Individual response of humans to ionising radiation: governing factors and importance for radiological protection

Tissue reactions and stochastic effects after exposure to ionising radiation are variable between individuals but the factors and mechanisms governing individual responses are not well understood. Individual responses can be measured at different levels of biological organization and using different endpoints following varying doses of radiation, including: cancers, non-cancer diseases and mortality in the whole organism; normal tissue reactions after exposures; and, cellular endpoints such as chromosomal damage and molecular alterations. There is no doubt that many factors influence the responses of people to radiation to different degrees. In addition to the obvious general factors of radiation quality, dose, dose rate and the tissue (sub)volume irradiated, recognized and potential determining factors include age, sex, life style (e.g., smoking, diet, possibly body mass index), environmental factors, genetics and epigenetics, stochastic distribution of cellular events, and systemic comorbidities such as diabetes or viral infections. Genetic factors are commonly thought to be a substantial contributor to individual response to radiation. Apart from a small number of rare monogenic diseases such as ataxia telangiectasia, the inheritance of an abnormally responsive phenotype among a population of healthy individuals does not follow a classical Mendelian inheritance pattern. Rather it is considered to be a multi-factorial, complex trait.

Abstract P2-06-02: Development of a first-in-class small molecule inhibitor (EC359) targeting oncogenic LIF/LIFR signaling for the treatment of triple negative breast cancer

Background: Leukemia inhibitory factor (LIF) and its receptor LIFR are over-expressed in multiple solid tumors and play a key role in tumor growth, progression, and resistance to standard anti-cancer treatments. Triple-negative breast cancer (TNBC) lacks targeted therapies and represents a disproportional share of breast cancer (BCa) mortality. TNBC exhibits autocrine stimulation of the LIF/LIFR axis and overexpression of LIF is associated with poorer relapse-free survival in BCa patients. LIF signaling also promotes maintenance of stem cells. Therefore, targeting the LIF/LIFR axis may have therapeutic utility in TNBC.

Methods: We rationally designed a small organic molecule (EC359) that emulates the LIF/LIFR binding site and functions as a LIFR inhibitor from a library of compounds. In silico docking studies were used to identify the putative interaction of the EC359 and LIF/LIFR complex. Direct binding of EC359 to LIFR was confirmed using surface plasmon resonance (SPR) and microscale thermophoresis technique (MST) assays. In vitro activity was tested using Cell-Titer Glo, MTT, invasion, and apoptosis assays. Mechanistic studies were conducted using Western blot, reporter gene assays, and RNA-seq analysis. Xenograft, patient-derived xenograft (PDX), and patient-derived explant (PDEX) models were used for preclinical evaluation and toxicity.

Results: Molecular docking studies showed that EC359 interacts at the LIF/LIFR binding interface. SPR and MST studies confirmed direct interaction of EC359 to LIFR. EC359 reduced the growth of TNBC cells with high potency (IC50 50-100nM) and promoted apoptosis. Further, EC359 treatment reduced invasion and stemness of TNBC cells. EC359 activity is dependent on the expression levels of LIFR and showed little or no activity on TNBC cells that have low levels of LIFR or ER+ve BCa cells. Further, EC359 significantly reduced the viability of cisplatin and taxane-resistant TNBC cells and enhanced the efficacy of HDAC inhibitors. Mechanistic and biochemical studies showed that EC359 interacts with LIFR and effectively blocking LIF/LIFR interactions. EC359 also blocked LIFR interactions with other LIFR ligands such as oncostatin M, ciliary neurotrophic factor, and cardiotrophin-1. EC359 treatment attenuated the activation of LIF/LIFR driven pathways including STAT3, mTOR, AKT, and MAPK. RNA-seq analysis identified regulation of apoptosis as one of the important pathway modulated by EC359. In TNBC xenograft and PDX assays, EC359 significantly reduced tumor progression. Further, using human primary BCa PDEX cultures, we demonstrated that EC359 has the potential to substantially reduce the proliferation of human BCa. Pharmacologically, EC359 exhibited high oral bioavailability and long half-life with a wide therapeutic window.

Conclusions: EC359 is a novel targeted therapeutic agent that inhibits LIF/LIFR oncogenic signaling in TNBC via a unique mechanism of action. EC359 has the distinct pharmacologic advantages of oral bioavailability, in vivo stability, and is associated with minimal systemic side effects. (DOD BCRP grant #BC170312)

Citation Format: Viswanadhapalli S, Luo Y, Sareddy GR, Santhamma B, Zhou M, Li M, Pratap UP, Altwegg KA, Li X, Srinivasan U, Ma S, Chang A, Riveros AC, Zhang KY, Dileep KV, Pan X, Murali R, Bajda M, Raj G, Brenner A, Manthati V, Rao M, Tekmal RR, Nair HB, Nickisch KJ, Vadlamudi RK. Development of a first-in-class small molecule inhibitor (EC359) targeting oncogenic LIF/LIFR signaling for the treatment of triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-02.

Abstract P2-02-03: FASN inhibition as a potential treatment for therapy of endocrine resistant breast cancer

INTRODUCTION: Fatty acid synthase (FASN) is a key enzyme in tumor cell biology controlling endogenous lipid biosynthesis. It is overexpressed in a biologically aggressive subset of tumors, including breast carcinoma. We previously reported prolonged stabilization of disease with TVB-2640 in patients with advanced metastatic breast cancer, including some endocrine resistant ER+ tumors. Using in vitro and in vivo models, we assessed the role of FASN inhibition by TVB-3166 (preclinical version of TVB-2640) for treatment of endocrine resistant breast cancer. METHODS: Breast tumor cells were incubated with TVB-3166 (200nM), imaged and analyzed by automated Live-Cell analysis system (IncuCyte). For tumor growth inhibition, cells (2X106)were subcutaneously injected into SCID mice implanted with estrogen pellets. Once tumors were measurable, mice were divided into treatment groups: tamoxifen (4mg/kg), TVB-3166 (60mg/kg) and the combination. Patient tumor explants were incubated for 72h on gelatin sponges in culture medium in the absence or presence of 200nM TVB-3166. Tissue were fixed in 10% formalin and processed into paraffin blocks. Sections were stained with H&E, ERα and Ki67. RESULTS: The effectiveness of FASN inhibition on the growth of tumor cells has been confirmed in a number of breast cancer cell lines such as MCF7, ZR75, MDA-MB-231 and others. TVB-3166 leads to a marked inhibition of growth in tamoxifen resistant (TamR) cells, which 15% greater than in the parent line. IHC and Western blot showed FASN inhibition leads to significantly reduction of ERα levels. Immunofluorescent confocal microscopy showed inhibition of FASN by TVB-3166 alters subcellular localization of ERα. TVB-3166 was able to significantly inhibit tamoxifen resistant breast tumor growth in mice (p<0.05). Additionally, TVB-3166 treatment of primary tumor explants decreased their proliferation (Ki67) compared to untreated controls (21% vs 38%, p<0.01). CONCLUSION: Our preclinical data provide evidence that FASN inhibition by TVB-3166 presents a promising therapeutic strategy for treating of endocrine resistant breast cancer. RNA sequencing of tumor explants is being performed to evaluate FASN inhibition impact on canonical and non-canonical ERα signaling pathways.

Citation Format: Gruslova A, Sareddy GR, Vadlamudi RK, Viswanadhapalli S, Brenner A. FASN inhibition as a potential treatment for therapy of endocrine resistant breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-02-03.

Abstract P1-03-12: The ratio of omega-3 to omega-6 PUFAs impact cancer cell phenotype in the tumor microenvironment

Background: Studies have shown that obesity is associated with a worse breast cancer prognosis. Besides the effect of different stages of diagnosis and co-morbidities, recent data from our published in vitro and retrospective studies suggests that this phenomenon may occur because the obese state promotes a more aggressive cancer phenotype through the cyclooxygenase (COX-2) pathway and its production of prostaglandin E2 (PGE2). The metabolization of omega-3 fatty acids decreases the production of PGE2, and have been shown to have potential benefit to cancer patients by decreasing inflammation-related signaling. Our previous clinical trial showed mixed results in the effect of omega-3 PUFA supplements on PGE2 production in post-menopausal obese women. This led us to the hypothesis that the ratio of omega-3 to omega-6 PUFAs have differential effects on cell types within the tumor microenvironment, impacting cancer cell phenotype.

Approach: In vitro experiments, including wound-healing assays to determine motility, and clonogenic assays to determine overall survival, were performed to determine if exposure to higher ratios of omega-6 to omega-3 fatty acids lead to a more aggressive cancer phenotype. MCF-7 breast cancer cells were treated with the following fatty acid ratios of omega-6 (arachidonic acid (AA)) to omega-3 (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)): 46:1, 20:1, 10:1, and 1.3:1. The wound-healing assays showed greater motility with higher ratios of omega-6 to omega-3 fatty acids conditions and the clonogenic assays showed greater survival with the higher ratios.

Conclusion: These data indicate that lowering ratios of omega-6 to omega-3 fatty acids may lessen the aggressiveness of breast cancer cells and be beneficial to some patients. Studies are on-going to investigate the impact of PUFA ratios on cancer cell phenotype directly, including proliferation and invasion, as well as the indirect effects from modulation of the other cells within the tumor microenvironment, including the macrophages and adipocytes.

Citation Format: Winikka L, Quach D, Harlow B, Brenner A, Munoz N, Tiziani S, deGraffenried L. The ratio of omega-3 to omega-6 PUFAs impact cancer cell phenotype in the tumor microenvironment [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-03-12.

Abstract P1-02-02: FASN inhibition by TVB-3166 associates with breast cancer subtype

Fatty acid synthase (FASN) is overexpressed in numerous tumor types, including breast carcinomas, and promotes changes in the genetic program controlling lipid biosynthesis. While inhibiting FASN appears to be an attractive therapeutic approach under development, the success of this approach may depend on the identification of tumor subtypes with specific metabolic requirements. Applying a comprehensive profile of circulating tumor cells (CTC) using canonical pathway gene sets, we identified a correlation of metabolic subtypes with breast tumor subtype. A lipogenic subtype is strongly associated with Luminal A subtype, whereas the glycolytic subtype associated with Luminal B tumors. The triple negative subtype was more heterogeneous and had the expression of both sets of gene. Such a difference in the metabolic profile may dictate differential sensitivity to inhibitors targeting de novo lipid synthesis, including FASN. This was supported by in vitro studies using selective FASN inhibitor, TVB-3166. Exposure to TVB-3166 over 14 days incubation in Advanced MEM with 1% charcoal-stripped FBS selectively inhibited growth and viability of Luminal A breast cancer cells, but had no effect on Luminal B subtype. This was further confirmed in short-term patient derived cultures. Mechanistic studies suggest that TVB-3166 quickly disrupts FA synthesis leading to the disruption of the lipid raft architecture and tumor cell death through an apoptotic mechanism. In conclusion, our findings highlight that success of targeting cancer metabolism directly may depend on identification of tumor subtypes with specific metabolic requirements.

Citation Format: Gruslova AB, Chen C-L, Wang C-M, Elledge RM, Kaklamani VG, Lathrop K, Huang TH, Brenner A. FASN inhibition by TVB-3166 associates with breast cancer subtype [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-02-02.

Abstract P3-07-10: Modulation of FASN under obese conditions

Introduction: Obesity is known to be associated with a worse breast cancer prognosis, in part through altering metabolism in cells of the tumor microenvironment. In particular, changes in metabolism associated with fatty acid utilization have been noted in not only breast cancer, but also several other cancer types. This includes changes to both expression and activity of the Fatty Acid Synthase enzyme (FASN), which is responsible for production of long chain fatty acids, including palmitate. These changes in long chain fatty acid production can modulate tumor behavior through modulation of energy utilization such as beta-oxidation, as well as plasma membrane modulation with phospholipids. Our previous studies have demonstrated that exposure to obese conditions induces significant changes in breast cancer cell proliferation. Additionally, obesity modulates activity of other cells within the tumor microenvironment, including adipocytes, which might influence the cancer cell itself. We hypothesize one particular mechanism that supports these changes is obesity-induced upregulation of FASN and that FASN may be a viable target to limit obesity-induced progression.

Methods and Results: FASN has been shown to promote cancer cell proliferation through generating fatty acid precursors required for cell proliferation, altering membrane fluidity, and activating oncogenic signaling pathways. To determine if modulation of FASN is an important mechanism by which obesity promotes disease progression, MCF-7 breast cancer cells and human pre-adipocyte cells (ASC) were exposed to 2% sera from obese postmenopausal women and 2% sera from non-obese (control) women. Preliminary quantitative PCR results demonstrated that exposure to the obese sera resulted in increased expression of FASN in both the cancer cells as well as the ASC. Current studies are on-going to determine if 1) FASN up-regulation results in increased long-chain and free fatty acid production in both the cancer and adipocyte cells, 2) whether changes in long chain and free fatty acid production results in altered metabolism and plasma membrane status and 3) whether targeting FASN with a new generation of FASN inhibitors currently being investigated in the clinic can modulate obesity-induced disease progression.

Conclusions: Our findings indicate that obesity promotes upregulation of FASN in several cells within the tumor microenvironment, including adipocytes and the cancer cell itself. We have also found that using a FASN inhibitor is effective in limiting cancer cell viability and proliferation. Our on-going studies will confirm if this is an important mechanism by which obesity promotes disease progression. Since FASN inhibitors are currently being investigated in the clinic, the results of these studies will provide a better understanding of how obesity alters the biology of the disease, and may identify a novel target for improving patient outcomes.

Citation Format: Pham T, Oberman A, Kim I, Lee G, Quach D, Galván G, Jolly C, Cavazos D, Brenner A, deGraffenried L. Modulation of FASN under obese conditions [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-07-10.

Abstract P4-04-03: Obesity-induced EMT in luminal A breast cancer cells

Introduction: Obesity is associated with a worse prognosis in breast cancer, including the less aggressive ER+ luminal A subtype, but the mechanisms by which it promotes disease progression are unclear, making treatment difficult. Obese breast cancer patients have a higher risk of a more aggressive disease compared to lean patients, which is associated with treatment resistance and metastasis. The mechanisms promoting obesity-driven metastasis are not understood, but several studies have indicated that obesity is associated with a “stem-like” phenotype. A “reprogramming” occurs, transforming stationary, epithelial cells to motile, malignant cells that exhibit a more aggressive phenotype than their stromal counterparts. Our data suggest that in vitro exposure of luminal A breast cancer cells to obese conditions may induce an epithelial to mesenchymal transition (EMT), which is characterized by a more stem-like phenotype, resistance to treatment (chemo, hormone and radiation), as well as greater metastatic potential. This has let us to hypothesize that one critical mechanism by which obesity promotes a more aggressive disease is through inducing an EMT reprogramming, resulting in a more stem-like phenotype.

Methods and Results: Both in vitro and translational approaches will be done to determine if obesity induces epigenetic reprograming associated with a more stem-like phenotype. MCF-7 ER+ breast cancer cells exposed to 2% sera from obese (BMI ≥ 30) postmenopausal women demonstrated a significant increase in expression of both SNAIL1 and TWIST transcription factors (9-fold and 4-fold, respectively) which are implicated in EMT and potentially stem-cell programming, compared to those exposed to sera from lean women. Current studies are underway to determine if this is observed in other ER+ luminal A cell lines, including T47D, and whether induced changes in these transcription factors results in changes in signaling pathways associated with EMT, including TGFβ, which can activate the PI3K–AKT, ERK MAPK, p38 MAPK and JNK pathways and WNT signaling, which promotes EMT by stabilizing β-catenin. Additionally, the luminal A cell lines will be assessed for changes in other factors known to modulate breast cancer cell programming, including KLF4, OCT4, SOX2, and NANOG.

Conclusions: Our earlier studies have demonstrated that obesity promotes a more aggressive disease even in luminal A disease. The mechanisms for this remain unclear. Our exciting preliminary findings suggest that obesity might induce a reprogramming of the luminal A well-differentiated cell to a more stem-like phenotype. Our results will lay an important foundation for understanding how obesity modulates breast cancer disease progression, whether this programming may provide therapeutic target to improve response and overall survival in the obese patient.

Citation Format: Hayden A, Quach D, Galvan G, Patodia R, Brenner A, deGraffenried L. Obesity-induced EMT in luminal A breast cancer cells [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 P4-04-03.

Abstract P6-17-03: The importance of the ultimate ratio of Omega-6 to Omega-3 fatty acids in the efficacy of fish oil supplements in suppressing inflammation in obese postmenopausal women

Over the last decade, a large body of evidence has established that obesity is associated with a worse breast cancer prognosis for both pre- and postmenopausal women. There are several mechanisms which have been proposed for promoting this effect, including stage of diagnosis and co-morbidities, but more recent evidence suggests that the obese state is associated with changes in the biology of the disease, promoting a more aggressive phenotype. Our recently published in vitro and retrospective studies suggest that this is due, at least in part, through cyclooxygenase 2 (COX-2)-derived prostaglandin E2 (PGE2), and that interventions that suppress COX-2 PGE2 production may provide significant benefit for the obese ER+ patient in preventing many of the cancer-promoting effects associated with obesity. Omega-3 fatty acids have demonstrated anti-cancer benefit through multiple mechanisms, including suppression of inflammation-related signaling. DHA and EPA (omega-3 PUFAs found in fish oil) modulate inflammatory responses through COX-2 dependent and independent mechanisms. However, previous studies investigating the potential anti-cancer benefit of omega-3 PUFA and fish oil supplementation have produced mixed results, and none have focused specifically on the obese patient population.

To determine if supplementation with non-steroidal anti-inflammatory drugs (NSAIDs), including omega-3 fatty acids, can effectively suppress PGE2 production in the obese postmenopausal patient, we conducted a double-blind, prospective Phase 0, comparative, 30 day, non-interventional study with correlative biomarker endpoints. One hundred twenty (120) postmenopausal women without breast cancer were randomized to three arms 1. ASA 81mg po daily, 2. 1500mg of docosahexaoic acid (DHA) and 2500mg eicosapentanoic acid (EPA) given daily and 3. Combined ASA and DHA/EPA at above doses. Serum samples were collected prior to and on day 29 of taking the supplements. PGE2 levels in the pre- and post-supplement serum samples were analyzed in triplicate by ELISA and presented as the percentage of change between post- and pre-supplement levels. Of the women in Arm 2 (DHA + EPA only), only 55% demonstrated a significant suppression of PGE2 levels after 30 day of supplements, compared to those in Arm 1 (ASA), in which 80% demonstrated a significant response.

We anticipate that the omega-3 fatty acid supplements were not as effective in as large a population as the aspirin due to a failure to reach a critical ratio between circulating levels omega-6 and omega-3 fatty acids, which has been shown by our own group and others to be a key determinant of cellular response. Studies are on-going to analyze the PUFA levels in both the pre and post supplement serum samples, and pre-clinical studies are being conducted to determine if the ratio of omega-6 to omega-3 PUFAs modulates PGE2 production in several different cell types, including macrophages, adipocytes and the breast cell itself. These results will be critical for moving clinical studies utilizing these agents forward, both in terms of elucidating the mechanism mediating an effect, and also in identifying an accurate biomarker for monitoring compliance and response.

Citation Format: Quach D, Lengfelder L, Winnika L, Harlow B, Galvan G, Jolly C, Brenner A, deGraffenried L. The importance of the ultimate ratio of Omega-6 to Omega-3 fatty acids in the efficacy of fish oil supplements in suppressing inflammation in obese postmenopausal women [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 P6-17-03.

Novel KDM1A inhibitors induce differentiation and apoptosis of glioma stem cells via unfolded protein response pathway

Glioma stem cells (GSCs) have a central role in glioblastoma (GBM) development and chemo/radiation resistance, and their elimination is critical for the development of efficient therapeutic strategies. Recently, we showed that lysine demethylase KDM1A is overexpressed in GBM. In the present study, we determined whether KDM1A modulates GSCs stemness and differentiation and tested the utility of two novel KDM1A-specific inhibitors (NCL-1 and NCD-38) to promote differentiation and apoptosis of GSCs. The efficacy of KDM1A targeting drugs was tested on purified GSCs isolated from established and patient-derived GBMs using both in vitro assays and in vivo orthotopic preclinical models. Our results suggested that KDM1A is highly expressed in GSCs and knockdown of KDM1A using shRNA-reduced GSCs stemness and induced the differentiation. Pharmacological inhibition of KDM1A using NCL-1 and NCD-38 significantly reduced the cell viability, neurosphere formation and induced apoptosis of GSCs with little effect on differentiated cells. In preclinical studies using orthotopic models, NCL-1 and NCD-38 significantly reduced GSCs-driven tumor progression and improved mice survival. RNA-sequencing analysis showed that KDM1A inhibitors modulate several pathways related to stemness, differentiation and apoptosis. Mechanistic studies showed that KDM1A inhibitors induce activation of the unfolded protein response (UPR) pathway. These results strongly suggest that selective targeting of KDM1A using NCL-1 and NCD-38 is a promising therapeutic strategy for elimination of GSCs.

Estimating the melting point, entropy of fusion, and enthalpy of fusion of organic compounds via SPARC

The entropy of fusion, enthalpy of fusion, and melting point of organic compounds can be estimated through three models developed using the SPARC (SPARC Performs Automated Reasoning in Chemistry) platform. The entropy of fusion is modelled through a combination of interaction terms and physical descriptors. The enthalpy of fusion is modelled as a function of the entropy of fusion, boiling point, and flexibility of the molecule. The melting point model is the enthalpy of fusion divided by the entropy of fusion. These models were developed in part to improve SPARC's vapour pressure and solubility models. These models have been tested on 904 unique compounds. The entropy model has a RMS of 12.5 J mol(-1) K(-1). The enthalpy model has a RMS of 4.87 kJ mol(-1). The melting point model has a RMS of 54.4°C.

Abstract P3-14-12: Phase 0 study evaluating COX2 inhibition on circulating PGE2 levels from obese subjects

Introduction: Obesity is associated with poor breast cancer outcomes in postmenopausal women in response to aromatase inhibitor therapy. Our prior studies have shown an association between reduced recurrence rate and use of cyclooxygenase-2 (COX-2) inhibiting non-steroidal anti-inflammatory drugs (NSAIDs) in obese breast cancer patients. The mechanism proposed was a decrease in prostaglandin E2 (PGE2) and reduced activation of the aromatase promote locally in the breast.

Methods: Postmenopausal women of varying body habitus were recruited at the CTRC in San Antonio and underwent randomized assignment to 1 of 3 arms: ASA 81mg daily, 1500mg of docosahexaenoic acid (DHA) and 2500mg eicosapentaenoic acid (EPA) given daily, or combined ASA and DHA/EPA. Sera were collected prior to and following 28 days of exposure, and cytokines including prostaglandin E2 were assessed via enzyme-linked immunosorbant assay (ELISA). Conditioned media was generated by exposing macrophages to patient sera in order to see if the patient sera induced PGE2 concentration in vitro.

Results: Thirty of the planned 120 subjects have completed assessment. No toxicity has been noted. In 71% of the patients, serum PGE2 levels decreased, but only 60% demonstrated concurrent decrease in serum PGE2 levels as well as macrophage PGE2 production, while almost all (88%) of the patients whose serum did not demonstrate a decrease in PGE2 levels also demonstrated no decrease in induced levels.

Conclusion: NSAIDs appear to effectively decrease circulating levels of PGE2 in most obese women. However, one third of the subjects did not demonstrate concurrent suppression of induced PGE2 from macrophages. These data suggest that circulating levels of PGE2 may not be reflective of local tumor microenvironment levels, and other pro-inflammatory circulating factors may be responsible for regulating local inflammatory responses. Final analysis will be completed and presented at the SABCS meeting.

Citation Format: Lengfelder L, Brenner A, Bowers L, Apte S, Galván G, Kist K, deGraffenried L. Phase 0 study evaluating COX2 inhibition on circulating PGE2 levels from obese subjects. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-14-12.

Non-radiation risk factors for leukemia: A case-control study among chornobyl cleanup workers in Ukraine

BACKGROUND

Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types. We investigated the potential for additional effects of occupational and lifestyle factors on leukemia risk in this radiation-exposed cohort.

METHODS

In a case-control study of chronic lymphocytic and other leukemias among Chornobyl cleanup workers, we collected data on a range of non-radiation exposures. We evaluated these and other potential risk factors in analyses adjusting for estimated bone marrow radiation dose. We calculated Odds Ratios and 95% Confidence Intervals in relation to lifestyle factors and occupational hazards.

RESULTS

After adjusting for radiation, we found no clear association of leukemia risk with smoking or alcohol but identified a two-fold elevated risk for non-CLL leukemia with occupational exposure to petroleum (OR=2.28; 95% Confidence Interval 1.13, 6.79). Risks were particularly high for myeloid leukemias. No associations with risk factors other than radiation were found for chronic lymphocytic leukemia.

CONCLUSIONS

These data - the first from a working population in Ukraine - add to evidence from several previous reports of excess leukemia morbidity in groups exposed environmentally or occupationally to petroleum or its products.

Non-thyroid cancer in Northern Ukraine in the post-Chernobyl period: Short report

The Chernobyl nuclear power plant accident in Ukraine in 1986 led to widespread radioactive releases into the environment - primarily of radioiodines and cesium - heavily affecting the northern portions of the country, with settlement-averaged thyroid doses estimated to range from 10 mGy to more than 10 Gy. The increased risk of thyroid cancer among exposed children and adolescents is well established but the impact of radioactive contamination on the risk of other types of cancer is much less certain. To provide data on a public health issue of major importance, we have analyzed the incidence of non-thyroid cancers during the post-Chernobyl period in a well-defined cohort of 13,203 individuals who were <18 years of age at the time of the accident. The report is based on standardized incidence ratio (SIR) analysis of 43 non-thyroid cancers identified through linkage with the National Cancer Registry of Ukraine for the period 1998 through 2009. We compared the observed and expected number of cases in three cancer groupings: all solid cancers excluding thyroid, leukemia, and lymphoma. Our analyses found no evidence of a statistically significant elevation in cancer risks in this cohort exposed at radiosensitive ages, although the cancer trends, particularly for leukemia (SIR=1.92, 95% confidence interval: 0.69; 4.13), should continue to be monitored.

Hormonal and reproductive factors and risk of postmenopausal thyroid cancer in the NIH-AARP Diet and Health Study

BACKGROUND

Worldwide, thyroid cancer incidence rates are higher among women than men. While this suggests a possible etiologic role of female sex hormones, clear associations between hormonal and reproductive factors and thyroid cancer have not been observed. However, few large prospective studies have been conducted.

METHODS

Hazard ratios (HRs) and 95% confidence intervals (CIs) for hormonal and reproductive factors and incident thyroid cancer were estimated using Cox regression methods in the prospective US NIH-AARP Diet and Health Study. Between 1995 and 2006, 312 first primary incident thyroid cancers were diagnosed among 187,865 postmenopausal women ages 50-71 at baseline.

RESULTS

Thyroid cancer was not associated with ages at menarche or menopause, menopause type, or parity. Oral contraceptive use for ≥10 years (vs. never use) was inversely associated with thyroid cancer risk (HR, 0.48; 95%CI, 0.28-0.84; P(trend)=0.01). Women who reported current menopausal hormone therapy at baseline had an increased thyroid cancer risk vs. never users (HR 1.38; 95% CI: 1.07-1.79) but there was no trend with increasing duration of use. Women with benign breast disease (BBD) had a significantly higher thyroid cancer risk vs. women without BBD (HR, 1.47; 95% CI, 1.09-1.99).

CONCLUSIONS

Our results do not support a strong role for female hormonal and reproductive factors including ages at menarche and menopause, type of menopause or parity, in thyroid cancer etiology among postmenopausal women. Compared with previous studies, no clear patterns emerge for exogenous hormone use but further analysis in large, prospective populations may be informative. The HR for BBD is consistent with the one previous prospective analysis that examined this association.

Estimation of the thyroid doses for ukrainian children exposed in utero after the chernobyl accident

This paper describes methods for estimating thyroid doses to Ukrainian children who were subjects of an epidemiological study of prenatal exposure and presents the calculated doses. Participants were 2,582 mother-child pairs in which the mother had been pregnant at the time of the Chernobyl accident on 26 April 1986 or in the 2-3 mo following when (131)I in fallout was still present. Among these, 1,494 were categorized as "exposed;" a comparison group of 1,088 was considered "relatively unexposed." Individual in utero thyroid dose estimates were found to range from less than 1 mGy to 3,200 mGy, with an arithmetic mean of 72 mGy. Thyroid doses varied primarily according to stage of pregnancy at the time of exposure and level of radioactive contamination at the location of residence. There was a marked difference between the dose distributions of the exposed and comparison groups, although nine children in the latter group had calculated doses in the range 100-200 mGy. For those children who were born after the accident and prior to the end of June 1986, postnatal thyroid doses were also estimated. About 7.7% (200) of the subjects received thyroid doses after birth that were at least 10% of their cumulative doses.

Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor

The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8-10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin - at an MLSS of 6-9 g/L - showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected.

Prevalence of hyperthyroidism after exposure during childhood or adolescence to radioiodines from the chornobyl nuclear accident: dose-response results from the Ukrainian-American Cohort Study

Relatively few data are available on the prevalence of hyperthyroidism (TSH concentrations of <0.3 mIU/liter, with normal or elevated concentrations of free T4) in individuals exposed to radioiodines at low levels. The accident at the Chornobyl (Chernobyl) nuclear plant in Ukraine on April 26, 1986 exposed large numbers of residents to radioactive fallout, principally to iodine-131 ((131)I) (mean and median doses  =  0.6 Gy and 0.2 Gy). We investigated the relationship between (131)I and prevalent hyperthyroidism among 11,853 individuals exposed as children or adolescents in Ukraine who underwent an in-depth, standardized thyroid gland screening examination 12-14 years later. Radioactivity measurements taken shortly after the accident were available for all subjects and were used to estimate individual thyroid doses. We identified 76 cases of hyperthyroidism (11 overt, 65 subclinical). Using logistic regression, we tested a variety of continuous risk models and conducted categorical analyses for all subjects combined and for females (53 cases, n  =  5,767) and males (23 cases, n  =  6,086) separately but found no convincing evidence of a dose-response relationship between (131)I and hyperthyroidism. There was some suggestion of elevated risk among females in an analysis based on a dichotomous dose model with a threshold of 0.5 Gy chosen empirically (OR  =  1.86, P  =  0.06), but the statistical significance level was reduced (P  =  0.13) in a formal analysis with an estimated threshold. In summary, after a thorough exploration of the data, we found no statistically significant dose-response relationship between individual (131)I thyroid doses and prevalent hyperthyroidism.

A screening study of thyroid cancer and other thyroid diseases among individuals exposed in utero to iodine-131 from Chernobyl fallout

BACKGROUND

Like stable iodine, radioiodines concentrate in the thyroid gland, increasing thyroid cancer risk in exposed children. Data on exposure to the embryonic/fetal thyroid are rare, raising questions about use of iodine 131 (I-131) in pregnant women. We present here estimated risks of thyroid disease from exposure in utero to I-131 fallout from the Chernobyl nuclear accident.

METHODS

We conducted a cross-sectional thyroid screening study (palpation, ultrasound, thyroid hormones, and, if indicated, fine needle aspiration) from 2003 to 2006. Participants were 2582 mother-child pairs from Ukraine in which the mother had been pregnant at the time of the accident on April 26, 1986, or 2 months after the time during which I-131 fallout was still present (1494 from contaminated areas, 1088 in the comparison group). Individual cumulative in utero thyroid dose estimates were derived from estimated I-131 activity in the mother's thyroid (mean 72 mGy; range 0-3230 mGy).

RESULTS

There were seven cases of thyroid carcinoma and one case of Hurthle cell neoplasm identified as a result of the screening. Whereas the estimated excess odds ratio per gray for thyroid carcinoma was elevated (excess odds ratio per gray 11.66), it was not statistically significant (P = 0.12). No radiation risks were identified for other thyroid diseases.

CONCLUSION

Our results suggest that in utero exposure to radioiodines may have increased the risk of thyroid carcinoma approximately 20 yr after the Chernobyl accident, supporting a conservative approach to medical uses of I-131 during pregnancy.

Comparison of three chromogenic media and enrichment broth media for the detection of methicillin-resistant Staphylococcus aureus from mucocutaneous screening specimens : Comparison of MRSA chromogenic media

This study compares the performance of three chromogenic culture agar plates, chromID MRSA, MRSA-Screen and MRSA-Select, by challenging with a collection of Staphylococcus aureus strains and screening samples obtained from hospitalised patients. All chromogenic media showed excellent sensitivity (>95%) and specificity after 18 h on the methicillin-resistant Staphylococcus aureus (MRSA) collection strains, but the specificity of MRSA-Screen decreased markedly after 42 h. Sixty-eight of 1,002 screening specimens yielded MRSA on at least one medium. The sensitivity of all media to detecting MRSA after 18 h was <50%, but this increased to 75% (chromID MRSA), 81% (MRSA-Screen) and 72% (MRSA-Select) after 42 h and 85% after enrichment and plating on the same media. The specificity at 18 h was excellent, but was significantly lower for MRSA-Screen after 42 h and enrichment. In conclusion, all media showed equivalent sensitivities after 18 h of incubation and performed better when enriched before inoculation. MRSA-Screen was more sensitive but less specific than the two other media after 42 h of incubation.

Catalytic wet air oxidation of aniline with nanocasted Mn-Ce-oxide catalyst

The catalytic wet air oxidation of aqueous solution containing 1000 ppm aniline was conducted in a trickle-bed reactor packed with a novel nanocasted Mn-Ce-oxide catalyst (surface area of 300 m2/g) prepared using SBA-15 silica as a hard template. A range of liquid hourly space velocities (5-20 h(-1)) and temperatures (110-140 degrees C) at 10 bar of oxygen were tested. The experiments were conducted to provide the intrinsic performance of the catalysts. Complete aniline conversion, 90% TOC conversion, and 80% nitrogen mineralization were achieved at 140 degrees C and 5 h(-1). Blank experiments yielded relatively low homogeneous aniline (<35%) and negligible TOC conversions. Fast deactivation of the catalysts was experienced due to leaching caused by complexation with aniline. Acidification of the solution with HCI (molar HCI to aniline ratio of 1.2) was necessary to avoid colloidization and leaching of the nanoparticulate catalyst components. The catalyst displayed stable performance for over 200 h on stream.

Safety and feasibility of long-term temozolomide treatment in patients with high-grade glioma

We surveyed neuro-oncologists regarding patients treated with temozolomide for at least 12 cycles or 12 months. Patients receiving first-line temozolomide for a median 13 cycles had a median progression-free survival (PFS) of 14 months. Patients with recurrent disease receiving a median 14 cycles had a median PFS of 15.5 months. A small percentage of patients experienced grade III to IV toxicity. These results suggest that long-term treatment with temozolomide is feasible and well tolerated.

Iodine excretion in regions of Ukraine affected by the Chornobyl Accident: experience of the Ukrainian-American cohort study of thyroid cancer and other thyroid diseases

Urinary iodine concentrations were measured in 11,926 subjects who are participants in the Ukrainian-American Cohort Study of Thyroid Cancer and Other Thyroid Diseases Following the Chornobyl Accident. Measurements were made in two time periods corresponding to the first and second thyroid screening cycles (1998-2000, 2001-2003). These time periods fall before and after initiation of a government program to increase iodine sufficiency. Median urinary iodine concentrations did increase in the later time period compared to the earlier [47.5 microg/L, 95% confidence interval (CI) 46.5-48.9 microg/L versus 41.7 microg/L, 95% CI 40.4-42.5 microg/L], but levels remained in the mild-to-moderate iodine deficiency range as defined by the World Health Organization (WHO), indicating the need for further efforts at iodination. In both time periods, urinary iodine levels were found to vary by place of residence and were lower in rural compared to urban areas. Iodine status needs to be considered when evaluating risk of thyroid cancer and other thyroid diseases.

Macrophagic myofasciitis: a summary of Dr. Gherardi's presentations

Dr. R.K. Gherardi presented two papers at the symposium, detailing his researches into a proposed new clinical entity which he has entitled Macrophagic Myofasciitis (MMF). In his first paper he described the histopathologic and immunologic characteristics of the condition, and in the second, the clinical and serologic features. Dr. Gherardi believes that MMF, a syndrome of ascending myalgias, fatigue and diffuse musculoskeletal pain, may be related to a chronic immune response to aluminum granulomas persisting at the sites of prior immunization with aluminum adjuvated vaccines.

Lung cancer and environmental tobacco smoke in a non-industrial area of China

We report results from a population-based case-control study of lung cancer and environmental tobacco smoke (ETS) among never-smokers conducted in 2 rural prefectures of China, including 200 female and 33 male lung cancer cases, and 407 female and 114 male controls, matched on age, sex and prefecture of current residence. The odds ratio (OR) for ever-exposed to ETS was 1.19 (95% CI 0.7-2.0), with a significant trend (p<0.05) with increasing exposure. ORs were 1.00, 1.04, 1.13 and 1.51 for non-exposed, <10, 10-19 and >/=20 pack-years of ETS exposure, respectively. Excess risks were limited to ETS exposures in childhood (</=18 years of age). The OR for ever-exposed to ETS in childhood, adjusting for ETS exposure in adulthood, was 1. 52 (95% CI 1.1-2.2), with a significant trend (p<0.01) with increasing pack-years of childhood exposure, 1.00, 1.43, 1.81 and 2. 95, respectively. After adjustment for ETS in childhood, there was no excess risk from adult ETS exposure. The OR for ever-exposed to ETS in adulthood was 0.90 (95% CI 0.-1.4). These results were not affected by adjustment for type of residential dwelling, type or amount of fuel used, perceived indoor smokiness, or measures of socioeconomic status, or omitting next-of-kin respondents.

Lung cancer and indoor air pollution in rural china

PURPOSE: Indoor air pollution has been linked with lung cancer in China. In contrast to previous studies conducted in urban areas with high levels of industrial pollution, we undertook a lung cancer case-control study in a rural area of China, where residents live in underground dwellings. We evaluated the effects of radon, wood and coal combustion, cooking oil fumes, and environmental tobacco smoke on lung cancer risk.METHODS: We enrolled 886 lung cancer cases (656 males, 230 females) diagnosed between 1994-98, aged 30-75 years and 1765 frequency matched population-based controls from two prefectures in Gansu Province in Northwestern China. We conducted interviews with subjects or next of kin on smoking, housing characteristics, fuel use and cooking practices. Year-long radon detectors were placed in current and former homes of subjects.RESULTS: Subjects primarily used coal (22%), wood (56%) or a combination of both (22%) for heating. Odds Ratios (OR) for lung cancer rose with increasing percent of time that coal was used to heat homes over the past 30 years (ORs = 1.00, 1.17, 1.35, 1.23 compared to wood only, adjusted to smoking, P for trend = 0.025). Among non-smoking females and males, the OR for ever exposed to environmental tobacco smoke was 1.19, 95% CI = 0.7-2.0 with a significant trend for increasing years of exposure. Fumes from cooking with rapeseed oil increased the risk of lung cancer (OR = 1.56, 95% CI = 1.0-2.5) among non-smoking women. Among these women, occasional and frequent eye and throat irritation during cooking appeared to be associated with increased risk of lung cancer (ORs = 1.00, 1.42, 2.28, p trend < 0.01), whereas, increasing level of smokiness during cooking did not appear to affect risk.CONCLUSIONS: There is a suggestion that coal used for heating, environmental tobacco smoke, and cooking oil fumes contribute to the risk of lung cancer in this rural area of China.

Lung cancer and environmental tobacco smoke in a non-industrial area of China

We report results from a population-based case-control study of lung cancer and environmental tobacco smoke (ETS) among never-smokers conducted in 2 rural prefectures of China, including 200 female and 33 male lung cancer cases, and 407 female and 114 male controls, matched on age, sex and prefecture of current residence. The odds ratio (OR) for ever-exposed to ETS was 1.19 (95% CI 0.7-2.0), with a significant trend (p<0.05) with increasing exposure. ORs were 1.00, 1.04, 1.13 and 1.51 for non-exposed, <10, 10-19 and >/=20 pack-years of ETS exposure, respectively. Excess risks were limited to ETS exposures in childhood (</=18 years of age). The OR for ever-exposed to ETS in childhood, adjusting for ETS exposure in adulthood, was 1. 52 (95% CI 1.1-2.2), with a significant trend (p<0.01) with increasing pack-years of childhood exposure, 1.00, 1.43, 1.81 and 2. 95, respectively. After adjustment for ETS in childhood, there was no excess risk from adult ETS exposure. The OR for ever-exposed to ETS in adulthood was 0.90 (95% CI 0.-1.4). These results were not affected by adjustment for type of residential dwelling, type or amount of fuel used, perceived indoor smokiness, or measures of socioeconomic status, or omitting next-of-kin respondents.

Prevalence of hypertension in patients with type II diabetes in referral versus primary care clinics

We compared the prevalence of hypertension in patients with non-insulin-dependent diabetes mellitus (NIDDM) in referral and primary care practices using definitions of The Fifth Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC-V), while controlling for other risk factors such as hypertension, obesity, smoking, and age. Patients (n = 1443) were enrolled consecutively from a large referral practice at the Jackson Diabetes Center and four primary care clinics in the vicinity. Blood pressures were measured at three clinic visits after a 5-min rest in a sitting position using a standard clinical sphygmomanometer. Charts were reviewed to determine diabetes duration, insulin usage, height, weight, smoking history, use of antihypertensive and oral hypoglycemic medications, socioeconomic status, and race. Patients were classified as hypertensive based on JNC-V definitions or if they were on antihypertensive medication. Hypertension was termed uncontrolled if blood pressure was JNC-V Stage 2 or higher while on antihypertensive medication. Seventy-eight percent of referral clinic and 55% of primary care clinic patients had either JNC-V State 1 or higher hypertension or were on antihypertensive medication. Actual blood pressures indicated that more patients had JNC-V Stage 1 (mild) or higher hypertension in referral compared to primary care clinics (62% versus 48% p = 0.01) but fewer had JNC-V Stage 2 or higher (moderate-severe) hypertension (12% versus 19% p = 0.002). Patients seen in the referral clinic were significantly more likely to have greater age, greater duration of diabetes, higher insulin dosage, longer smoking history, antihypertensive medication, and live outside the metropolitan area. By logistic regression, the odds of hypertension were significantly increased with age (OR 1.51/decade), BMI greater than 27 (OR 2.17), diabetes duration (OR 1.04/year), and insulin dosage (OR 1.74/U/kg). Current smoking and attending a referral clinic were not significantly related. The odds of moderate-severe hypertension were significantly increased with age (OR 1.23/ decade), decreased by attending a referral clinic (OR 0.45), and not significantly related to other confounders in the model. The prevalence of hypertension among patients with NIDDM was higher in referral than primary care clinics. The higher prevalence in the referral practice can be accounted for by the greater severity of associated risk factors in the referral practice patients; however, most patients will be diagnosed and treated for hypertension prior to referral. More patients in the referral practice were on hypertensive medication, which lowered the stage or severity of hypertension but still not to the normal range. The results suggest that the primary detection of hypertension in patients with type II diabetes resides with the primary care physician. Management of hypertension will require both a delineation and acceptance of responsibilities between the primary care physician and diabetes specialists.

Real-time measurement of skin radiation during cardiac catheterization

A novel skin dose monitor was used to measure radiation incident on maximal X-ray exposed skin during 135 diagnostic and 65 interventional coronary procedures. For the diagnostic studies (n = 135), mean skin dose was 180 +/- 64 mGy; for PTCA (n = 35), it was 1021 +/- 674 mGy, single stents (n = 25) 1529 +/- 601 mGy, and multiple stents with rotational atherectomy (n = 5) 2496 +/- 1028 mGy. The dose independently increased with more cine runs, more fluoroscopy, and greater patient weight. Physicians should consider the potential for adverse radiation exposure when planning coronary interventional cases and deciding on the X-ray mode and angles used.

[Recurrence after curative operation of non-small-cell bronchial carcinoma]

The poor prognosis of bronchial carcinoma is reflected among other things in a high recurrence rate. In general, recurrence is inoperable and only suitable for conservative/palliative management. The rate of curative surgical reintervention may be increased by early identification of recurrence. The value of tumour follow-up and the role of reoperation need to be assessed. 150 patients who underwent curative resection of non-small-cell lung cancer were followed-up for a mean of 4.5 years as part of a comprehensive after-care program. Fifty patients (33%) developed a recurrence at a mean of 13 months after operation. A second curative resection was possible in 9 patients (6%) with a mean survival of 22 months. Six of these patients had re-thoracotomy (completion pneumonectomy in 4 for local recurrence, mediastinal metastasectomy in 2), and in 3 patients a solitary cerebral metastasis was excised. Our results show that with focused, schematic tumour follow-up early recognition of recurrence is possible. Despite this, reoperation is only indicated in a selected group of patients because of multifocal recurrence, or local or functional inoperability. Further intensification of tumour follow-up is limited by personnel, logistical, and financial considerations. As an alternative, individualised, function-oriented tumour after-care could be considered.