High-Dose Rate Brachytherapy Alone for Treatment of Unfavorable Intermediate Risk Prostate Cancer: A Propensity-Score Matched Analysis

PURPOSE/OBJECTIVE(S)

To demonstrate the feasibility of high-dose rate brachytherapy (HDR BT) as monotherapy for unfavorable intermediate risk (UIR) prostate cancer by comparing survival outcomes of HDR BT alone against external beam radiation therapy (EBRT) + HDR BT boost, +/- androgen deprivation therapy (ADT) using propensity-score matched (PSM) data.

MATERIALS/METHODS

This retrospective study queried two data registries collecting patient data from 1991 to present. 633 patients with UIR prostate cancer treated with HDR BT alone, HDR BT+EBRT or HDR+EBRT+ADT were included. HDR BT patients received 42-45Gy/6 fractions (fx) or 27 Gy/2 fx. For HDR BT+EBRT, the HDR dose was 20-24 Gy/2 fx, 24 Gy/4 fx, or 15 Gy/1 fx. EBRT patients received 45 Gy/25 fx to the prostate +/- pelvic nodes. GU/GI toxicities were graded according to the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Time-to-event analyses were carried out to evaluate the relationship between treatments and five primary endpoints of interest: freedom from biochemical recurrence (FFBC), freedom from distant metastasis (FFDM), freedom from local failure (FFLF), cancer specific survival (CSS), and overall survival (OS) at 5 years. PSM was performed with one-to-n matching. Logistic regression was used to estimate the respective propensity scores. The five potential confounders identified were T-stage, Gleason score, pre-treatment PSA, age, and percent positive cores. Balance was checked using the standardized mean difference of covariates. Univariate and multivariate analyses were conducted on the matched data. Toxicity analysis was performed via association between a change in pre- and post-treatment GU/GI toxicity status and the treatment group, as well as incidence of post-treatment severe GI/GU toxicity (grade 3 or higher) and the treatment group.

RESULTS

Univariate analysis with Kaplan-Meier method and log rank test comparison between the three cohorts demonstrated no significant difference in all survival outcomes FFBC, FFDM, FFLF, CSS, OS (p = 0.15, 0.19, 0.29, 0.57, 0.28, respectively). Multivariate analysis with Cox proportional hazard regression showed no differences in HR for FFBC and OS (p = 0.95, 0.11) with addition of EBRT, or with EBRT+ADT (p = 0.17, 0.24); no fit was obtainable for FFDM, CSS, FFLF. Toxicities between the three cohorts were not significantly different when comparing post-treatment and baseline GI/GU symptoms (p = 0.53/1). No Grade 2 or 3 GI toxicities were identified, while 8%/1% HDR patients, 10%/1% HDR+EBRT patients, and 12%/2% HDR+EBRT+ADT patients experienced Grade 2/3 GU toxicities. The incidence of grade 3 or higher GU toxicities between the three groups was not significantly different (p = 0.91).

CONCLUSION

This propensity-score matched study demonstrates the feasibility of HDR BT alone for effective treatment of UIR prostate cancer when compared to HDR+EBRT or HDR+EBRT+ADT, while potentially minimizing the added toxicities of EBRT and the undesirable side effect profile of ADT.

Liposome Consolidated with Cyclodextrin Provides Prolonged Drug Retention Resulting in Increased Drug Bioavailability in Brain

Although butylidenephthalide (BP) is an efficient anticancer drug, its poor bioavailability renders it ineffective for treating drug-resistant brain tumors. However, this problem is overcome through the use of noninvasive delivery systems, including intranasal administration. Herein, the bioavailability, drug stability, and encapsulation efficiency (EE, up to 95%) of BP were improved by using cyclodextrin-encapsulated BP in liposomal formulations (CDD1). The physical properties and EE of the CDD1 system were investigated via dynamic light scattering, transmission electron microscopy, UV–Vis spectroscopy, and nuclear magnetic resonance spectroscopy. The cytotoxicity was examined via MTT assay, and the cellular uptake was observed using fluorescence microscopy. The CDD1 system persisted for over 8 h in tumor cells, which was a considerable improvement in the retention of the BP-containing cyclodextrin or the BP-containing liposomes, thereby indicating a higher BP content in CDD1. Nanoscale CDD1 formulations were administered intranasally to nude mice that had been intracranially implanted with temozolomide-resistant glioblastoma multiforme cells, resulting in increased median survival time. Liquid chromatography–mass spectrometry revealed that drug biodistribution via intranasal delivery increased the accumulation of BP 10-fold compared to oral delivery methods. Therefore, BP/cyclodextrin/liposomal formulations have potential clinical applications for treating drug-resistant brain tumors.

Exosomes in clinical trial and their production in compliance with good manufacturing practice

Exosomes, 60–200-nm extracellular vesicles secreted from cells, have been used as an active pharmaceutical ingredient or drug carrier in disease treatment. Human- and plant-derived exosomes are registered in clinical trials, but more complete reports are available for human-derived exosomes. Because exosomes act as vesicles and carry cell secreting components, they have been used as drug or peptide vehicles to treat diseases. The dendritic cells (DCs) and mesenchymal stem cells (MSCs) are two popular cell sources for exosome preparation. Exosomes from DCs can initiate inflammation in patients, particularly in patients with cancer, as they contain the tumor antigen to induce specific inflammation response. A well-established cell bank of MSCs is available, and these cells can be used as an alternative source for exosome preparation. The major application of MSC-derived exosomes is in inflammation treatment. Exosomes in clinical trials need to comply with good manufacturing practice (GMP). Three important issues are prevalent in GMP for exosomes, i.e., upstream of cell cultivation process, downstream of the purification process, and exosome quality control. This paper concisely reviews exosome development, including exosome generation and clinical trial application.

Integration of PEG 400 into a self-nanoemulsifying drug delivery system improves drug loading capacity and nasal mucosa permeability and prolongs the survival of rats with malignant brain tumors

Introduction: Kolliphor^® EL (K-EL) is among the most useful surfactants in the preparation of emulsions. However, it is associated with low hydrophobic drug loading in the resulting emulsified formulation.

Methods: In this study, a formulation for intranasal administration of butylidenephthalide (Bdph), a candidate drug against glioblastoma (GBM), was prepared. Physical characteristics of the formulation such as particle size, zeta potential, conductivity, and viscosity were assessed, as well as its cytotoxicity and permeability, in order to optimize the formulation and improve its drug loading capacity.

Results: The optimized formulation involved the integration of polyethylene glycol 400 (PEG 400) in K-EL to encapsulate Bdph dissolved in dimethyl sulfoxide (DMSO), and it exhibited higher drug loading capacity and drug solubility in water than the old formulation, which did not contain PEG 400. Incorporation of PEG 400 as a co-surfactant increased Bdph loading capacity to up to 50% (v/v), even in formulations using Kolliphor^® HS 15 (K-HS15) as a surfactant, which is less compatible with Bdph than K-EL. The optimized Bdph formulation presented 5- and 2.5-fold higher permeability and cytotoxicity, respectively, in human GBM than stock Bdph. This could be attributed to the high drug loading capacity and the high polarity index due to DMSO, which increases the compatibility between the drug and the cell. Rats bearing a brain glioma treated with 160 mg/kg intranasal emulsified Bdph had a mean survival of 37 days, which is the same survival time achieved by treatment with 320 mg/kg stock Bdph. This implies that the optimized emulsified formulation required only half the Bdph dose to achieve an efficacy similar to that of stock Bdph in the treatment of animals with malignant brain tumor.

Role of infiltrated leucocytes in tumour growth and spread

Leucocytes are a major component of the tumour microenvironment. Recent studies have indicated that the infiltration and activity of these host cells are regulated by the tumour to promote its survival and progression. Through the production of an array of growth factors, proteases and angiogenic mediators, leucocytes in the tumour microenvironment promote tumour growth, angiogenesis and metastasis.

Total esophageal reconstruction using a tubed parascapular free flap

A method for total esophageal reconstruction when intestinal options are no longer available is presented. The technique described utilizes the parascapular microsurgical free flap, which is tubed and interposed between the cervical esophagus and the gastric remnant in the abdomen. The technique involves a well-recognized microsurgical flap and may be added to the armamentarium for total esophageal reconstruction.

Angiogenesis and vascular growth factor receptor expression in malignant melanoma

The growth and metastases of many solid tumors are dependent on the recruitment of new blood vessels. Tumor angiogenesis is most likely initiated by paracrine release of growth factors that bind to their corresponding endothelial cell surface receptors. To determine whether angiogenesis and growth factor receptor expression are consistent findings in malignant melanoma, primary human melanomas were examined for mRNA expression of receptors for fibroblast growth factors (FGFR-1, FGFR-2), vascular endothelial growth factor (VEGFR-1, VEGFR-2), and the receptors Tiel and Tie2. Charts were reviewed and archival formalin-fixed, paraffin-embedded primary tumors were obtained from patients with thin (<1 mm; n = 10), intermediate (1 to 4 mm; n = 10), or thick malignant melanoma (>4 mm; n = 8). Also examined was whether melanoma cell lines could induce endothelial growth factor receptor synthesis by metabolic labeling. It was found that tumor vascularity did not correlate with clinical stage, melanoma thickness, or clinical outcome. It was also found that melanoma cell lines were not capable of directly regulating endothelial cell synthesis of growth factor receptors. However, expression of Tiel and VEGFR-2 mRNA by the tumor vasculature in select stage IA-IIB patients, and FGFR-1 mRNA expression by the tumor cells in the same clinical stages was found. The expression of these growth factor receptors did not correlate with clinical outcome. These data suggest that angiogenesis is not a prominent characteristic of primary malignant melanoma lesions and that the endothelial cell expression of Tiel and VEGFR-2 in vivo is probably not directly induced by the tumor.

Methemoglobinemia secondary to topical silver nitrate therapy--a case report

Methemoglobinemia is a rare complication in individuals exposed to nitrates or nitrites. Whereas methemoglobinemia is a recognized potential complication in burn patients treated with topical 0.5% silver nitrate solution, no report of methemoglobinemia in burn patients has been present in the literature for more than 15 years. We raise consciousness about this complication with a case report of a 12-month-old child with necrotizing fasciitis resulting from a cutaneous flank infection. The patient developed cyanosis 20 days after initiation of topical treatment with 0.5% silver nitrate solution. Intravenous injection of methylene blue can restore normal blood oxygenation.

Complexity in uterine macrophage responses to cytokines in mice

Uterine stromal macrophages change dramatically in density and morphology through the estrous cycle and during early pregnancy, whereas those in the mesometrial triangle do not undergo these changes. The mononuclear phagocytic growth factor, colony-stimulating factor-1 (CSF-1), regulates both the density and morphology of uterine macrophage populations, as shown by the fact that uterine macrophages are depleted and more rounded in the absence of CSF-1 caused by the osteopetrotic (csfm(op)) null mutation, compared to those of normal mice. Restoration of circulating CSF-1 to the nullizygous mice did not affect stromal macrophage density although it restored the population in the mesometrial triangle. This suggests CSF-1 regulation of these macrophage populations by local and humoral routes, respectively. Nevertheless, even in the absence of CSF-1, stromal macrophage population density varies 30-fold through the estrous cycle, suggesting the involvement in their regulation of factors other than CSF-1, such as the chemokines, which are chemoattractive for macrophages. The mRNA for the chemokines JE (MCP-1), C10, RANTES, and MIP1alpha are expressed in the uterus, with elevated levels observed on the first day of pregnancy. Such molecules, together with CSF-1, may play a role in modulating the complexities of uterine macrophage dynamics in response to sex steroid hormones and mating.

A1, a Bcl-2 family member, prolongs cell survival and permits myeloid differentiation

A1, a bcl-2 family member, has been identified as a hematopoietic-specific, early inducible gene. In this study it is shown that stable transfection of A1 into an interleukin-3 (IL-3)-dependent myeloid precursor cell line, 32D c13, leads to a retardation of IL-3 withdrawal-induced cell death similar to that observed with transfection of bcl-2. However, unlike bcl-2. A1 expression permits the accumulation of differentiated myeloid cells both before and after IL-3 withdrawal. Total cell accumulation, on the other hand, is considerably greater after IL-3 deprivation in the bcl-2 transfectant than in A1-expressing cells. Cells cotransfected with the two genes behave similarly to cells singly transfected with bcl-2, except that viability following IL-3 withdrawal is somewhat further enhanced. These results suggest that these two proteins have distinct roles that may be related to the divergent regulation of their expression during myeloid differentiation.

HIV infection and surgeons

The human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome, which remains uniformly fatal in affected individuals. A common route of HIV transmission is via inoculation of contaminated blood, which may occur during surgical procedures. Surgeons may estimate their risk of HIV infection over a 30-year surgical career based on HIV prevalence among surgical patients, percutaneous injury rate per operation, and seroconversion rate. Surgeons can reduce their risk by various means, but the most pragmatic is by reducing the rate of percutaneous injury through optimal surgical technique and proper precautions.

Selective induction of the beta chemokine C10 by IL-4 in mouse macrophages

The beta chemokines are a family of 8- to 12-kDa leukocyte chemoattractants that are typically produced by activated macrophages or lymphocytes. We examined the expression in primary macrophages of a recently described, and as yet functionally uncharacterized, murine beta chemokine, C10, and contrasted its regulation with that of several other beta chemokines. Although three other beta chemokines, macrophage inflammatory protein-1 alpha (MIP-1 alpha), JE, and RANTES, were all induced by LPS treatment of bone marrow-derived macrophages (BMM) and/or resident peritoneal macrophages (RPM), LPS stimulation of C10 was never observed. Conversely, IL-3 and granulocyte macrophage-CSF (GM-CSF) strongly induced C10 in both macrophage populations, whereas MIP-1 alpha and RANTES showed a weaker induction restricted to BMM. JE was strongly induced but only in BMM. Finally, IL-4 strongly induced C10 in a dose-dependent manner in both BMM and RPM but failed to stimulate any of the other three beta chemokines. The accumulation of C10 protein in culture supernatants paralleled the induction of mRNA, and the combination of IL-4 and GM-CSF led to enhanced protein levels. The expression of the C10 message in response to cytokines was completely blocked by cycloheximide, whereas the other three chemokines were all overexpressed in the presence of this inhibitor. These results demonstrate a sharp divergence between the regulation of C10 expression and that of other chemokines and suggest that this molecule may have distinct functions in host defense.

Selective induction of the beta chemokine C10 by IL-4 in mouse macrophages

The beta chemokines are a family of 8- to 12-kDa leukocyte chemoattractants that are typically produced by activated macrophages or lymphocytes. We examined the expression in primary macrophages of a recently described, and as yet functionally uncharacterized, murine beta chemokine, C10, and contrasted its regulation with that of several other beta chemokines. Although three other beta chemokines, macrophage inflammatory protein-1 alpha (MIP-1 alpha), JE, and RANTES, were all induced by LPS treatment of bone marrow-derived macrophages (BMM) and/or resident peritoneal macrophages (RPM), LPS stimulation of C10 was never observed. Conversely, IL-3 and granulocyte macrophage-CSF (GM-CSF) strongly induced C10 in both macrophage populations, whereas MIP-1 alpha and RANTES showed a weaker induction restricted to BMM. JE was strongly induced but only in BMM. Finally, IL-4 strongly induced C10 in a dose-dependent manner in both BMM and RPM but failed to stimulate any of the other three beta chemokines. The accumulation of C10 protein in culture supernatants paralleled the induction of mRNA, and the combination of IL-4 and GM-CSF led to enhanced protein levels. The expression of the C10 message in response to cytokines was completely blocked by cycloheximide, whereas the other three chemokines were all overexpressed in the presence of this inhibitor. These results demonstrate a sharp divergence between the regulation of C10 expression and that of other chemokines and suggest that this molecule may have distinct functions in host defense.

Increased expression of Fc gamma RI on isolated PMN from individuals of African descent

Fc gamma R plays an important role in host defense, triggering and/or facilitating many immunologic responses. Of the three defined Fc gamma Rs, Fc gamma RI (CD64) is not known to be constitutively expressed on normal PMN. We report here that there is markedly increased expression of Fc gamma RI on the PMN of normal, healthy blacks, detected by binding of monoclonal antibody to this receptor. This may have significant implications when multiracial data are pooled in studies of receptor expression as markers of response to various chemotherapeutic agents.

Characterization of A1, a novel hemopoietic-specific early-response gene with sequence similarity to bcl-2

Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates hemopoietic cell proliferation, differentiation, and functional activation by inducing the expression of specific genes. As part of an investigation of the regulation of gene expression by GM-CSF, we have previously identified a novel murine GM-CSF-inducible gene, A1. In this report, we present the complete nucleotide sequence of the A1 mRNA as well as a portion of the 5' flanking region, and describe the expression pattern of the gene. The results demonstrate that A1 is a hemopoietic tissue-specific gene that is expressed in several hemopoietic cell lineages, including T-helper lymphocytes, macrophages, and neutrophils. In murine bone marrow-derived macrophages, A1 gene expression is rapidly and transiently induced by GM-CSF, and the induction was independent of de novo protein synthesis. In addition to GM-CSF, a transient induction of A1 mRNA accumulation was observed in response to LPS in macrophages. This induction is not mediated by IL-1 alpha or IL-6, neither of which stimulate A1. In the myeloid precursor cell line, 32D cl3, A1 gene expression is stably induced during granulocyte colony-stimulating factor-stimulated myeloid cell differentiation. The A1 message encodes a predicted polypeptide with an M(r) of 20,024 and no signal peptide. The peptide sequence contains a region of 80 amino acids that shows similarity to bcl-2 and to the recently described bcl-2-related gene, MCL1. These data demonstrate that A1 is a novel early-response gene whose expression is associated with a variety of stimuli and occurs in several hemopoietic cell types.

Characterization of A1, a novel hemopoietic-specific early-response gene with sequence similarity to bcl-2

Granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates hemopoietic cell proliferation, differentiation, and functional activation by inducing the expression of specific genes. As part of an investigation of the regulation of gene expression by GM-CSF, we have previously identified a novel murine GM-CSF-inducible gene, A1. In this report, we present the complete nucleotide sequence of the A1 mRNA as well as a portion of the 5' flanking region, and describe the expression pattern of the gene. The results demonstrate that A1 is a hemopoietic tissue-specific gene that is expressed in several hemopoietic cell lineages, including T-helper lymphocytes, macrophages, and neutrophils. In murine bone marrow-derived macrophages, A1 gene expression is rapidly and transiently induced by GM-CSF, and the induction was independent of de novo protein synthesis. In addition to GM-CSF, a transient induction of A1 mRNA accumulation was observed in response to LPS in macrophages. This induction is not mediated by IL-1 alpha or IL-6, neither of which stimulate A1. In the myeloid precursor cell line, 32D cl3, A1 gene expression is stably induced during granulocyte colony-stimulating factor-stimulated myeloid cell differentiation. The A1 message encodes a predicted polypeptide with an M(r) of 20,024 and no signal peptide. The peptide sequence contains a region of 80 amino acids that shows similarity to bcl-2 and to the recently described bcl-2-related gene, MCL1. These data demonstrate that A1 is a novel early-response gene whose expression is associated with a variety of stimuli and occurs in several hemopoietic cell types.

The effects of IL-1, IL-2, and tumor necrosis factor on polymorphonuclear leukocyte Fc gamma receptor-mediated phagocytosis. IL-2 down-regulates the effect of tumor necrosis factor

It has been reported that the Fc gamma R-mediated phagocytic activity of polymorphonuclear leukocytes (PMN) from patients with acute bacterial infections is markedly enhanced when compared with healthy controls. Inasmuch as several potent cytokines are known to be involved in inflammatory and infectious processes, we studied the effects of three such cytokines (IL-1 beta, IL-2, and TNF-alpha) on normal PMN Fc gamma R-mediated phagocytosis. IL-1 beta and TNF alpha both caused a significant increase in the ingestion of EIgG by adherent PMN. In combination, IL-1 beta and TNF-alpha had an additive effect, even when each was used at its optimal concentration. In contrast to the enhancing effects mediated by IL-1 beta and TNF-alpha, IL-2 alone had no significant effect on PMN phagocytosis. Notably, however, IL-2 at a concentration of 10(4) U/ml partially inhibited TNF-alpha-mediated enhancement of phagocytosis by decreasing TNF binding to the PMN cell surface. This inhibitory effect of IL-2 on TNF was reversed by anti-IL-2 antibody and mAb directed against the low affinity IL-2R (anti-Tac), whereas mAb directed against the intermediate affinity receptor (mik-beta 1) had no such effect. These findings may have important physiologic implications, because patients receiving IL-2 therapy have been shown to have increased susceptibility to infection.

The effects of IL-1, IL-2, and tumor necrosis factor on polymorphonuclear leukocyte Fc gamma receptor-mediated phagocytosis. IL-2 down-regulates the effect of tumor necrosis factor

It has been reported that the Fc gamma R-mediated phagocytic activity of polymorphonuclear leukocytes (PMN) from patients with acute bacterial infections is markedly enhanced when compared with healthy controls. Inasmuch as several potent cytokines are known to be involved in inflammatory and infectious processes, we studied the effects of three such cytokines (IL-1 beta, IL-2, and TNF-alpha) on normal PMN Fc gamma R-mediated phagocytosis. IL-1 beta and TNF alpha both caused a significant increase in the ingestion of EIgG by adherent PMN. In combination, IL-1 beta and TNF-alpha had an additive effect, even when each was used at its optimal concentration. In contrast to the enhancing effects mediated by IL-1 beta and TNF-alpha, IL-2 alone had no significant effect on PMN phagocytosis. Notably, however, IL-2 at a concentration of 10(4) U/ml partially inhibited TNF-alpha-mediated enhancement of phagocytosis by decreasing TNF binding to the PMN cell surface. This inhibitory effect of IL-2 on TNF was reversed by anti-IL-2 antibody and mAb directed against the low affinity IL-2R (anti-Tac), whereas mAb directed against the intermediate affinity receptor (mik-beta 1) had no such effect. These findings may have important physiologic implications, because patients receiving IL-2 therapy have been shown to have increased susceptibility to infection.

Effects of ethanol on CRF release in vitro

Acute ethanol exposure produces activation of the brain-pituitary-adrenal (BPA) axis, resulting in the release of ACTH, beta-endorphin, and glucocorticoids. While elevated levels of plasma glucocorticoids are also found after chronic ethanol administration, plasma ACTH and beta-endorphin are normal or reduced. It is also unclear whether chronic ethanol exposure results in tolerance to the stimulatory effect of ethanol on BPA activity. To determine the site and mechanism of ethanol action on the BPA axis we studied the CRF secretory profile in a superfused rat hypothalamic preparation after chronic ethanol administration in vivo and the CRF responses after acute ethanol exposure in vitro. Superfused hypothalami from normal and pair-fed control rats released CRF-like immunoreactive material (CRF-LI) in a pulsatile manner, with a mean (+/- SE) frequency of 5.1 +/- 0.7 pulses/h. In contrast, the pulse frequency of CRF-LI release from hypothalami of rats receiving chronic ethanol treatment (fed an alcohol-containing liquid diet for 2 weeks) increased dramatically; the basal mean CRF level, pulse amplitude, and pulse duration remained unchanged. Hypothalamic CRF content was decreased. This chronic ethanol exposure also altered the dose-response characteristics of CRF release when ethanol was introduced acutely, as a pulse, into the in vitro preparation. Acute exposure to 20 mg/100 ml ethanol produced greater release of CRF-LI from control hypothalami than from chronic ethanol-exposed hypothalami. A further elevation above basal levels was produced by 200 mg/100 ml ethanol in control, but not ethanol-exposed, hypothalami. Secretion of CRF from ethanol-exposed hypothalami in response to depolarizing concentrations of potassium chloride was suppressed. Chronic ethanol treatment had no effect on CRF-LI and CRF bioactivity responses to stimulation with acetylcholine. These findings suggest the presence of a high frequency pulse-generating mechanism for CRF release in the hypothalamus. This pulsatile secretory mechanism is altered by chronic ethanol exposure of the animals in vivo. Chronic intoxication resulted in tolerance to the stimulatory effect of ethanol on CRF release in vitro.