Consistent and effective method to define the mouse estrous cycle stage by a deep learning-based model

The mouse estrous cycle is divided into four stages: proestrus (P), estrus (E), metestrus (M), and diestrus (D). The estrous cycle affects reproductive hormone levels in a wide variety of tissues. Therefore, to obtain reliable results from female mice, it is important to know the estrous cycle stage during sampling. The stage can be analyzed from a vaginal smear under a microscope. However, it is time-consuming, and the results vary between evaluators. Here, we present an accurate and reproducible method for staging the mouse estrous cycle in digital whole-slide images (WSIs) of vaginal smears. We developed a model using a deep convolutional neural network (CNN) in a cloud-based platform, Aiforia Create. The CNN was trained by supervised pixel-level multiclass semantic segmentation of image features from 171 hematoxylin-stained samples. The model was validated by comparing the results obtained by CNN with those of four independent researchers. The validation data included three separate studies comprising altogether 148 slides. The total agreement attested by the Fleiss kappa value between the validators and the CNN was excellent (0.75), and when D, E, and P were analyzed separately, the kappa values were 0.89, 0.79, and 0.74, respectively. The M stage is short and not well defined by the researchers. Thus, identification of the M stage by the CNN was challenging due to the lack of proper ground truth, and the kappa value was 0.26. We conclude that our model is reliable and effective for classifying the estrous cycle stages in female mice.

The lack of HSD17B3 in male mice results in disturbed Leydig cell maturation and endocrine imbalance akin to humans with HSD17B3 deficiency

Hydroxysteroid (17β) dehydrogenase type 3 (HSD17B3) deficiency causes a disorder of sex development in humans, where affected males are born with female-appearing external genitalia, but are virilized during puberty. The hormonal disturbances observed in the Hsd17b3 knockout mice (HSD17B3KO), generated in the present study, mimic those found in patients with HSD17B3 mutations. Identical to affected humans, serum T in the adult HSD17B3KO mice was within the normal range, while a striking increase was detected in serum A-dione concentration. This resulted in a marked reduction of the serum T/A-dione ratio, a diagnostic hallmark for the patients with HSD17B3 deficiency. However, unlike humans, male HSD17B3KO mice were born with normally virilized phenotype, but presenting with delayed puberty. In contrast to the current belief, data from HSD17B3KO mice show that the circulating T largely originates from the testes, indicating a strong compensatory mechanism in the absence of HSD17B3. The lack of testicular malignancies in HSD17B3KO mice supports the view that testis tumors in human patients are due to associated cryptorchidism. The HSD17B3KO mice presented also with impaired Leydig cell maturation and signs of undermasculinization in adulthood. The identical hormonal disturbances between HSD17B3 deficient knockout mice and human patients make the current mouse model valuable for understanding the mechanism of the patient phenotypes, as well as endocrinopathies and compensatory steroidogenic mechanisms in HSD17B3 deficiency.

Insights into the role of androgen receptor in human testicular peritubular cells

Contractile smooth muscle-like peritubular cells build the wall of seminiferous tubules in men. They are crucial for sperm transport and complement the functions of Sertoli cells by secreting factors, including glial cell line-derived neurotrophic factor. Previous studies revealed that they also secrete the chemokine C-X-C motif chemokine ligand 12 (CXCL12), which has known roles in spermatogenesis. Peritubular cells express the androgen receptor (AR), which is retained in isolated human testicular peritubular cells. We aimed to explore AR-regulated functions in human testicular peritubular cells. Bearing in mind that infertile men often have high aromatase activity, which may lower intratesticular androgen concentrations, an animal model for male infertility was studied. These mice display an age-dependent loss in spermatogenesis due to high aromatase activity. Human testicular peritubular cells were exposed to dihydrotestosterone or the antiandrogen flutamide. We studied AR, smooth muscle cell markers, glial cell line-derived neurotrophic factor and 15 secreted factors previously identified, including CXCL12. We used qPCR, Western blotting, ELISA or selected reaction monitoring (SRM). In the animal model for male infertility, we employed qPCR and immunohistochemistry. Dihydrotestosterone increased AR and flutamide prevented these actions. The smooth muscle cell markers calponin and smooth muscle actin were likewise increased, while cell size or cellular proliferation was not changed. Dihydrotestosterone did not increase glial cell line-derived neurotrophic factor or CXCL12 secretion but increased levels of serine proteinase inhibitor (SERPIN) E1. The animal model for male infertility with high aromatase activity showed reduced numbers of AR-immunoreactive testicular peritubular cells, suggesting that altered androgen and/or oestrogen levels could influence AR-mediated responses in peritubular cells. Androgens act on human testicular peritubular cells to enhance AR levels, their contractile phenotype and to modulate the secretion of some secreted factors. This study suggests that some aspects of human peritubular cell functions are regulated by androgens.

Prä- und intraoperative Volumenbestimmung bei Craniopharyngiomcysten

Die richtige Dosierung des 90Y für die intracavitäre Therapie bei monocystischen Craniopharyngiomen setzt die genaue Bestimmung des Cystenvolumens voraus. Der intraoperativen Volumenbestimmung mittels Radionuklid-Verdünnungsanalyse wurde die präoperative Volumetrie mit Hilfe von Computertomographieaufnahmen gegenübergestellt. Die Ergebnisse beider Verfahren zeigten eine gute übereinstimmung. Zur frühzeitigen Erkennung von Komplikationen werden Aufnahmen mit der Gammakamera als notwendig erachtet.

Phase 2 placebo-controlled, double-blind trial of dasatinib added to gemcitabine for patients with locally-advanced pancreatic cancer

Background

Pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate with limited treatment options. Gemcitabine provides a marginal survival benefit for patients with advanced PDAC. Dasatinib is a competitive inhibitor of Src kinase, which is overexpressed in PDAC tumors. Dasatinib and gemcitabine were combined in a phase 1 clinical trial where stable disease was achieved in two of eight patients with gemcitabine-refractory PDAC.

Patients and methods

This placebo-controlled, randomized, double-blind, phase II study compared the combination of gemcitabine plus dasatinib to gemcitabine plus placebo in patients with locally advanced, non-metastatic PDAC. Patients received gemcitabine 1000 mg/m2 (30-min IV infusion) on days 1, 8, 15 of a 28-day cycle combined with either 100 mg oral dasatinib or placebo tablets daily. The primary objective was overall survival (OS), with safety and progression-free survival (PFS) as secondary objectives. Exploratory endpoints included overall response rate, freedom from distant metastasis, pain and fatigue progression and response rate, and CA19-9 response rate.

Results

There was no statistically significant difference in OS between the two treatment groups (HR = 1.16; 95% confidence interval [CI]: 0.81-1.65; P = 0.5656). Secondary and exploratory endpoint analyses also showed no statistically significant differences. The burden of toxicity was higher in the dasatinib arm.

Conclusions

Dasatinib failed to show increased OS or PFS in patients with locally advanced PDAC. Alternative combinations or trial designs may show a role for src inhibition in PDAC treatment.

Sterile inflammation as a factor in human male infertility: Involvement of Toll like receptor 2, biglycan and peritubular cells

Changes in the wall of seminiferous tubules in men with impaired spermatogenesis imply sterile inflammation of the testis. We tested the hypothesis that the cells forming the wall of seminiferous tubules, human testicular peritubular cells (HTPCs), orchestrate inflammatory events and that Toll like receptors (TLRs) and danger signals from the extracellular matrix (ECM) of this wall are involved. In cultured HTPCs we detected TLRs, including TLR2. A TLR-2 ligand (PAM) augmented interleukin 6 (IL-6), monocyte chemo-attractant protein-1 (MCP-1) and pentraxin 3 (PTX3) in HTPCs. The ECM-derived proteoglycan biglycan (BGN) is secreted by HTPCs and may be a TLR2-ligand at HTPCs. In support, recombinant human BGN increased PTX3, MCP-1 and IL-6 in HTPCs. Variable endogenous BGN levels in HTPCs derived from different men and differences in BGN levels in the tubular wall in infertile men were observed. In testes of a systemic mouse model for male infertility, testicular sterile inflammation and elevated estradiol (E2) levels, BGN was also elevated. Hence we studied the role of E2 in HTPCs and observed that E2 elevated the levels of BGN. The anti-estrogen ICI 182,780 blocked this action. We conclude that TLR2 and BGN contribute to sterile inflammation and infertility in man.

Weight gain and inflammation regulate aromatase expression in male adipose tissue, as evidenced by reporter gene activity

Obesity and white adipose tissue (WAT) inflammation are associated with enhanced aromatization in women, but little is known about the regulation of aromatase (CYP19A1) gene expression in male WAT. We investigated the impact of weight gain and WAT inflammation on the regulation of CYP19A1 in males, by utilizing the hARO-Luc aromatase reporter mouse model containing a >100-kb 5'-region of the human CYP19A1 gene. We show that hARO-Luc reporter activity is enhanced in WAT of mice with increased adiposity and inflammation. Dexamethasone and TNFα, as well as forskolin and phorbol 12-myristate 13-acetate, upregulate hARO-Luc activity, suggesting the involvement of promoters I.4 and I.3/II. Furthermore, we show that diet enriched with antioxidative plant polyphenols attenuates WAT inflammation and hARO-Luc activity in obese males. In conclusion, our data suggest that obesity-associated WAT inflammation leads to increased peripheral CYP19A1 expression in males, and that polyphenol-enriched diet may have the potential to attenuate excessive aromatization in WAT of obese men.

High levels of the extracellular matrix proteoglycan decorin are associated with inhibition of testicular function

Decorin (DCN), a component of the extracellular matrix of the peritubular wall and the interstitial areas of the human testis, can interact with growth factor (GF) signalling, thereby blocking downstream actions of GFs. In the present study the expression and regulation of DCN using both human testes and two experimental animal models, namely the rhesus monkey and mouse, were examined. DCN protein was present in peritubular and interstitial areas of adult human and monkey testes, while it was almost undetectable in adult wild type mice. Interestingly, the levels and sites of testicular DCN expression in the monkeys were inversely correlated with testicular maturation markers. A strong DCN expression associated with the abundant connective tissue of the interstitial areas in the postnatal through pre-pubertal phases was observed. In adult and old monkeys the DCN pattern was similar to the one in normal human testes, presenting strong expression at the peritubular region. In the testes of both infertile men and in a mouse model of inflammation associated infertility (aromatase-overexpressing transgenic mice), the fibrotic changes and increased numbers of tumour necrosis factor (TNF)-α-producing immune cells were shown to be associated with increased production of DCN. Furthermore, studies with human testicular peritubular cells isolated from fibrotic testis indicated that TNF-α significantly increased DCN production. The data, thus, show that an increased DCN level is associated with impaired testicular function, supporting our hypothesis that DCN interferes with paracrine signalling of the testis in health and disease.

T cell-tumor interaction directs the development of immunotherapies in head and neck cancer

The competent immune system controls disease effectively due to induction, function, and regulation of effector lymphocytes. Immunosurveillance is exerted mostly by cytotoxic T-lymphocytes (CTLs) while specific immune suppression is associated with tumor malignancy and progression. In squamous cell carcinoma of the head and neck, the presence, activity, but also suppression of tumor-specific CTL have been demonstrated. Functional CTL may exert a selection pressure on the tumor cells that consecutively escape by a combination of molecular and cellular evasion mechanisms. Certain of these mechanisms target antitumor effector cells directly or indirectly by affecting cells that regulate CTL function. This results in the dysfunction or apoptosis of lymphocytes and dysregulated lymphocyte homeostasis. Another important tumor-escape mechanism is to avoid recognition by dysregulation of antigen processing and presentation. Thus, both induction of functional CTL and susceptibility of the tumor and its microenvironment to become T cell targets should be considered in CTL-based immunotherapy.

Abstract P6-14-06: Prospective Testing of Three Different Gene-Signatures for Patient Selection for Dasatinib Therapy in Metastatic Breast Cancer

Background: Several gene signature-based predictors of response to targeted drugs have been proposed in the literature but none has been prospectively tested as patient selection tools in the clinic. The goal of this trial is to assess the positive predictive value of 3 conceptually different multi-gene signatures as predictors of response to the multitargeted kinase inhibitor dasatinib.

Methods: This clinical trial requires biopsy of a metastatic lesion for gene expression profiling and employs a parallel, multi-arm, two-step, phase II design. Three markers are assessed including a (i) cell-line derived dasatinib-sensitivity signature, (ii) a src-pathway activity signature and (iii) a dasatinib target index calculated as the weighted average expression of all known dasatinib targets. Only markerpositive patients are treated with dasatinib 100 mg po daily and each marker arm is considered as a separate study with early stopping rules for futility (minimum sample size 9, maximum sample size 40/marker arm). A predictor is considered worthy of further study if the clinical benefit rate (i.e. positive predictive value) is ≥25%.

Results: Forty seven patients were accrued from July 2009 through June, 2010, 49 biopsies were performed (soft tissues n=31, liver n=8, bone n=3, lung n=1, adrenal gland n=1), 6 samples had poor cellularity and 3 failed array QC. There was no patient recall, hospitalization or emergency room visit due to biopsy procedure. The median time from biopsy to genomic prediction result was 5 days (range 3-7). Twenty three (57%) patients had positive result for at least 1 predictor (5 were positive for 2) and 20 are receiving therapy (3 withdraw or progressed before therapy began). Responses as of June 2010; Target index arm (n=9): 5 PD (progressive disease), 4 SD (3 stable disease at 8 weeks 1 SD at 16 weeks); SRC Pathway arm (n=5): 3 PD, 2 SD at 8 weeks; Cell line predictor arm (n=6): 2 PD, 1 SD at 8 weeks, 3 not yet reached response evaluation. None of the 3 predictive marker arms have met early stopping yet and accrual is ongoing. Conclusion: Gene-expression signature based patient selection for targeted therapy is feasible and FNA biopsies of metastatic lesions for genomic testing are safe. Updated efficacy results will be reported.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P6-14-06.

Sunitinib in metastatic thymic carcinomas: laboratory findings and initial clinical experience

BACKGROUND

Thymic carcinoma (TC) is a rare aggressive tumour. Median survival with current treatments is only 2 years. Sunitinib is a multi-targeted tyrosine kinase inhibitor that has shown benefit in various other cancers.

METHODS

Laboratory analyses of snap-frozen tumour tissues were performed to detect activation and genetic mutations of receptor tyrosine kinases (RTKs) in TC samples. On the basis of molecular analyses showing activation of multiple RTKs in their tumour, four patients with metastatic TCs refractory to conventional therapies were treated with sunitinib according to standard protocols.

RESULTS

RTK analysis in three of the patients showed activation of multiple RTKs, including platelet-derived growth factor-beta and vascular endothelial growth factor 3. Mutations of EGFR, c-KIT, KRAS, and BRAF genes were not found. Administration of sunitinib yielded a partial remission (lasting 2 to 18+ months) according to the RECIST criteria in three patients and stable disease with excellent metabolic response in 18F-FDG-PET in another one. The overall survival with sunitinib treatment ranges from 4 to 40+ months. Withdrawal of the drug in one patient prompted rapid tumour progression that could be controlled by re-administration of sunitinib.

CONCLUSIONS

Sunitinib is an active treatment for metastatic TC. A panel of molecular analyses may be warranted for optimal patient selection.

Biomarker Analyses in Phase 2 Single-Agent Trials of Dasatinib for Breast Cancer

Background: Dasatinib (BMS-354825) is a potent SRC inhibitor being studied in several solid tumors including breast cancer. Expression profiling of breast cancer cell lines led to the identification of genes putatively correlated with dasatinib sensitivity.1,2 Inhibition of Src-family kinases may have complex effects on angiogenesis; circulating levels of VEGFR2 and collagen type IV (CollIV) are related to changes in VEGF signaling. Two Phase 2 single-agent trials of dasatinib3,4 have been performed in patients with locally-advanced or metastatic advanced breast cancers. Tumor markers may be used to predict clinical benefit and circulating biomarkers may reveal key mechanisms of action.Methods: Biomarker data from two Phase 2 trials including 114 patients were aggregated for this analysis. Archival tumor tissue from most recent prior surgery was collected in both trials; tumor samples were submitted for 38 of 44 patients with triple-negative, 39 of 46 patients with ER/PR+, and 20 of 24 patients with Her2/neu-amplified breast cancer. The initial dasatinib dose of 100 mg BID (n=46) was reduced to 70 mg BID (n=68) to improve tolerability. Based on mRNA results, immunohistochemical (IHC) procedures were developed for caveolin (Cav), phospho-Cav (p-Cav; scored as membrane vs cytoplasmic), EphA2 and IGFBP-2. Staining intensity was expressed on a scale of 0–3. Plasma was collected at baseline and after 2 and 4 weeks of dasatinib treatment and analyzed for VEGFR2 and CollIV by enzyme-linked immunosorbent assay (ELISA). Quantitative biomarker values pre-treatment and at ≥1 on-study time point for 71 of 114 patients were expressed as percent change from baseline. Tumor mRNA expression is being analyzed in all available tissue.Results: Protocol-defined clinical benefit was observed in 13 patients: 4 with triple-negative, 7 with ER/PR+, and 2 with Her2+ (which were also ER+) malignancies. Tumor tissue was prioritized and adequate for analysis in 89 tumors for Cav, 80 for p-Cav, 88 for EphA2 and 84 for IGFBP-2. Positive IHC (2-3+ intensity) was recorded for Cav in 35% of patients, with 11% and 25% positive for p-Cav in cytoplasm and membrane, respectively, and in 27% for EphA2 and 23% for IGFBP-2. No association was detected between clinical benefit and IHC results. Consistent increases in plasma biomarkers were observed in >90% of subjects. Median percent change (at Days 15 & 29, respectively) was 22% & 27% in VEGFR2 and 32% & 46% in CollIV; the mechanism of this change is being further investigated. Increased CollIV on treatment was associated with drug-related Grade 3-4 adverse events in first 4 weeks and with clinical benefit, but not with tumor subtype. Data on mRNA expression will be presented.Conclusions: The selected IHC analytes did not predict clinical benefit in these trials. Consistent early increases in VEGFR2 and CollIV suggest an effect of dasatinib on vascular endothelium which appears related to both safety and efficacy.1. Huang et al. Cancer Res. 2007;67(5):2226-38.2. Finn et al. Breast Cancer Res Treat. 2007;105(3):319-26.3. Finn et al. SABCS 2008;abstract 3118.4. Mayer et al. ASCO 2009;abstract 1011.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2034.

Dasatinib Plus Capecitabine for Advanced Breast Cancer: Safety and Efficacy Data from Phase 1 Study CA180-004

Background: SRC is a potential therapeutic target in breast cancer and has a central role in hormone therapy resistance and in osteoclast activity. Dasatinib is a potent SRC inhibitor that inhibits breast cancer cell proliferation and migration in vitro, including synergy with 5FU in some cell lines, and inhibits osteoclast activity in clinical trials. CA180-004 is a phase 1 study designed to identify dose-limiting toxicities (DLT) and recommended phase 2 doses of dasatinib plus capecitabine in women with advanced breast cancer (ABC). Safety and efficacy data are now reported with additional follow-up.Methods: Cohorts of pts with ABC were treated at four dose levels (DL) with capecitabine (mg/m2 twice daily [BID] on D1-14 of 21-day cycles) and dasatinib (mg daily): DL1: capecitabine 825 + dasatinib 50 BID; DL2: capecitabine 825 + dasatinib 70 BID; DL3: capecitabine 1000 + dasatinib 70 BID; DL3a: capecitabine 1000 + dasatinib 100 once daily (QD). All pts had performance status 0-1, prior taxane and/or anthracycline and ≤2 prior chemotherapy-containing regimens for advanced disease. Disease assessments were performed every 6 weeks. DL3a was expanded for further safety and efficacy estimate using best objective response and progression-free survival (PFS) rates.Results: To date, 47 pts with ABC have been treated, 31 in escalation phase plus 16 in expansion (5 too early). Median age was 52 years (range 35-77). Tumor subtypes: 14% were Her2-amplified, 57% ER+ or PR+, 29% triple-negative. Safety was previously reported (ASCO 2009) for escalation phase; no MTD was defined based on DLTs. Of 20 evaluable pts in DL3a, 2 DLTs have been observed: 1 pneumonia, pain and pleural effusion plus 1 diarrhea, neutropenia, vomiting, mucositis and anemia. The most common drug-related adverse events (AEs, any grade) were headache, fatigue/asthenia, nausea/vomiting, diarrhea, hand-foot syndrome (HFS) and pleural effusion. The most common grade 3/4 AEs were fatigue/asthenia, HFS, vomiting and diarrhea. To date, 19 have remained on treatment ≥4 months, including 3 for >1 year. Median duration of treatment (n=42) was 13 weeks; 23 pts have discontinued for progression and 7 for toxicity. Of 38 pts with on-study assessment, 6 had confirmed partial response (treatment durations 17+, 23, 25, 36+, 71, 73 wks), 6 had unconfirmed partial or clinical response (5, 11, 13, 18, 23+, 24 wks), and 9 had prolonged stable disease (16+, 17, 23+, 24+, 25+, 29, 39+, 48+, 63+ wks). Updated efficacy data, including PFS by hormone receptor status, will be presented.Conclusions: Dasatinib and capecitabine combination treatment was well tolerated and encouraging efficacy was observed. Further assessment of this combination is warranted.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3092.

Dasatinib in advanced HER2/neu amplified and ER/PR-positive breast cancer: Phase II study CA180088

1011

Background: SRC family kinases (SFKs) are involved in numerous signaling pathways including from ER and HER-2 receptors, as well as osteoclast function. Dasatinib is a potent oral inhibitor of SFKs. A phase II trial was performed in patients (pts) with ER+ and/or PR+ and/or HER-2-amplified progressive advanced breast cancer. Subsequent to study initiation, dasatinib demonstrated similar efficacy with a lower incidence of key side-effects at 100 mg once daily in CML and prostate cancer. Methods: Pts with measurable disease and progression after chemotherapy and other targeted agents were treated with dasatinib on a continuous twice-daily (BID) schedule; RECIST-defined response rate was primary endpoint. Results: Sixty-eight pts, 24 with HER-2-amplified and 44 with HER-2-normal, ER+ and/or PR+ disease, were treated. Original starting dose of 100 mg BID (23 pts) was reduced to 70 mg BID (45 pts) due to fluid retention, fatigue, or GI toxicity. Median age was 55 years; nearly all pts (93%) had prior therapy in advanced setting. 59 were radiographically-evaluable (8 discontinued for toxicity and 1 inevaluable). We observed 3 partial responses lasting 9, 9 and 8+ mos plus 6 stable disease ≥16 weeks (range 24–33 wks). All 9 controlled tumors were ER/PR+, 2 were also HER-2-amplified; thus, disease control rate was 19% in the 47 radiographically-evaluable pts with ER/PR+ disease. Median dose intensity was 136 mg/day at 70 mg BID and 175 mg/day at 100 mg BID; median duration of therapy was 1.8 mos in both dose groups. Most pts (75%) discontinued for disease progression. The most common drug-related AEs were diarrhea (49%), headache (34%), nausea (34%), asthenia (32%), pleural effusion (31%), musculoskeletal pain (25%), and vomiting (24%). Drug-related grade 3–4 AEs were reported in 37% of pts and comparable between doses, but related serious AEs were less frequent at 70 mg BID than 100 mg BID (16% vs 26%). Grade 3–4 laboratory abnormalities were uncommon. PK and biomarker analyses will be presented. Conclusions: Encouraging single-agent activity was observed with dasatinib in pts with advanced ER+ breast cancers. Future studies will address the combination of dasatinib with hormonal therapies using a better-tolerated once daily schedule.

[Table: see text]

Dasatinib plus capecitabine (Cap) for progressive advanced breast cancer (ABC): Phase I study CA180004

1012

Background: SRC family kinases (SFK) mediate numerous signal-transduction pathways relevant to breast cancer as well as osteoclast function. Dasatinib, a potent oral inhibitor of SFK and other kinases has preclinical activity in breast models and in vitro synergy with Cap in some breast cancer cell lines (KPL-4 and HCC-70). A phase I trial of dasatinib plus Cap was conducted to define dose-limiting toxicities (DLT), maximum tolerated (MTD), and recommended phase II (RP2D) doses. Methods: Sequential cohorts of pts with ABC were treated with Cap twice daily (BID) on days 1–14 and dasatinib daily in 21-day cycles using dose levels (DL) for Cap (mg/m2) and dasatinib (mg): DL1: Cap 825 + dasatinib 50 BID; DL2: Cap 825 + dasatinib 70 BID; DL3: Cap 1000 + dasatinib 70 BID; DL3a: Cap 1000 + dasatinib 100 once daily (QD). All pts had ECOG performance status 0–1, had prior anthracycline and/or taxane, and received ≤2 regimens in advanced setting. MTD was based on DLT in first cycle and RP2D also based on tolerability of additional cycles. Results: 31 pts with ABC, median age 53 years (range 36–78) were treated. Number of pts treated/evaluable for DLT/reported DLT (event) were DL1: 7/6/1 (headache, grade 3); DL2: 9/7/0; DL3: 6/6/1 (diarrhea, grade 3), and DL3a: 9/9/1 (pneumonia, grade 3). Most frequent AEs related to either drug and occurring at any time on study (n pts) were nausea (12), vomiting (7), diarrhea (6), abdominal pain (2), fatigue (8), headache (7), musculoskeletal pain (1), and pleural effusion (4); hand-foot syndrome (5) was as expected for Cap alone. 11 patients experienced a Grade 3–4 non-hematologic AE at some point during the study. Laboratory abnormalities were uncommon. To date, 20 pts have continued treatment for ≥6 weeks and 9 pts for ≥12 weeks. Number of pts who (at any time) reduced dasatinib/reduced Cap/discontinued for toxicity were DL1: 2/2/1; DL2 2/2/3; DL3: 2/1/2; DL3a: 0/1/1. Updated safety and efficacy data will be presented. Conclusions: Dasatinib + Cap was tolerated without unexpected combined-treatment toxicity; few pts required dose reduction in later cycles. The recommended phase II dose, Cap 1000 plus dasatinib 100 QD, is well tolerated and will be studied for efficacy in an expanded patient cohort.

[Table: see text]

Phase II trial of dasatinib in triple-negative breast cancer: results of study CA180059

Abstract #3118

Background: Dasatinib (SprycelR; BMS-354825) is a potent orally-available inhibitor of Src-family kinases and other kinases with anti-proliferative, anti-osteoclastic and anti-metastatic activity demonstrated pre-clinically. Expression profiling suggested that basal-like cancers may be preferentially sensitive to dasatinib. Methods: A Phase II single-agent trial of dasatinib, using a continuous schedule, was performed in patients with advanced triple-negative (as proxy for basal-like) breast cancers. Subjects were required to have measurable locally-advanced or metastatic triple-negative (ER/PR-negative, Her2-normal) disease and prior anthracycline and/or taxane therapy. A 2-stage Gehan design was adopted, with RECIST-defined response as primary endpoint; subjects discontinued for toxicity were considered non-responders. The original dasatinib dose of 100 mg BID (n=21) was reduced to 70 mg BID (n=23) to improve tolerability. Biomarkers were analyzed in tumor and plasma samples obtained for PK analysis. Results: From 12/06 through 12/07, 44 subjects were treated at 14 institutions: median age 55 yrs, median time from diagnosis 30 mo, prior therapy for advanced disease in 29 (66%). Of 43 response-evaluable subjects, 7 discontinued for toxicity prior to on-study assessment. Of 36 subjects with radiographic assessment, there were 2 confirmed PR [1 continues >1 year + 1 discontinued for intolerance at week 16] plus 2 SD lasting >16 weeks. Four additional subjects had transient clinical benefit reflected by improvement in bone pain (anecdotal) or short-term tumor shrinkage (reductions of 11 - 29%). Tolerability was improved at a dose of 70 mg compared with 100 mg BID. In preliminary analysis, fewer subjects experienced any serious adverse event (13% at 70 mg BID vs 48% at 100 mg BID), fewer reported Grade 3 toxicity, including gastrointestinal (10% vs 26%), pleural effusion (4% vs 9%), generalized edema (0% vs 9%) or pericardial effusion (0% vs 9%), and fewer had dasatinib dose reduction (24% vs 61%). Fatigue, myalgia/arthralgia and headache were comparable at the two doses. No Grade 4 drug-related events occurred. Grade 3-4 abnormal laboratory values were uncommon. Biomarker and PK data will be presented. Conclusions: Modest but encouraging single-agent activity was observed with dasatinib in patients with advanced triple-negative breast cancers, with clinical benefit rate of 9.3% (4/43). Future studies are warranted to address optimal dose and schedule of dasatinib in combination with chemotherapy for this challenging tumor type.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3118.

Increased frequency and suppressive function of CD4+ CD25high regulatory T-cells in acute myeloid leukemia patients

7054

Background: Regulatory CD4+CD25+ T cells (T reg) are critical regulators of immune tolerance. However, the functional role of T reg in human tumor immunity has been less well studied. The frequency of circulating Treg is increased in patients with solid malignancies. We evaluated the frequency, phenotype and suppressive function of T reg in patients with acute myeloid leukemia (AML). Methods: The frequency and phenotype of CD4+ CD25high T cells were investigated in the peripheral blood of fifteen newly diagnosed AML patients prior to any treatment and fifteen healthy donors by multiparameter flow cytometry. The suppressive function of Treg was evaluated using CFSE-labeled fresh autologous CD4+CD25- T cells activated with an anti-CD3 antibody. Results: The percentage of circulating CD4+ CD25high Treg was higher (p <0.001) in the AML patients (5.2 ± 1.3%, range 0.4 −7%) compared to healthy donors (1.1 ± 0.2%, range 0.8–1.5%). T reg expressing Foxp3, CTLA-4, CD45 RO, CCR4 and Fas receptor (CD95) were significantly elevated in the circulation of AML patients, but GITR expression on Treg was low. Suppression mediated by T reg co-incubated with proliferating autologous responders was also significantly higher (p<0.001) in AML than that mediated by control T reg (75 ± 6% vs 12%± 4%). Conclusions: These results indicate that T reg accumulate in the periphery of patients with AML and have vigorous suppressive functions. This high suppressive activity may impair the host anti-tumor responses and promote leukemogenesis.

No significant financial relationships to disclose.

Tumorangiogenese und Immunsuppression

BACKGROUND

Angiogenesis and tumor-associated immunosuppression are two of the hallmarks of carcinogenesis. In previous studies we demonstrated in vitro that HNSCC tumor cells attract monocytes via monocyte chemotactic protein-1 (MCP-1) and activate them via transforming growth factor-beta 1(TGF-beta1) to secrete interleukin (IL)-1alpha, which in turn stimulates tumor cells to secrete increased levels of the angiogenic and immunosuppressive vascular endothelial growth factor (VEGF). These findings suggest that interaction between the immune system and VEGF-mediated angiogenesis is important for progression of HNSCC. Recent studies in vitro show that retinoic acid (RA) downregulates the release of MCP-1 and TGF-beta1 by tumor cells. Therefore, we investigated the ability of RA to modulate the ability of tumor cells to recruit and activate monocytes for participation in VEGF-mediated angiogenesis and immunosuppression in vivo.

MATERIAL AND METHODS

Mice (ten/group) were injected daily with RA (160 microg/kg) for 3 weeks. After that time mice were sacrificed, and paraffin sections of tumors were obtained and stained for VEGF-A, CD68, and PECAM (CD31) by immunohistochemistry. The lungs, liver, and myocardium were analyzed for macro- and micrometastases. The plasma protein levels of VEGF-A and MCP-1 were determined by ELISA.

RESULTS

In RA-treated mice tumors regressed completely and RA prevented metastases (p=0.00) and macrophage infiltration (p=0.007). Treated mice downregulated VEGF-A (0 pg/ml) and MCP-1 (12 pg/ml) in peripheral blood (p=0.001).

CONCLUSION

Our findings suggest a new therapeutic possibility: the development of treatment protocols that can block each of the ways in which tumors induce new blood vessel growth and immunosuppression of the host.

Outsourcing manufacturing

In addition to increasing their technical ability, some contract manufacturers are expanding the capacity of their operations by 20% per year. This article outlines how to capitalise on this trend and successfully move a manufacturing operation to a contract manufacturer.

A phase I study of cranial radiation therapy with concomitant continuous infusion paclitaxel in children with brain tumors

BACKGROUND

The prognosis of children with high-grade astrocytomas of the central nervous system is grim and has not been substantially improved by conventional chemoradiotherapy. We performed a multi-institutional phase I study to determine the toxicities and tolerance of concurrent external beam radiation of the brain and a unique dose-schedule of paclitaxel as a radiation sensitizer.

PROCEDURE

Paclitaxel was delivered intravenously as a continuous 24 h/day, 7 days/week infusion during the entire 6-week course of fixed schedule standard radiation therapy. The dose of paclitaxel was escalated in patient cohorts in standard phase I design.

RESULTS

Eleven patients (eight brain stem gliomas, one glioblastoma multiforme, and two gliomatosis cerebri) were treated. Dose-limiting toxicity was encountered in the two patients treated at 6 mg/(m(2)/24 h), both of whom developed severe obstipation requiring prolonged hospitalization.

CONCLUSIONS

We have shown in this first study of its kind that paclitaxel can be administered safely to children as a 6-week continuous infusion concurrent with cranial irradiation. The maximally tolerated and recommended phase II dose is 4 mg/(m(2)/day). The benefits of taxanes as clinical radiation sensitizers for children with high-grade gliomas, if any, remain to be determined.

Paclitaxel for the treatment of progressive or recurrent childhood brain tumors: a pediatric oncology phase II study

PURPOSE

To assess the efficacy and define the toxicity of paclitaxel given at a dosage of 350 mg/m2 every 3 weeks as a 24-hour continuous infusion to children with recurrent or progressive primary brain tumors.

PATIENTS AND METHODS

Seventy-three eligible patients, ages 4 months to 19 years, with progressive or recurrent primary brain tumors were treated according to a Pediatric Oncology Group (POG) phase II protocol with paclitaxel (POG 9330). Tumor histologic strata included: astrocytoma (n = 4), malignant glioma (n = 13), medulloblastoma (n = 16), brain stem glioma (n = 15), ependymoma (n = 13), and miscellaneous histologies (n = 12). All patients had previous histologic confirmation of a primary intracranial or spinal cord tumor with magnetic resonance imaging or computed tomography documentation of unequivocally measurable progressive or recurrent disease. All patients had received previous therapy including surgery, radiation therapy, and/or chemotherapy, but no patient had been previously treated on more than one phase II trial. Paclitaxel was administered as a 24-hour intravenous infusion at a dosage of 350 mg/m2 every 3 weeks. Neurologic and neuroradiologic reevaluations were performed after every second course. Patients were allowed to continue therapy for a total of 18 cycles in the absence of progressive disease or unacceptable toxicity.

RESULTS

Seventy-five patients were enrolled onto the POG 9330 protocol; two ineligible patients were removed from the study before receiving any therapy. Of the 73 eligible patients, 72 were evaluable for toxicity and 70 were either fully or partially evaluable for disease response. There was one complete response and three partial responses (5.7%). Twenty patients had stable disease for more than 2 months. Toxicities included mild nausea, central nervous system toxicity, myelosuppression, and febrile neutropenia, including one septic death. One grade 2 and two grade 3 allergic reactions occurred. No cardiac toxicities or arthralgias were reported.

CONCLUSION

Paclitaxel is well tolerated in children with recurrent or progressive brain tumors at this dosage and schedule and may result in short-term disease stabilization in this patient population. The lack of a significant number of patients with measurable disease regression, however, precludes it from being identified as an active agent when administered as a single agent by 24-hour continuous infusion.

Constant expression of cyclooxygenase-2 gene in prostate and the lower urinary tract of estrogen-treated male rats

Expression of cyclooxygenase-2 (E. C. 1.14.99.1) in prostate and the lower urinary tract (LUT) of the neonatally estrogenized male rat has been studied by using a COX-2's PCR fragment of 724 nt spanning 3 introns and a 478nt internal standard for quantitative RT-PCR. The same fragment of 724 nt was used for RNA probe in Northern hybridization. Neonatal estrogenization (10 microg/day of diethylstilbestrol on days 1-5) had no effect on COX-2 expression in prostatic urethra, prostatic lobes, or bladder. Acute estrogen treatment of castrated animals did not induce COX-2 expression, either. In addition the differential expression of basal level of COX-2 in the different lobes of prostate in normal rat was demonstrated. Our results suggest a constant expression of COX-2 gene in prostate and the lower urinary tract of the neonatally estrogenized (neoDES) rats. The present study indicates that the increased expression of COX-2 is probably not essential for the estrogen-driven development of stromal inflammation or hyperplastic and dysplastic alterations in the prostate of neoDES rats.

Microkeratome-assisted posterior keratoplasty

Microkeratome-assisted posterior keratoplasty is a new surgical technique that may be valuable in treating patients with corneal decompensation secondary to endothelial dysfunction. A hinged anterior stromal flap is fashioned in the host cornea using a microkeratome, and the diseased posterior stroma and endothelium are resected. A complementary donor stromal button is prepared using a microkeratome and an artificial anterior chamber. The donor button is transplanted and secured with sutures, and the flap is repositioned. The flap can be lifted later to remove the sutures or to correct residual refractive errors using an excimer laser. This technique may allow the use of infant corneal donor tissue and may improve the outcomes of posterior keratoplasty.

Differential expression of estrogen receptors alpha and beta in adult rat accessory sex glands and lower urinary tract

Estrogens induce pronounced structural and functional changes in male accessory sex glands and the lower urinary tract in both sexes, but the exact mechanisms of estrogen action are not fully understood. This study was undertaken to localise the tissue cell types that express estrogen receptor in adult rats, and to determine the receptor subtype (ERalpha and ERbeta) in order to identify sites that may respond directly to estrogens. In the male accessory sex glands (seminal vesicles, prostatic lobes and ampullary glands), ERbeta mRNA and protein were strongly expressed in the epithelium but not in the stroma, while ERalpha mRNA was present only in the fibromuscular tissue surrounding the prostatic collecting ducts in the posterior periurethral region and in ampullary gland stroma. In the epithelium of the urinary bladder and urethra of both sexes, high level of ERbeta mRNA and protein, but no ERalpha mRNA, was detected. The connective tissue in urinary bladder of both males and females, as well as that in prostatic urethra in males expressed ERalpha mRNA. The neural cells in the autonomic ganglia of the prostatic plexus were strongly positive for ERbeta mRNA, but were completely devoid of ERalpha. We conclude that ERbeta is the predominant ER subtype in the epithelium of adult male rat accessory sex glands and the lower urinary tract of both males and females, as well as in the prostatic neural plexus regulating the function of the lower urinary tract in males, while ERalpha is present only in the stromal compartment of distinct sites. These results indicate that in these tissues in intact adults there are multiple targets for direct estrogen action. Furthermore, the differential or complementary expression of the two ER subtypes suggests that they may have specific functions, and may explain the complex structural and functional changes induced by estrogens.

Differential expression of estrogen receptors alpha and beta in adult rat accessory sex glands and lower urinary tract

Estrogens induce pronounced structural and functional changes in male accessory sex glands and the lower urinary tract in both sexes, but the exact mechanisms of estrogen action are not fully understood. This study was undertaken to localise the tissue cell types that express estrogen receptor in adult rats, and to determine the receptor subtype (ER alpha and ER beta) in order to identify sites that may respond directly to estrogens. In the male accessory sex glands (seminal vesicles, prostatic lobes and ampullary glands), ER beta mRNA and protein were strongly expressed in the epithelium but not in the stroma, while ER alpha mRNA was present only in the fibromuscular tissue surrounding the prostatic collecting ducts in the posterior periurethral region and in ampullary gland stroma. In the epithelium of the urinary bladder and urethra of both sexes, high level of ER beta mRNA and protein, but no ER alpha mRNA, was detected. The connective tissue in urinary bladder of both males and females, as well as that in prostatic urethra in males expressed ER alpha mRNA. The neural cells in the autonomic ganglia of the prostatic plexus were strongly positive for ER beta mRNA, but were completely devoid of ER alpha. We conclude that ER beta is the predominant ER subtype in the epithelium of adult male rat accessory sex glands and the lower urinary tract of both males and females, as well as in the prostatic neural plexus regulating the function of the lower urinary tract in males, while ER alpha is present only in the stromal compartment of distinct sites. These results indicate that in these tissues in intact adults there are multiple targets for direct estrogen action. Furthermore, the differential or complementary expression of the two ER subtypes suggests that they may have specific functions, and may explain the complex structural and functional changes induced by estrogens.

Distribution of collagen XII and XIV in the bladder wall of the male rat with outlet obstruction

PURPOSE

Our previous studies indicate that neonatal estrogenization with diethylstilbestrol (neoDES) of male mice and rats causes partial outlet obstruction. In the present study, type XII and XIV collagens were localized in the bladder to study their role in the development of obstruction.

MATERIALS AND METHODS

The bladder sections immunostained with smooth muscle specific a-actin antibody were double labeled either with collagen type XII or type XIV antibodies. The specimens were then analyzed with conventional and confocal fluorescence microscope.

RESULTS

Type XII and XIV collagens were not evenly distributed in the bladder. Further, in neonatally estrogenized rats collagen XIV appeared inside smooth muscle fascicles.

CONCLUSIONS

Non-overlapping distributions of collagen XII and XIV suggest their different roles in the urinary bladder. Penetration of collagen XIV inside smooth muscle fascicles may have a role in the development of DES-induced partial outlet obstruction.

Differentiation between vasculoprotective and uterotrophic effects of ligands with different binding affinities to estrogen receptors alpha and beta

Estrogen-based drug therapy in cardiovascular diseases has been difficult because it has not been possible to separate the wanted vasculoprotective effect from the unwanted effects of the hormone to the reproductive system. Here, we demonstrate that, after endothelial denudation of rat carotid artery, the mRNA of the classical estrogen receptor (ERalpha) is constitutively expressed at a low level whereas the expression of the novel ERbeta mRNA increases >40-fold. Under in situ hybridization and immunohistochemistry, ERbeta mRNA and protein colocalize with the smooth muscle cells in the media and neointima. Treatment of ovariectomized female rats with the isoflavone phytoestrogen genistein, which shows 20-fold higher binding affinity to ERbeta than to ERalpha, or with 17beta-estradiol, which does not differentiate between the two receptors, provides similar dose-dependent vasculoprotective effect in rat carotid injury model. In addition in concentrations <10 microM, both ligands are equally inhibitory to the replication and migration of smooth muscle cells in vitro. However, only treatment with 17beta-estradiol, but not with genistein, is accompanied with a dose-dependent uterotrophic effect. The results suggest that preferential targeting to ERbeta will provide vasculoprotective estrogen analogs devoid of effects to the reproductive system.

Dietary phytoestrogens and their role in hormonally dependent disease

Epidemiological studies suggest that diets rich in phytoestrogens (plant estrogens), particularly soy and unrefined grain products, may be associated with low risk of breast and prostate cancer. It has also been proposed that dietary phytoestrogens could play a role in the prevention of other estrogen-related conditions, namely cardiovascular disease, menopausal symptoms and post-menopausal osteoporosis. However, there is no direct evidence for the beneficial effects of phytoestrogens in humans. All information is based on consumption of phytoestrogen-rich diets, and the causal relationship and the mechanisms of phytoestrogen action in humans still remain to be demonstrated. In addition, the possible adverse effects of phytoestrogens have not been evaluated. It is plausible that phytoestrogens, as any exogenous hormonally active agent, might also cause adverse effects in the endocrine system, i.e. act as endocrine disrupters.

Genistein exerts estrogen-like effects in male mouse reproductive tract

The aim of this study was to evaluate the estrogenicity of genistein in the neonatal and adult male mouse reproductive tract. In intact adults, genistein (2.5 mg s.c./kg of body weight/day for 9 days) reduced testicular and serum testosterone concentrations, pituitary LH-content and prostate weight. In castrated adults, genistein (0.025-2.5 mg s.c./kg of body weight) increased expression of c-fos gene in prostatic urethra. In adult, neonatally estrogenized mice showing an increased estrogen sensitivity, a 10-day treatment with genistein (2.5 mg s.c./kg of body weight) induced development of squamous epithelial metaplasia in prostatic collecting ducts. Neonatally, only a very high dose of genistein (1 mg/pup per day; i.e. approximately 500 mg/kg of body weight) induced persistent structural changes, similar to those seen in mice treated neonatally with diethylstilbestrol, in the urethroprostatic complex. These results suggest that in adult males, genistein induces the typical estrogenic effects in doses comparable to those present in soy-based diets, while in neonatal animals, considerably higher doses are required to show estrogen-like activity.

Effect of long-term salmeterol treatment on exercise-induced asthma

BACKGROUND

With long-term administration of salmeterol, the extent of protection afforded by the drug against experimental precipitants of asthma such as methacholine and adenosine may decrease. Whether this effect extends to a clinically relevant stimulus such as exercise is unknown.

METHODS

We performed a random-order, double-blind, crossover trial in 20 patients with exercise-induced asthma. Each patient received inhaled salmeterol or placebo twice daily for a month, with a one-week washout period between treatments. The patients performed cycle ergometry while breathing frigid air 30 minutes after the morning dose and 9 hours later on the 1st, 14th, and 29th study days. The primary end point was the extent of the decrease in forced expiratory volume in 1 second (FEV1) 10 minutes after exertion.

RESULTS

With placebo, significant airway narrowing developed at all times (mean [+/-SE] decrease from base line in FEV1, 19+/-2 percent in the morning and 18+/-2 percent in the evening). The morning dose of salmeterol attenuated the degree of bronchoconstriction at all times (decrease in FEV1 on day 1, 5+/-2 percent; on day 14, 10+/-3 percent; and on day 29, 9+/-3 percent; P=0.10). Its ability to act throughout the day, however, decreased with long-term administration (decrease in FEV1 from morning to evening on day 1, 6+/-2 percent; on day 14, 15+/-3 percent; and on day 29, 14+/-3 percent; P=0.003).

CONCLUSIONS

Protection against exercise-induced asthma is maintained with long-term administration of salmeterol, but the length of time that the drug remains active after a single dose decreases.

Comparison of two dosage regimens of albuterol in acute asthma

BACKGROUND

The standard therapy for acute episodes of asthma in the United States consists of three 2.5-mg doses of aerosolized albuterol given every 20 minutes. Whether this approach represents optimum therapy has never been tested.

METHODS

This study employed a prospective, sequential design in which the effects of two doses of 5.0 mg of aerosolized albuterol administered during 40 minutes (high dose) were contrasted with the standard dose (three 2.5-mg doses). Improvements in pulmonary function, clinical resolution of the asthma attacks, and admission rates were used as primary endpoints. Both regimens were part of an overall care plan that involved objective, pretested decision algorithms.

RESULTS

In an emergency department, 160 patients who presented with acute exacerbations of asthma received either standard (n = 80) or high-dose (n = 80) albuterol treatment. There were no significant baseline differences in gender, racial composition, clinical signs and symptoms, medication use, or peak expiratory flow (PEF) between the groups. Both treatment schedules were effective, but the high-dose regimen increased lung function more rapidly and to a greater extent than standard-dose therapy. It also resulted in lower charges to third party payers. More subjects attained the discharge criteria quicker and left the emergency department with peak expiratory flows closer to normal. Fewer patients in the high-dose group were admitted, but this trend did not quite reach statistical significance.

CONCLUSIONS

Two 5.0-mg treatments of aerosolized albuterol at a 40-minute interval provide effective therapy for acute exacerbations of asthma. This combination of dose and frequency promotes maximum bronchodilatation, increases efficiency, and reduces the risks of undertreatment.

Inhibition of 17beta-hydroxysteroid oxidoreductase by flavonoids in breast and prostate cancer cells

Several flavonoids and isoflavonoids were found to inhibit 17beta-oxidoreduction of estrogens by the purified 17beta-HSOR type 1, or in cell lines expressing 17beta-HSOR type 1 enzyme (T-47D breast cancer cells) or type 2 (PC-3 prostate cancer cells). The structural demands for the inhibition of estrone (E1) reduction and estradiol (E2) oxidation catalyzed by 17beta-HSOR types 1 and 2, respectively, were not identical. Flavones, flavanones, and isoflavones hydroxylated at both the double ring (positions 5 and 7) and ring B (position 4') were the most potent inhibitors of E1 reduction in T-47D cells, and by the purified type 1 enzyme whereas flavones hydroxylated at positions 3, 5, and 7 of rings A and C, with or without a hydroxyl group in ring B, were capable of inhibiting E2 oxidation in PC-3 cells. Change to flavanone structure, or hydroxylation at position 3 of ring C of flavones, or methylation of the hydroxyl group at position 4' of ring B of flavones and isoflavones reduced or abolished their inhibitory activity on E1 reduction in T-47D cells. On the contrary, hydroxyl group at position 3 of flavones (flavonol structure) markedly increased the inhibition of E2 oxidation in PC-3 cells. Thus, changes in the number and location of hydroxyl groups may discriminate inhibition of E1 reduction and E2 oxidation. Some of the differences may be due to differences in pharmacokinetics of these compounds in T-47D and PC-3 cells. Inhibition of 17beta-HSORs could lead to an alteration in the availability of the highly active endogenous estrogen, but the effects of these compounds in vivo cannot be predicted on the basis of these results alone. Some of these compounds (isoflavones) are estrogenic per se, and they may replace endogenous estrogens, whereas flavones are only very weakly estrogenic or nonestrogenic. Regarding prevention or treatment of estrogen-related diseases, apigenin, coumestrol, and genistein raise special interest.

Phytoestrogens: potential endocrine disruptors in males

Exposure to diethylstilbestrol (DES) induces persistent structural and functional alterations in the developing reproductive tract of males. It is possible that xenoestrogens other than DES alter sexual differentiation in males and account for the increasing incidence of developmental disorders of the reproductive tract in men and wild animals. Phytoestrogens (coumestans, isoflavonoids, flavonoids, and lignans) present in numerous edible plants are quantitatively the most important environmental estrogens when their hormonal potency is assessed in vitro. They exert their estrogenic activity by interacting with estrogen receptors (ERs) in vitro. They may also act as antiestrogens by competing for the binding sites of estrogen receptors or the active site of the estrogen biosynthesizing and metabolizing enzymes, such as aromatase and estrogen-specific 17 beta-hydroxysteroid oxidoreductase (type 1). In theory, phytoestrogens and structurally related compounds could harm the reproductive health of males also by acting as antiestrogens. There are very little data on effects of phytoestrogens in males. Estrogenic effects in wildlife have been described but the evidence for the role of phytoestrogens is indirect and seen under conditions of excessive exposure. In doses comparable to the daily intake from soybased feed, isoflavonoids such as genistein were estrogen agonists in the prostate of adult laboratory rodents. When given neonatally, no persistent effects were observed. In contrast, the central nervous system (CNS)-gonadal axis and the male sexual behavior of the rat appear to be sensitive to phytoestrogens during development. The changes were similar but not identical to those seen after neonatal treatment with DES, but higher doses of phytoestrogens were needed.

Observations on the effects of aerosolized albuterol in acute asthma

To determine the dose of albuterol required to terminate acute episodes of asthma, 92 acutely ill subjects received three doses of 2.5 mg each by nebulization every 20 min. Peak expiratory flow rates (PEFR) and signs and symptoms were serially monitored. A dose-response increase in pulmonary function was found, but only 66% of the subjects improved sufficiently to be sent home. Of these, 56% required < or = 5.0 mg of drug to reach the discharge threshold, whereas the remainder needed 7.5 mg. In 34% of participants, albuterol was ineffectual. These individuals were characterized by more severe obstruction at presentation, and after three doses of medication their PEFR still did not exceed 40% of the expected value. Further treatment in the emergency department (ED) or hospital was not immediately helpful, and these patients ultimately required 3.8 +/- 0.4 d of inpatient care to become asymptomatic. There were no discernible differences between responders and nonresponders in the type or quantity of medications used. However, the nonresponders had more severe disease as measured by recurrent hospitalizations and ED visits. This study demonstrates that, in emergency situations, albuterol does not relieve acute airway obstruction in all asthmatic individuals with equal efficacy. Two-thirds of patients are sensitive, and in these patients 5 to 7.5 mg of albuterol provides optimal treatment. In the remainder, albuterol, even in high doses, has little effect for days.

The influence of parasympatholytics on the resolution of acute attacks of asthma

PURPOSE

To evaluate the role of parasympatholytics in the resolution of acute attacks of asthma.

METHODS

This study employed a prospective sequential design in which the influence of 0.5 and 1.0 mg of ipratropium bromide on peak expiratory flow rates (PEFR), hospital admissions, and length of stay (LOS) in the emergency department (ED) was evaluated. The parasympatholytic was added to a well-investigated standard therapeutic regimen that was anchored by the use of repetitive doses of albuterol, and employed pretested decision algorithms.

RESULTS

One hundred and thirty-one patients received ipratropium (l) and 123 who did not (NI) served as controls. There were no significant pretreatment between group differences in gender, racial composition clinical signs and symptoms, or PEFR. The presence of ipratropium in the regimen did not influence discharge/admission patterns, LOS, the rate of improvement of the patients, or the level of PEFR achieved.

CONCLUSION

Anticholinergic agents such as ipratropium are not first-line treatments for acute asthma. They do not add any therapeutic benefit to the effects of albuterol given in divided doses over 1 hour, nor do they facilitate recovery in patients whose immediate response to sympathomimetics is impaired.

Treatment of intraocular retinoblastoma with carboplatin and etoposide chemotherapy

PURPOSE

Management of intraocular retinoblastoma was initiated with 2-drug chemotherapy in an effort to improve the rate of vision preservation and ocular salvage and to avoid or delay the use of external beam radiation treatment.

METHODS

Six patients with intraocular retinoblastoma (five bilateral; one unilateral, 1 month old) received 6 to 7 monthly cycles of intravenously administered carboplatin and etoposide (VP-16) as primary treatment. No eyes were enucleated primarily. Twelve of the 33 discrete tumors in the 11 study eyes received prophylactic supplemental treatment with cryotherapy or laser hyperthermia. Response was documented with frequent eye examinations with the patient under general anesthesia and with repeated fundus photography.

RESULTS

All eight larger tumors (> 10-mm diameter) underwent dramatic regression after treatment with chemotherapy alone, and six of these tumors ultimately became fully calcific. One larger tumor and two smaller tumors showed post-treatment growth, each within 2 months after completion of chemotherapy. Six larger tumors were observed without growth or further treatment for 7 to 21 months after completion of chemotherapy. Subretinal fluid resorbed completely in four of four eyes with extensive retinal detachment, and vitreous seeding diminished considerably in four of four eyes. In five eyes, intraocular disease recurrence at a distance from any initially observed tumor eventually required treatment with external beam radiation (three eyes) or enucleation (three eyes). Eight of 11 involved eyes were salvaged, including 5 of 8 with larger tumors and 4 of 4 with vitreous seeding; 4 retained eyes received no radiation exposure, including 3 with larger tumors and 1 with vitreous seeding. Good vision was preserved in six eyes, two of which were markedly improved after occlusion therapy for amblyopia. There was no extraocular disease recurrence and no serious harm from treatment during observation ranging from 12 to 40 months after diagnosis.

CONCLUSION

Chemotherapy with carboplatin and etoposide shows promise as initial treatment for intraocular retinoblastoma. Further study is indicated to define its proper role in the management of this disease.

Hyperfractionated craniospinal radiation in medulloblastoma

From 1986 to 1991, 13 patients at Northwestern Memorial Hospital were entered onto a pilot study designed to test the feasibility of treating children with medulloblastoma (11 patients) or primitive neuroectodermal tumors of the cerebral hemispheres (2 patients) with hyperfractionated craniospinal radiotherapy (HFxRT). Follow-up times ranged from 10 to 96 months with a median of 53 months. The patients were prospectively divided among three treatment arms depending on prior treatment history, if any, and degree of surgical resection. The 3 patients in group I had undergone gross total resection of the primary site, receiving 64.8 Gy to the primary site and 31.2 Gy directed to the craniospinal axis (CSA). Of these 3 patients, patient 1 had residual disease in the thoracic spine at T-10. The 8 patients in group II, who had gross residual disease remaining at the primary site, received 72 Gy to the primary site and 34 Gy to the CSA. Five of these eight patients in group II also received 8-in-1 chemotherapy. The 2 patients in group III had already failed chemotherapy and were then treated with 60 Gy to the primary site and 26 Gy to the CSA. Of the 11 patients in groups I and II, 7 of the 11 (64%) have never recurred. Two of the three group-I patients have not recurred, and 5 of the 7 group-II patients have not recurred. In addition, patient 7 (group II) remains alive after salvage with bone marrow transplant, following a local failure bordering the tentorium. Unfortunately, neither of the group-III patients could be salvaged with HFxRT. Acute/subacute toxicities included 7 cases of external auditory canal or skin desquamation, 2 cases of postradiation somnolence, and 1 case each of poor wound healing and neutropenia. Chronic toxicities included hypothyroidism in 2 patients and growth problems in 2 patients. Neuropsychologic complications affected only the 3 youngest patients in the study. Three patients developed neurologic sequelae attributed to radiation, including 1 with progressive urinary incontinence, 1 who developed a transient ischemic attack, and 1 who became progressively ataxic. Our research, although based on a small number of patients, suggests that hyperfractionated radiation therapy to craniospinal access is feasible and that the survival results are favorable. This treatment strategy should be further explored in a phase-III randomized trial.

Optic pathway tumors in children: the effect of neurofibromatosis type 1 on clinical manifestations and natural history

OBJECTIVE

To distinguish the clinical manifestations and natural history of optic pathway tumors (OPT) associated with neurofibromatosis type 1 (NF-1 OPT) from that of OPT not associated with NF-1 (non-NF-1 OPT).

METHODS

Two groups of children with OPT were compared: (1) 17 children with NF-1 OPT who were followed prospectively, and (2) 19 children with non-NF-1 OPT who were identified retrospectively by a review of medical records.

RESULTS

Precocious puberty was a common initial sign in the children with NF-1 OPT (5/17), and was not found in any patients without NF-1. In contrast, children with non-NF-1 OPT had symptoms attributable to increased intracranial pressure (12/19 and nystagmus (5/19); these symptoms were not found in any patient with NF-1. Decreased visual acuity at the time of diagnosis was common in both groups. There was no significant difference between the children with NF-1 OPT and those with non-NF-1 OPT as to age at diagnosis or sex distribution. Optic nerve involvement was more common in NF-1 (p < 0.001). Both isolated and bilateral optic nerve tumors were found exclusively in children with NF-1, whereas chiasmal (p = 0.016) and optic tract involvement (p = 0.001) were more common in those with non-NF-1 OPT. Radiographic evidence of hydrocephalus was found in none of the children with NF-1 OPT compared with 79% of the non-NF-1 OPT group. Progressive disease was seen in 12% of patients with NF-1 OPT compared with 63% of those with non-NF-1 OPT.

CONCLUSIONS

Differences exist between NF-1 OPT and non-NF-1 OPT both at the time of diagnosis and during follow-up. Optic pathway tumors caused by NF-1 and non-NF-1 OPT have different biologic properties that distinguish both their initial clinical manifestations and their natural history.

Numerical sex chromosomal abnormalities in pineal teratomas by cytogenetic analysis and fluorescence in situ hybridization

BACKGROUND

Central nervous system teratomas are a rare subgroup of extragonadal germ cell tumors. Previous studies show ovarian mature teratomas to be karyotypically normal; those with increasing immaturity show increasing cytogenetic abnormalities. Adult testicular teratomas, regardless of maturity, most often show the i sochromosome 12p, a consistent chromosomal abnormality seen in adult testicular germ cell tumors. This study investigates the cytogenetic abnormalities of six central nervous system teratomas by the use of routine karyotypic analysis and fluorescence in situ hybridization.

EXPERIMENTAL DESIGN

Karyotypic analysis was performed on two tumors. Four additional tumors were analyzed by dual-labeled fluorescence in situ hybridization. Paraffin blocks were disaggregated, and nuclei were hybridized with both biotin- and digoxigenin-labeled probes to the centromeric domains of the X and Y chromosomes, respectively. Tumor cells were scored for X and Y copy number. Tumor ploidy was determined by image analysis of the disaggregated specimens.

RESULTS

The patients (five male, one female) ranged from 2 to 25 years of age. All presented with a solitary mass in the suprasellar region. A mature teratoma was 48, XXYY; an immature teratoma was 47, XXY, dir dup 11 (q12-22). Lymphocyte analysis of the second patient showed a normal constitutional karyotype. Fluorescence in situ hybridization analysis of four additional patients showed both one mature and one immature teratoma from male hosts to have 2X and 1Y signals in the majority of the cells. An immature teratoma from a male host showed 2X and 2Y signals. The above three tumors were diploid by static image analysis. An immature teratoma from a female host showed multiple (four to six) X signals in more than 70% of the cells. Ploidy analysis was unavailable for this case.

CONCLUSIONS

Although patients with Klinefelter syndrome (47,XXY) and patients with 46,XY gonadal dysgenesis show an increased incidence of germ cell tumors, numerical sex chromosomal abnormalities have not been described in extragonadal teratomas. Our results support a role for sex chromosomes in the development of central nervous system teratomas.

A pilot study of isotretinoin in the treatment of juvenile chronic myelogenous leukemia

BACKGROUND

Juvenile chronic myelogenous leukemia (CML) is a rare myeloproliferative disease of infants and young children for which there is no effective therapy other than allogeneic bone marrow transplantation. In vitro, isotretinoin (13-cis-retinoic acid) attenuates both the spontaneous proliferation of leukemic peripheral-blood progenitor cells (granulocyte-macrophage colony-forming units) and their selective hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). We conducted a pilot study to evaluate the clinical efficacy of isotretinoin in juvenile CML.

METHODS

To be eligible the patients had to have newly diagnosed untreated disease, leukocytosis with monocytosis, marrow with less than 25 percent blasts, hepatosplenomegaly, no chromosomal abnormalities, and negative viral cultures and antibody titers. Isotretinoin was administered orally in single daily doses of 100 mg per square meter of body-surface area. When possible, patients subsequently underwent bone marrow transplantation.

RESULTS

Ten children (median age, 10 months) were enrolled in the study. In all 10 there was spontaneous colony formation of leukemic progenitor cells in vitro. In the eight patients tested there was hypersensitivity to GM-CSF. The only toxic effect of isotretinoin therapy was cheilitis in two patients. Four children had disease progression. Two children had complete responses to isotretinoin (normalization of the white-cell count and disappearance of organomegaly), three had partial responses (more than a 50 percent reduction in the white-cell count and degree of organomegaly), and one had a minimal response (more than a 50 percent reduction in the white-cell count, but a 26 to 50 percent reduction in the degree of organomegaly). The median duration of response was 37 months (range, 6 to 83). Three of the four children who had a complete or partial response and who did not undergo bone marrow transplantation were alive 36 to 83 months after the diagnosis of juvenile CML. The spontaneous colony formation in vitro was reduced in samples from the five patients in whom this factor was reassessed during treatment. There was also a reduction in the hypersensitivity of leukemic progenitor cells to GM-CSF in the two patients retested.

CONCLUSIONS

Isotretinoin can induce durable clinical and laboratory responses in patients with juvenile CML.