Clinical Performance of a Gene-Based Machine Learning Classifier in Assessing Risk of Developing OUD in Subjects Taking Oral Opioids: A Prospective Observational Study

OBJECTIVE

To reduce the incidence of Opioid Use Disorder (OUD), multiple guidelines recommend assessing the risk of OUD prior to prescribing oral opioids. Although subjective risk assessments are available to help classify subjects at risk for OUD, we are aware of no clinically validated objective risk assessment tools. An objective risk assessment based on genetics may help inform shared decision-making prior to prescribing short-duration oral opioids.

METHODS

A multicenter, observational cohort of adults exposed to prescription oral opioids for 4-30 days was conducted to determine the performance of an OUD classifier derived from machine learning (ML). From this cohort, the demographics of the U.S. adult opioid-prescribed population were used to create a blinded, random, representative group of subjects (n=385) for analysis to accurately estimate the performance characteristics in the intended use population. Genotyping was performed via a qualitative SNP microarray on DNA extracted from buccal samples.

RESULTS

In the study subjects, the classifier demonstrated 82.5% sensitivity (95% confidence intervals: 76.1%-87.8%) and 79.9% specificity (73.7-85.2%), with no statistically significant differences in clinical performance observed based on gender, age, length of follow-up from opioid exposure, race, or ethnicity.

CONCLUSION

This study demonstrates an ML classifier may provide additional objective information regarding a patient's risk of developing OUD. This information may enable subjects and healthcare providers to make more informed decisions when considering the use of oral opioids.

Multi-variant Genetic Panel for Genetic Risk of Opioid Addiction

Over 116 million people worldwide have chronic pain and prescription dependence. In the US, opioids account for the majority of overdose deaths, and in 2014, almost 2 million Americans abused or were dependent on prescription opioids. Genetic factors may play a key role in opioid prescription addiction. Herein, we describe genetic variations between opioid addicted and non-addicted populations and derive a predictive model determining risk of opioid addiction. This case cohort study compares the frequency of 16 single nucleotide polymorphisms involved in the brain reward pathways in patients with and without opioid addiction. Data from 37 patients with prescription opioid or heroin addiction and 30 age and gender matched controls were used to design the predictive score. The predictive score was then tested on an additional 138 samples to determine generalizabilty. Results for Method Derivation of Observed data: ROC statistic=0.92, sensitivity=82% (95% CI: 66-90), specificity=75% (95% CI:56-87). TreeNet "learn" data: ROC statistic=0.92, sensitivity=92%, specificity=90%, precision=92%, and overall correct=91%. Results of Generalizability data: Sensitivity=97% (95% CI: 90 to 100), specificity=87% (95% CI: 86 to 93), positive likelihood ratio=7.3 (95% CI: 4.0 to 13.5), and negative likelihood ratio=0.03 (95% CI: 0.01 to 0.13). This negative likelihood ratio can be used as an evidence based measure to exclude patients with a high risk of opioid addicition or substance use disorder. By identifying patients with a lower risk for opioid addiction, our model may inform therapeutic decisions.

Dip-pen nanolithography: controlling surface architecture on the sub-100 nanometer length scale

A new method for patterning surfaces with organic structures, termed "dip-pen" nanolithography (DPN), has been developed. DPN allows one to deliver collections of molecules to a surface in a positive printing mode. The technique offers 15 nm linewidths and 5 nm spatial resolution. Current capabilities and future applications of DPN are discussed.

Elevated bone turnover predicts for bone metastasis in postmenopausal breast cancer: results of NCIC CTG MA.14

PURPOSE

We investigated the association of bone-only relapse with a pretreatment marker of bone resorption: serum beta C-terminal telopeptide (B-CTx) of type I collagen.

METHODS

Pretreatment serum B-CTx concentrations were determined from 621 of 667 patients with primary breast cancer enrolled onto the NCIC CTG MA.14 phase III adjuvant trial of tamoxifen with or without octreotide. Recurrence-free survival (RFS) was a secondary end point; the focus here was bone-only relapse. We analyzed continuous or categorical (.71 ng/mL cut point) serum B-CTx in stepwise forward multivariate Cox regression, adjusted for trial stratification factors. We also examined B-CTx and bone relapse by pretrial chemotherapy status.

RESULTS

At median 7.9 years follow-up, 123 of 621 patients experienced recurrence; 19 (3.1%) of 621 had bone-only recurrence, and 47 (7.5%) of 621 had bone plus other sites of recurrence. Larger pathologic tumor size (P = .001) and elevated continuous and categorical serum B-CTx were associated with shorter bone-only RFS (both P = .02) when added to a model with factors significant in the main trial analyses (hazard ratio [HR], 3.43 and 3.50, respectively; 95% CI, 1.20 to 9.77 and 1.26 to 9.75, respectively). The univariate HR for B-CTx was 2.80 (95% CI, 1.05 to 7.48; P = .03). Elevated serum B-CTx was also associated with shorter bone-only RFS (P = .02) when added to a model with factors significant in the main trial analyses. Serum B-CTx level was not associated with any other type of recurrence. Serum B-CTx was not significantly different for patients who underwent pretrial chemotherapy, compared with those who did not (P = .27), nor did pretrial chemotherapy affect bone relapse (P = .48 for bone only; P = .76 for bone with other relapse).

CONCLUSION

Higher pretreatment serum B-CTx was a significant predictor of shorter RFS for bone-only metastasis. Increased bone resorption creates an environment that promotes growth of breast cancer cells.

Topical testosterone for breast cancer patients with vaginal atrophy related to aromatase inhibitors: a phase I/II study

PURPOSE

Controversy exists about whether vaginal estrogens interfere with the efficacy of aromatase inhibitors (AIs) in breast cancer patients. With the greater incidence of vaginal atrophy in patients on AIs, a safe and effective nonestrogen therapy is necessary. We hypothesized that vaginal testosterone cream could safely treat vaginal atrophy in women on AIs.

METHODS

Twenty-one postmenopausal breast cancer patients on AIs with symptoms of vaginal atrophy were treated with testosterone cream applied to the vaginal epithelium daily for 28 days. Ten women received a dose of 300 μg, 10 received 150 μg, and one was not evaluable. Estradiol levels, testosterone levels, symptoms of vaginal atrophy, and gynecologic examinations with pH and vaginal cytology were compared before and after therapy.

RESULTS

Estradiol levels remained suppressed after treatment to <8 pg/mL. Mean total symptom scores improved from 2.0 to 0.7 after treatment (p < .001) and remained improved 1 month thereafter (p = .003). Dyspareunia (p = .0014) and vaginal dryness (p <.001) improved. The median vaginal pH decreased from 5.5 to 5.0 (p = .028). The median maturation index rose from 20% to 40% (p < .001). Although improvement in total symptom score was similar for both doses (-1.3 for 300 μg, -0.8 for 150 μg; p = .37), only the 300-μg dose was associated with improved pH and maturation values.

CONCLUSIONS

A 4-week course of vaginal testosterone was associated with improved signs and symptoms of vaginal atrophy related to AI therapy without increasing estradiol or testosterone levels. Longer-term trials are warranted.

Effect of adjuvant chemotherapy on bone resorption marker beta C-telopeptide (B-CTX) in postmenopausal women

594

Background: In NCIC CTG MA.14, a randomized trial of tamoxifen versus tamoxifen + octreotide LAR, we found a measure of bone resorption, serum B-CTx, to be significantly associated with bone-only first recurrence. Administration of chemotherapy was permitted, and chemotherapy was a stratification factor (never, concurrent, sequential). It was unclear whether pretrial B-CTx serum levels would be affected by prior administration of chemotherapy, and whether timing of chemotherapy was associated with who had bone only, or bone and other site relapse. Methods: Serum B-CTx concentration (Serum CrossLaps Nordic Biosciences, Copenhagen, DN) was determined pretrial therapy in 621 of 667 primary breast cancer patients on MA.14. We tested for differences in continuous B-CTx levels in those who had assessment before (any) chemotherapy (included those who had none) versus those who were assessed after chemotherapy with an ANOVA test. We also used exact Fisher tests to examine whether there was an association between timing of (any) chemotherapy and 1) B-CTx values in upper 2.5% range for healthy pre-menopausal women; 2) bone only recurrence; and 3) concurrent bone and other relapse. Results: Serum B-CTx was assessed before (any) chemotherapy on 382/621 (61.5%) of patients, and after chemotherapy on 239/621 (38.5%). There were no significant differences in serum B-CTx values (p = 0.27). We found 92/621 (14.8%) of patients had high serum B-CTx levels compared with healthy pre-menopausal women; similar proportions of these women received chemotherapy after B-CTx assessment (p = 0.42). Furthermore, there were no differences in timing of (any) chemotherapy and those who had bone only recurrence (p = 0.48) or bone and other type of relapse (p = 0.76). Conclusions: Chemotherapy in the adjuvant setting had no significant effect on bone resorption marker B-CTX serum levels.

No significant financial relationships to disclose.

Correlation of plasma levels of free insulin-like growth factor 1 and clinical benefit of the IGF-IR inhibitor figitumumab (CP- 751, 871)

3539

Background: Free IGF-1 (fIGF-1) represents the biologically active fraction of IGF-1, the main circulating ligand of the Insulin-like Growth Factor type I Receptor (IGF-IR). Signaling through the IGF-IR induces tumor survival and resistance to cancer therapy. Figitumumab (F) (CP-751,871) inhibits IGF-1-induced IGF-IR autophosphorylation with an IC50 of 0.42 nmol/L. Methods: Plasma levels of fIGF-1 were measured in a phase 1b/2 multi-center study of Paclitaxel (T) and Carboplatin (C) and F in patients (pts) with treatment-naïve NSCLC. Other serum markers of the IGF-IR pathway, including circulating soluble IGF-IR (sIGF-IR), IGFBP3 and ALS (acid-labile subunit), were also investigated. The Kaplan-Meier method was used to estimate median survival times. Results: A total of 536 blood samples from 159 pts were analyzed. Baseline median and range fIGF-1 were 0.53 and 0.07–1.99 ng/mL. fIGF-1 directly correlated with IGFBP3 and ALS, and inversely with sIGF-IR (Rho=-0.430, p=0.03). Treatment with F resulted in dose-dependent accumulation of fIGF-1 with a sustained >10 fold increase in fIGF-1 plasma levels at the 20 mg/kg dose, suggesting complete systemic blockade of fIGF-1 binding to the IGF-IR. sIGF-IR decreased and IGFBP3 increased in response to F, but increases in IGBP3 were more modest than those of fIGF-1. Baseline plasma levels of fIGF-1 had a 96.6% negative predictive value for PFS status at 6 months (p=0.03). Median PFS were respectively 2.73 and 6.53 months for TC alone and TC with F (20 mg/kg) in the high fIGF-1 group (p=0.001) while no significant treatment effect of F was observed in the low (<0.54 ng/mL) fIGF-1 group. Sixty three percent of pts with high fIGF-1 had tumors of adenocarcinoma histology. Conclusions: IGF-1 is a key element in the biology of NSCLC of adenocarcinoma histology and its determination may contribute to the identification of pts who benefit from figitumumab therapy.

[Table: see text]

Elevated plasma endoglin (CD105) predicts decreased response and survival in a metastatic breast cancer trial of hormone therapy

Background Endoglin (CD105) is a co-receptor for TGF-beta, is expressed by human vascular endothelial cells, and plays a major role in angiogenesis. Materials and methods Pretreatment EDTA plasma from 224 metastatic breast cancer patients enrolled in a phase III 2nd-line hormone therapy trial and 50 control subjects were assayed for endoglin using an ELISA. Results The female control group (n = 50) plasma endoglin upper limit of normal was defined as the mean + 2 SD (8.7 ng/ml). The breast cancer patient plasma endoglin was 6.40 +/- 2.23 ng/ml (range 3.00-19.79 ng/ml). Elevated plasma endoglin levels were detected in 26 of 224 patients (11.6%). Patients with elevated plasma endoglin had a reduced clinical benefit rate (CR + PR + Stable) (15 vs. 42%) (P = 0.01) to hormone therapy. TTP was shorter for patients with elevated plasma endoglin, but did not reach statistical significance (P = 0.2). Patients with elevated plasma endoglin had decreased overall survival (median 645 vs. 947 days) (P = 0.005). Conclusion Elevated pretreatment plasma endoglin levels predicted for decreased clinical benefit and a shorter overall survival in metastatic breast cancer patients treated with 2nd-line hormone therapy.

Serum TIMP-1 and response to the aromatase inhibitor letrozole versus tamoxifen in metastatic breast cancer

PURPOSE

To determine the effect of elevated serum TIMP-1 on the response of patients with metastatic breast cancer to an aromatase inhibitor versus tamoxifen.

PATIENTS AND METHODS

Five hundred twenty-two patients estrogen receptor-positive metastatic breast cancer were randomly assigned to receive first-line hormone therapy with letrozole or tamoxifen. Serum tissue inhibitor of metalloproteinases-1 (TIMP-1) levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

Pretreatment serum TIMP-1 was elevated in 120 (23%) of 522 patients. Patients with elevated serum TIMP-1 had a significantly reduced objective response rate (19.2% v 30.6%; odds ratio, 0.54; P = .01), duration of response (median, 15.5 v 26.2 months; P = .001), time to treatment progression (TTP; median, 4.5 v 9.2 months; HR, 1.78; P = .0001), time to treatment failure (median, 3.5 v 9.0 months; HR, 1.77; P = .0001), and overall survival (median, 20.3 v 35.8 months; HR, 1.77; P = .0001) compared with patients with normal pretreatment TIMP-1 levels. Letrozole was superior to tamoxifen in both the normal serum TIMP-1 group (median TTP, 11.8 v 8.6 months; P = .003) and in the elevated serum TIMP-1 group (median, 6.1 v 3.2 months; P = .03) In multivariate analysis, elevated serum TIMP-1 remained an independent predictor of both shorter TTP (HR, 1.46; P = .002) and survival (HR, 1.44; P = .002), as did serum HER-2. Combined analysis of both serum TIMP-1 and HER-2/neu conferred additional ability to predict significantly different clinical outcomes compared to using either biomarker alone.

CONCLUSION

Patients with elevated pretreatment serum TIMP-1 had a significantly reduced response and survival. Serum TIMP-1 was an independent predictive and prognostic factor. Blockade of TIMP-1 and HER-2/neu activity may be beneficial in a subset of patients with breast cancer.

Effects of tetramethoxystilbene on hormone-resistant breast cancer cells: biological and biochemical mechanisms of action

Secondary resistance to hormonal therapy for breast cancer commonly develops after an initial response to tamoxifen or aromatase inhibitors. Agents to abrogate these adaptive changes would substantially enhance the long-term benefits of hormonal therapy. Our studies with a stilbene derivative called TMS (2,3',4,5'-tetramethoxystilbene) identified unexpected effects with potential utility for treatment of breast tumors secondarily resistant to hormonal therapy. TMS was originally developed as an inhibitor of cytochrome P450 1B1 to block the conversion of estradiol to 4-OH-estradiol. While studying this agent in three models of hormone resistance, we detected direct antitumor effects not related to its role as an inhibitor of catecholestrogens. During examination of the mechanisms involved, we showed that treatment with 3 micromol/L TMS for 24 h inhibited tubulin polymerization and microtubule formation, caused a cell cycle block at the G2-M phase, and induced apoptosis. TMS also inhibited activated focal adhesion kinase (FAK), Akt, and mammalian target of rapamycin (mTOR) and stimulated c-jun-NH2-kinase and p38 mitogen-activated protein kinase activity. With respect to antitumor effects, TMS at a concentrations of 0.2 to 0.3 micromol/L inhibited the growth of long-term tamoxifen-treated MCF-7 cells by 80% and fulvestrant-treated MCF-7 cells by 70%. In vivo studies, involving 8 weeks of treatment with TMS via a 30-mg s.c. implant, reduced tumor volume of tamoxifen-resistant MCF-7 breast cancer xenografts by 53%. Our data suggest that TMS is a promising therapeutic agent because of its unique ability to block several pathways involved in the development of hormone resistance.

Pharmacodynamic properties of the anti-IGF-IR monoclonal antibody CP-751,871 in cancer patients

3587

Background: The Insulin like Growth Factor I receptor (IGF-IR), a tyrosine kinase, is widely expressed in human tissues. IGF- IR and its ligands (IGF-I and IGF-II) are expressed by many human cancers (e.g., breast, prostate, colorectal and non-small cell lung). Binding of the ligands to the IGF-IR activates key cellular signaling pathways important for stimulating cellular proliferation and inhibiting apoptosis. IGF- I and IGF-II are present in the circulation, but also locally expressed in neoplastic tissue. Bioavailability of these ligands is regulated by a family of IGF binding proteins (IGFBPs1–6). CP-751,871, a fully human monoclonal antibody, is a highly specific and potent inhibitor of IGF-IR activation. In vitro experiments show that binding of CP 751,871 to IGF-IR induces receptor internalization and degradation. This antibody has been shown to have antineoplastic activity using both in vivo and in vitro pre-clinical models. Methods: Blood samples were collected for characterization of the pharmacokinetic and pharmacodynamic properties of CP-751,871 in phase 1 trials of this agent given to cancer patients either alone or in combination with chemotherapy. The endpoints assessed included among others: CP-751,871 plasma concentrations, total and free IGF-I, IGFBP-3, soluble IGF-IR and IGF-IR expression on granulocytes and tumor cells. Results: CP 751,871 exposure increased with dose over the 800-fold dose range investigated. Pharmacokinetic profiles were consistent with target-mediated disposition. A dose-dependent downregulation of soluble IGF-IR serum concentration and IGF-IR expression was observed, with sustained inhibition for the entire dosing period (3–4 week cycles) observed at doses ≥ 1.5 mg/kg. As predicted for an agent that interferes with IGF-I action, IGF-I and IGFBP-3 serum levels were up-regulated in a similar dose-dependent manner. Conclusions: The pharmacodynamic endpoints of clinical trials provide evidence that CP-751,871 targets IGF-IR in granulocytes, tumor cells and tissues involved in regulation of the growth hormone -IGF-I axis. These data provide proof of principle for the use of CP-751,871 as a first-in-class therapeutic approach to inhibit the IGF-IR pathway in cancer patients.

No significant financial relationships to disclose.

Elevated serum M-CSF level predicts reduced survival in metastatic breast cancer patients

10591

Background: Macrophage colony stimulating factor (M-CSF) and its receptor (CSF-1R, the c-fms oncogene protein product) have been reported to be expressed in a variety of cancers, including breast cancer. The M-CSF produced by breast cancer cells and surrounding stromal cells increases osteoclast formation and maturation and enhances the expression of stromal RANK ligand, both of which increase osteolytic bone degradation. In this study we evaluated the predictive and prognostic potential of circulating M-CSF in metastatic breast cancer patients treated with hormone therapy. Methods: Using an M-CSF ELISA (R&D Systems, Minneapolis, MN), M-CSF concentration was determined in pretreatment sera from 204 metastatic breast cancer patients enrolled in a phase III 2nd-line hormone therapy trial of fadrozole vs. megace, and also in sera from 25 post-menopausal control female subjects. Results: The serum M-CSF level from the 25 healthy post-menopausal female control subjects had a mean ± SD of 835.6 ± 276.1 pg/ml (range 319.0 - 1,465.8 pg/ml). The upper limit of normal was defined as the 95th percentile of the serum M-CSF level from the female control group (1277 pg/ml). Pretreatment serum M-CSF levels from the metastatic breast cancer patients ranged from 82.2 - 3,019.8 pg/ml, and were found elevated above the upper limit of normal in 15 of 204 patients (7.35 %). Patients with elevated pretreatment serum M- CSF did not have a significantly different objective response rate, clinical benefit rate, or time to progression to hormone therapy; but these patients did have significantly reduced overall survival (median survival 10.0 months) compared to patients with normal serum M-CSF levels (median survival 24.3 months)(p = 0.007). In multivariate analysis with serum HER-2/neu included as a covariate, elevated serum M-CSF level remained a significant independent variable for reduced survival (p= 0.032). Conclusions: Pretreatment serum M-CSF levels were elevated in 7 % of metastatic breast cancer patients compared to healthy female control subjects, and these patients had significantly reduced overall survival. Serum M-CSF deserves further study to determine its predictive and prognostic biomarker potential in breast cancer patients.

No significant financial relationships to disclose.

Elevated plasma tissue inhibitor of metalloproteinase-1 level predicts decreased response and survival in metastatic breast cancer

BACKGROUND

Tissue inhibitors of metalloproteinase (TIMPs) have at least 2 different functions. They inhibit the catalytic activity of matrix metalloproteinases, and they act as growth factors.

METHODS

Pretreatment ethylenediamine tetracetic acid plasma TIMP-1 was assayed from 251 patients who were enrolled in a Phase III, second-line, hormone therapy trial, and from a control group of 50 healthy, postmenopausal women by using the TIMP-1 enzyme-linked immunosorbent assay.

RESULTS

The plasma TIMP-1 levels from the postmenopausal control group (n = 50 women) were 201 +/- 86 ng/mL mean +/- standard deviation (range, 49-455 ng/mL). The upper limit of normal was defined as the mean +/- 2 standard deviations of the control group (373 ng/mL). Patient pretreatment plasma TIMP-1 levels ranged from 70 ng/mL to 982 ng/mL. Plasma TIMP-1 was elevated above the mean + 2 standard deviations of the control group (373 ng/mL) in 19 patients (7.6%). In univariate analysis, patients who had elevated versus normal plasma TIMP-1 levels had a reduced clinical benefit rate (CBR) (16% vs 42%; P = .03). The time to progression (TTP) (84 days vs 174 days; P < .0001) and overall survival (141 days vs 860 days; P = .0001) also were significantly shorter in patients who had elevated TIMP-1 levels. TTP and overall survival also were significantly shorter in patients who had higher TIMP-1 plasma levels when it was analyzed as a continuous variable. In multivariate analysis, elevated plasma TIMP-1 level remained a prognostic factor for reduced overall survival (P < .0001) along with elevated serum HER-2/neu (P < .0001) and the presence of visceral metastases (P = .008).

CONCLUSIONS

Elevated pretreatment plasma levels of TIMP-1 predicted a decreased response to second-line hormone therapy and reduced survival in women with metastatic breast cancer.

Elevated plasma endoglin (CD105) predicts decreased response and survival in metastatic breast cancer patients

10091

Background: Endoglin (CD105) is a proliferation-associated surface protein expressed by human vascular endothelial cells. It is a co-receptor for transforming growth factor (TGF) -β1 and TGF-β3, and plays a major role in angiogenesis. Upregulation of endoglin has been reported in endothelial cells of breast and colorectal cancers, and elevated levels of serum endoglin have been associated with tumor metastasis in breast cancer patients. Materials and Methods: Pretreatment EDTA plasma from 224 metastatic breast cancer patients enrolled in a phase III 2nd-line hormone therapy trial and 50 healthy post-menopausal female controls were assayed for soluble endoglin using a double-antibody sandwich ELISA from R&D Systems (Minneapolis, MN). Results: In the post-menopausal female control group (n=50), the mean ± SD for plasma endoglin levels were 5.00 ± 1.84 ng/ml, with a range of 2.38–9.83 ng/ml. The upper limit of normal was defined as the mean + 2 SD (8.7 ng/ml) for plasma endoglin. In the breast cancer patient group, the mean ± SD for plasma endoglin was 6.40 ± 2.23 ng/ml, with a range of 3.00–19.79 ng/ml. Elevated plasma endoglin levels were detected in 26 of 224 patients (11.6%). Patients with elevated vs. normal plasma endoglin levels had a reduced clinical benefit rate (CR +PR+Stable)(15% vs. 42%)(p=0.01) to hormone therapy. Time to progression (TTP) was shorter for patients with elevated vs. normal plasma endoglin levels, but did not reach statistical significance (p=0.2). Patients with elevated plasma endoglin had decreased overall survival (median 645 days vs. 947 days)(p=0.005). Another plasma angiogenic marker, soluble Tie-2 receptor, did not significantly correlate with clinical outcome. A weak correlation existed between plasma endoglin and Tie-2 (r =.54, p<0.00001). There was no correlation between plasma endoglin levels and the presence of bone metastasis vs. other sites of metastases. Conclusions: Elevated pretreatment plasma endoglin levels predicted for decreased clinical benefit rate to 2nd-line hormone therapy and a shorter overall survival in metastatic breast cancer patients. Circulating endoglin levels deserve further study for monitoring anti-angiogenic therapy.

[Table: see text]

Elevated serum ras level predicts decreased survival in patients with hematologic malignancies

6562

Background: Ras is a GDP/GTP binding G protein that acts as a molecular switch converting signals from the cell membrane to the nucleus to regulate cell proliferation, differentiation, and protein synthesis. Activation of ras oncogenes has been identified in a variety of cancers, including 30% of acute myelogenous leukemia patients. The purpose of our study was to evaluate serum ras levels and correlate with survival in hematologic cancer patients. Methods: A novel ras p21 ELISA (Oncogene Science/Bayer Diagnostics, Cambridge, MA) employing two monoclonal antibodies reactive with H, K, and N ras was utilized to quantify total ras levels in serum obtained from patients with various hematologic malignancies including acute myelogenous leukemia (AML), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), and chronic lymphocytic leukemia (CLL). Results: The total leukemia patient group consisted of 52 patients. At the 75th percentile serum ras cutpoint (524 pg/ml) 11/52 patients were defined as elevated for serum ras. From this patient group, 38 patients had clinical followup available and were included in the Kaplan-Meier analysis of overall survival. Patients with elevated serum ras (>524 pg/ml) had significantly shorter overall survival compared to those without (median OS 205 vs. 677 days) (p= 0.04). In a multivariate analysis including serum ras level and type of leukemia, serum ras level remained a significant independent variable for shorter overall survival (p=0.004). Within leukemia subtypes 2/18 AML, 4/9 CML, 3/7 ALL, and 0/4 CLL patients had elevated serum ras levels. Conclusions: Leukemia patients with elevated serum ras levels had a significantly shorter overall survival. Serum ras should be evaluated as a potential biomarker in larger leukemia trials, especially for response to treatment with inhibitors of the ras signaling pathway.

[Table: see text]

Serum carboxyterminal telopeptide (ICTP) as a prognostic marker in bone metastases (BM) treated with bisphosphonates

10107

Background: Biochemical markers of bone turnover, such as N- and C-terminal cross-linking telopeptide of type I collagen have been evaluated as prognostic matkers in patients with BM. In one of such study, we found that ICTP was not affected by bisphosphonate (BP) therapy (Costa, et al., JCO 2002; 20:850–856). In this prospective study we analyzed whether the baseline level of ICTP was predictive of skeletal related events (SREs) as defined by: pathologic fractures (PF), radiation to treat BM (RT) or spinal cord compression (SCC); time to progression (TTP) and overall survival (OS) in patients with BM from solid tumors under BP therapy. Methods: We studied 116 BM patients, median age: 64 years; 67% females; 61% breast cancer; 19% prostate cancer; and 20% other tumor types. The x-ray pattern of BM was lytic in 54% patients, blastic in 23%, and mixed in 21%. At the time of study entry, all patients had serum ICTP levels measured with RIA reagents from Orion Diagnostica (reference range: 2.5–4.0 μg/L). A serum ICTP cutoff of 6.2 μg/L was established using the mean + 2D. The occurrence of SREs was recorded during the study and an objective evaluation of BM status was performed every 4–6 months. During the time period on study, patients received treatment with IV zoledronate (57%), IV pamidronate (28%), or more than one BP. The proportional hazards model was used to investigate the correlation of ICTP baseline level with time to first SRE (TTSRE), TTP, and OS; and Poisson regression with the skeletal morbidity rate (SMR): number of SREs/person/year. Results: The median follow-up was 21 months. 81.9% patients had ICTP level above 6.2 μg/L and the mean value of ICTP was 15.1 (SD 11.9) μg/L. During the time period on study, 38% had PF, 57% had RT, and 9.5% had SCC. Median TTSRE was 20 months and the SMR was 0.84. Median TTP was 12 months and median OS time was 29 months. ICTP levels above 6.2 μg/L were associated with increased mortality risk (hazard ratio (HR) 2.86, 95%CI 1.37–6.00, p=0.005) and increased SMR (incidence rate ratio 1.88, 95%CI 0.98–3.60, p=0.057), but not with TTP (HR 1.18, 95%CI 0.67–2.07, p=0,57) or TTSRE (HR 1.59, 95%CI 0.82–3.08, p=0.17). Conclusions: Elevated serum ICTP levels is associated with decreased survival and increased incidence of SREs in BM patients on BP therapy.

No significant financial relationships to disclose.

NCCN Task Force Report: Bone Health and Cancer Care

Higher incidences of osteoporosis and osteopenia are found in cancer patients, particularly in women receiving aromatase inhibitors or with chemotherapy-induced ovarian failure, or in men with prostate cancer and androgen deprivation therapy. Therefore, management of long-term bone health is emerging as an important aspect of comprehensive cancer care. Patients with cancer typically have a number of additional risk factors for osteoporosis that should prompt screening, regardless of patient age or sex. Maintaining bone health requires a broad knowledge base, including understanding underlying bone metabolism and how it is affected by both cancer itself and the drugs used to treat cancer, the effect of chemotherapy-induced menopause on bone health, bone markers and imaging techniques used to assess bone health, therapeutic strategies to maintain bone health, and treatment of bone metastases, including surgery for pathologic fractures. Multiple members of the healthcare team may need to be involved in education and care of the patient. This report summarizes discussion of these and other issues regarding bone health and cancer care from the NCCN Bone Health and Cancer Care Task Force meeting in early 2006.

NCCN Task Force Report: Bone Health and Cancer Care

Higher incidences of osteoporosis and osteopenia are found in cancer patients, particularly in women receiving aromatase inhibitors or with chemotherapy-induced ovarian failure, or in men with prostate cancer and androgen deprivation therapy. Therefore, management of long-term bone health is emerging as an important aspect of comprehensive cancer care. Patients with cancer typically have a number of additional risk factors for osteoporosis that should prompt screening, regardless of patient age or sex. Maintaining bone health requires a broad knowledge base, including understanding underlying bone metabolism and how it is affected by both cancer itself and the drugs used to treat cancer, the effect of chemotherapy-induced menopause on bone health, bone markers and imaging techniques used to assess bone health, therapeutic strategies to maintain bone health, and treatment of bone metastases, including surgery for pathologic fractures. Multiple members of the healthcare team may need to be involved in education and care of the patient. This report summarizes discussion of these and other issues regarding bone health and cancer care from the NCCN Bone Health and Cancer Care Task Force meeting in early 2006. (JNCCN 2006;4(Suppl 2):S1-S24)

Serum epidermal growth factor receptor/HER-2 predicts poor survival in patients with metastatic breast cancer

BACKGROUND

Epidermal growth factor receptor (EGFR, HER-1, and erbB1) is overexpressed in primary breast cancer and had been identified as a poor prognostic factor.

METHODS

Pretreatment serum EGFR levels were quantified by using an enzyme-linked immunoadsorbent assay in a Phase III first-line trial of letrozole and tamoxifen and were correlated with patient outcomes.

RESULTS

Serum EGFR levels in a control group of 117 healthy, postmenopausal women measured 64.1 +/- 13.3 ng/mL (mean +/- standard deviation). Using a cutoff EGFR level of 44.1 ng/mL from the control group (5% nonparametric method), 53 of 535 patients (10%) had decreased serum levels of EGFR. Patients with decreased serum EGFR had no significant difference in objective response rate (ORR), clinical benefit rate (CBR), time to progression (TTP), or time to treatment failure (TTF); however, they did have significantly reduced survival compared with patients who had normal serum EGFR levels (median survival, 23.3 months vs. 30.9 months; P = .007). A combined analysis of pretreatment serum EGFR and HER-2 yielded no additional predictive information for ORR, CBR, TTP, or TTF compared to serum HER-2 alone. However, in the current analysis, a subgroup of patients who had decreased serum EGFR and normal serum HER-2 was identified (n = 39 of 535 patients; 7.3%) that had significantly reduced survival compared with patients who had normal serum levels of both EGFR and HER-2 (median survival, 23.5 months vs. 37.1 months; P = .005). In multivariate analysis, a decreased serum EGFR level remained a significant independent prognostic factor for decreased survival (hazards ratio, 1.58; P = .007).

CONCLUSIONS

In patients who had metastatic breast cancer, decreased serum EGFR/normal serum HER-2 predicted shorter survival compared with patients who had normal levels of serum EGFR/HER-2. This patient subgroup deserves further study to assess their response to and selection for anti-EGFR-directed therapies.

Serum HER-2/neu conversion to positive at the time of disease progression in patients with breast carcinoma on hormone therapy

BACKGROUND

Prolonged exposure of breast carcinoma cells in vitro to tamoxifen results in tamoxifen resistance. Tamoxifen-resistant cells express increased HER-2/neu mRNA and protein. The objective of this study was to determine whether patients with metastatic or locally advanced breast carcinoma who have negative serum HER-2/neu status at the initiation of first-line hormone therapy with letrozole or tamoxifen convert to positive serum HER-2/neu status at the time of disease progression and to determine whether serum HER-2/neu conversion to positive status is associated with response to therapy and overall survival.

METHODS

Serum samples were obtained at baseline and at the time of disease progression from 240 patients who initially had negative serum HER-2/neu status (< 15 ng/mL). A manual microtiter, enzyme-linked immunosorbent assay that was specific for the extracellular domain of the HER-2/neu (c-erbB-2) oncoprotein product was used to quantitate serum levels.

RESULTS

Among 240 patients, 61 patients (26%) converted from serum HER-2/neu negative to positive (> 15 ng/mL) at the time of disease progression. Thirty-two of 129 patients (25%) who were treated with tamoxifen and 29 of 111 patients (26%) who were treated with letrozole became converted to positive serum HER-2/neu status at the time of disease progression. The response rate and the time to disease progression on first-line hormone therapy were not affected by serum HER-2/neu conversion. The survival of patients who converted to positive serum HER-2/neu status was significantly shorter compared with the survival of patients who remained negative for serum HER-2/neu. A multivariate analysis revealed that conversion to positive serum HER-2/neu status was an independent prognostic variable for survival.

CONCLUSIONS

Conversion to positive serum HER-2/neu status occurred in approximately 25% of patients who received first-line hormone therapy. Conversion to serum HER-2/neu-positive status occurred with equal frequency in antiestrogen and aromatase-inhibitor therapy. The current results showed that serum conversion to HER-2/neu-positive status was an independent risk factor for decreased survival in patients with breast carcinoma.

Serum HER-2/neu and response to the aromatase inhibitor letrozole versus tamoxifen

PURPOSE

To determine the effect of elevated serum HER-2/neu on the response of metastatic breast cancer patients to an aromatase inhibitor versus an antiestrogen.

PATIENTS AND METHODS

Five hundred sixty-two estrogen receptor-positive metastatic breast cancer patients were randomized to first-line hormone therapy with either letrozole or tamoxifen. An automated enzyme-linked immunosorbent assay was used to detect serum HER-2/neu.

RESULTS

For patients with normal serum HER-2/neu (70.5%), objective response rate (ORR; 39% in letrozole-treated patients v 26% in tamoxifen-treated patients; P =.008), clinical benefit (CB; 57% v 45%; P =.016), time to progression (TTP; median, 12.2 v 8.5 months; P =.0019), and time to treatment failure (TTF; median, 11.6 v 6.2 months; P =.0066) were significantly better in patients treated with letrozole. In the elevated HER-2/neu group (29.5%), there was no significant difference in ORR (17% in letrozole-treated patients v 13% in tamoxifen-treated patients; P =.45) or CB (33% v 26%; P =.31), but there was a strong trend in favor of a longer TTP with letrozole (median, 6.1 v 3.3 months; P =.0596) and a significantly longer TTF with letrozole (median, 6.0 v 3.2 months; P =.0418). Multivariate analysis revealed that elevated serum HER-2/neu was a negative predictor for ORR and TTP.

CONCLUSION

Patients with normal serum HER-2/neu receiving letrozole demonstrated a significantly greater ORR and CB and longer TTP and TTF than patients receiving tamoxifen. Although in patients with elevated serum HER-2/neu there was no significant difference between letrozole and tamoxifen in ORR or CB, there was a strong trend favoring longer TTP and significantly longer TTF with letrozole.

Measures of aggression and mood changes in male weightlifters with and without androgenic anabolic steroid use

Supraphysiologic doses of testosterone are associated with increased aggression that is hypothesized to be a function of testosterone serum concentrations, mood, and personality. The study attempted to characterize this relationship among weightlifters who were users (n = 10) and nonusers (n = 18) of anabolic steroids. Participants were interviewed using the Modified Mania Rating Scale and Hamilton Rating Scale for Depression to assess mood, the Buss-Durkee Hostility Inventory (BDHI) and Point Subtraction Aggression Paradigm (PSAP) to assess aggression, and the Personality Disorder Questionnaire (PDQ-R) to assess personality. Blood samples were obtained for the determination of total, free, and weakly bound testosterone. Comparisons of continuous variables between testosterone users and non-users were performed with a parametric (unpaired t-test) or non-parametric (Mann-Whitney) test where appropriate. Correlations with testosterone were examined separately for testosterone users and non-users, using Spearman rank correlation. The subjective (BDHI) and objective (PSAP) assessments of aggression found that supranormal testosterone concentrations were associated with increased aggression. However, the PDQ-R results suggest that this finding was confounded by the personality disorder profile of the steroid users, because steroid users demonstrated Cluster B personality disorder traits for antisocial, borderline, and histrionic personality disorder.

Relationship of Serum HER-2/neu and Serum CA 15-3 in Patients with Metastatic Breast Cancer

Background: Serum HER-2/neu antigen concentrations have been reported to correlate with increased tumor volume in patients with breast cancer. We measured serum CA 15-3, a surrogate marker of disease burden, and correlated serum CA 15-3 with serum HER-2/neu and analyzed the association of both markers with clinical outcomes.

Methods: Pretreatment serum samples from 566 patients were retrospectively analyzed from 2 phase III clinical trials of estrogen receptor-positive (ER+), ER−/progesterone receptor-positive, or ER status unknown metastatic breast cancer patients randomized in two similar studies to receive second-line hormone therapy with either megestrol acetate or an aromatase inhibitor (fadrozole). The extracellular domain of the HER-2/neu (c-erbB-2) oncogene and serum CA 15-3 were measured by ELISA on the Bayer Immuno 1.

Results: Serum HER-2/neu protein was increased in 168 patients (30%), and CA 15-3 was increased in 337 (60%) patients. Serum CA 15-3 and HER-2/neu were weakly correlated (r = 0.39; P &lt;0.0001). The clinical benefit (complete responses plus partial responses plus stable disease) of endocrine therapy was significantly lower in patients with increased serum HER-2/neu. When adjusted for serum HER-2/neu, serum CA 15-3 was not predictive of response rates. The median time to progression was shorter in patients with increased serum HER-2/neu (89 days) compared with patients with normal serum HER-2/neu (176 days). Survival was significantly shorter in patients with increased serum HER-2/neu (513 vs 869 days; P &lt;0.0001) or increased serum CA 15-3 (689 vs 939 days; P &lt;0.0001). This observation was confirmed by multivariate analysis.

Conclusions: Serum HER-2/neu is a significant independent predictive and prognostic factor in hormone receptor-positive metastatic breast cancer, even when adjusted for tumor burden as measured by CA 15-3. The combination of increased serum HER-2/neu and increased serum CA 15-3 predicts a worse prognosis than does increased CA 15-3 alone.

Relationship of serum HER-2/neu and serum CA 15-3 in patients with metastatic breast cancer

BACKGROUND

Serum HER-2/neu antigen concentrations have been reported to correlate with increased tumor volume in patients with breast cancer. We measured serum CA 15-3, a surrogate marker of disease burden, and correlated serum CA 15-3 with serum HER-2/neu and analyzed the association of both markers with clinical outcomes.

METHODS

Pretreatment serum samples from 566 patients were retrospectively analyzed from 2 phase III clinical trials of estrogen receptor-positive (ER(+)), ER(-)/progesterone receptor-positive, or ER status unknown metastatic breast cancer patients randomized in two similar studies to receive second-line hormone therapy with either megestrol acetate or an aromatase inhibitor (fadrozole). The extracellular domain of the HER-2/neu (c-erbB-2) oncogene and serum CA 15-3 were measured by ELISA on the Bayer Immuno 1.

RESULTS

Serum HER-2/neu protein was increased in 168 patients (30%), and CA 15-3 was increased in 337 (60%) patients. Serum CA 15-3 and HER-2/neu were weakly correlated (r = 0.39; P <0.0001). The clinical benefit (complete responses plus partial responses plus stable disease) of endocrine therapy was significantly lower in patients with increased serum HER-2/neu. When adjusted for serum HER-2/neu, serum CA 15-3 was not predictive of response rates. The median time to progression was shorter in patients with increased serum HER-2/neu (89 days) compared with patients with normal serum HER-2/neu (176 days). Survival was significantly shorter in patients with increased serum HER-2/neu (513 vs 869 days; P <0.0001) or increased serum CA 15-3 (689 vs 939 days; P <0.0001). This observation was confirmed by multivariate analysis.

CONCLUSIONS

Serum HER-2/neu is a significant independent predictive and prognostic factor in hormone receptor-positive metastatic breast cancer, even when adjusted for tumor burden as measured by CA 15-3. The combination of increased serum HER-2/neu and increased serum CA 15-3 predicts a worse prognosis than does increased CA 15-3 alone.

Elevated serum Her-2/neu level predicts decreased response to hormone therapy in metastatic breast cancer

PURPOSE

To determine the effect of elevation of serum HER-2/neu on response to hormone therapy.

PATIENTS AND METHODS

Seven hundred nineteen metastatic patients with estrogen receptor-positive (ER(+)), progesterone receptor-positive, or both or ER status unknown breast cancer were randomized in three independent clinical trials to receive second-line hormone therapy with either megestrol acetate or an aromatase inhibitor (fadrozole or letrozole). An automated enzyme-linked immunosorbent assay specific for the extracellular domain of the HER-2/neu (c-erbB-2) oncoprotein product was used to detect serum levels.

RESULTS

Two hundred nineteen patients (30%) had elevated serum HER-2/neu protein levels, using the mean + 2 SD (15 ng/mL) from the serum of healthy women as an upper limit. Response to treatment was available for 711 patients. The response rate (complete responses plus partial responses plus stable disease) to endocrine therapy was 45% in 494 patients with non-elevated and 23% in 217 patients with elevated serum HER-2/neu levels (P <.0001). Median duration of treatment response (using the time to progression [TTP] variable for patients who responded) was shorter in the group with elevated serum HER-2/neu levels (11.7 months) compared with the patient group with non-elevated levels (17.4 months). TTP, time to treatment failure, and median survival (17.2 months v 29.6 months) were also significantly shorter in the patients with elevated serum HER-2/neu levels (P <.0001).

CONCLUSION

Patients with ER(+) and serum HER-2/neu-positive metastatic breast cancer are less likely to respond to hormone treatment and have a shorter duration of response than ER(+) and serum HER-2/neu-negative patients. Their survival duration is also shorter.

Reliability, validity, and applicability of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) for adults with multiple sclerosis

PURPOSE

To investigate the measurement properties of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) with respect to test-retest stability, alternate form reliability, construct validity and applicability.

METHOD

Data on satisfaction and quality of life impacts of mobility devices were obtained from 81 community-based adults with Multiple Sclerosis, using the QUEST 2.0 and the Psychosocial Impact of Assistive Devices Scale (PIADS). Subjects were assigned to four groups and a second QUEST 2.0 was administered one week later. Groups differed with respect to the format and the order in which alternate forms were presented. Measures of association were calculated between QUEST 2.0 and PIADS (n = 81) and between QUEST 2.0 alternate forms (n = 48). Respondents' reactions were considered.

RESULTS

The device subscale, services subscale, and total QUEST 2.0 scores achieved good test-retest stability (ICC 0.82, 0.82, 0.91). Alternate-form equivalence (ICC 0.89, 0.76, 0.91) was lower for services. The positive correlations between QUEST 2.0 and the three PIADS dimensions were fair to moderate for device and total QUEST 2.0 (r(p) 0.34 to 0.45) and fair with services (r(p) 0.27 to 0.30). The tool was positively received, with some restrictions for the services subscale.

CONCLUSIONS

These findings on the psychometric properties of the QUEST 2.0 reinforce the relevance of the device subscale as an important outcome measure for assistive technology MS users. Further assessment of the services subscale is needed.

Item analysis of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST)

The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) is an outcomes assessment tool designed to measure satisfaction with assistive technology in a structured and standardized way. The purpose of this article is to present the results of an analysis of the 24 items comprising QUEST and to explain how a subset of items demonstrating optimal measurement performance was selected. The criteria against which the items were measured were general acceptability, content validity, contribution to internal consistency, test-retest stability, and sensitivity. The items that ranked best in terms of these measurement properties were submitted to factorial analysis in order to complete the item selection. The first series of analyses reduced the item pool approximately by half, and the second series of analyses led to the final selection of 12 items. Factor analysis results suggested a bidimensional structure of satisfaction with assistive technology related to the assistive technology device (eight items) and services (four items). The 12-item revised version that will result from this study should prove to be a reliable and valid instrument for measuring outcomes in the field of assistive technology.

S-adenosylmethionine decarboxylase overexpression reduces invasiveness and tumorigenicity in nude mice of MCF-7 breast cancer cells

To elucidate the role of S-adenosylmethionine decarboxylase (SAMDC) in breast cancer biology, we have generated SAMDC overexpressing MCF-7 breast cancer cells. SAMDC overexpression did not alter in a major way growth properties of MCF-7 cells in soft agar, either under basal conditions or in response to estrogen and antiestrogen administration. SAMDC-MCF-7 cells, on the other hand, exhibited a markedly reduced invasive ability in matrigel (p=0.013). Furthermore, they were less tumorigenic in nude mice. The odds for control clones to form tumors were 3.13 (C.1.1.2-8.2, p=0.0184) higher than those for SAMDC clones. The odds ratio were identical in the absence and in the presence of estradiol. In addition, the growth rate of established tumors was slower for SAMDC than for control clones. Overall, our results are consistent with the notion that these phenotypic changes induced by SAMDC overexpression are primarily mediated by suppression of cellular putrescine (and, possibly, spermidine) levels.

Use of markers of bone turnover for monitoring bone metastases and the response to therapy

Metastatic bone disease is a frequent complication of breast and other cancers, resulting in skeletal complications that are a significant cause of morbidity and mortality. Bone metastases can be difficult to diagnose radiologically and it can also be difficult to evaluate patients' response to treatment by using the methods that are currently available (radiography, bone scans, and computed axial tomography scans). These are relatively insensitive procedures, thus, there is a requirement for new methods for assessing bone response to ensure patients benefit from the optimum type and duration of treatment. Biochemical markers of bone turnover, such as N-telopeptide and the pyridinium cross-links pyridinoline and deoxypyridinoline, may provide information on bone dynamics that in turn may reflect disease activity in bone. Several studies have shown bone markers to be elevated in cancer patients who have documented evidence of metastatic bone disease. Increased levels are also observed in some patients without clinical evidence of bone metastases, when compared with normal subjects. Rises in such markers may be the first indication of bone involvement and therefore may potentially be useful in early diagnosis of progression. Preliminary data suggest bone marker level correlates with the extent of metastatic disease and the number of skeletal sites involved. Markers of bone turnover may be helpful in identifying those patients likely to respond to bisphosphonate treatment. Such markers are also potentially useful in monitoring the effectiveness of bisphosphonate therapy in the management of bone metastases, in both patients with metastatic breast disease and multiple myeloma.

Effect of alpha-difluoromethyl-ornithine on the expression and function of the epidermal growth factor receptor in human breast epithelial cells in culture

We have previously shown that ornithine decarboxylase (ODC) overexpression enhances the transforming effects of HER-2neu and epidermal growth factor (EGF) in normal MCF-10A human breast epithelial cells. Our data suggest that such potentiation may be mediated by activation of the mitogen-activated protein kinase (MAPK) pathway and, possibly, STAT signalling. To further explore the interaction between the polyamine pathway and EGF/HER-2neu signalling in this system, we inhibited endogenous ODC activity with alpha-difluoromethylornithine (DFMO) and assessed the effects of this blockade on the expression of EGF receptors (EGFR) and HER-2neu as well as activation of downstream EGF target genes. We found that DFMO administration to MCF-10A cells increased EGF-R mRNA and protein levels in a dose-response fashion, while HER-2neu expression was not affected. The effect of DFMO was mediated through polyamine depletion since it could be reversed by exogenous putrescine administration. Our results also indicated that the increase in EGFR induced by DFMO was not a non-specific consequence of inhibition of cell proliferation. The upregulated EGFRs were functional since they could be phosphorylated by EGF and they were able to promote phosphorylation of downstream signalling molecules including ERK, STAT-3, and STAT-5. We propose that physiologic levels of ODC activity may be critical for regulation of a yet undefined signalling pathway, whose blockade by DFMO leads to a compensatory increase in functional EGFR.

Key dimensions of client satisfaction with assistive technology: a cross-validation of a Canadian measure in The Netherlands

The purpose of this study was to conduct a cross-validation of the bidimensional structure of a satisfaction measure with assistive technology. Data were drawn from a follow-up study of 243 subjects who had been administered the Dutch version of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST). Ratings related to 12 satisfaction items were analysed. Factor analysis results showed that the underlying structure of satisfaction with assistive technology consists of two dimensions related to assistive technology, Device (eight items) and Services (four items), accounting for 40% of the common variance. This finding was consistent with a previous Canadian study and was interpreted as supporting the adequacy and stability of the QUEST measure of satisfaction. Although the structure is delineated, further studies are recommended to support its use in European countries.

Interrater reliability of the modified Jadad quality scale for systematic reviews of Alzheimer's disease drug trials

Drug therapies for Alzheimer's disease (AD) have been evaluated in clinical trials over the past 2 decades. Systematic reviews of AD drug trials can shed more light on the efficacy of pharmaceutical interventions. The modified Jadad scale can be used to assess the quality of trial reports that are candidates for inclusion in these systematic reviews. The interrater reliability of the modified Jadad scale was examined during such a review. Three blinded reviewers rated the quality of 42 AD drug trial reports: the intraclass correlation coefficient was 0.90. The modified Jadad scale appears to be a useful tool for AD research because of the very good interrater reliability. Also, it is composed of items that are well suited to the specific disease characteristics of AD. Further research should focus on the validity of this instrument.