Electroencephalogram Biomarkers from Anesthesia Induction to Identify Vulnerable Patients at Risk for Postoperative Delirium

BACKGROUND

Postoperative delirium is a common complication in elderly patients undergoing anesthesia. Even though it is increasingly recognized as an important health issue, the early detection of patients at risk for postoperative delirium remains a challenge. This study aims to identify predictors of postoperative delirium by analyzing frontal electroencephalogram at propofol-induced loss of consciousness.

METHODS

This prospective, observational single-center study included patients older than 70 yr undergoing general anesthesia for a planned surgery. Frontal electroencephalogram was recorded on the day before surgery (baseline) and during anesthesia induction (1, 2, and 15 min after loss of consciousness). Postoperative patients were screened for postoperative delirium twice daily for 5 days. Spectral analysis was performed using the multitaper method. The electroencephalogram spectrum was decomposed in periodic and aperiodic (correlates to asynchronous spectrum wide activity) components. The aperiodic component is characterized by its offset (y intercept) and exponent (the slope of the curve). Computed electroencephalogram parameters were compared between patients who developed postoperative delirium and those who did not. Significant electroencephalogram parameters were included in a binary logistic regression analysis to predict vulnerability for postoperative delirium.

RESULTS

Of 151 patients, 50 (33%) developed postoperative delirium. At 1 min after loss of consciousness, postoperative delirium patients demonstrated decreased alpha (postoperative delirium: 0.3 μV2 [0.21 to 0.71], no postoperative delirium: 0.55 μV2 [0.36 to 0.74]; P = 0.019] and beta band power [postoperative delirium: 0.27 μV2 [0.12 to 0.38], no postoperative delirium: 0.38 μV2 [0.25 to 0.48]; P = 0.003) and lower spectral edge frequency (postoperative delirium: 10.45 Hz [5.65 to 15.04], no postoperative delirium: 14.56 Hz [9.51 to 16.65]; P = 0.01). At 15 min after loss of consciousness, postoperative delirium patients displayed a decreased aperiodic offset (postoperative delirium: 0.42 μV2 (0.11 to 0.69), no postoperative delirium: 0.62 μV2 [0.37 to 0.79]; P = 0.004). The logistic regression model predicting postoperative delirium vulnerability demonstrated an area under the curve of 0.73 (0.69 to 0.75).

CONCLUSIONS

The findings suggest that electroencephalogram markers obtained during loss of consciousness at anesthesia induction may serve as electroencephalogram-based biomarkers to identify at an early time patients at risk of developing postoperative delirium.

EDITOR’S PERSPECTIVE

On dynamical properties of electrons in Anderson-Mott insulators

Properties of electrons in non-crystalline (alias disordered) systems has been a very active research topic for over half a century, since Anderson's ground breaking paper on localization. In strongly disordered systems electrons become Anderson and Mott localized. Interactions become important because screening by localized electrons is ineffective. Dynamical theories for such systems have long been controversial. Nevertheless one theory came to prominence in the literature and is often invoked and/or used. It is shown here that that theory is unsatisfactory in several aspects. It is based on the one-particle density of states, which turns out to be irrelevant to the problem it addresses. Another shortcoming is an implicit conjecture that interacting electrons move independently of each other. The theory is also in questionable agreement with experiment. It is shown that two other theories are free of those problems. They are useful for different types of studies, are compatible with each other and in agreement with experiment.

Abstract PD5-05: Metabolic obesity, adipose inflammation and aromatase: Potential drivers of breast cancer risk in women with normal body mass index

Background: Elevated body mass index (BMI) is associated with increased risk of postmenopausal breast cancer, which may be partly attributable to an inflammation-aromatase axis. Most individuals with elevated BMI harbor white adipose tissue inflammation (WATi), defined by the presence of crown-like structures in the breast (CLS-B). CLS-B are composed of a dead/dying adipocyte surrounded by CD68+ macrophages. This inflammation is associated with activation of NF-κB and elevated expression of aromatase, which could contribute to tumor development. Additionally, WATi correlates with several circulating changes, including hyperinsulinemia, which increase breast cancer risk. Although breast WATi correlates with rising BMI, it is also present in some normal BMI individuals. Beyond inherited germline syndromes, the etiology of breast cancer in individuals with normal BMI is not well understood. Here we examined the impact of breast WATi on breast aromatase expression and circulating factors in women with normal BMI.

Methods: Non-tumorous breast tissue and fasting blood were collected from 72 women with BMI < 25 kg/m2 undergoing mastectomy at MSKCC. Breast inflammation was detected by the presence of CLS-B using CD68 immunohistochemistry. The primary objective was to determine if breast WATi in normal BMI individuals correlates with elevated aromatase levels in the breast, measured by qPCR, western blotting, immunofluorescence and enzyme activity. Secondary objectives included assessment of breast adipocyte size and circulating metabolic and inflammatory factors.

Results: Breast inflammation was present in 39% of women. Median BMI was 23.0 (range 18.4 to 24.9) in women with breast WATi versus 21.8 (range 17.3 to 24.6) in those without inflammation (P=0.04). Aromatase mRNA expression was positively correlated with WATi (CLS-B/cm2; P=0.002). Those with severe WATi had highest aromatase mRNA levels, compared to those with no or mild WATi (P=0.005). Aromatase protein, assessed by measuring adipose stromal cell-specific immunofluorescence or western blotting, and activity were also higher in CLS-B+ cases compared to CLS-B- (P<0.001). Breast WATi correlated with larger adipocytes (P=0.01) and higher circulating levels of C-reactive protein, leptin, insulin, and triglycerides (P<0.05). Insulin resistance, characterized by the homeostasis model (HOMA2-IR), correlated with breast WATi (P=0.004). Finally, leptin, a known inducer of aromatase and driver of cancer growth, correlated with higher breast aromatase levels (P=0.02) and larger adipocytes (P<0.01).

Conclusions: A metabolically unhealthy state occurs in women with inflamed breast adipose despite having a normal BMI. This subclinical inflammatory state is characterized by elevated aromatase in the breast, insulin resistance, and dysplipidemia. The presence of enlarged adipocytes in the breasts of normal BMI women with inflammation suggests a state of hyperadiposity which could not be predicted based on BMI alone. These findings indicate that normal BMI metabolic obesity may be associated with increased cancer risk. Our results suggest that objective measurements of adiposity rather than BMI may help to identify individuals at increased risk for disease.

Citation Format: Iyengar NM, Brown KA, Zhou XK, Subbaramaiah K, Giri DD, Gucalp A, Howe LR, Zahid H, Bhardwaj P, Wendel NK, Falcone DJ, Morrow M, Wang H, Williams S, Pollak M, Hudis CA, Dannenberg AJ. Metabolic obesity, adipose inflammation and aromatase: Potential drivers of breast cancer risk in women with normal body mass index [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD5-05.

Intranasal insulin influences the olfactory performance of patients with smell loss, dependent on the body mass index: A pilot study

BACKGROUND

The application of intranasal insulin in healthy humans has been linked to improved memory function, reduced food intake, and increased olfactory thresholds. There has also been some correlation between the morbidities associated with central nervous system (CNS) insulin resistance, such as type II diabetes mellitus, Alzheimer's disease, obesity, and impaired odour recognition. Given that impaired odour recognition is an important component of olfactory performance, mechanisms that govern these effects may account for impaired olfactory functions in anosmic patients.

METHODOLOGY

Ten patients with post-infectious olfactory loss received intranasal administration of 40 IU insulin or a placebo solution, as well as olfactory performance tests before and after administration.

RESULTS

When administered insulin, patients exhibited an immediate performance improvement with regard to olfactory sensitivity and olfactory intensity ratings. In addition, more odours were correctly identified. Furthermore, an improvement in the odour identification task was detected in patients with higher body mass index.

CONCLUSION

Results of this pilot study shed light on the link between cerebral insulin level and an impaired sense of smell. This research line might provide a better understanding of olfactory loss in relation to eating and dietary behavior, and could offer opportunities to develop faster therapeutic intervention for patients with olfactory dysfunction.

GH safety workshop position paper: a critical appraisal of recombinant human GH therapy in children and adults

Recombinant human GH (rhGH) has been in use for 30 years, and over that time its safety and efficacy in children and adults has been subject to considerable scrutiny. In 2001, a statement from the GH Research Society (GRS) concluded that 'for approved indications, GH is safe'; however, the statement highlighted a number of areas for on-going surveillance of long-term safety, including cancer risk, impact on glucose homeostasis, and use of high dose pharmacological rhGH treatment. Over the intervening years, there have been a number of publications addressing the safety of rhGH with regard to mortality, cancer and cardiovascular risk, and the need for long-term surveillance of the increasing number of adults who were treated with rhGH in childhood. Against this backdrop of interest in safety, the European Society of Paediatric Endocrinology (ESPE), the GRS, and the Pediatric Endocrine Society (PES) convened a meeting to reappraise the safety of rhGH. The ouput of the meeting is a concise position statement.

P2-12-28: Studies of a Malignancy-Associated Protein, Osteopontin, in NCIC CTG MA.14, a Randomized Trial of Tamoxifen Versus Combined Tamoxifen and Octreotide LAR in Adjuvant Treatment of Women with Early Breast Cancer

Background

We have shown, in women with metastatic breast cancer (BC), that high baseline plasma osteopontin (OPN) levels and increases over time are associated with poor survival. In primary BC, increased immunohistochemical (IHC) expression of OPN in tumour is associated with poorer survival and is elevated in lymph node metastases relative to primary tumour. Our current study evaluates tumour and baseline/serial plasma OPN levels after resection of primary BC.

Methods: In NCIC CTG MA.14, 667 postmenopausal women post surgery received 5 yrs Tamoxifen (T) +/− 2 yrs monthly Octreotide LAR. There were no differences in survival outcomes between arms. OPN was assayed by IHC in primary BC. OPN was measured in plasma at baseline (up to 4 mos post randomization) and serially in recurrent (18 mos time window) versus non-recurrent cases, by ELISA. Statistical Analysis: IHC and plasma OPN had Box-Cox variance stabilization transformations (power 0.5; logarithm). Descriptive characterization of both OPN measurements is provided for all patients, by baseline patient and tumour characteristics, and by recurrence status. Univariate stratified log-rank statistics and hazard ratios with 95% CI were generated for intention to treat (ITT), event free survival (EFS), relapse fee survival (RFS), overall survival, any bone RFS, and non-bone RFS. Stratified step-wise forward Cox regression was used, with factor added if p<0.05.

Results: From 667 MA.14 patients, 647 patients were assessed for OPN: 462 (69%) by IHC; 387 (58%) at baseline in plasma (with 2,542 samples total from serial sampling). IHC % tumor positivity had mean 33.9% (95% CI 30.2%-37.9%), while baseline plasma OPN was mean 46.1 (44.6−47.6) ng/ml. In 80 women with recurrence, mean OPN during the recurrence window was 60.7 (52.8−69.8) ng/ml. Neither baseline IHC or plasma OPN levels were significantly associated with any of the endpoints in either univariate or multivariate analyses. Older age (p=0.02), greater nodal involvement (p=0.001), higher baseline body mass index (p<0.0001), and higher tumour grade (p<0.0001) were multivariately associated with shorter EFS. Baseline plasma OPN was not correlated with IHC OPN (Pearson 0.02, p=0.73).

Discussion: Mean baseline OPN plasma level 46.1 ng/ml (median 45 ng/ml) in MA.14 was similar to our previous findings in healthy women (median 47 ng/ml). In contrast, we previously showed that 63% of 158 women with a new diagnosis of metastatic BC had elevated OPN levels with median value 177 ng/ml. Our results thus far suggest that tumor and plasma levels, while associated with prognosis in metastatic BC, may not be so in primary BC following surgery. However, in MA.14, the 80 women with recurrent BC had significantly higher mean OPN in the recurrence window, 60.7 ng/ml, than at baseline. We will present further analyses exploring this finding.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-12-28.

MS3-3: Energy Metabolism in Breast Cancer: Translational Science Insights Relevant to Effects of Diet, Exercise, and Metformin on Risk and Prognosis

Energy metabolism is relevant to breast cancer at both the cellular and whole organism levels. Whole organism energy balance determines body mass, which has been associated with variations in both breast cancer risk and prognosis. Experimentally, breast carcinogenesis is facilitated by excess caloric intake and inhibited by caloric restriction. The simplistic notion that excess food intake provides additional energy to breast epithelial cells at risk for transformation or to breast cancers, leading to aggressive behavior, is not supported by experimental data. Rather, variations in energy balance have important influences on the hormonal and cytokine environment of the patient, and these influence carcinogenesis and tumor behaviour. Experimental models provide evidence that one such mediating hormone is insulin. Most breast cancers have insulin receptors. When mice with breast cancer are experimentally manipulated to have insulin deficiency (type I) diabetes, tumor growth rate is slowed (despite hyperglycemia). Conversley, when mice are provided with a “junk food” diet, insulin levels rise, tumor insulin receptor activation increases, and tumors grow more quickly. However, when breast cancers evolve to have activating muations in signalling networks downstream of insulin receptors, they become more aggressive and unresponsive to variations in energy intake and insulin no longer influences their behavior.

There is retrospective pharmacoepidemiologic evidence for a substantial ( ∼50%) reduction in breast cancer risk in type II (hyperinsulinemic) diabetic patients prescribed metformin. This has contributed to current interest in the hypothesis that metformin has uses in cancer prevention or treatment. Metformin acts to reduce cellular ATP production by inhibiting mitochondrial respiratory complex I. This results in activation of AMPK. In liver, this results in reduced gluconeogenesis, which reduces the hyperglycemia and hyperinsulinemia of type II diabetes. This systemic effect may reduce proliferation of the subset of neoplasms that are growth stimulated by insulin, but does not operate in the absence of baseline hyperinsulinemia. Other mechanisms of metformin action involve direct effects on at-risk or transformed cells. These mechanisms require adequate levels of the drug in the relevant cells, but metformin doses used in diabetes treatment may not achieve optimum concentrations in cancers, particularly those that lack the active transport molecules responsible for cellular metformin uptake. Overall, laboratory studies suggest that any benefits of metformin will not be homogeneous among a population of at-risk women in a prevention context, nor among breast cancer patients in a treatment context. The validation of candidate predictive biomarkers for metformin benefit, together with more detailed pharmokinetic data, may allow for optimized clinical trial design. Further research is also required to clarify if metformin should best be evaluated as a single agent or in combinations. Thus, metformin and derivatives can be regarded as lead compounds for optimization, and this line of research may lead to novel metabolic approaches to breat cancer prevention and treatment.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr MS3-3.

Long-term effects of insulin glargine on the risk of breast cancer

AIMS/HYPOTHESIS

There have been growing concerns regarding the long-term effects of insulin glargine (A21Gly,B31Arg,B32Arg human insulin) on the risk of breast cancer.

METHODS

We used the UK's General Practice Research Database (GPRD) to identify a cohort of women aged 40 years or over with type 2 diabetes, treated with insulin during 2002-2006 and followed until the first breast cancer diagnosis or 31 December 2009. After the users of insulin glargine had been matched with users of other insulins on age, calendar time and duration of prior insulin use, the HR of breast cancer associated with insulin glargine use was estimated using a Cox proportional hazards model, adjusted for known risk factors for breast cancer.

RESULTS

The cohort comprised 15,227 women, including 4,579 glargine users and 10,648 users of other insulins, of which 246 developed breast cancer during up to 8 years follow-up (incidence rate 4.1 per 1,000 per year). Insulin glargine use was not associated with an increased risk of breast cancer during the first 5 years of use (HR 0.9; 95% CI 0.7-1.3). The risk tended to increase after 5 years (HR 1.8; 95% CI 0.8-4.0), and significantly so for the women who had been on insulin before starting glargine (HR 2.7; 95% CI 1.1-6.5).

CONCLUSIONS/INTERPRETATION

The risk of breast cancer in women with type 2 diabetes is not increased during the first 5 years of insulin glargine use. However, longer-term use may increase this risk, particularly in women with longstanding use of insulin before starting insulin glargine.

A tripartite complex composed of ETV6-NTRK3, IRS1 and IGF1R is required for ETV6-NTRK3-mediated membrane localization and transformation

ETV6-NTRK3 (EN), a chimeric tyrosine kinase generated by t(12;15) translocations, is a dominantly acting oncoprotein in diverse tumor types. We previously showed that insulin-like growth factor 1 receptor (IGF1R) is essential for EN-mediated oncogenesis and that insulin receptor substrate 1 (IRS1) is constitutively tyrosine phosphorylated and bound by EN in transformed cells. Given that IRS1 is also an adapter for IGF1R, we hypothesized that IRS1 might localize EN to IGF1R at the membrane to activate phosphatidylinositol 3-kinase (PI3K)-Akt, which is critical for EN oncogenesis. In this study, we examined EN/IRS1/IGF1R complexes in detail. We find that both IRS1 and kinase active IGF1R are required for EN transformation, that tyrosine phosphorylated IRS1 is present in high molecular weight complexes with EN and IGF1R, and that EN colocalizes with IGF1R at the plasma membrane. Both IGF1R kinase activity and an intact cytoplasmic Y950 residue, the IRS1-docking site of IGF1R, are required, confirming the importance of the IGF1R/IRS1 interaction for EN oncogenesis. The dual specificity IGF1R and insulin receptor (INSR) inhibitor, BMS-536924, blocks EN transformation activity, cell survival and its interaction with IRS proteins, and induces a striking shift of EN proteins to smaller sized molecular complexes. We conclude that a tripartite complex of EN, IRS1 and IGF1R localizes EN to the membrane and that this is essential for EN-mediated transformation. These findings provide an explanation for the observed IGF1R dependency of EN transformation. Blocking IGF1R kinase activity may, therefore, provide a tractable therapeutic strategy for the many tumor types driven by the EN oncoprotein.

Effect of intermittent fasting on prostate cancer tumor growth in a mouse model

Caloric restriction (CR) has been shown to have anti-cancer properties. However, CR may be difficult to apply in humans secondary to compliance and potentially deleterious effects. An alternative is intermittent CR, or in the extreme case intermittent fasting (IF). In a previous small pilot study, we found 2 days per week of IF with ad libitum feeding on the other days resulted in trends toward prolonged survival of mice bearing prostate cancer xenografts. We sought to confirm these findings in a larger study. A total of 100 (7- to 8-week-old) male severe combined immunodeficiency mice were injected subcutaneously with 1 × 10(5) LAPC-4 prostate cancer cells. Mice were randomized to either ad libitum Western Diet (44% carbohydrates, 40% fat and 16% protein) or ad libitum Western Diet with twice-weekly 24 h fasts (IF). Tumor volumes and mouse bodyweights were measured twice weekly. Mice were killed when tumor volumes reached 1000 mm(3). Serum and tumor were collected for analysis of the insulin/insulin-like growth factor 1 (IGF-1) hormonal axis. Overall, there was no difference in mouse survival (P=0.37) or tumor volumes (P ≥ 0.10) between groups. Mouse body weights were similar between arms (P=0.84). IF mice had significantly higher serum IGF-1 levels and IGF-1/IGFBP-3 ratios at killing (P<0.001). However, no difference was observed in serum insulin, IGFBP-3 or tumor phospho-Akt levels (P ≥ 0.39). IF did not improve mouse survival nor did it delay prostate tumor growth. This may be secondary to metabolic adaptations to the 24 h fasting periods. Future studies are required to optimize CR for application in humans.

Examination of TIMP-1 Levels and Relapse-Free Survival for Patients in NCIC CTG MA.14 Who Received Adjuvant Tamoxifen +/- Octreotide LAR

Background: Tissue inhibitor of metalloproteinase-1 (TIMP-1) has been shown to have diverse multifunctional roles in tumorigenesis. AL/KL/SA postulated from first line metastatic endocrine therapy that elevated pre-treatment serum TIMP-1 required additional therapy. NCIC CTG MA.14 adjuvant endocrine trial permitted examination of whether TIMP-1 serum levels post-chemotherapy was associated with RFS. Methods: NCIC CTG MA.14 is a trial where 667 postmenopausal patients were randomized to receive adjuvant tamoxifen +/- octreotide LAR with a stratification factor of no, concurrent or sequential chemotherapy. For the purposes of this work, this was simplified to whether a patient had or had not received adjuvant chemotherapy prior to the serum draw. Serum TIMP-1 was assessed on &gt;90% of the trial patients. We examined the effect of baseline TIMP-1 levels on relapse-free survival (RFS) of 1) all types, 2) bone only, 3) all types of bone, and 4) non-bone, by timing of chemotherapy before the serum draw utilizing continuous TIMP (ng/ml) and categorical TIMP (&lt;454, &gt;454 ng/ml, based on 95% non-parametric cut-point for healthy post-menopausal females). Data were available on patient and tumour characteristics of age (years), pathologic tumour size (cm), pathologic lymph node status (# nodes), IGF-1, C-peptide, IGFBP-3. Step-wise forward Cox multivariate models were used where a factor was added if p&lt;=0.05, and interaction terms were added for TIMP-1 level and timing of chemotherapy. Results: High (categorical) TIMP-1 was significantly associated with longer RFS (p=0.04) in the non-bone RFS multivariate model in the subgroup of patients who had prior chemotherapy, but not in those who did not. The interaction between TIMP-1 and administration of chemotherapy before serum draw was significant (p=0.02). High (continuous) TIMP-1 was significantly associated with longer bone only RFS (p=0.04) in subgroup who had no chemotherapy before the serum draw, but not in those who may or may not have had it after. There was no significant interaction effect. Categorical and continuous TIMP-1 were not associated with any other type of RFS. Conclusions: We found a predictive benefit with the assessment of serum TIMP-1 in hormone receptor positive patients, that high TIMP-1 levels after adjuvant chemotherapy were predictive of a reduction in non-bone RFS.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3022.

Molecular bases for sensitivity to figitumumab (CP-751,871) in NSCLC

8091

Background: Signaling of Insulin like Growth Factors (IGFs) through the IGF type 1 receptor (IGF-IR) induces tumor resistance to cancer therapy. Bioavailability of IGFs is regulated by IGF-binding proteins (IGFBP), of which IGFBP3 is the most abundant. Figitumumab (F) (CP-751,871), a specific IGF-IR inhibitor, has shown phase 2 activity in NSCLC in some histologies (i.e., squamous cell and adenocarcinoma) but not others (i.e, large cell or NOS tumors). Methods: Protein expression of members of the IGF-IR pathway, EGFR and differentiation markers was determined in core biopsies from 230 NSCLC pts, including 52 pts enrolled in F trials. Plasma concentration of IGF-1 and related proteins was determined in 159 NSCLC pts in F trials. Gene expression profiling was conducted in 35 NSCLC cell lines treated with F. Results: Squamous NSCLC had the highest IGF-IR expression (p=0.057). An association with better outcome was seen for E-cadherin expression (HR =0.62, 0.46–0.82 95% CI, p=0.005) and clustering by E-cadherin levels revealed a strong correlation between IGF-IR and EGFR expression in the high E-cadherin group (p<0.001). This subset included 73% of the squamous cell tumors investigated (N=44). Plasma levels of free IGF-1 (fIGF-1) were low and not predictive of response in squamous cell. In contrast, pts with adenocarcinoma had high plasma fIGF-1 levels (p=0.06) that correlated with vimentin expression (Rho=0.732, p=0.06), and both fIGF-1 and vimentin were predictive of F clinical benefit (p=0.03). Large cell/NOS NSCLC expressed the highest levels of vimentin (p<0.001) but had low E-cadherin and IGF-IR expression and low fIGF-1 plasma levels. Analysis of anchorage independent growth in NSCLC cell lines confirmed that F activity is independently associated to IGF-IR overexpression (p=0.02) and IGFBP3 under-expression (p=0.009). Conclusions: IGF-IR overexpression and increased free IGFs/low IGFBP are key independent mechanisms of sensitivity to F in NSCLC of squamous and adenocarcinoma cell histologies.

[Table: see text]

[Table: see text]

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]

Effective temperature in relaxation of Coulomb glasses

We study relaxation in two-dimensional Coulomb glasses up to macroscopic times. We use a kinetic Monte Carlo algorithm especially designed to escape efficiently from deep valleys around metastable states. We find that, during the relaxation process, the site occupancy follows a Fermi-Dirac distribution with an effective temperature much higher than the real temperature T. Long electron-hole excitations are characterized by T(eff), while short ones are thermalized at T. We argue that the density of states at the Fermi level is proportional to T(eff) and is a good thermometer to measure it. T(eff) decreases extremely slowly, roughly as the inverse of the logarithm of time, and it should affect hopping conductance in many experimental circumstances.

Circulating tumor cells expressing the insulin growth factor-1 receptor (IGF-1R): Method of detection, incidence and potential applications

3507

Purpose: To detect IGF-1R on circulating tumor cells (CTCs) as a biomarker in the clinical development of a monoclonal human antibody, CP-751,871, targeting IGF-1R. Experimental Design: An automated sample preparation and analysis system for enumerating CTCs (Celltracks) was adapted for detecting IGF-1R positive CTCs with a diagnostic antibody targeting a different IGF-1R epitope to CP-751,871. This assay was utilized in three phase I trials of CP-751,871 as a single agent or with chemotherapy and was validated using cell lines and blood samples from healthy volunteers and patients with metastatic carcinoma. Results: There was no interference between the analytical and therapeutic antibodies. CP-751,871 was well tolerated as a single agent, and in combination with docetaxel or carboplatin and paclitaxel, at doses ranging from 0.05 mg/kg to 20 mg/kg. Eighty patients were enrolled on phase 1 studies of CP-751,871, with 47 (59%) patients having CTCs detected during the study. Prior to treatment 26 patients (33%) had CTCs, with 23 having detectable IGF-1R positive CTCs. CP-751,871 alone, and CP-751,871 with cytotoxic chemotherapy, decreased CTCs and IGF-1R positive CTCs; these increased towards the end of the 21-day cycle in some patients, falling again with retreatment. CTCs were commonest in advanced hormone refractory prostate cancer (11/20). Detectable IGF-1R expression on CTCs before treatment with CP-751,871 and docetaxel was associated with a higher frequency of PSA decline by more than 50% (6/10 vs 2/8 patients). A relationship was observed between sustained falls in CTCs counts and PSA declines by more than 50%. Conclusions: IGF-1R expression is detectable by immunofluorescence on CTCs. These data support the further evaluation of CTCs in pharmacodynamic studies and patient selection, particularly in advanced prostate cancer.

No significant financial relationships to disclose.

An integrated assessment of options for rural wastewater management in Austria

This paper reports a recently finished, interdisciplinary project on rural wastewater management in Austria. The objective of the project was to study alternative wastewater management options based on separation of the wastewater into its constituent parts, and to compare them with conventional ones. Thereby, a feasibility study of both conventional and alternative options for wastewater management in six model regions was carried out. Life cycle costs and social acceptance were analysed by using a case study-based assessment approach. However, hygienic and environmental risks were evaluated on a more general level. In order to complement the findings, a survey on urine separation system users in the Solar City of Linz was conducted. Based on these assessments and empirical findings, the paper concludes that options using a full separation of all wastewater fractions should be considered with care. Options based on a separation of only grey water and black water or in the liquid/solid phase can offer ecological and financial advantages over conventional options. Further, options combining wastewater management and regional biogas plants were identified as an interesting solution. However, legal constraints restrict this option currently.

Insulin-like growth factor-binding protein-3 inhibition of prostate cancer growth involves suppression of angiogenesis

Insulin-like growth factor-binding protein-3 (IGFBP-3) is a multifunctional protein that induces apoptosis utilizing both insulin-like growth factor receptor (IGF)-dependent and -independent mechanisms. We investigated the effects of IGFBP-3 on tumor growth and angiogenesis utilizing a human CaP xenograft model in severe-combined immunodeficiency mice. A 16-day course of IGFBP-3 injections reduced tumor size and increased apoptosis and also led to a reduction in the number of vessels stained with CD31. In vitro, IGFBP-3 inhibited both vascular endothelial growth factor- and IGF-stimulated human umbilical vein endothelial cells vascular network formation in a matrigel assay. This action is primarily IGF independent as shown by studies utilizing the non-IGFBP-binding IGF-1 analog Long-R3. Additionally, we used a fibroblast growth factor-enriched matrigel-plug assay and chick allantoic membrane assays to show that IGFBP-3 has potent antiangiogenic actions in vivo. Finally, overexpression of IGFBP-3 or the non-IGF-binding GGG-IGFBP-3 mutant in Zebrafish embryos confirmed that both IGFBP-3 and the non-IGF-binding mutant inhibited vessel formation in vivo, indicating that the antiangiogenic effect of IGFBP-3 is an IGF-independent phenomenon. Together, these studies provide the first evidence that IGFBP-3 has direct, IGF-independent inhibitory effects on angiogenesis providing an additional mechanism by which it exerts its tumor suppressive effects and further supporting its development for clinical use in the therapy of patients with prostate cancer.

Randomized phase II study of two doses of gefitinib in hormone-refractory prostate cancer: a trial of the National Cancer Institute of Canada-Clinical Trials Group

PURPOSE

Overexpression of the epidermal growth factor receptor has been demonstrated in advanced prostate cancer and is associated with a poor outcome. A multi-institutional, randomized, phase II study was undertaken by the National Cancer Institute of Canada-Clinical Trials Group to evaluate the efficacy and toxicity of two doses of oral gefitinib in patients with minimally symptomatic, hormone-refractory prostate cancer (HRPC).

PATIENTS AND METHODS

Between July and November 2001, 40 patients with HRPC and increasing prostate-specific antigen (PSA) or progression in measurable disease who had not received prior chemotherapy were randomly assigned to 250 mg (n = 19) or 500 mg (n = 21) oral gefitinib daily continuously. The primary end points were PSA response rate and objective measurable response. Functional Assessment of Cancer Therapy Prostate Cancer Subscale (FACT-P) quality-of-life questionnaires were completed at baseline and during treatment.

RESULTS

None of the patients demonstrated a PSA or objective measurable response. Five (14.3%) of 35 assessable patients had stable PSA (one patient at 250 mg and four patients at 500 mg), and five patients (14.3%) had a best response of stable disease (duration, 2.5 to 16.8 months). No significant effect on the rate of increase in PSA was seen. The most common drug-related nonhematologic toxicities observed were grade 1 to 2 diarrhea (250 mg, 65%; 500 mg, 56%), fatigue (250 mg, 29%; 500 mg, 33%), and grade 1 to 2 skin rash (250 mg, 24%; 500 mg, 39%). FACT-P scores decreased during treatment, indicating worsening of symptoms compared with baseline.

CONCLUSION

Gefitinib did not result in any responses in PSA or objective measurable disease at either dose level. Gefitinib has minimal single-agent activity in HRPC.

Co-targeting IGF-1R and c-kit: synergistic inhibition of proliferation and induction of apoptosis in H 209 small cell lung cancer cells

Most small cell lung cancers (SCLC) coexpress the c-kit protein tyrosine receptor kinase and its ligand stem cell factor, resulting in an autocrine loop. As SCLC growth is also driven by insulin-like growth factor-1 receptor (IGF-1R) signalling, tyrphostins AG 1024 and 1296 (inhibitors of IGF-1R and c-kit activity, respectively) were used to co-target these receptors in H 209 SCLC cells. Combination treatment caused synergy in proliferation inhibition and in apoptosis induction, and also enhanced reduction in phosphorylation of Erk1/Erk2, suggesting that co-targeting IGF-1R and c-kit in SCLC may be more effective than single-agent therapies.