Twenty-five cases of MCC were treated at the London Regional Cancer Center between 1987 and 1997. Thirteen cases treated with chemotherapy were reviewed with 191 cases from the literature. RESULTS At presentation, 24 patients had localized skin lesions (stage I) and one had locoregional involvement (stage II). Among the nine cases with recurrent nodal disease, six had chemotherapy as a component of salvage treatment. They were all free of disease at a median of 19 months (range, 12 to 37 months). In contrast, two patients who had salvage radiotherapy alone died of disease. Overall survival (OS) and disease-free survival (DFS) were 59% and 43%, respectively, at two years. Median OS and DFS were 29 months (range, 1 to 133 months) and 9 months (range, 1 to 133 months), respectively. Nodal disease developed in 12 (50%) of 24 patients with stage I disease, and distant metastases developed in six (25%) of 24. Including those from the literature, there were 204 cases treated with chemotherapy. Cyclophosphamide/doxorubicin (or epirubicin)/vincristine combination +/- prednisone was the most commonly used chemotherapy regimen (47 cases), with an overall response rate of 75.7% (35.1% complete, 35. 1% partial, and 5.4% minor responses). Etoposide/cisplatin (or carboplatin) was the next most commonly used regimen (27 cases), with an overall response rate of 60% (36% complete and 24% partial responses). The difference in response rate was not statistically significant (P =.19). Among the 204 cases, there were seven (3.4%) toxic deaths. CONCLUSION Chemoradiation for locally recurrent or advanced disease may be an option for patients with a good performance status.


JAMA Pediatrics | 2009

A School-Based Program to Prevent Adolescent Dating Violence: A Cluster Randomized Trial

David A. Wolfe; Claire V. Crooks; Peter G. Jaffe; Debbie Chiodo; Richard Hughes; Wendy E. Ellis; Larry Stitt; Allan Donner

OBJECTIVE To determine whether an interactive curriculum that integrates dating violence prevention with lessons on healthy relationships, sexual health, and substance use reduces physical dating violence (PDV). DESIGN Cluster randomized trial with 2.5-year follow-up; prespecified subgroup analyses by sex. SETTING Grade 9 health classes. PARTICIPANTS A total of 1722 students aged 14-15 from 20 public schools (52.8% girls). Intervention A 21-lesson curriculum delivered during 28 hours by teachers with additional training in the dynamics of dating violence and healthy relationships. Dating violence prevention was integrated with core lessons about healthy relationships, sexual health, and substance use prevention using interactive exercises. Relationship skills to promote safer decision making with peers and dating partners were emphasized. Control schools targeted similar objectives without training or materials. MAIN OUTCOME MEASURES The primary outcome at 2.5 years was self-reported PDV during the previous year. Secondary outcomes were physical peer violence, substance use, and condom use. Analysis was by intention-to-treat. RESULTS The PDV was greater in control vs intervention students (9.8% vs 7.4%; adjusted odds ratio, 2.42; 95% confidence interval, 1.00-6.02; P = .05). A significant group x sex interaction effect indicated that the intervention effect was greater in boys (PDV: 7.1% in controls vs 2.7% in intervention students) than in girls (12.1% vs 11.9%). Main effects for secondary outcomes were not statistically significant; however, sex x group analyses showed a significant difference in condom use in sexually active boys who received the intervention (114 of 168; 67.9%) vs controls (65 of 111 [58.6%]) (P < .01). The cost of training and materials averaged CA


International Journal of Radiation Oncology Biology Physics | 2000

Allelic loss of chromosome 1p and radiotherapy plus chemotherapy in patients with oligodendrogliomas

Glenn Bauman; Y Ino; Keisuke Ueki; Magdalena C. Zlatescu; Barbara Fisher; David R. Macdonald; Larry Stitt; David N. Louis; J G Cairncross

16 per student. CONCLUSION The teaching of youths about healthy relationships as part of their required health curriculum reduced PDV and increased condom use 2.5 years later at a low per-student cost.


International Journal of Radiation Oncology Biology Physics | 2013

Predicting Radiation Pneumonitis After Chemoradiation Therapy for Lung Cancer: An International Individual Patient Data Meta-analysis

David A. Palma; Suresh Senan; Kayoko Tsujino; R.B. Barriger; Ramesh Rengan; Marta Moreno; Jeffrey D. Bradley; Tae Hyun Kim; Sara Ramella; Lawrence B. Marks; Luigi De Petris; Larry Stitt; George Rodrigues

INTRODUCTION Allelic loss of the short arm of chromosome 1 predicts radiographic response to chemotherapy and long overall survival times in patients with anaplastic oligodendrogliomas. Using a database of patients with oligodendrogliomas in whom chromosome 1p status was known, we explored whether allelic loss of 1p also predicted longer duration of tumor control when radiotherapy was part of the initial treatment of these patients. MATERIALS AND METHODS We measured progression-free survival following radiotherapy in a cohort of patients with World Health Organization (WHO) Grade II and WHO Grade III oligodendrogliomas. The effects on progression-free survival of patient age, Karnofsky performance score (KPS), tumor grade when irradiated and chromosome 1p status were examined by univariate and multivariate statistical analyses. For the subset of patients with newly diagnosed anaplastic oligodendrogliomas, relationships between use of chemotherapy, chromosome 1p status and progression-free survival were also examined. RESULTS Fifty-five patients (29 male, 26 female; ages 18-75 years; median, 44 years; KPS 50-90, median 80) were irradiated for either a WHO Grade II (n = 19) or Grade III (n = 36) oligodendroglioma. Twenty-eight patients had chemotherapy immediately prior to radiotherapy, and 27 had chemotherapy at progression following radiotherapy. The median radiation dose was 54 Gy in 30 fractions. Loss of heterozygosity (LOH) at chromosome 1p was evident in 36 tumors and absent in 19. Overall median progression-free survival after radiotherapy was 40.4 months. Median progression-free survival was 55.0 months for patients whose tumors harbored 1p loss vs. 6.2 months for those patients whose tumors retained both copies of chromosome 1p (p < 0.001). On both univariate and multivariate analyses, chromosome lp loss was the principal independent predictor of longer progression-free survival for patients with Grade II and III oligodendrogliomas. For Grade III oligodendrogliomas, chemotherapy as an adjunct to radiotherapy prolonged tumor control for those patients whose tumors harbored allelic loss of chromosome 1p (p = 0.004). CONCLUSION These data suggest allelic loss of chromosome 1p in patients with oligodendroglial neoplasms predicts longer progression-free survival among patients receiving radiotherapy +/- chemotherapy as part of their initial treatment. Chromosome 1p loss may be an important stratification variable in future therapeutic trials of oligodendroglioma.


International Journal of Radiation Oncology Biology Physics | 1999

Pretreatment factors predict overall survival for patients with low-grade glioma : A recursive partitioning analysis

Glenn Bauman; Knut Lote; David A. Larson; Lukas J.A. Stalpers; Christopher Leighton; Barbara Fisher; William M. Wara; David R. Macdonald; Larry Stitt; J. Gregory Cairncross

BACKGROUND Radiation pneumonitis is a dose-limiting toxicity for patients undergoing concurrent chemoradiation therapy (CCRT) for non-small cell lung cancer (NSCLC). We performed an individual patient data meta-analysis to determine factors predictive of clinically significant pneumonitis. METHODS AND MATERIALS After a systematic review of the literature, data were obtained on 836 patients who underwent CCRT in Europe, North America, and Asia. Patients were randomly divided into training and validation sets (two-thirds vs one-third of patients). Factors predictive of symptomatic pneumonitis (grade ≥2 by 1 of several scoring systems) or fatal pneumonitis were evaluated using logistic regression. Recursive partitioning analysis (RPA) was used to define risk groups. RESULTS The median radiation therapy dose was 60 Gy, and the median follow-up time was 2.3 years. Most patients received concurrent cisplatin/etoposide (38%) or carboplatin/paclitaxel (26%). The overall rate of symptomatic pneumonitis was 29.8% (n=249), with fatal pneumonitis in 1.9% (n=16). In the training set, factors predictive of symptomatic pneumonitis were lung volume receiving ≥20 Gy (V(20)) (odds ratio [OR] 1.03 per 1% increase, P=.008), and carboplatin/paclitaxel chemotherapy (OR 3.33, P<.001), with a trend for age (OR 1.24 per decade, P=.09); the model remained predictive in the validation set with good discrimination in both datasets (c-statistic >0.65). On RPA, the highest risk of pneumonitis (>50%) was in patients >65 years of age receiving carboplatin/paclitaxel. Predictors of fatal pneumonitis were daily dose >2 Gy, V(20), and lower-lobe tumor location. CONCLUSIONS Several treatment-related risk factors predict the development of symptomatic pneumonitis, and elderly patients who undergo CCRT with carboplatin-paclitaxel chemotherapy are at highest risk. Fatal pneumonitis, although uncommon, is related to dosimetric factors and tumor location.


Cancer | 2002

Plasma osteopontin : associations with survival and metastasis to bone in men with hormone-refractory prostate carcinoma

Sebastien J. Hotte; Eric Winquist; Larry Stitt; Sylvia M. Wilson; Ann F. Chambers

PURPOSE Three databases were pooled and analyzed to determine which groupings of prognostic factors best predicted overall survival for patients with low-grade gliomas treated with surgery and immediate or delayed radiotherapy. METHODS AND MATERIALS Databases of patients with low-grade gliomas compiled at the London Regional Cancer Centre (LRCC), the Norwegian Radium Hospital (NRH), and the University of California, San Francisco (UCSF) were merged. Inclusion criteria for the pooled analysis included: age > or =18 years and histologically confirmed low-grade (World Health Organization Grade II) supratentorial fibrillary astrocytoma, oligodendroglioma or mixed oligoastrocytoma. Factors analyzed for prognostic significance included: age at diagnosis, gender, seizures at presentation, presence of enhancement on computed tomography (CT) or magnetic resonance imaging (MRI), Karnofsky Performance Status (KPS) at diagnosis, histology, extent of surgical resection, timing of radiotherapy, and treating institution. Univariate and multivariate analysis of overall survival for these factors was performed. Recursive partitioning was performed to generate prognostic groups using these factors. RESULTS From the combined databases, 401 patients were eligible for analysis. Median survival for the entire group was 95 months/7.9 years. On univariate analysis age 18-40, presence of seizures at presentation, KPS > or =70, treating institution, and absence of contrast enhancement were associated with improved overall survival. On multivariate analysis, these factors remained independent predictors of improved overall survival. Recursive partitioning analysis yielded four prognostic groups with statistically different median survivals (MS): Group I (n = 41: KPS <70, age >40) MS 12 months; Group II (n = 34: KPS > or =70, age >40, enhancement present) MS 46 months; Group III (n = 138: KPS <70, age 18-40 or KPS > or =70 age >40, no enhancement) MS 87 months; Group IV (n = 188: KPS > or =70, age 18-40) MS 128 months. CONCLUSION Clusters of pretreatment prognostic factors described subgroups of low-grade glioma patients with divergent overall survivals. Consideration of these prognostic subgroups may be important when considering timing of interventions for these patients and in the stratification of patients for clinical trials.


Gut | 2015

The relationship between infliximab concentrations, antibodies to infliximab and disease activity in Crohn's disease

Niels Vande Casteele; Reena Khanna; Barrett G. Levesque; Larry Stitt; Guangyong Zou; Sharat Singh; Steve Lockton; Scott Hauenstein; Linda Ohrmund; Gordon R. Greenberg; Paul Rutgeerts; Ann Gils; William J. Sandborn; Severine Vermeire; Brian G. Feagan

Osteopontin (OPN) is a secreted glycoprotein that is detectable in human body fluids. Its increased expression has been found in many malignancies, and a stimulatory effect on human prostate carcinoma cells in vitro has been demonstrated. Plasma OPN levels have been associated with tumor burden and survival in patients with metastatic breast carcinoma. The authors explored these associations in men with hormone‐refractory prostate carcinoma (HRPC).


Canadian Medical Association Journal | 2005

Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial

Gerald N. Predy; Vinti Goel; Ray Lovlin; Allan Donner; Larry Stitt; Tapan K. Basu

Objective Although low infliximab trough concentrations and antibodies to infliximab (ATI) are associated with poor outcomes in patients with Crohns disease (CD), the clinical relevance of ATI in patients with adequate infliximab concentrations is uncertain. We evaluated this question using an assay sensitive for identification of ATI in the presence of infliximab. Design In an observational study, 1487 trough serum samples from 483 patients with CD who participated in four clinical studies of maintenance infliximab therapy were analysed using a fluid phase mobility shift assay. Infliximab and ATI concentrations most discriminant for remission, defined as a C-reactive protein concentration of ≤5 mg/L, were determined by receiver operating characteristic curves. A multivariable regression model evaluated these factors as independent predictors of remission. Results Based upon analysis of 1487 samples, 77.1% of patients had detectable and 22.9% had undetectable infliximab concentrations, of which 9.5% and 71.8%, respectively, were positive for ATI. An infliximab concentration of >2.79 μg/mL (area under the curve (AUC)=0.681; 95% CI 0.632 to 0.731) and ATI concentration of <3.15 U/mL (AUC=0.632; 95% CI 0.589 to 0.676) were associated with remission. Multivariable analysis showed that concentrations of both infliximab trough (OR 1.8; 95% CI 1.3 to 2.5; p<0.001) and ATI (OR 0.57; 95% CI 0.39 to 0.81; p=0.002) were independent predictors of remission. Conclusions The development of ATI increases the probability of active disease even at low concentrations and in the presence of a therapeutic concentration of drug during infliximab maintenance therapy. Evaluation of strategies to prevent ATI formation, including therapeutic drug monitoring with selective infliximab dose intensification, is needed.

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Edward Yu

University of Western Ontario

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Mark Vincent

University of Western Ontario

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Brian G. Feagan

University of Western Ontario

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Richard J. Novick

University of Western Ontario

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Guangyong Zou

University of Western Ontario

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George Rodrigues

University of Western Ontario

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Patricia Tai

University of Saskatchewan

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