Procalcitonin and cytokine profiles in engraftment syndrome in pediatric stem cell transplantation.

BACKGROUND: Diagnosis of engraftment syndrome (ES) following allogeneic hematopoietic stem cell transplantation (HSCT) can be a challenge due to the systemic presentation and alternative etiologies. With a goal of establishing biomarkers to more accurately distinguish ES, we prospectively analyzed levels of cytokines during HSCT. PROCEDURES: We performed a prospective study of children ≤21 years who underwent allogeneic HSCT. Blood samples for interleukin (IL)-6, IL-8, IL-10, IL-1b, IL-12p70, interferon-γ, tumor necrosis factor alpha (TNF-α) and procalcitonin were obtained from each subject prior to conditioning, at day 0, and then biweekly through engraftment and at days 30, 60 and 100. Patients were evaluated for ES, infection and acute graft-versus-host disease. Cytokines were analyzed by values at engraftment, and also compared to pre-conditioning and day 0 values to evaluate for change from baseline. RESULTS: A total of 30 subjects (median age: 7 years, min.-max.: 1-21 years) were enrolled of whom 5 had ES. Characterization of the cytokine profile revealed differences between day 0 from pre-HSCT, with a trend towards differences in IL-10, IL-12p70, interferon-γ and TNF-α at the time of ES. For IL8 and procalcitonin, there was evidence that the absolute difference (or fold change) between engraftment and pre-conditioning or day 0 differed according to ES. In particular, procalcitonin increased from baseline (15.1 median fold increase in ES+ versus 2.31 median fold increase in ES-, P = 0.0006, median difference: 13.8, 95% confidence interval: 6.33, 65.6). CONCLUSIONS: Our data provide one of the first prospective studies evaluating cytokines in pediatric allogeneic HSCT and suggest that elevated procalcitonin may serve as a biomarker for ES. Further studies to evaluate this finding are warranted.

Romidepsin in peripheral and cutaneous T-cell lymphoma: mechanistic implications from clinical and correlative data.

Romidepsin is an epigenetic agent approved for the treatment of patients with cutaneous or peripheral T-cell lymphoma (CTCL and PTCL). Here we report data in all patients treated on the National Cancer Institute 1312 trial, demonstrating long-term disease control and the ability to retreat patients relapsing off-therapy. In all, 84 patients with CTCL and 47 with PTCL were enrolled. Responses occurred early, were clinically meaningful and of very long duration in some cases. Notably, patients with PTCL receiving romidepsin as third-line therapy or later had a comparable response rate (32%) of similar duration as the total population (38%). Eight patients had treatment breaks of 3.5 months to 10 years; in four of six patients, re-initiation of treatment led to clear benefit. Safety data show slightly greater haematological and constitutional toxicity in PTCL. cDNA microarray studies show unique individual gene expression profiles, minimal overlap between patients, and both induction and repression of gene expression that reversed within 24 h. These data argue against cell death occurring as a result of an epigenetics-mediated gene induction programme. Together this work supports the safety and activity of romidepsin in T-cell lymphoma, but suggests a complex mechanism of action.

Soluble CD27-pool in humans may contribute to T cell activation and tumor immunity.

The interaction between CD27 and its ligand, CD70, has been implicated in regulating cellular immune responses to cancer. In this article, we report on the role of soluble CD27 (sCD27) in T cell activation and its elevation in the serum of cancer patients after immunotherapy. In vitro, sCD27 is preferentially derived from activated CD4(+) T cells. Adding sCD27 to stimulated PBMCs increases T cell activation and proliferation, and is associated with the immunologic synapse-related proteins myosin IIA, high mobility group box 1, and the TCR Vß-chain. The pool of serum sCD27 is shown to be greater in healthy donors than in cancer patients. However, metastatic cancer patients treated with immunotherapy showed a significant increase in the serum sCD27-pool posttherapy (p < 0.0005); there was also an increased trend toward an association between enhanced sCD27-pool posttherapy and overall survival (p = 0.022). The identification of sCD27 as an immune modulator associated with enhanced human T cell activation in vitro and in vivo provides a rationale for developing new immunotherapeutic strategies aimed at enhancing sCD27 for treating cancer and potentially other diseases.

Epidithiodiketopiperazines (ETPs) exhibit in vitro antiangiogenic and in vivo antitumor activity by disrupting the HIF-1α/p300 complex in a preclinical model of prostate cancer.

The downstream targets of hypoxia inducible factor-1 alpha (HIF-1α) play an important role in tumor progression and angiogenesis. Therefore, inhibition of HIF-mediated transcription has potential in the treatment of cancer. One attractive strategy for inhibiting HIF activity is the disruption of the HIF-1α/p300 complex, as p300 is a crucial coactivator of hypoxia-inducible transcription. Several members of the epidithiodiketopiperazine (ETP) family of natural products have been shown to disrupt the HIF-1α/p300 complex in vitro; namely, gliotoxin, chaetocin, and chetomin. Here, we further characterized the molecular mechanisms underlying the antiangiogenic and antitumor effects of these ETPs using a preclinical model of prostate cancer. In the rat aortic ring angiogenesis assay, gliotoxin, chaetocin, and chetomin significantly inhibited microvessel outgrowth at a GI50 of 151, 8, and 20 nM, respectively. In vitro co-immunoprecipitation studies in prostate cancer cell extracts demonstrated that these compounds disrupted the HIF-1α/p300 complex. The downstream effects of inhibiting the HIF-1α/p300 interaction were evaluated by determining HIF-1α target gene expression at the mRNA and protein levels. Dose-dependent decreases in levels of secreted VEGF were detected by ELISA in the culture media of treated cells, and the subsequent downregulation of VEGFA, LDHA, and ENO1 HIF-1α target genes were confirmed by semi-quantitative real-time PCR. Finally, treatment with ETPs in mice bearing prostate tumor xenografts resulted in significant inhibition of tumor growth. These results suggest that directly targeting the HIF-1α/p300 complex with ETPs may be an effective approach for inhibiting angiogenesis and tumor growth.

A combination trial of vaccine plus ipilimumab in metastatic castration-resistant prostate cancer patients: immune correlates.

We recently reported the clinical results of a Phase I trial combining ipilimumab with a vaccine containing transgenes for prostate-specific antigen (PSA) and for a triad of costimulatory molecules (PROSTVAC) in patients with metastatic castration-resistant prostate cancer. Thirty patients were treated with escalating ipilimumab and a fixed dose of vaccine. Of 24 chemotherapy-naïve patients, 58 % had a PSA decline. Combination therapy did not exacerbate the immune-related adverse events associated with ipilimumab. Here, we present updated survival data and an evaluation of 36 immune cell subsets pre- and post-therapy. Peripheral blood mononuclear cells were collected before therapy, at 13 days and at 70 days post-initiation of therapy, and phenotyped by flow cytometry for the subsets of T cells, regulatory T cells, natural killer cells, and myeloid-derived suppressor cells. Associations between overall survival (OS) and immune cell subsets prior to treatment, and the change in a given immune cell subset 70 days post-initiation of therapy, were evaluated. The median OS was 2.63 years (1.77-3.45). There were trends toward associations for longer OS and certain immune cell subsets before immunotherapy: lower PD-1(+)Tim-3(NEG)CD4EM (P = 0.005, adjusted P = 0.010), higher PD-1(NEG)Tim-3(+)CD8 (P = 0.002, adjusted P = 0.004), and a higher number of CTLA-4(NEG) Tregs (P = 0.005, adjusted P = 0.010). We also found that an increase in Tim-3(+) natural killer cells post- versus pre-vaccination associated with longer OS (P = 0.0074, adjusted P = 0.015). These results should be considered as hypothesis generating and should be further evaluated in larger immunotherapy trials.

The immunological and clinical effects of mutated ras peptide vaccine in combination with IL-2, GM-CSF, or both in patients with solid tumors.

BACKGROUND: Mutant Ras oncogenes produce proteins that are unique to cancer cells and represent attractive targets for vaccine therapy. We have shown previously that vaccinating cancer patients with mutant ras peptides is feasible and capable of inducing a specific immune response against the relevant mutant proteins. Here, we tested the mutant ras peptide vaccine administered in combination with low dose interleukin-2 (IL-2) or/and granulocyte-macrophage colony-stimulating factor (GM-CSF) in order to enhance the vaccine immune response. METHODS: 5000 µg of the corresponding mutant ras peptide was given subcutaneously (SQ) along with IL-2 (Arm A), GM-CSF (Arm B) or both (Arm C). IL-2 was given SQ at 6.0 million IU/m²/day starting at day 5, 5 days/week for 2 weeks. GM-CSF was given SQ in a dose of 100 µg/day one day prior to each ras peptide vaccination for 4 days. Vaccines were repeated every 5 weeks on arm A and C, and every 4 weeks on arm B, for a maximum of 15 cycles or until disease progression. RESULTS: We treated 53 advanced cancer patients (38 with colorectal, 11 with pancreatic, 1 with common bile duct and 3 with lung) on 3 different arms (16 on arm A, 18 on arm B, and 19 on arm C). The median progression free survival (PFS) and overall survival (OS) was 3.6 and 16.9 months, respectively, for all patients evaluable for clinical response (n = 48). There was no difference in PFS or OS between the three arms (P = 0.73 and 0.99, respectively). Most adverse events were grade 1-2 toxicities and resolved spontaneously. The vaccine induced an immune response to the relevant ras peptide in a total of 20 out of 37 evaluable patients (54%) by ELISPOT, proliferative assay, or both. While 92.3% of patients on arm B had a positive immune response, only 31% of patients on arm A and 36% of patients on arm C had positive immune responses (P = 0.003, Fisher's exact test). CONCLUSIONS: The reported data showed that IL-2 might have a negative effect on the specific immune response induced by the relevant mutant ras vaccine in patients with advanced cancer. This observation deserves further investigations. TRIAL REGISTRATION: NCI97C0141.

Pazopanib inhibits the activation of PDGFRß-expressing astrocytes in the brain metastatic microenvironment of breast cancer cells.

Brain metastases occur in more than one-third of metastatic breast cancer patients whose tumors overexpress HER2 or are triple negative. Brain colonization of cancer cells occurs in a unique environment, containing microglia, oligodendrocytes, astrocytes, and neurons. Although a neuroinflammatory response has been documented in brain metastasis, its contribution to cancer progression and therapy remains poorly understood. Using an experimental brain metastasis model, we characterized the brain metastatic microenvironment of brain tropic, HER2-transfected MDA-MB-231 human breast carcinoma cells (231-BR-HER2). A previously unidentified subpopulation of metastasis-associated astrocytes expressing phosphorylated platelet-derived growth factor receptor ß (at tyrosine 751; p751-PDGFRß) was identified around perivascular brain micrometastases. p751-PDGFRß(+) astrocytes were also identified in human brain metastases from eight craniotomy specimens and in primary cultures of astrocyte-enriched glial cells. Previously, we reported that pazopanib, a multispecific tyrosine kinase inhibitor, prevented the outgrowth of 231-BR-HER2 large brain metastases by 73%. Here, we evaluated the effect of pazopanib on the brain neuroinflammatory microenvironment. Pazopanib treatment resulted in 70% (P = 0.023) decrease of the p751-PDGFRß(+) astrocyte population, at the lowest dose of 30 mg/kg, twice daily. Collectively, the data identify a subpopulation of activated astrocytes in the subclinical perivascular stage of brain metastases and show that they are inhibitable by pazopanib, suggesting its potential to prevent the development of brain micrometastases in breast cancer patients.

Levels of peripheral CD4(+)FoxP3(+) regulatory T cells are negatively associated with clinical response to adoptive immunotherapy of human cancer.

CD4(+)FoxP3(+) regulatory T cells (Tregs) have been shown to suppress T cell-mediated host immune responses against self- and nonself-antigens; however, the impact of CD4(+) Tregs on human antitumor immune responses and their influence on cancer treatment are unknown. In the present study, we explored the factors that influence CD4(+) Treg reconstitution in patients receiving adoptive immunotherapy following conditioning regimens designed to enhance T-cell function and evaluated potential associations between CD4(+) Treg levels and clinical responses to therapy. The analysis of 4 trials employing nonmyeloablative chemotherapy with or without total body irradiation (TBI) before adoptive T-cell transfer revealed that the percentage and number of reconstituting CD4(+)FoxP3(+) Tregs observed in the peripheral blood was higher in nonresponders than in responders. The addition of TBI resulted in a further depletion of CD4(+) Tregs, and the degree of depletion was dependent on the TBI dose. The number of administered doses of IL-2 was found to be positively associated with peripheral Treg reconstitution. These observations provide strong evidence that endogenous CD4(+) Tregs have a negative impact on cancer therapy, and suggest that strategies reducing Treg levels may provide clinical benefit to cancer patients. All 5 clinical trials are registered at www.clinicaltrials.gov as NCT00001832, NCT00096382, NCT00335127, NCT00509496, and NCT00513604.

The Combination of Trametinib and Ganitumab is Effective in RAS-Mutated PAX-Fusion Negative Rhabdomyosarcoma Models.

PURPOSE: PAX-fusion negative rhabdomyosarcoma (FN RMS) is driven by alterations in the RAS/MAP kinase pathway and is partially responsive to MEK inhibition. Overexpression of IGF1R and its ligands is also observed in FN RMS. Preclinical and clinical studies have suggested that IGF1R is itself an important target in FN RMS. Our previous studies revealed preclinical efficacy of the MEK1/2 inhibitor, trametinib, and an IGF1R inhibitor, BMS-754807, but this combination was not pursued clinically due to intolerability in preclinical murine models. Here, we sought to identify a combination of an MEK1/2 inhibitor and IGF1R inhibitor, which would be tolerated in murine models and effective in both cell line and patient-derived xenograft models of RAS-mutant FN RMS. EXPERIMENTAL DESIGN: Using proliferation and apoptosis assays, we studied the factorial effects of trametinib and ganitumab (AMG 479), a mAb with specificity for human and murine IGF1R, in a panel of RAS-mutant FN RMS cell lines. The molecular mechanism of the observed synergy was determined using conventional and capillary immunoassays. The efficacy and tolerability of trametinib/ganitumab was assessed using a panel of RAS-mutated cell-line and patient-derived RMS xenograft models. RESULTS: Treatment with trametinib and ganitumab resulted in synergistic cellular growth inhibition in all cell lines tested and inhibition of tumor growth in four of six models of RAS-mutant RMS. The combination had little effect on body weight and did not produce thrombocytopenia, neutropenia, or hyperinsulinemia in tumor-bearing SCID beige mice. Mechanistically, ganitumab treatment prevented the phosphorylation of AKT induced by MEK inhibition alone. Therapeutic response to the combination was observed in models without a mutation in the PI3K/PTEN axis. CONCLUSIONS: We demonstrate that combined trametinib and ganitumab is effective in a genomically diverse panel of RAS-mutated FN RMS preclinical models. Our data also show that the trametinib/ganitumab combination likely has a favorable tolerability profile. These data support testing this combination in a phase I/II clinical trial for pediatric patients with relapsed or refractory RAS-mutated FN RMS.

Association of type O blood with pancreatic neuroendocrine tumors in Von Hippel-Lindau syndrome.

BACKGROUND: ABO blood type antigens are expressed not only on human red blood cells, but also throughout the gastrointestinal tract and in normal pancreatic tissue. Previous studies have identified an association between ABO blood type and various malignancies. We analyzed the association of ABO blood type with pancreatic neuroendocrine tumors (PNETs) in a high-risk cohort of patients with Von Hippel-Lindau (VHL) syndrome. METHODS: A retrospective review was performed of 798 patients with VHL syndrome. Blood type was confirmed for 181 patients. Fisher's exact test and Mehta's modification to Fisher's exact test were used to test for an association between ABO blood type and manifestations of VHL syndrome. RESULTS: We found a strong trend for association between O blood type and pancreatic disease manifestation in patients with VHL syndrome (P = 0.047). More importantly, there was a significant association of O blood type with solid pancreatic lesions consistent with PNETs (P = 0.0084). Patients with solid pancreatic lesions who met criteria for surgical resection at the National Institutes of Health also had a higher rate of O blood type than those who did not require surgery (P = 0.051). CONCLUSIONS: Our findings suggest an association between O blood type and pancreatic manifestation of disease in patients with VHL syndrome, especially for PNETs. Screening and surveillance approaches for pancreatic lesions in patients with VHL syndrome should also consider patient blood type. The possibility of A, B, H misexpression in PNETs should also be explored to determine whether the serologic association with disease translates into a relationship with tissue pathology.

The three isoforms of nitric oxide synthase distinctively affect mouse nocifensive behavior.

Nitric oxide synthases (NOSs) have been shown to modulate thermal hyperalgesia and mechanical hypersensitivity in inflammatory and neuropathic pain. However, little is known about the effect of NOSs on baseline function of sensory nerve fibers. Using genetic deficiency and pharmacologic inhibition of NOSs, we examined the impact of the three isoforms NOS1, NOS2, and NOS3 on baseline nocifensive behavior by measuring current vocalization threshold in response to electrical stimulation at 5, 250, 2000 Hz that preferentially stimulate C, Aδ, and Aß fibers. In response to 5, 250 and 2000 Hz, NOS1-deficient animals had significantly higher current vocalization thresholds compared with wild-type. Genetic deficiency of NOS2 was associated with higher current vocalization thresholds in response to 5 Hz (C-fiber) stimulation. In contrast, NOS3-deficient animals had an overall weak trend toward lower current vocalization thresholds at 5 Hz and significantly lower current vocalization threshold compared with wild-type animals at 250 and 2000 Hz. Therefore, NOSs distinctively affect baseline mouse current vocalization threshold and appear to play a role on nocifensive response to electrical stimulation of sensory nerve fibers.

Survey of nursing integration of genomics into nursing practice.

PURPOSE: Translating clinically valid genomic discoveries into practice is hinged not only on technologic advances, but also on nurses-the largest global contingent of health providers-acquiring requisite competencies to apply these discoveries in clinical care. The study aim was to assess practicing nurse attitudes, practices, receptivity, confidence, and competency of integrating genomics into nursing practice. DESIGN: A convenience sample of practicing nurses was recruited to complete an online survey that assessed domains from Roger's Diffusion of Innovations Theory and used family history utilization as the basis for competency assessment. METHODS: Results were tabulated and analyzed using descriptive statistical techniques. FINDINGS: Two-hundred-thirty-nine licensed registered nurses, 22 to 72 years of age, with a median of 20 years in practice, responded, for an overall response rate of 28%. Most were White (83%), female (92%), and held baccalaureate degrees (56%). Seventy-one percent considered genetics to be very important to nursing practice; however, 81% rated their understanding of the genetics of common diseases as poor or fair. Per-question response rates varied widely. Instrument assessment indicated that modifications were necessary to decrease respondent burden. CONCLUSIONS: Respondents' perceived genomic competency was inadequate, family history was not routinely utilized in care delivery, and the extent of family history varied widely. However, most nurses indicated interest in pursuing continuing genomic education. CLINICAL RELEVANCE: Findings from this study can lead to the development of targeted education that will facilitate optimal workforce preparation for the ongoing influx of genetics and genomics information, technologies, and targeted therapies into the healthcare arena. This pilot study provides a foundation on which to build the next step, which includes a national nursing workforce study.

Gray zone lymphoma: chromosomal aberrations with immunophenotypic and clinical correlations.

The term gray zone lymphoma has been applied to tumors that demonstrate transitional morphologic and immunophenotypic features between classical Hodgkin's lymphoma and diffuse large B-cell lymphoma, especially primary mediastinal large B-cell lymphoma. Histopathological and genetic data are limited for these unusual cases. We analyzed cases of gray zone lymphoma (n=27), mediastinal composite lymphoma (n=3) and mediastinal synchronous/metachronous lymphoma (n=3) by morphology, immunophenotyping and fluorescence in situ hybridization. Mediastinal involvement was assured in 24/33 patients (73%). The patient cohort showed a male predominance (M:F ratio; 20:13) and a median age of 32 years (range, 16-91 years). Patients with mediastinal disease were significantly younger (median age: 29.5 years) than patients presenting without evident mediastinal disease (median age: 55 years). Gains including amplifications in 2p16.1 (REL/BCL11A locus) were observed in 33% of all patients, whereas alterations affecting the JAK2/PDL2 locus in 9p24.1 were present in 55%. Further studies revealed rearrangement of the CIITA locus at 16p13.13 in 8/30 cases (27%) and 7/26 cases (27%) demonstrated gains of 8q24 (MYC). Genetic aberrations involving 2p16.1, 9p24.1 and 8q24 showed a higher incidence in cases with evident mediastinal involvement. However, this was not statistically significant when compared with cases without known mediastinal involvement. Twelve of the 27 cases of gray zone lymphoma were morphologically more reminiscent of classical Hodgkin's lymphoma, whereas the other gray zone lymphomas presented with morphological features more closely resembling large B-cell lymphoma. Both morphological groups of gray zone lymphoma were similarly positive for Cyclin E (75 and 93%) and p63 (50 and 53%, respectively) expression. These findings further support a close relationship between gray zone lymphoma, classical Hodgkin's lymphoma and primary mediastinal large B-cell lymphoma, and suggest that some cases of gray zone lymphoma without mediastinal disease may share similar genetic alterations.

Modulating the expression of IFN regulatory factor 8 alters the protumorigenic behavior of CD11b+Gr-1+ myeloid cells.

CD11b(+)Gr-1(+)-expressing cells, termed myeloid-derived suppressor cells, can mediate immunosuppression and tumor progression. However, the intrinsic molecular events that drive their protumorigenic behavior remain to be elucidated. Although CD11b(+)Gr-1(+) cells exist at low frequencies in normal mice, it also remains unresolved whether they are biologically distinct from those of tumor-bearing hosts. These objectives were investigated using CD11b(+)Gr-1(+) cells from both implantable (4T1) and autochthonous (mouse mammary tumor virus-polyomavirus middle T Ag (MMTV-PyMT)) mouse models of mammary carcinoma. Limited variation was observed in the expression of markers associated with immunoregulation between CD11b(+)Gr-1(+) cells of both tumor models, as well as with their respective controls (Cnt). Despite limited differences in phenotype, tumor-induced CD11b(+)Gr-1(+) cells were found to produce a more immunosuppressive cytokine profile than that observed by Cnt CD11b(+)Gr-1(+) cells. Furthermore, when admixed with tumor cells, CD11b(+)Gr-1(+) cells from tumor-bearing mice significantly enhanced neoplastic growth compared with counterpart cells from Cnt mice. However, the protumorigenic behavior of these tumor-induced CD11b(+)Gr-1(+) cells was significantly diminished when the expression of IFN regulatory factor 8, a key myeloid-associated transcription factor, was enhanced. The loss of this protumorigenic effect occurred independently of the host immune system and correlated with a CD11b(+)Gr-1(+) cytokine/chemokine production pattern that resembled cells from nontumor-bearing Cnt mice. Overall, our data indicate that 1) tumor-induced CD11b(+)Gr-1(+) cells from both cancer models were phenotypically similar, but biologically distinct from their nontumor-bearing counterparts and 2) modulation of IFN regulatory factor 8 levels in tumor-induced CD11b(+)Gr-1(+) cells can significantly abrogate their protumorigenic behavior, which may have important implications for cancer therapy.

Tumor Doubling Time Using CT Volumetric Segmentation in Metastatic Adrenocortical Carcinoma.

Adrenocortical carcinoma (ACC) is a rare malignancy with an overall unfavorable prognosis. Clinicians treating patients with ACC have noted accelerated growth in metastatic liver lesions that requires rapid intervention compared to other metastatic locations. This study measured and compared the growth rates of metastatic ACC lesions in the lungs, liver, and lymph nodes using volumetric segmentation. A total of 12 patients with metastatic ACC (six male; six female) were selected based on their medical history. Computer tomography (CT) exams were retrospectively reviewed and a sampling of ≤5 metastatic lesions per organ were selected for evaluation. Lesions in the liver, lung, and lymph nodes were measured and evaluated by volumetric segmentation. Statistical analyses were performed to compare the volumetric growth rates of the lesions in each organ system. In this cohort, 5/12 had liver lesions, 7/12 had lung lesions, and 5/12 had lymph node lesions. A total of 92 lesions were evaluated and segmented for lesion volumetry. The volume doubling time per organ system was 27 days in the liver, 90 days in the lungs, and 95 days in the lymph nodes. In this series of 12 patients with metastatic ACC, liver lesions showed a faster growth rate than lung or lymph node lesions.

Longitudinal evaluation of peripheral nerve sheath tumors in neurofibromatosis type 1: growth analysis of plexiform neurofibromas and distinct nodular lesions.

BACKGROUND: Understanding the natural history of non-malignant peripheral nerve sheath tumors (PNSTs) in neurofibromatosis type 1 (NF1) is critical to optimal clinical care and the development of meaningful clinical trials. METHODS: We longitudinally analyzed growth of plexiform neurofibromas (PNs) and of PNSTs with distinct nodular appearance (distinct nodular lesions [DNLs]) using volumetric MRI analysis in patients enrolled on a natural history study (NCT00924196). RESULTS: DNLs were observed in 58/122 (45.6%) patients (median 2 DNLs/patient). In DNLs that developed during follow-up, median age of development was 17 years. A moderate negative correlation was observed between the estimated PN growth rate and patients' age at initial MRI (Spearman's r [95% CI]: -0.60 [-0.73, -0.43], n = 70), whereas only a weak correlation was observed for DNLs (Spearman's r [95% CI]: -0.25 [-0.47, 0.004]; n = 61). We observed a moderate negative correlation between tumor growth rate and baseline tumor volume for PNs and DNLs (Spearman's r [95% CI]: -0.52 [-0.67, -0.32] and -0.61 [-0.75, -0.42], respectively). Spontaneous tumor volume reduction was observed in 10 PNs and 7 DNLs (median decrease per year, 3.6% and 7.3%, respectively). CONCLUSION: We corroborate previously described findings that most rapidly growing PNs are observed in young children. DNLs tend to develop later in life and their growth is minimally age related. Distinct growth characteristics of PNs and DNLs suggest that these lesions have a different biology and may require different clinical management and clinical trial design. In a subset of PNs and DNLs, slow spontaneous regression in tumor volume was seen.

Pediatric PK/PD Phase I Trial of Pexidartinib in Relapsed and Refractory Leukemias and Solid Tumors Including Neurofibromatosis Type I-Related Plexiform Neurofibromas.

PURPOSE: Simultaneously targeting the tumor and tumor microenvironment may hold promise in treating children with refractory solid tumors. Pexidartinib, an oral inhibitor of tyrosine kinases including colony stimulating factor 1 receptor (CSF-1R), KIT, and FLT3, is FDA approved in adults with tenosynovial giant cell tumor. A phase I trial was conducted in pediatric and young adult patients with refractory leukemias or solid tumors including neurofibromatosis type 1-related plexiform neurofibromas. PATIENTS AND METHODS: A rolling six design with dose levels (DL) of 400 mg/m2, 600 mg/m2, and 800 mg/m2 once daily for 28-day cycles (C) was used. Response was assessed at regular intervals. Pharmacokinetics and population pharmacokinetics were analyzed during C1. RESULTS: Twelve patients (4 per DL, 9 evaluable) enrolled on the dose-escalation phase and 4 patients enrolled in the expansion cohort: median (lower, upper quartile) age 16 (14, 16.5) years. No dose-limiting toxicities were observed. Pharmacokinetics appeared linear over three DLs. Pharmacokinetic modeling and simulation determined a weight-based recommended phase II dose (RP2D). Two patients had stable disease and 1 patient with peritoneal mesothelioma (C49+) had a sustained partial response (67% RECIST reduction). Pharmacodynamic markers included a rise in plasma macrophage CSF (MCSF) levels and a decrease in absolute monocyte count. CONCLUSIONS: Pexidartinib in pediatric patients was well tolerated at all DL tested, achieved target inhibition, and resulted in a weight-based RPD2 dose.

Interferon regulatory factor-8 modulates the development of tumour-induced CD11b+Gr-1+ myeloid cells.

Tumour-induced myeloid-derived suppressor cells (MDSC) promote immune suppression and mediate tumour progression. However, the molecular basis for the generation of MDSC, which in mice co-express the CD11b(+) and Gr-1(+) cell surface markers remains unclear. Because CD11b(+)Gr-1(+) cells expand during progressive tumour growth, this suggests that tumour-induced events alter signalling pathways that affect normal myeloid cell development. Interferon regulatory factor-8 (IRF-8), a member of the IFN-gamma regulatory factor family, is essential for normal myelopoiesis. We therefore examined whether IRF-8 modulated tumour-induced CD11b(+)Gr-1(+) cell development or accumulation using both implantable (4T1) and transgenic (MMTV-PyMT) mouse models of mammary tumour growth. In the 4T1 model, both splenic and bone marrow-derived CD11b(+)Gr-1(+) cells of tumour-bearing mice displayed a marked reduction in IRF-8 expression compared to control populations. A causal link between IRF-8 expression and the emergence of tumour-induced CD11b(+)Gr-1(+) cells was explored in vivo using a double transgenic (dTg) mouse model designed to express transgenes for both IRF-8 and mammary carcinoma development. Despite the fact that tumour growth was unaffected, splenomegaly, as well as the frequencies and absolute numbers of CD11b(+)Gr-1(+) cells were significantly lower in dTg mice when compared with single transgenic tumour-bearing mice. Overall, these data reveal that IRF-8 plays an important role in tumour-induced development and/or accumulation of CD11b(+)Gr-1(+) cells, and establishes a molecular basis for the potential manipulation of these myeloid populations for cancer therapy.

Strategies to improve long-term outcome in stage IIIB inflammatory breast cancer: multimodality treatment including dose-intensive induction and high-dose chemotherapy.

Inflammatory breast cancer (IBC) is a rare clinicopathologic entity with a poor prognosis, lagging far behind any other form of nonmetastatic breast cancer. Since the advent of systemic chemotherapy over 35 years ago, only minimal progress has been made in long-term outcome. Although multiple randomized trials of high-dose chemotherapy and autologous progenitor cell transplantation (ASCT) for the treatment of breast cancer have yielded disappointing results, these data are not necessarily relevant to IBC, a distinct clinical and pathologic entity. Therefore, the optimal multimodality therapy for IBC is not well established, and remains unsatisfactory. We treated 21 women with nonmetastatic IBC with a multimodality strategy including high-dose melphalan (Mel)/etoposide and ASCT. The treatment was overall tolerated with acceptable morbidity, and no post-ASCT 100-day mortality. With a median potential follow-up of approximately 8 years, the estimated progression-free survival (PFS), event-free survival (EFS), and overall survival (OS) at 6 years from on-study date are: 67%, 55%, and 69%, respectively. These results from a small phase II study are among the most promising of mature outcome data for IBC. They strongly suggest, along with results of several already published phase II trials, that ASCT could play a significant role in the first line treatment of IBC.

Radiofrequency ablation induces antigen-presenting cell infiltration and amplification of weak tumor-induced immunity.

PURPOSE: To evaluate the influence of subtotal radiofrequency (RF) ablation on a tumor-specific immune response in a murine tumor model and to explore the role of intratumoral dendritic cells (ITDCs) in mediating this effect. MATERIALS AND METHODS: Animal work was performed according to an approved protocol and in compliance with the National Cancer Institute Animal Care and Use Committee guidelines and regulations. A murine urothelial carcinoma (MB49) model expressing the male minor histocompatibility (HY) antigen was inoculated subcutaneously in female mice. Fourteen days later, splenic T cells were analyzed with enzyme-linked immunosorbent spot for HY immune response (n = 57). In subsequent experiments, mice were randomized into control (n = 7), RF ablation, ITDC (n = 9), and RF ablation + ITDC (n = 9) groups and monitored for tumor growth. Eleven days after treatment, tumors were harvested for histologic and immunohistochemical analysis. Animals demonstrating complete tumor regression were rechallenged in the contralateral flank. RESULTS: Animals treated with subtotal RF ablation showed significant increases in tumor-specific class I and II responses to HY antigens and tumor regression. RF ablation, ITDC, and combined groups demonstrated similar levels of antigen-presenting cell infiltration; all groups demonstrated greater levels of infiltration compared with untreated controls. ITDC injection also resulted in tumor regression. However, combination therapy did not enhance tumor regression when compared with either treatment alone. Rechallenged mice in RF ablation, ITDC, and combination groups demonstrated significant tumor growth inhibition compared with controls. CONCLUSION: Subtotal RF ablation treatment results in enhanced systemic antitumor T-cell immune responses and tumor regression that is associated with increased dendritic cell infiltration. ITDC injection mimics the RF ablation effect but does not increase immune responses when injected immediately after RF ablation.