Success of Liquid Tumor Biopsy in Men with Metastatic Prostate Cancer According to Self-Identified Race

PURPOSE/OBJECTIVE(S)

Liquid biopsy using cell-free DNA (cfDNA) is increasingly used to identify somatic prostate cancer (PrCa) alterations when tissue biopsy of a metastatic lesion is infeasible or impractical. High-risk somatic alterations identified by cfDNA have been recently shown to predict the benefit of metastasis-directed therapy with stereotactic body radiation therapy in PrCa. However, given the older age of PrCa patients, liquid biopsy is often contaminated with alterations related to clonal hematopoiesis of indeterminate potential (CHIP), generating uncertainty in the clinical utility of the results. Given the higher incidence and aggressiveness of metastatic PrCa in Black men, we sought to determine if the success of cfDNA testing varied by race in a large and diverse cohort of United States Veterans with metastatic PrCa, hypothesizing that race would not influence the success of cfDNA testing.

MATERIALS/METHODS

Veterans with metastatic PrCa underwent next-generation sequencing of cfDNA biopsy specimens through the VA National Precision Oncology Program from February 2019 to November 2022. Successful identification of PrCa with cfDNA testing was defined as the identification of an alteration in one or more PrCa-related related genes in the gene panel tested (AR, CDK12, SPOP, MED12, CCND1, BRAF, AKT1, TMPRSS2, ERG, ETV1, and ETV4). Univariate logistic regression was employed to explore the association between patient self-identified race, as well as other patient and disease-specific factors at the time of cfDNA biopsy, with the likelihood of yielding a successful cfDNA biopsy result.

RESULTS

A total of 2066 cfDNA tests from 1985 Veterans were related to a diagnosis of PrCa, passed quality control measures, and were linkable to patient-level demographics. Median age at testing was 74, median PSA at testing was 22.7, median PSA doubling time (PSADT) was 3.6 months, and median Gleason score was 8. 57% of Veterans self-identified as White, 33% as Black, and 10% as Other. Eight hundred fourteen (39%) tests were deemed successful by finding a PrCa related gene alteration. Among successful tests, the most frequently encountered alterations were AR alterations in 60.4% White men and 33.9% Black men (p = 0.72), followed by TMPRSS2 alterations in 70.3% White men and 22.0% Black men (p<0.001). Despite a lower rate of PrCa-specific alterations in Black men, on univariate analysis, Veteran self-identified race was not associated with successful cfDNA testing (OR 0.95, 95% CI 0.78-1.14, p = 0.6), whereas PSA in quintiles 2-4, PSADT <12 months, and unit increase in Gleason score were associated with successful cfDNA testing (p<0.01 for all).

CONCLUSION

Successful cfDNA biopsy in metastatic PrCa is associated with PSA and PSADT, but not related to patient self-identified race. In appropriate clinical scenarios, patients who self-identify as Black or White are equally likely to have PrCa-specific alterations detected on cfDNA testing when evaluating metastatic PrCa patients for local and systemic therapies.

A simple setup for in situ alkali metal electronic spin polarimetry

Faraday rotation is considered a gold standard measurement of the electronic spin polarization of an alkali metal vapor produced under optical pumping. However, during the production of large volumes of hyperpolarized xenon gas, transmission monitoring measurements, otherwise known as field cycling measurements, are generally employed to measure the spin polarization of alkali metal atoms in situ as this method is easier to implement than Faraday rotation on standard polarizer setups. Here, we present a simple, low-cost experimental setup to perform Faraday rotation measurements of the electronic spin polarization of alkali metal atoms that can be easily implemented on standard polarizer setups. We then compare Rb polarization measurements obtained with the Faraday rotation method to those obtained with the transmission monitoring method. To our knowledge, a direct comparison of these methods has never been made. Overall, we found good agreement between the two methods, but at low Rb density and high laser power, we found evidence of nonlinear magneto-optical effects that may prevent Faraday rotation from being used under these conditions.

Retrospective analysis of the use of tranexamic acid in critically ill dogs and cats (2018-2019): 266 dogs and 28 cats

OBJECTIVE

To describe the signalment, dosing, adverse events, and patient diagnosis for dogs and cats admitted to the critical care unit (CCU) receiving tranexamic acid (TXA).

DESIGN

Case series from 2018 to 2019.

SETTING

Private referral and primary care veterinary hospital.

ANIMALS

Two hundred and sixty-six dogs and 28 cats.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Records of dogs and cats admitted to the CCU that received TXA were evaluated. A diagnosis was assigned to each patient based on the International Statistical Classification of Diseases system. "Neoplasia" ([most frequently] hemangiosarcoma) (89/226 [39%]) and "diseases of the blood and blood forming organs" (idiopathic hemoabdomen, pericardial effusion) (78/226 [34%]) were the most common disease processes for which dogs received TXA. In cats, "diseases of the blood and blood forming organs" (idiopathic hemoabdomen) (9/28 [32%]), "neoplasia" (hemangiosarcoma, mast cell tumor, carcinoma) (7/28 [25%]), and "injury, poisoning, or certain other consequences of external causes" (high-rise syndrome) (5/28 [17%]) were most common. One hundred and forty-eight dogs (65%) and 13 cats (46%) underwent an invasive procedure during hospitalization. Thirty percent (70/226) of dogs received a packed RBC (pRBC) transfusion. Administration of TXA before or after pRBC transfusion did not significantly affect median dose of pRBC administered (P = 0.808). The median IV dose of TXA was similar for dogs and cats at 10 mg/kg. One cat received a 10 times overdose of TXA and did not suffer any appreciable adverse effects. Adverse events were reported in 1.7% (4/226) of dogs including hypersalivation (3/226) and seizure (1/226) in a dog that received a cumulative dose of 280 mg/kg of TXA. Hypersalivation was the only adverse event reported in 3% (1/28) of cats.

CONCLUSION

TXA is primarily utilized in critically ill dogs and cats diagnosed with neoplasia, bleeding disorders, and trauma at this institution. Adverse events were infrequent and largely mild.

Medical complications of obesity: heightened importance in a COVID era

Background

Obesity is a major public health problem associated with significant medical complications.

Main body

This review examines 8 primary diseases: type 2 diabetes, hypertension, dementia, non-alcoholic fatty liver disease, polycystic ovarian syndrome, dyslipidemia, cancer, and their manifestations in obese patients. A total of 39 articles were used for this review. The authors conducted limited review, searching PubMed and Google Scholar databases using a combination of key words “COVID-19” or “SARS-COV2”, “type 2 diabetes”, “hypertension”, “dementia”, “non-alcoholic fatty liver disease”, “polycystic ovarian syndrome”, “dyslipidemia”, “cancer”, and “obesity”. No specific date limitation was used. Obesity exacerbates many medical conditions and has recently been identified as an independent risk factor for COVID-19 severity. This sets obesity at the pinnacle of all disease complications. The long-term impact of obesity ranges from financial burden on the health system, lower life expectancy, and reduced survival rates.

Conclusion

Obesity is an important modifiable risk factor. There is the need for healthcare providers to understand the medical complications associated with obesity to optimize patient care.

A79 AIMING TO PROVIDE EARLIER CARE WHILE REDUCING SPECIALTY CLINIC WAIT TIMES: DEVELOPING A RELIABLE PROCESS OF ASSESSING THE ELIGIBILITY OF GASTROENTEROLOGY REFERRALS FOR PRIMARY CARE PATHWAYS

Background

Gastrointestinal (GI) diseases are common and are a source of substantial morbidity, mortality, and cost, accounting for the largest share of medical referrals from primary care physicians (PCPs) in Canada. Long wait times and increasing numbers of referrals for GI consultation have thus become a significant issue, and while awaiting consultation many patients experience impaired quality of life. Primary care clinical pathways are structured care plans outlining detailed steps for treating patients with specific GI conditions, supporting the translation of clinical guidelines into local protocols and clinical practice.

Aims

To identify the proportion of referrals sent from PCPs to the Queen’s Gastroenterology division that meet the eligibility criteria for a clinical care pathway.

Methods

A review was conducted to identify the proportion of non-urgent referrals in triage sent from PCPs to the Queen’s Gastroenterology division that met the criteria for a clinical care pathway from July 2019 to May 2020. The reason for referral from PCP to gastroenterology was recorded. Individual patient characteristics included in each referral letter were assessed, including age, sex, GI symptoms or signs, relevant clinical features (i.e. time course of symptoms, frequency of bowel movements), relevant laboratory parameters (i.e. CBC, LFTs, electrolytes) or any investigations ordered to evaluate the cause of the patient’s symptoms or signs by the PCP. Four reviewers assessed an initial sample of 200 referral letters and classified each patient’s eligibility for a primary care pathway (GERD, diarrhea, IBS, dyspepsia, or ineligible). After every 100 referrals, discrepancies were reviewed, and a consensus was reached for each case. Data from 100 subsequent referral letters were collected by two independent reviewers, and the inter-rater reliability was calculated. Following a high level of agreement, the final 70 referrals were assessed by two reviewers.

Results

Out of 370 referrals sent from PCPs to the Queen’s Gastroenterology division from July 2019 to December 2019, a total of 170 (46%) met the eligibility criteria for a clinical care pathway. From the eligible referrals, the proportion of patients in each pathway were as follows: 35% GERD, 12% diarrhea, 34% IBS and 19% dyspepsia. The inter-rater reliability for the first 100 referrals assessed by two independent reviewers was 94% (κ = 0.873).

Conclusions

These findings demonstrate that a significant proportion of the patient population referred from PCPs to Queen’s Gastroenterology would be eligible for a primary care pathway. Future steps include implementing these pathways to determine their effectiveness in reducing wait times and empowering PCPs to care for patients who do not require specialist referral.

Funding Agencies

None

Nb3Sn multicell cavity coating system at Jefferson Lab

Superconducting radio frequency niobium cavities are the building blocks of modern accelerators for scientific applications. Lower surface resistance, higher fields, and high operating temperatures advance the reach of the future accelerators for scientific discovery as well as potentially enabling cost-effective industrial solutions. We describe the design and performance of an Nb₃Sn coating system that converts the inner surface of niobium cavities to an Nb₃Sn film. The niobium surface, heated by radiation from the niobium retort, is exposed to Sn and SnCl₂ vapor during the heat cycle, which results in about 2 μm Nb₃Sn film on the niobium surface. Film composition and structure as well as radio frequency properties with 1-cell R&D cavities and 5-cell practical accelerator cavities are presented.

Effect of Different Fat Sources and Vitamin E Isoforms/Levels on Carcass Characteristics and Meat Quality of Pigs Grown to 150 Kg

ObjectivesThe objective was to evaluate the effect of supplementing α- and γ-tocopherol vitamin E isoforms with corn oil and tallow on carcass characteristics and meat quality of pigs grown to heavier weights (>150 kg).Materials and MethodsIndividually fed pigs (n = 72; 36 barrows, 36 gilts; 28.55 ± 1.16 kg) were randomly assigned to 12 dietary treatments in a 2 × 6 factorial arrangement. Fat treatments were tallow and corn oil (5?). The vitamin E treatments included four levels of α-tocopheryl-acetate (ATA; 11, 40, 100, and 200 ppm) and two levels of mixed tocopherols (primarily γ-tocopherol; 40 and 100 ppm). Pigs were humanely slaughtered at approximately 150 kg. 45 min pH was taken at the 10th rib. After 24 h chill (4°C), carcass measurements were taken (carcass length, backfat depth at first rib, last rib, 10th rib and last lumbar, loin muscle area, and 24 h pH at the 10th rib). In addition, wholesale weights from the Boston butt (IMPS #406), shoulder picnic (IMPS #405), loin (IMPS #412), and belly (IMPS #408) and spareribs were recorded. Furthermore, bellies were divided into eight sections and the average depth was taken at each section and the vertical and lateral belly flex was measured. Drip loss was determined by suspending a 1.3cm chop at 4°C for 48 h and purge loss was determined from approximately 2kg vacuum packaged loin muscle sections at 0, 7, 14, and 30d. Objective (Hunter Lab Colorimeter XE Plus) and subjective (NPPC color, marbling and firmness scores) measurements were taken at the 10th rib. Data analysis were performed in SAS by least squares analysis of variance using the generalized linear model as a randomized complete block design. The individual pig served as the experimental unit and results were reported as least square means.ResultsThere were no differences in dressing percentage, 24 h pH, backfat depth, loin muscle area, primal cuts, purge loss, and drip loss between the two vitamin E isoforms. Fat treatments did not affect dressing percentage, 45 min and 24 h pH, backfat depth, loin muscle area, primal cuts, purge loss, drip loss as well as objective and subjective color. Although not significant (P = 0.07), pork from the γ-tocopherol pigs had a lower pH than the ATA treatment. The γ-tocopherol supplementation tended to have a lighter subjective color (P = 0.06) as well as increased L*, decreased a*, and increased the hue angle calculations at 7d shelf-life. The belly depth was greater (P = 0.01) along with higher lateral (P < 0.01) and a lower vertical (P < 0.01) flex for pigs fed tallow.ConclusionIn conclusion, feeding tallow to heavy weight pigs (150 kg) could improve belly firmness. Also, α-tocopherol did not improve shelf-life stability and γ-tocopherol could negatively affect subject and objective pork loin color.

Role of the Ocean's AMOC in setting the Uptake Efficiency of Transient Tracers

The central role played by the ocean's Atlantic Meridional Overturning Circulation (AMOC) in the uptake and sequestration of transient tracers is studied in a series of experiments with the GISS and MIT ocean circulation models. Forced by observed atmospheric timeseries of CFC-11, both models exhibit realistic distributions in the ocean, with similar surface biases but different response over time. To better understand what controls uptake, we ran idealized forcing experiments in which the AMOC strength varied over a wide range, bracketing the observations. We found that differences in the strength and vertical scale of the AMOC largely accounted for the different rates of CFC-11 uptake and vertical distribution thereof. A 2-box model enables us to quantify, and relate uptake efficiency of passive tracers to AMOC strength and how uptake efficiency decreases in time. We also discuss the relationship between passive tracer and heat uptake efficiency, of which the latter controls the transient climate response to anthropogenic forcing in the North Atlantic. We find that heat uptake efficiency is substantially less (by about a factor of five) than that for a passive tracer.

Interactive nature of climate change and aerosol forcing

The effect of changing cloud cover on climate, based on cloud-aerosol interactions, is one of the major unknowns for climate forcing and climate sensitivity. It has two components: (1) the impact of aerosols on clouds and climate due to in situ interactions (i.e., rapid response) and (2) the effect of aerosols on the cloud feedback that arises as climate changes-climate feedback response. We examine both effects utilizing the NASA Goddard Institute for Space Studies ModelE2 to assess the indirect effect, with both mass-based and microphysical aerosol schemes, in transient twentieth century simulations. We separate the rapid response and climate feedback effects by making simulations with a coupled version of the model as well as one with no sea surface temperature or sea ice response ("atmosphere-only" simulations). We show that the indirect effect of aerosols on temperature is altered by the climate feedbacks following the ocean response, and this change differs depending upon which aerosol model is employed. Overall, the effective radiative forcing (ERF) for the "direct effect" of aerosol-radiation interaction (ERFari) ranges between -0.2 and -0.6 W m^-2 for atmosphere-only experiments, while the total effective radiative forcing, including[C0]the indirect effect (ERFari+aci) varies between about -0.4 and -1.1 W m^-2 for atmosphere-only simulations; both ranges are in agreement with those given in Intergovernmental Panel on Climate Change (2013). Including the full feedback of the climate system lowers these ranges to -0.2 to -0.5 W m^-2 for ERFari and -0.3 to -0.74 W m^-2 for ERFari+aci. With both aerosol schemes, the climate change feedbacks have reduced the global average indirect radiative effect of atmospheric aerosols relative to what the emission changes would have produced, at least partially due to its effect on tropical upper tropospheric clouds.

Modeling the QBO-Improvements resulting from higher-model vertical resolution

Using the NASA Goddard Institute for Space Studies (GISS) climate model, it is shown that with proper choice of the gravity wave momentum flux entering the stratosphere and relatively fine vertical layering of at least 500 m in the upper troposphere-lower stratosphere (UTLS), a realistic stratospheric quasi-biennial oscillation (QBO) is modeled with the proper period, amplitude, and structure down to tropopause levels. It is furthermore shown that the specified gravity wave momentum flux controls the QBO period whereas the width of the gravity wave momentum flux phase speed spectrum controls the QBO amplitude. Fine vertical layering is required for the proper downward extension to tropopause levels as this permits wave-mean flow interactions in the UTLS region to be resolved in the model. When vertical resolution is increased from 1000 to 500 m, the modeled QBO modulation of the tropical tropopause temperatures increasingly approach that from observations, and the "tape recorder" of stratospheric water vapor also approaches the observed. The transport characteristics of our GISS models are assessed using age-of-air and N₂O diagnostics, and it is shown that some of the deficiencies in model transport that have been noted in previous GISS models are greatly improved for all of our tested model vertical resolutions. More realistic tropical-extratropical transport isolation, commonly referred to as the "tropical pipe," results from the finer vertical model layering required to generate a realistic QBO.

THE EARTH SYSTEM PREDICTION SUITE: Toward a Coordinated U.S. Modeling Capability

The Earth System Prediction Suite (ESPS) is a collection of flagship U.S. weather and climate models and model components that are being instrumented to conform to interoperability conventions, documented to follow metadata standards, and made available either under open source terms or to credentialed users. The ESPS represents a culmination of efforts to create a common Earth system model architecture, and the advent of increasingly coordinated model development activities in the U.S. ESPS component interfaces are based on the Earth System Modeling Framework (ESMF), community-developed software for building and coupling models, and the National Unified Operational Prediction Capability (NUOPC) Layer, a set of ESMF-based component templates and interoperability conventions. This shared infrastructure simplifies the process of model coupling by guaranteeing that components conform to a set of technical and semantic behaviors. The ESPS encourages distributed, multi-agency development of coupled modeling systems, controlled experimentation and testing, and exploration of novel model configurations, such as those motivated by research involving managed and interactive ensembles. ESPS codes include the Navy Global Environmental Model (NavGEM), HYbrid Coordinate Ocean Model (HYCOM), and Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPS®); the NOAA Environmental Modeling System (NEMS) and the Modular Ocean Model (MOM); the Community Earth System Model (CESM); and the NASA ModelE climate model and GEOS-5 atmospheric general circulation model.

Community-Based Participatory Research Conceptual Model: Community Partner Consultation and Face Validity

A national community-based participatory research (CBPR) team developed a conceptual model of CBPR partnerships to understand the contribution of partnership processes to improved community capacity and health outcomes. With the model primarily developed through academic literature and expert consensus building, we sought community input to assess face validity and acceptability. Our research team conducted semi-structured focus groups with six partnerships nationwide. Participants validated and expanded on existing model constructs and identified new constructs based on "real-world" praxis, resulting in a revised model. Four cross-cutting constructs were identified: trust development, capacity, mutual learning, and power dynamics. By empirically testing the model, we found community face validity and capacity to adapt the model to diverse contexts. We recommend partnerships use and adapt the CBPR model and its constructs, for collective reflection and evaluation, to enhance their partnering practices and achieve their health and research goals.

Massive lindane overdose with toxicokinetics analysis

BACKGROUND

Lindane is a possible carcinogen with known teratogenicity and immunologic and neurotoxic properties. Despite reports of seizures, coma, and death associated with its use as well as banning of its environmental use by the Environmental Protection Agency (EPA), the US Food and Drug Administration (FDA) still allows treatment with lindane as a second-line scabicide and pediculicide. We present a case of a massive suicidal ingestion of lindane in which the patient survived the ingestion, though he did expire shortly thereafter from an unrelated cause pre-discharge.

METHODS

Pharmacokinetic analysis of serum lindane concentrations was performed with Phoenix® WinNONLIN®. The estimated distribution half-life for lindane was 10.3 h, and the terminal half-life was 162.9 h, much longer than the previously reported terminal half-life of 25-36 h. Because of this long half-life, repeated lindane exposures may lead to accumulation of lindane in the tissues.

RESULT

After overdose, toxicity may be delayed and full recovery may be prolonged.

137Cs activities and 135Cs/137Cs isotopic ratios from soils at Idaho National Laboratory: a case study for contaminant source attribution in the vicinity of nuclear facilities

Radiometric and mass spectrometric analyses of Cs contamination in the environment can reveal the location of Cs emission sources, release mechanisms, modes of transport, prediction of future contamination migration, and attribution of contamination to specific generator(s) and/or process(es). The Subsurface Disposal Area (SDA) at Idaho National Laboratory (INL) represents a complicated case study for demonstrating the current capabilities and limitations to environmental Cs analyses. (137)Cs distribution patterns, (135)Cs/(137)Cs isotope ratios, known Cs chemistry at this site, and historical records enable narrowing the list of possible emission sources and release events to a single source and event, with the SDA identified as the emission source and flood transport of material from within Pit 9 and Trench 48 as the primary release event. These data combined allow refining the possible number of waste generators from dozens to a single generator, with INL on-site research and reactor programs identified as the most likely waste generator. A discussion on the ultimate limitations to the information that (135)Cs/(137)Cs ratios alone can provide is presented and includes (1) uncertainties in the exact date of the fission event and (2) possibility of mixing between different Cs source terms (including nuclear weapons fallout and a source of interest).

Dynamics of heavy-Rydberg ion-pair formation in K(14p,20p)-SF6, CCl4 collisions

The dynamics of formation of heavy-Rydberg ion-pair states through electron transfer in K(np)-SF6, CCl4 collisions is examined by measuring the velocity, angular, and binding energy distributions of the product ion pairs. The results are analyzed with the aid of a Monte Carlo collision code that models both the initial electron capture and the subsequent evolution of the ion pairs. The model simulations are in good agreement with the experimental data and highlight the factors such as Rydberg atom size, the kinetic energy of relative motion of the Rydberg atom and target particle, and (in the case of attaching targets that dissociate) the energetics of dissociation that can be used to control the properties of the product ion-pair states.

Venous thrombosis in an ALS population over four years

We conducted a retrospective chart review of all ALS patients seen at our institution over four years to determine the incidence of venous thromboembolism and to identify risk factors in this population. Events occurred in 13 of 438 patients (2.97%), yielding an annual incidence rate of 33.1 events per 1,000 patients (95% CI 17.5-55.3). ALS patients have a risk of venous thromboembolism that is higher than the general population but lower than the population of patients with acute stroke or spinal cord injury. Immobility was significantly associated with increased risk of venous thrombosis (RR = 4.96; 95% CI 1.39-17.78).

Effects of the Perfluorochemical Emulsion FMIQ on the Radiation Response of EMT6 Tumours

The effects of FMIQ, a perfluorochemical emulsion based on perfluoro-N-methyldecahydroisoquinoline, were examined using BALB/c mice and EMT6 mammary carcinomas. The radiobiological effects of FMIQ were similar to those found previously for Fluosol in the same tumour/host system. Although the perfluorochemical content (20% w/v) and oxygen-carrying capacity of FMIQ are similar to those of Fluosol, the formulation of FMIQ offers some advantages over that of Fluosol. For example, FMIQ has greater stability during storage. FMIQ also is formulated without pluronic F-68 and is based on a perfluorochemical (FMIQ) having a shorter tissue dwell time than the perfluorotripropylamine in Fluosol; it therefore may produce fewer side-effects than Fluosol. The lifetime of the circulating perfluorochemical droplets in BALB/c mice was longer than FMIQ than for Fluosol; this could offer an advantage in fractionated radiotherapy. These findings give reason to expect that FMIQ may prove to be a better emulsion than Fluosol for clinical use as an adjunct to cancer therapy.

Gene expression patterns of oncogenic signaling pathways provide a novel approach to targeted therapeutics in advanced non-small cell lung cancer (NSCLC)

7503

Gene expression profiles reflect unique aspects of individual tumors and may characterize tumor heterogeneity in NSCLC. We used gene expression signatures that reflect the deregulation of major oncogenic signaling pathways (Ras, PI3 kinase, Akt, Src, β-catenin, E2F, and Myc) to identify patterns of pathway activation in 118 samples from patients with recurrent (n = 69) and metastatic (n = 49) NSCLC. These individuals, in particular, the patients with metastatic disease are likely to be resistant to standard chemotherapy pointing to the need for alternative therapeutic options. As one approach to this challenge, we used Affymetrix expression data to identify patterns of pathway deregulation in patients with advanced (recurrent/metastatic) disease and compared them to our previously described data on early stage NSCLC (n = 91). Unique to the recurrent and metastatic disease cohorts, a majority of the tumors (greater than 80%) had deregulation of multiple signaling pathways. In particluar, NSCLC tumors with deregulated Src and Myc pathways had a much worse prognosis than those with deregulated Ras and Akt pathways [median survival: 15.5 months vs. 55.3 months, hazard ratio: 2.6, p < 0.01]. Further, using cell proliferation assays, we have shown that the predicted deregulation of Ras, Src and PI3K pathways was directly proportional (p < 0.01, log rank test) to the sensitivity of NSCLC cell lines (n = 17) to agents that specifically target these pathways, suggesting that an ability to profile the status of oncogenic pathways in a tumor sample provides an opportunity to better characterize the oncogenic process in patients with recurrent and advanced NSCLC. More importantly, such a strategy provides a novel approach to targeted therapeutics in NSCLC by guiding the appropriate use of pathway specific inhibitors. Finally, data on gene expression patterns involving other signatures representing unique cancer biology relevant to NSCLC (e.g. hypoxia, chromosomal instability, and angiogenesis) will be also be presented.

No significant financial relationships to disclose.

A multicenter phase II study of erlotinib and bevacizumab in patients with metastatic melanoma

8539

Background: Erlotinib and bevacizumab have demonstrated activity in a number of malignancies by virtue of interrupting interdependent signaling pathways thought important in tumorigenesis. Melanoma may be an appropriate target based on its expression of EGFR and VEGF. We conducted a phase II multi-institutional trial evaluating erlotinib and bevacizumab in advanced melanoma patients. Methods: Eligibility included measurable disease, ECOG PS = 0–1, adequate organ function, no more than one prior therapy for metastatic disease, and CNS metastases were allowed if limited and controlled. Patients received oral erlotinib 150 mg/day and bevacizumab 10 mg/kg IV Q 2 weeks with tumor evaluation every 8 weeks. The primary outcomes were response rate (RR), response duration, and frequency of PFS >6 months. Secondary outcomes included overall survival, safety, and tolerability. A two-stage accrual design was employed ensuring that = 3/21 patients had PFS >6 months before additional patients were accrued. Results: As of Nov 2006, 29 patients with metastatic melanoma were enrolled. A total of 23 patients were evaluable for response. The majority was male 19/29 (65%) and had a median age = 62 yrs (range 35–78 years). Fifteen of the 29 had stage M1c disease (51.7%) and 18/29 (62.1%) had a PS = 1. Ten patients (34%) had prior adjuvant therapy and 6 patients (21%) prior therapy for metastatic disease. There were 2/23 (9%) partial responses lasting < 6 months and 5/23 (22%) had stable disease lasting > 6 months. The median progression free survival of evaluable patients was 96 days (95% CI: 50 - 142 days). A total of 25 grade III toxicities were observed with the most common being rash/pruritis (n=4), pain (n=4), fatigue (n=3), hypertension (n=2) and diarrhea (n=2). Two grade IV toxicities were observed (myocardial infarction and bowel perforation) both thought to be due to bevacizumab. Conclusion: The combination of erlotinib (150 mg/day) and bevacizumab (10 mg/kg) appears potentially active in patients with metastatic melanoma with largely tolerable toxicities. Accrual of a total of 41 patients will be completed shortly.

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