Biomarker analysis from completely resected NSCLC patients enrolled in an adjuvant erlotinib clinical trial (RADIANT)

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Background: RADIANT is a phase III trial comparing erlotinib 150 mg daily vs. placebo (2:1) in stage IB-IIIA NSCLC patients with EGFR-positive tumors (IHC and/or FISH), following complete surgical resection. Planned accrual is 945 patients. Correlative biomarker studies on primary tumor tissue, whole blood, and serum are key components of the study. Methods: Tumor tissue was evaluated by IHC for protein expression of EGFR (PharmDx Kit, Dako with + ≥ 1% positive tumor cells), by FISH for gene expression of EGFR (Vysis, Abbott), and by Wave HS for EGFR and Kras mutations. Results: Among 655 tissue samples analyzed, 96% were EGFR IHC+ and 74% EGFR FISH+. Of the 476 tissue samples analyzed to date for mutations (mut), 12% had activating EGFR and 19% had Kras mut. Preliminary comparisons suggest that EGFR mut rate increased while Kras mut rate decreased with tumor stage. EGFR mut occurred in 29/178 (16%) females (F) vs. 23/271 (8%) males (M), 19/57 (33%) Asians (A) vs. 33/392 (8%) non-Asians (NA), and 29/66 (44%) never smokers (NS) vs. 23/383 (6%) current or former smokers (S). The differences between A vs. NA and NS vs. S were significantly different (P <0.0001) for all comparisons made. Kras mut occurred in 40/180 (22%) F vs. 48/280 (17%) M, 4/57 (7%) A vs. 84/403 (21%) NA, and 3/68 (4%) NS vs. 85/392 (22%) S. The difference between A vs. NA and NS vs. S were significantly different (P ≤0.0389) for all comparisons made. In adenoca, 51/254 (20%) had EGFR and 79/261 (30%) had Kras mut, and in SCC, 0/157 (0%) had EGFR and 3/162 (2%) had Kras mut. One tumor sample demonstrated both an activating EGFR and Kras mut. Conclusions: Ongoing comprehensive biomarker assessment in the RADIANT population indicates successful sample collection and analysis. FISH positivity rates are greater than observed in late-stage tumors. Remaining results in this early-stage population are consistent with those observed in advanced-stage disease. Once complete, this study will provide a robust biomarker dataset on which to evaluate predictive and prognostic response markers, which may help determine who may benefit from treatment with erlotinib in the adjuvant setting.

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The relationship of K-ras mutations and EGFR gene copy number to outcome in patients treated with Erlotinib on National Cancer Institute of Canada Clinical Trials Group trial study PA.3

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Background: The National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) PA.3 study compared treatment with the EGFR tyrosine kinase inhibitor erlotinib to placebo in patients with advanced stage pancreatic carcinoma who were receiving gemcitabine. This study demonstrated a significant advantage in survival [HR=0.82; P<0.04] and in progression free survival [HR=0.77; P<0.004] for patients who received erlotinib [Moore MJ et al, J Clin Oncol 2007]. While high-level expression of EGFR is common in pancreatic cancer, EGFR protein expression level as evaluated by immunohistochemistry did not predict which patients might benefit from erlotinib. In non- small cell lung cancer (NSCLC) where erlotinib has shown a survival benefit; the use of EGFR copy number measured by FISH is a better predictive factor for benefit, and patients whose tumor had a K-ras mutation do not respond nor benefit. Methods: The NCIC-CTG PA.3 trial had a sample size of 569 and NCIC.CTG has collected 280 archival formalin-fixed and paraffin embedded tumor biopsy or primary resection specimens from patients randomized on study. Many were fine needle aspirates and a total of 181 had sufficient tissue to allow molecular analysis. We performed a K-ras mutation analysis by PCR of exon 2 followed by sequencing, with negative results being validated by DHPLC. EGFR gene copy number was analysed by fluorescent in situ hybridization. Both methods were performed on all tumor samples adequate for analysis. Results: Overall 146 cases were suitable for K-ras mutation analysis and preliminary results have identified K-ras mutation in 90 patients [76%] and wild type KRAS in 29 patients; the remainder are pending. A total of 118 cases are suitable for EGFR FISH analysis, results have been obtained in 73 patients, and the remaining cases are pending. The correlations between K-ras mutational status and EGFR copy number, and outcomes [survival and disease control] in patients randomized to both erlotinib and placebo will be presented.

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Effect of glucocorticoid therapy on energy intake in children treated for acute lymphoblastic leukemia

Despite a widespread belief that glucocorticoid therapy is associated with positive energy balance and excess weight gain there is a dearth of quantitative evidence about its effects and the underlying mechanisms of any effects. The primary aim of the present study was to quantify the effect of dexamethasone and prednisone treatment on energy intake in children treated for childhood acute lymphoblastic leukemia. A secondary aim was to test for differences in excess weight gain between patients treated using the 2 glucocorticoids. We measured energy intake in 26 patients (mean +/- SD age, 6.3 +/- 2.3 yr) during a 5-d period "on" steroids and again in the week before steroid treatment. Changes in body mass index from diagnosis to 1 and 2 yr postdiagnosis were expressed as SD scores. Steroid treatment was associated with a significant increase in energy intake of approximately 20% (mean paired difference, 1.7 MJ/d; SD, 2.8; 95% confidence interval, 0.7-2.8 MJ/d), with no significant difference between the 2 steroids. The mean change in body mass index SD score was +0.38 (SD, 1.10; P < 0.05) to 1 yr and +0.68 (SD, 1.38; P < 0.05) to 2 yr, with no significant difference between the 2 groups of patients. Glucocorticoid treatment in childhood acute lymphoblastic leukemia increases energy intake markedly, and this effect contributes to the excess weight gain and obesity characteristic of patients being treated for acute lymphoblastic leukemia.

Navigating ambulatory referral: a standardized process

Significant funding and structure changes to healthcare in Ontario in the mid-90's led The Hospital for Sick Children in Toronto to examine patient referral processes. In an effort to streamline access and encourage more appropriate referrals, the hospital tested and implemented three major changes. This article outlines these changes using the PDSA (Plan, Do, Study, Act) improvement framework and summarizes the results from this project.

The effects of peroxisome proliferators on protein abundances in mouse liver

We have investigated the effects of five peroxisome proliferators (PPs : clofibric acid, DEHP, WY14,643, nafenopin, and LY171883) on the abundances of a large number of proteins in the livers of treated mice at 5- and 35-day time points. LY171883 was investigated at a range of doses, and one of its close structural analogs that is not a peroxisome proliferator (LY163443) was included as a negative control compound. Liver samples were analyzed by quantitative 2-D electrophoresis. Data for a selected set of 107 liver protein spots that respond strongly to at least one of the test compounds was subjected to principal component analysis to search for global protein pattern changes. The first component (PC1) accounted for 51% of the total data variance and was identified as a global measure of peroxisome proliferation by its correlation with enzymatic peroxisomal beta-oxidation. Component PC2 (7%) separated 5- and 35-day exposures, and PC3 (5%) separated groups treated with LY163443 from the rest. We used PC1 as a surrogate for equivalent dose in order to examine the effects of diverse compounds, with widely differing potencies, on a common scale. Analyzed in this way, the data indicate that all the peroxisome proliferators tested produce effects over wide time and dose ranges that fall on or near a single curve. Examination of specific protein responses showed that many proteins individually show a unified response curve, but that curves for different proteins were different. In particular, it appears that some constitutive proteins showing modest inductions with a high dose plateau (such as cytosolic epoxide hydrolase) are inducible at lower doses than some proteins showing very strong, nonplateaued inductions (such as the 80-kDa peroxisomal bifunctional enzyme). The results provide support for a unified receptor-based mechanism controlling the main PP response, but demonstrate that individual responsive genes can show quite different dose-response curves.

Voice intensity of prospective cochlear implant candidates and normal hearing adult males

Voice intensity in 19 prospective cochlear implant candidates, all adventitiously profoundly sensorineurally deaf adult males, was investigated. For the first time with objective data, it was shown that such deaf subjects spoke with significantly increased voice intensity and with greater intensity fluctuations than normal hearing male speakers. Neither length of time of profound deafness nor history of hearing aid use significantly affected voice intensity. Based on quantitative data, rehabilitation of voice intensity problems in the adventitiously deaf is indicated.

Vibrotactile stimulation for the adventitiously deaf: an alternative to cochlear implantation

Acoustic correlates of the prosodic features identifying English contrastive stress, ie, fundamental frequency (Fo), duration and intensity, and listener perceptions were investigated in a profoundly adventitiously deaf subject (D) pre/postvibrotactile stimulation, and in an age-peer normally-hearing person as a control (N). Stimuli were a group of general American English words in which a change of function from noun to verb was associated with a shift of stress from initial to final syllable, eg, CON'test vs conTEST'. Prior to vibrotactile stimulation, D was unable to produce contrastive stress correctly. Only final syllable intensity differences were noted, but proved to be inadequate cues for contrastive stress. Vibrotactile stimulation resulted in changes, specifically significantly higher Fo for initial stressed vs unstressed syllables, significantly louder intensity for final stressed vs unstressed syllables, and significantly longer duration for final stressed vs unstressed syllables. Perceptually, listeners judged D's contrastive stress placement as always occurring on the final syllable previbrotactile stimulation and as 78% correct postvibrotactile stimulation. N's contrastive stress placement was always correct. It was concluded that use of vibrotactile stimulation enhanced D's production and resulted in listeners' perceptions of correct prosody.