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Featured researches published by R. John Simes.


The New England Journal of Medicine | 2008

K-ras Mutations and Benefit from Cetuximab in Advanced Colorectal Cancer

Christos Stelios Karapetis; Shirin Khambata-Ford; Derek J. Jonker; Dongsheng Tu; Niall C. Tebbutt; R. John Simes; Haji Chalchal; Jeremy David Shapiro; Sonia Robitaille; Timothy Jay Price; Lois Shepherd; Christiane Langer; Malcolm J. Moore; John Zalcberg

BACKGROUND Treatment with cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor, improves overall and progression-free survival and preserves the quality of life in patients with colorectal cancer that has not responded to chemotherapy. The mutation status of the K-ras gene in the tumor may affect the response to cetuximab and have treatment-independent prognostic value. METHODS We analyzed tumor samples, obtained from 394 of 572 patients (68.9%) with colorectal cancer who were randomly assigned to receive cetuximab plus best supportive care or best supportive care alone, to look for activating mutations in exon 2 of the K-ras gene. We assessed whether the mutation status of the K-ras gene was associated with survival in the cetuximab and supportive-care groups. RESULTS Of the tumors evaluated for K-ras mutations, 42.3% had at least one mutation in exon 2 of the gene. The effectiveness of cetuximab was significantly associated with K-ras mutation status (P=0.01 and P<0.001 for the interaction of K-ras mutation status with overall survival and progression-free survival, respectively). In patients with wild-type K-ras tumors, treatment with cetuximab as compared with supportive care alone significantly improved overall survival (median, 9.5 vs. 4.8 months; hazard ratio for death, 0.55; 95% confidence interval [CI], 0.41 to 0.74; P<0.001) and progression-free survival (median, 3.7 months vs. 1.9 months; hazard ratio for progression or death, 0.40; 95% CI, 0.30 to 0.54; P<0.001). Among patients with mutated K-ras tumors, there was no significant difference between those who were treated with cetuximab and those who received supportive care alone with respect to overall survival (hazard ratio, 0.98; P=0.89) or progression-free survival (hazard ratio, 0.99; P=0.96). In the group of patients receiving best supportive care alone, the mutation status of the K-ras gene was not significantly associated with overall survival (hazard ratio for death, 1.01; P=0.97). CONCLUSIONS Patients with a colorectal tumor bearing mutated K-ras did not benefit from cetuximab, whereas patients with a tumor bearing wild-type K-ras did benefit from cetuximab. The mutation status of the K-ras gene had no influence on survival among patients treated with best supportive care alone. (ClinicalTrials.gov number, NCT00079066.)


Lancet Oncology | 2011

Survival after neoadjuvant chemotherapy or chemoradiotherapy for resectable oesophageal carcinoma: an updated meta-analysis.

Katrin Marie Sjoquist; Bryan Burmeister; B. Mark Smithers; John Zalcberg; R. John Simes; Andrew P. Barbour; Val Gebski

BACKGROUND In a previous meta-analysis, we identified a survival benefit from neoadjuvant chemotherapy or chemoradiotherapy before surgery in patients with resectable oesophageal carcinoma. We updated this meta-analysis with results from new or updated randomised trials presented in the past 3 years. We also compared the benefits of preoperative neoadjuvant chemotherapy compared with neoadjuvant chemoradiotherapy. METHODS To identify additional studies and published abstracts from major scientific meetings, we searched Medline, Embase, and Central (Cochrane clinical trials database) for studies published since January, 2006, and also manually searched for abstracts from major conferences from the same period. Only randomised studies analysed by intention to treat were included, and searches were restricted to those databases citing articles in English. We used published hazard ratios (HRs) if available or estimates from other survival data. We also investigated treatment effects by tumour histology and relations between risk (survival after surgery alone) and effect size. FINDINGS We included all 17 trials from the previous meta-analysis and seven further studies. 12 were randomised comparisons of neoadjuvant chemoradiotherapy versus surgery alone (n=1854), nine were randomised comparisons of neoadjuvant chemotherapy versus surgery alone (n=1981), and two compared neoadjuvant chemoradiotherapy with neoadjuvant chemotherapy (n=194) in patients with resectable oesophageal carcinoma; one factorial trial included two comparisons and was included in analyses of both neoadjuvant chemoradiotherapy (n=78) and neoadjuvant chemotherapy (n=81). The updated analysis contained 4188 patients whereas the previous publication included 2933 patients. This updated meta-analysis contains about 3500 events compared with about 2230 in the previous meta-analysis (estimated 57% increase). The HR for all-cause mortality for neoadjuvant chemoradiotherapy was 0.78 (95% CI 0.70-0.88; p<0.0001); the HR for squamous-cell carcinoma only was 0.80 (0.68-0.93; p=0.004) and for adenocarcinoma only was 0.75 (0.59-0.95; p=0.02). The HR for all-cause mortality for neoadjuvant chemotherapy was 0.87 (0.79-0.96; p=0.005); the HR for squamous-cell carcinoma only was 0.92 (0.81-1.04; p=0.18) and for adenocarcinoma only was 0.83 (0.71-0.95; p=0.01). The HR for the overall indirect comparison of all-cause mortality for neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy was 0.88 (0.76-1.01; p=0.07). INTERPRETATION This updated meta-analysis provides strong evidence for a survival benefit of neoadjuvant chemoradiotherapy or chemotherapy over surgery alone in patients with oesophageal carcinoma. A clear advantage of neoadjuvant chemoradiotherapy over neoadjuvant chemotherapy has not been established. These results should help inform decisions about patient management and design of future trials. FUNDING Cancer Australia and the NSW Cancer Institute.


Lancet Oncology | 2005

Surgery alone versus chemoradiotherapy followed by surgery for resectable cancer of the oesophagus: a randomised controlled phase III trial

Bryan Burmeister; B. Mark Smithers; Val Gebski; Lara Fitzgerald; R. John Simes; Peter G. Devitt; Stephen P. Ackland; D. C. Gotley; David Joseph; Jeremy Millar; John North; Euan Walpole; James W. Denham

BACKGROUND Resection remains the best treatment for carcinoma of the oesophagus in terms of local control, but local recurrence and distant metastasis remain an issue after surgery. We aimed to assess whether a short preoperative chemoradiotherapy regimen improves outcomes for patients with resectable oesophageal cancer. METHODS 128 patients were randomly assigned to surgery alone and 128 patients to surgery after 80 mg/m(2) cisplatin on day 1, 800 mg/m(2) fluorouracil on days 1-4, with concurrent radiotherapy of 35 Gy given in 15 fractions. The primary endpoint was progression-free survival. Secondary endpoints were overall survival, tumour response, toxic effects, patterns of failure, and quality of life. Analysis was done by intention to treat. FINDINGS Neither progression-free survival nor overall survival differed between groups (hazard ratio [HR] 0.82 [95% CI 0.61-1.10] and 0.89 [0.67-1.19], respectively). The chemoradiotherapy-and-surgery group had more complete resections with clear margins than did the surgery-alone group (103 of 128 [80%] vs 76 of 128 [59%], p=0.0002), and had fewer positive lymph nodes (44 of 103 [43%] vs 69 of 103 [67%], p=0.003). Subgroup analysis showed that patients with squamous-cell tumours had better progression-free survival with chemoradiotherapy than did those with non-squamous tumours (HR 0.47 [0.25-0.86] vs 1.02 [0.72-1.44]). However, the trial was underpowered to determine the real magnitude of benefit in this subgroup. INTERPRETATION Preoperative chemoradiotherapy with cisplatin and fluorouracil does not significantly improve progression-free or overall survival for patients with resectable oesophageal cancer compared with surgery alone. However, further assessment is warranted of the role of chemoradiotherapy in patients with squamous-cell tumours.


The New England Journal of Medicine | 2013

Rapid Blood-Pressure Lowering in Patients with Acute Intracerebral Hemorrhage

Craig S. Anderson; Emma Heeley; Yining Huang; Ji-Guang Wang; Christian Stapf; Candice Delcourt; Richard Lindley; Thompson G. Robinson; Pablo M. Lavados; Bruce Neal; Jun Hata; Hisatomi Arima; Mark W. Parsons; Yuechun Li; Jinchao Wang; Stephane Heritier; Qiang Li; Mark Woodward; R. John Simes; Stephen M. Davis; John Chalmers

BACKGROUND Whether rapid lowering of elevated blood pressure would improve the outcome in patients with intracerebral hemorrhage is not known. METHODS We randomly assigned 2839 patients who had had a spontaneous intracerebral hemorrhage within the previous 6 hours and who had elevated systolic blood pressure to receive intensive treatment to lower their blood pressure (with a target systolic level of <140 mm Hg within 1 hour) or guideline-recommended treatment (with a target systolic level of <180 mm Hg) with the use of agents of the physicians choosing. The primary outcome was death or major disability, which was defined as a score of 3 to 6 on the modified Rankin scale (in which a score of 0 indicates no symptoms, a score of 5 indicates severe disability, and a score of 6 indicates death) at 90 days. A prespecified ordinal analysis of the modified Rankin score was also performed. The rate of serious adverse events was compared between the two groups. RESULTS Among the 2794 participants for whom the primary outcome could be determined, 719 of 1382 participants (52.0%) receiving intensive treatment, as compared with 785 of 1412 (55.6%) receiving guideline-recommended treatment, had a primary outcome event (odds ratio with intensive treatment, 0.87; 95% confidence interval [CI], 0.75 to 1.01; P=0.06). The ordinal analysis showed significantly lower modified Rankin scores with intensive treatment (odds ratio for greater disability, 0.87; 95% CI, 0.77 to 1.00; P=0.04). Mortality was 11.9% in the group receiving intensive treatment and 12.0% in the group receiving guideline-recommended treatment. Nonfatal serious adverse events occurred in 23.3% and 23.6% of the patients in the two groups, respectively. CONCLUSIONS In patients with intracerebral hemorrhage, intensive lowering of blood pressure did not result in a significant reduction in the rate of the primary outcome of death or severe disability. An ordinal analysis of modified Rankin scores indicated improved functional outcomes with intensive lowering of blood pressure. (Funded by the National Health and Medical Research Council of Australia; INTERACT2 ClinicalTrials.gov number, NCT00716079.).


JAMA | 2012

Association of LDL Cholesterol, Non–HDL Cholesterol, and Apolipoprotein B Levels With Risk of Cardiovascular Events Among Patients Treated With Statins: A Meta-analysis

S. Matthijs Boekholdt; Benoit J. Arsenault; Samia Mora; Terje R. Pedersen; John C. LaRosa; Paul J. Nestel; R. John Simes; Paul N. Durrington; Graham A. Hitman; K. M. A. Welch; David A. DeMicco; Aeilko H. Zwinderman; Michael Clearfield; John R. Downs; Andrew Tonkin; Helen M. Colhoun; Antonio M. Gotto; Paul M. Ridker; John J. P. Kastelein

CONTEXT The associations of low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), and apolipoprotein B (apoB) levels with the risk of cardiovascular events among patients treated with statin therapy have not been reliably documented. OBJECTIVE To evaluate the relative strength of the associations of LDL-C, non-HDL-C, and apoB with cardiovascular risk among patients treated with statin therapy. DESIGN Meta-analysis of individual patient data from randomized controlled statin trials in which conventional lipids and apolipoproteins were determined in all study participants at baseline and at 1-year follow-up. DATA SOURCES Relevant trials were identified by a literature search updated through December 31, 2011. Investigators were contacted and individual patient data were requested and obtained for 62,154 patients enrolled in 8 trials published between 1994 and 2008. DATA EXTRACTION Hazard ratios (HRs) and corresponding 95% CIs for risk of major cardiovascular events adjusted for established risk factors by 1-SD increase in LDL-C, non-HDL-C, and apoB. RESULTS Among 38,153 patients allocated to statin therapy, 158 fatal myocardial infarctions, 1678 nonfatal myocardial infarctions, 615 fatal events from other coronary artery disease, 2806 hospitalizations for unstable angina, and 1029 fatal or nonfatal strokes occurred during follow-up. The adjusted HRs for major cardiovascular events per 1-SD increase were 1.13 (95% CI, 1.10-1.17) for LDL-C, 1.16 (95% CI, 1.12-1.19) for non-HDL-C, and 1.14 (95% CI, 1.11-1.18) for apoB. These HRs were significantly higher for non-HDL-C than LDL-C (P = .002) and apoB (P = .02). There was no significant difference between apoB and LDL-C (P = .21). CONCLUSION Among statin-treated patients, on-treatment levels of LDL-C, non-HDL-C, and apoB were each associated with risk of future major cardiovascular events, but the strength of this association was greater for non-HDL-C than for LDL-C and apoB.


JAMA | 2009

Sex differences in mortality following acute coronary syndromes.

Laine Elliott; Dianne Gallup; Matthew T. Roe; Christopher B. Granger; Paul W. Armstrong; R. John Simes; Harvey D. White; Frans Van de Werf; Eric J. Topol; Judith S. Hochman; L. Kristin Newby; Robert A. Harrington; Robert M. Califf; Richard C. Becker; Pamela S. Douglas

CONTEXT Conflicting information exists about whether sex differences modulate short-term mortality following acute coronary syndromes (ACS). OBJECTIVES To investigate the relationship between sex and 30-day mortality in ACS, and to determine whether this relationship was modified by clinical syndrome or coronary anatomy using a large database across the spectrum of ACS and adjusting for potentially confounding clinical covariates. DESIGN, SETTING, AND PARTICIPANTS A convenience sample of patients pooled from 11 independent, international, randomized ACS clinical trials between 1993 and 2006 whose databases are maintained at the Duke Clinical Research Institute, Durham, North Carolina. Of 136 247 patients, 38 048 (28%) were women; 102 004 (26% women) with ST-segment elevation myocardial infarction (STEMI), 14 466 (29% women) with non-STEMI (NSTEMI), and 19 777 (40% women) with unstable angina. MAIN OUTCOME MEASURE Thirty-day mortality following ACS. RESULTS Thirty-day mortality was 9.6% in women and 5.3% in men (odds ratio [OR], 1.91; 95% confidence interval [CI], 1.83-2.00). After multivariable adjustment, mortality was not significantly different between women and men (adjusted OR, 1.06; 95% CI, 0.99-1.15). A significant sex by type of ACS interaction was demonstrated (P < .001). In STEMI, 30-day mortality was higher among women (adjusted OR, 1.15; 95% CI, 1.06-1.24), whereas in NSTEMI (adjusted OR, 0.77; 95% CI, 0.63-0.95) and unstable angina, mortality was lower among women (adjusted OR, 0.55; 95% CI, 0.43-0.70). In a cohort of 35 128 patients with angiographic data, women more often had nonobstructive (15% vs 8%) and less often had 2-vessel (25% vs 28%) and 3-vessel (23% vs 26%) coronary disease, regardless of ACS type. After additional adjustment for angiographic disease severity, 30-day mortality among women was not significantly different than men, regardless of ACS type. The relationship between sex and 30-day mortality was similar across the levels of angiographic disease severity (P for interaction = .70). CONCLUSIONS Sex-based differences existed in 30-day mortality among patients with ACS and vary depending on clinical presentation. However, these differences appear to be largely explained by clinical differences at presentation and severity of angiographically documented disease.


Circulation | 1996

Activated Partial Thromboplastin Time and Outcome After Thrombolytic Therapy for Acute Myocardial Infarction: Results From the Gusto-i Trial

Christopher B. Granger; Jack Hirsh; Robert M. Califf; Jacques Col; Harvey D. White; Amadeo Betriu; Lynn H. Woodlief; Kerry L. Lee; Edwin G. Bovill; R. John Simes; Eric J. Topol

BACKGROUND Although intravenous heparin is commonly used after thrombolytic therapy, few reports have addressed the relationship between the degree of anticoagulation and clinical outcomes. We examined the activated partial thromboplastin time (aPTT) in 29,656 patients in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) trial and analyzed the relationship between the aPTT and both baseline patient characteristics and clinical outcomes. METHODS AND RESULTS Intravenous heparin was administered as a 5000-U bolus followed by an initial infusion of 1000 U/h, with dose adjustment to achieve a target aPTT of 60 to 85 seconds. aPTTs were collected 6, 12, and 24 hours after thrombolytic administration. Higher aPTT at 24 hours was strongly related to lower patient weight (P < .00001) as well as older age, female sex, and lack of cigarette smoking (all PT< .0001). At 12 hours, the aPTT associated with the lowest 30-day mortality, stroke, and bleeding rates was 50 to 70 seconds. There was an unexpected direct relationship between the aPTT and the risk of subsequent reinfarction. There was a clustering of reinfarction in the first 10 hours after discontinuation of intravenous heparin. CONCLUSIONS Although the relationship between aPTT and clinical outcome was confounded to some degree by the influence of baseline prognostic characteristics, aPTTs higher than 70 seconds were found to be associated with higher likelihood of mortality, stroke, bleeding, and reinfarction. These findings suggest that until proven otherwise, we should consider the aPTT range of 50 to 70 seconds as optimal with intravenous heparin after thrombolytic therapy.


Journal of Clinical Oncology | 2010

Capecitabine, bevacizumab, and mitomycin in first-line treatment of metastatic colorectal cancer: Results of the Australasian Gastrointestinal Trials Group randomized phase III MAX study

Niall C. Tebbutt; Kate Wilson; Val Gebski; Michelle M. Cummins; Diana Zannino; Guy van Hazel; Bridget A. Robinson; Adam Broad; Vinod Ganju; Stephen P. Ackland; Garry Forgeson; David Cunningham; Mark P Saunders; Martin R. Stockler; Y. J. Chua; John Zalcberg; R. John Simes; Timothy Jay Price

PURPOSE To determine whether adding bevacizumab, with or without mitomycin, to capecitabine monotherapy improves progression-free survival (PFS) in patients with metastatic colorectal cancer (mCRC) in an open-label, three-arm randomized trial. PATIENTS AND METHODS Overall, 471 patients in Australia, New Zealand, and the United Kingdom with previously untreated, unresectable mCRC were randomly assigned to the following: capecitabine; capecitabine plus bevacizumab (CB); or capecitabine, bevacizumab, and mitomycin (CBM). We compared CB with capecitabine and CBM with capecitabine for progression-free survival (PFS). Secondary end points included overall survival (OS), toxicity, response rate (RR), and quality of life (QOL). RESULTS Median PFS was 5.7 months for capecitabine, 8.5 months for CB, and 8.4 months for CBM (capecitabine v CB: hazard ratio [HR], 0.63; 95% CI, 0.50 to 0.79; P < .001; C v CBM: HR, 0.59; 95% CI, 0.47 to 0.75; P < .001). After a median follow-up of 31 months, median OS was 18.9 months for capecitabine and was 16.4 months for CBM; these data were not significantly different. Toxicity rates were acceptable, and all treatment regimens well tolerated. Bevacizumab toxicities were similar to those in previous studies. Measures of overall QOL were similar in all groups. CONCLUSION Adding bevacizumab to capecitabine, with or without mitomycin, significantly improves PFS without major additional toxicity or impairment of QOL.


Circulation | 1996

Age and Outcome With Contemporary Thrombolytic Therapy Results From the GUSTO-I Trial

Harvey D. White; Gabriel I. Barbash; Robert M. Califf; R. John Simes; Christopher B. Granger; W. Douglas Weaver; Neal S. Kleiman; Philip E. Aylward; Joel M. Gore; Alec Vahanian; Kerry L. Lee; Allan M. Ross; Eric J. Topol

BACKGROUND Elderly patients with acute myocardial infarction have much to gain from reperfusion with thrombolytic therapy but are also at increased risk of adverse events. We examined outcomes according to age of patients receiving thrombolysis in an international trial. METHODS AND RESULTS Patients were randomized to streptokinase plus subcutaneous heparin, streptokinase plus intravenous heparin, accelerated tissue plasminogen activator (TPA) plus intravenous heparin, or streptokinase and TPA plus intravenous heparin. Clinical outcomes at 30 days (death, stroke, and nonfatal, disabling stroke) and 1-year mortality were summarized descriptively for patients aged < 65 (n = 24,708), 65 to 74 (n = 11,201), 75 to 85 (n = 4625), and > 85 years (n = 412) and assessed as continuous functions of age. Older patients had a higher-risk profile with regard to baseline clinical and angiographic characteristics. Mortality at 30 days increased markedly with age (3.0%, 9.5%, 19.6%, and 30.3% in the four groups, respectively), as did stroke, cardiogenic shock, bleeding, and reinfarction. Combined death or disabling stroke occurred less often with accelerated TPA in all but the oldest patients, who showed a weak trend toward a lower incidence with streptokinase plus subcutaneous heparin: odds ratio 1.13; 95% confidence interval 0.6, 2.1. Similarly, accelerated TPA treatment resulted in lower 1-year mortality in all but the oldest patients (47% TPA versus 40.3% streptokinase). CONCLUSIONS Lower mortality and greater net clinical benefit were seen with accelerated TPA in patients aged < or = 85 years. Because data are limited for patients aged > 85 years, the relative superiority of a given thrombolytic regimen cannot be determined. The interactions of stroke and mortality with newer thrombolytic strategies must be examined explicitly in older patients.


Journal of the American College of Cardiology | 2014

Very low levels of atherogenic lipoproteins and the risk for cardiovascular events: a meta-analysis of statin trials.

S. Matthijs Boekholdt; G. Kees Hovingh; Samia Mora; Benoit J. Arsenault; Pierre Amarenco; Terje R. Pedersen; John C. LaRosa; David D. Waters; David A. DeMicco; R. John Simes; Antony C. Keech; David Colquhoun; Graham A. Hitman; D. John Betteridge; Michael Clearfield; John R. Downs; Helen M. Colhoun; Antonio M. Gotto; Paul M. Ridker; Scott M. Grundy; John J. P. Kastelein

BACKGROUND Levels of atherogenic lipoproteins achieved with statin therapy are highly variable, but the consequence of this variability for cardiovascular disease risk is not well-documented. OBJECTIVES The aim of this meta-analysis was to evaluate: 1) the interindividual variability of reductions in low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), or apolipoprotein B (apoB) levels achieved with statin therapy; 2) the proportion of patients not reaching guideline-recommended lipid levels on high-dose statin therapy; and 3) the association between very low levels of atherogenic lipoproteins achieved with statin therapy and cardiovascular disease risk. METHODS This meta-analysis used individual patient data from 8 randomized controlled statin trials, in which conventional lipids and apolipoproteins were determined in all study participants at baseline and at 1-year follow-up. RESULTS Among 38,153 patients allocated to statin therapy, a total of 6,286 major cardiovascular events occurred in 5,387 study participants during follow-up. There was large interindividual variability in the reductions of LDL-C, non-HDL-C, and apoB achieved with a fixed statin dose. More than 40% of trial participants assigned to high-dose statin therapy did not reach an LDL-C target <70 mg/dl. Compared with patients who achieved an LDL-C >175 mg/dl, those who reached an LDL-C 75 to <100 mg/dl, 50 to <75 mg/dl, and <50 mg/dl had adjusted hazard ratios for major cardiovascular events of 0.56 (95% confidence interval [CI]: 0.46 to 0.67), 0.51 (95% CI: 0.42 to 0.62), and 0.44 (95% CI: 0.35 to 0.55), respectively. Similar associations were observed for non-HDL-C and apoB. CONCLUSIONS The reductions of LDL-C, non-HDL-C, and apoB levels achieved with statin therapy displayed large interindividual variation. Among trial participants treated with high-dose statin therapy, >40% did not reach an LDL-C target <70 mg/dl. Patients who achieve very low LDL-C levels have a lower risk for major cardiovascular events than do those achieving moderately low levels.

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Val Gebski

National Health and Medical Research Council

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Frans Van de Werf

Katholieke Universiteit Leuven

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Anthony Keech

National Health and Medical Research Council

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