Abstract OT2-1-02: Novel combination of toll-like receptor (TLR)-7 agonist imiquimod and local radiotherapy in the treatment of breast cancer chest wall recurrences or skin metastases

Background/Rationale: To assess the immune and systemic anti-tumor effects of the novel combination of local radiotherapy combined with imiquimod applied topically to breast cancer metastatic to skin. Breast cancer is the most common tumor, excluding melanoma, to metastasize to the skin in women. Chest wall recurrence is debilitating for patients, substantially affecting quality of life. Current treatment modalities for unresectable lesions are rarely curative and patients ultimately die of visceral metastases, indicating the need for more effective therapies. Imiquimod (IMQ), a synthetic TLR-7 agonist has immunomodulatory activity with profound effects on the tumor environment and can lead to tumor regression of cutaneous breast cancer metastases (Adams et al, Clin Ca Res, Dec 15, 2012). Accumulating evidence indicates that the potential of local radiotherapy to convert the tumor into an in-situ vaccine can be enhanced by combination with immunotherapy to achieve a therapeutic synergy. We have previously shown in a mouse model of cutaneous breast cancer that topical IMQ synergizes with local RT to induce complete tumor regression (REF). Importantly, this approach used a local treatment to generate anti-tumor immune responses with ability to control the tumor systemically (Dewan et al, Clin Ca Res Dec 15, 2012). This trial was designed to test the feasibility of translating this therapeutic synergy in the clinic (clinicaltrials.gov NCT01421017).

Methods: Eligibility includes patients with biopsy-confirmed breast cancer, measurable disease and skin metastases, ECOG PS 0-2 and adequate organ/marrow function. Radiation therapy is delivered to one area of skin metastases in five fractions of 6 Gy (days 1,3,5,8,10). IMQ 5% cream is applied topically to skin metastases overnight for 5 days/week for 8 weeks, beginning the evening of the first radiotherapy. Continuous imiquimod to all skin metastases even after completion of RT is based on our preclinical evidence of an improved effector phase of the immune response. Additional treatment cycles with IMQ/RT are permitted. Following a brief phase I portion to allow dose optimization in the event of unanticipated adverse events (3-3 design), the phase II study evaluates efficacy with a planned additional 25 patients. Primary endpoint is the response rate in untreated metastases, assessed by immune-related response criteria. Furthermore, the local tumor responses and safety of the combination will be determined; tumor FNA biopsies will be obtained to investigate signatures of immune-mediated rejection as recently described with IMQ mediated rejection of basal cell carcinomas; and peripheral lymphocytes will be examined for the induction/boosting of selected tumor antigen-specific T and B cell responses.

The phase I portion has been successfully completed with 6 patients without DLT. Enrollment into the phase II portion has begun. At present, a total of 11 patients have been enrolled.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-1-02.

Abstract P2-10-05: Lymphatic and pro-inflammatory candidate gene variations and breast-cancer related lymphedema

Background

Traditionally, breast cancer-related lymphedema is considered to be mainly due to the mechanical injury from cancer surgery. Recent research identified that inflammation-infection may be one of the important predictors for breast cancer-related lymphedema. This pilot study aimed to explore the associations between lymphatic and pro-inflammatory candidate gene variations and lymphedema following breast cancer treatment.

Methods

A prospective, longitudinal, repeated-measure, and comparative design was used to recruit a sample of 178 breast cancer survivors. To ensure the accuracy of lymphedema phenotype, lymphedema was classified into two phenotypes: lymphedema of arm and breast. Arm lymphedema refers to swelling in the affected arm that must have been validated by infra-red perometer-S350 and a bioimpedance device. Breast lymphedema refers to swelling in the affected breast validated by self-report and an observational scale since no objective measure is available.

Saliva samples were collected for DNA extraction from all the 178 participants. Candidate Gene Association Research Method was used to examine the eight genes known for inflammation and lymphatic specific growth factors, including candidate genes for inflammation, cytokines (IL1A, IL6, IL8, IL10, IL13) and PTGS2 (COX2), and lymphatic specific growth factors [VEGF-C & D]. Descriptive statistics, Chi-Squared tests for contingency tables and one-way analysis of variance for continuous variables were used to compare the genotypes for each of these genes in patients with and without lymphedema. Odds ratios of developing lymphedema are estimated.

Results

Among 178 survivors, 39 women were confirmed to have arm lymphedema by infra-red perometer-S350 and a bioimpedance device and 43 women had breast lymphedema. Five genes were significantly associated with breast cancer-related lymphedema. Specific single nucleic polymorphisms (SNPs) for lymphatic specific growth factors VEGF-C (rs4604006) and cytokine IL13 (rs1800925) were related to arm lymphedema. Specific SNPs of cytokine IL1A (rs1800587) and PTGS2 (COX2) (rs20417) were associated with breast lymphedema.

Conclusion

Our findings provided preliminary data on genetic susceptibility as a risk factor for breast cancer-related lymphedema. Findings of our study may serve as a preliminary foundation for a priori recognition of genetic risk that may facilitate lymphedema risk prediction prior to surgery and raises the potential for early intervention for a high-risk group.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-10-05.

Cell-cycle characteristics - alterable determinants of remission duration in a study of 179 standard risk newly diagnosed patients with acute myeloid-leukemia

Prognostic factors were related to remission duration among 179 standard risk newly diagnosed acute myeloid leukemia (AML) patients who received identical induction and consolidation therapies. Following a bromodeoxyuridine infusion, labeling indices of bone marrow aspirate/biopsy, durations of S-phase and cell cycle (Tc) were determined. Patients with slowly cycling myeloblasts had longer remissions (Log rank p=0.03) than those with rapidly cycling myeloblasts. Multivariate analysis demonstrated that both WBC and Tc contributed to remission duration (p=0.01 and 0.005 respectively). Patients with slowly proliferating leukemias have longer remissions probably due to slower regrowth of leukemia between chemotherapy courses.

Behavioral dynamics and neural grounding of a dynamic field theory of multi-object tracking

The ability to dynamically track moving objects in the environment is crucial for efficient interaction with the local surrounds. Here, we examined this ability in the context of the multi-object tracking (MOT) task. Several theories have been proposed to explain how people track moving objects; however, only one of these previous theories is implemented in a real-time process model, and there has been no direct contact between theories of object tracking and the growing neural literature using ERPs and fMRI. Here, we present a neural process model of object tracking that builds from a Dynamic Field Theory of spatial cognition. Simulations reveal that our dynamic field model captures recent behavioral data examining the impact of speed and tracking duration on MOT performance. Moreover, we show that the same model with the same trajectories and parameters can shed light on recent ERP results probing how people distribute attentional resources to targets vs. distractors. We conclude by comparing this new theory of object tracking to other recent accounts, and discuss how the neural grounding of the theory might be effectively explored in future work.

Search for charged Higgs bosons in e+e- collisions at [Formula: see text]

A search is made for charged Higgs bosons predicted by Two-Higgs-Doublet extensions of the Standard Model (2HDM) using electron-positron collision data collected by the OPAL experiment at [Formula: see text], corresponding to an integrated luminosity of approximately 600 pb-1. Charged Higgs bosons are assumed to be pair-produced and to decay into [Formula: see text], τντ or AW±. No signal is observed. Model-independent limits on the charged Higgs-boson production cross section are derived by combining these results with previous searches at lower energies. Under the assumption [Formula: see text], motivated by general 2HDM type II models, excluded areas on the [Formula: see text] plane are presented and charged Higgs bosons are excluded up to a mass of 76.3 GeV at 95 % confidence level, independent of the branching ratio BR(H±→τντ ). A scan of the 2HDM type I model parameter space is performed and limits on the Higgs-boson masses [Formula: see text] and mA are presented for different choices of tanβ.

P1-17-07: Phase II Trial of RAD001 Plus Carboplatin in Patients with Triple-Negative Metastatic Breast Cancer

Background: RAD001 is an oral mTOR inhibitor that has exhibited activity in breast cancer. Triple negative breast cancer cells are unable to repair double stranded DNA breaks and hence have sensitivity to platinum agents that cause interstrand cross-links. Rapamycin acts synergistically with platinum agents to induce apoptosis and inhibit proliferation in at least two different breast cancer cell lines (including ER/PR negative cell lines). We propose that combination RAD001 and carboplatin may have activity in triple-negative breast cancer.

Methods: The primary objective of the study is to determine clinical benefit (complete remission (CR) + partial remission (PR) + stable disease (SD)) and the toxicity of this combination in women with triple negative metastatic breast cancer who have had 0–3 prior chemotherapy regimens for metastatic disease. Secondary objectives are to determine progression free survival as well as investigating the relationship between pretreatment sensitivity (biopsy at baseline) and clinical response (biopsy post 2 cycles) using IHC staining for abundance of key proteins in the Akt-mTOR pathway and their activity using surrogate phosphorylation site-specific antibodies (Akt and phospho-serine 473, phospho-threonine and phospho-threonine 308 Akt; mTOR and phospho-serine 2448 mTOR; ribosome protein S6 kinase (S6K) and phospho-threonine 378 S6K; 4E-BP1 and phospho-serine 65 4E-BP1). Prior carboplatin is allowed. Women with treated brain metastasis are eligible. According to the original study plan, carboplatin AUC 6, was to be given intravenously every three weeks. Five mg of RAD001 was to be given daily with a 3 patient run-in and then 10 mg daily if there were no dose-limiting toxicities. Due to a unexpected amount of thrombocytopenia with this combination the dose of carboplatin was first amended to AUC 5 and most recently to AUC 4 with 5 mg of RAD001 (and no plan to escalate to 10 mg).

Results: Fourteen patients of a planned 25 have been recruited thus far. Median age is 58.5. Median number of prior regimens is 2 (0-3). Of the 7 patients assessable for response at this time, there have been 2 PR's and 5 patients with SD. One SD was achieved in a patient progressing on single agent carboplatin at study entry. Median duration of SD + PR is 28.5 weeks (5 patients have ongoing response ranging from 8–46.5 weeks). Five of 8 patients assessable for toxicity had grade 3 or 4 thrombocytopenia and 2 patients had grade 3 neutropenia. No cases of febrile neutropenia were observed. Four patients have required blood transfusion and one patient has required platelet transfusion. All patients have had treatment held and/or dose reductions secondary to hematological toxicity, however, since amended carboplatin dose the regimen has been very well tolerated with only one out of six patients) with grade 3 neutropenia and grade 3 thrombocytopenia. There have been no non-hematological grade 3 or 4 toxicities.

Conclusions: Clinical benefit was observed in all 7 assessable patients. Dose limiting thrombocytopenia was an unexpected side effect requiring protocol amendment. We continue to accrue study subjects at the amended dosing.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-17-07.