Surgical versus non-surgical management for patients with malignant bowel obstruction (S1316): a pragmatic comparative effectiveness trial

BACKGROUND

Malignant small bowel obstruction has a poor prognosis and is associated with multiple related symptoms. The optimal treatment approach is often unclear. We aimed to compare surgical versus non-surgical management with the aim to determine the optimal approach for managing malignant bowel obstruction.

METHODS

S1316 was a pragmatic comparative effectiveness trial done within the National Cancer Trials Network at 30 hospital and cancer research centres in the USA, Mexico, Peru, and Colombia. Participants had an intra-abdominal or retroperitoneal primary cancer confirmed via pathological report and malignant bowel disease; were aged 18 years or older with a Zubrod performance status 0-2 within 1 week before admission; had a surgical indication; and treatment equipoise. Participants were randomly assigned (1:1) to surgical or non-surgical treatment using a dynamic balancing algorithm, balancing on primary tumour type. Patients who declined consent for random assignment were offered a prospective observational patient choice pathway. The primary outcome was the number of days alive and out of the hospital (good days) at 91 days. Analyses were based on intention-to-treat linear, logistic, and Cox regression models combining data from both pathways and adjusting for potential confounders. Treatment complications were assessed in all analysed patients in the study. This completed study is registered with ClinicalTrials.gov, NCT02270450.

FINDINGS

From May 11, 2015, to April 27, 2020, 221 patients were enrolled (143 [65%] were female and 78 [35%] were male). There were 199 evaluable participants: 49 in the randomised pathway (24 surgery and 25 non-surgery) and 150 in the patient choice pathway (58 surgery and 92 non-surgery). No difference was seen between surgery and non-surgery for the primary outcome of good days: mean 42·6 days (SD 32·2) in the randomised surgery group, 43·9 days (29·5) in the randomised non-surgery group, 54·8 days (27·0) in the patient choice surgery group, and 52·7 days (30·7) in the patient choice non-surgery group (adjusted mean difference 2·9 additional good days in surgical versus non-surgical treatment [95% CI -5·5 to 11·3]; p=0·50). During their initial hospital stay, six participants died, five due to cancer progression (four patients from the randomised pathway, two in each treatment group, and one from the patient choice pathway, in the surgery group) and one due to malignant bowel obstruction treatment complications (patient choice pathway, non-surgery). The most common grade 3-4 malignant bowel obstruction treatment complication was anaemia (three [6%] patients in the randomised pathway, all in the surgical group, and five [3%] patients in the patient choice pathway, four in the surgical group and one in the non-surgical group).

INTERPRETATION

In our study, whether patients received a surgical or non-surgical treatment approach did not influence good days during the first 91 days after registration. These findings should inform treatment decisions for patients hospitalised with malignant bowel obstruction.

FUNDING

Agency for Healthcare Research and Quality and the National Cancer Institute.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Prospective Randomized Trial of Docetaxel Versus Best Supportive Care in Patients With Non-Small-Cell Lung Cancer Previously Treated With Platinum-Based Chemotherapy

PURPOSE

To evaluate whether treatment with single-agent docetaxel would result in longer survival than would best supportive care in patients with non-small-cell lung cancer who had previously been treated with platinum-based chemotherapy. Secondary end points included assessment of response (docetaxel arm only), toxicity, and quality of life.

PATIENTS AND METHODS: Patients with performance statuses of 0 to 2 and stage IIIB/IV non-small-cell lung cancer with either measurable or evaluable lesions were eligible for entry onto the study if they had undergone one or more platinum-based chemotherapy regimens and if they had adequate hematology and biochemistry parameters. They were excluded if they had symptomatic brain metastases or if they had previously been treated with paclitaxel. Patients were stratified by performance status and best response to cisplatin chemotherapy and were then randomized to treatment with docetaxel 100 mg/m² (49 patients) or 75 mg/m² (55 patients) or best supportive care. Patients in both arms were assessed every 3 weeks.

RESULTS

One hundred four patients (103 of whom were eligible for entry onto the study) were well balanced for prognostic factors. Of 84 patients with measurable lesions, six (7.1%) achieved partial responses (three patients at each dose level). Time to progression was longer for docetaxel patients than for best supportive care patients (10.6 v 6.7 weeks, respectively; P < .001), as was median survival (7.0 v 4.6 months; log-rank test, P = .047). The difference was more significant for docetaxel 75 mg/m² patients, compared with corresponding best supportive care patients (7.5 v 4.6 months; log-rank test, P = .010; 1-year survival, 37% v 11%; χ² test, P = .003). Febrile neutropenia occurred in 11 patients treated with docetaxel 100 mg/m², three of whom died, and in one patient treated with docetaxel 75 mg/m². Grade 3 or 4 nonhematologic toxicity, with the exception of diarrhea, occurred at a similar rate in both the docetaxel and best supportive care groups.

CONCLUSION

Treatment with docetaxel is associated with significant prolongation of survival, and at a dose of 75 mg/m², the benefits of docetaxel therapy outweigh the risks.

Combination Dabrafenib and Trametinib Versus Combination Nivolumab and Ipilimumab for Patients With Advanced BRAF-Mutant Melanoma: The DREAMseq Trial-ECOG-ACRIN EA6134

PURPOSE

Combination programmed cell death protein 1/cytotoxic T-cell lymphocyte-4-blockade and dual BRAF/MEK inhibition have each shown significant clinical benefit in patients with BRAFV600-mutant metastatic melanoma, leading to broad regulatory approval. Little prospective data exist to guide the choice of either initial therapy or treatment sequence in this population. This study was conducted to determine which initial treatment or treatment sequence produced the best efficacy.

PATIENTS AND METHODS

In a phase III trial, patients with treatment-naive BRAFV600-mutant metastatic melanoma were randomly assigned to receive either combination nivolumab/ipilimumab (arm A) or dabrafenib/trametinib (arm B) in step 1, and at disease progression were enrolled in step 2 to receive the alternate therapy, dabrafenib/trametinib (arm C) or nivolumab/ipilimumab (arm D). The primary end point was 2-year overall survival (OS). Secondary end points were 3-year OS, objective response rate, response duration, progression-free survival, crossover feasibility, and safety.

RESULTS

A total of 265 patients were enrolled, with 73 going onto step 2 (27 in arm C and 46 in arm D). The study was stopped early by the independent Data Safety Monitoring Committee because of a clinically significant end point being achieved. The 2-year OS for those starting on arm A was 71.8% (95% CI, 62.5 to 79.1) and arm B 51.5% (95% CI, 41.7 to 60.4; log-rank P = .010). Step 1 progression-free survival favored arm A (P = .054). Objective response rates were arm A: 46.0%; arm B: 43.0%; arm C: 47.8%; and arm D: 29.6%. Median duration of response was not reached for arm A and 12.7 months for arm B (P < .001). Crossover occurred in 52% of patients with documented disease progression. Grade ≥ 3 toxicities occurred with similar frequency between arms, and regimen toxicity profiles were as anticipated.

CONCLUSION

Combination nivolumab/ipilimumab followed by BRAF and MEK inhibitor therapy, if necessary, should be the preferred treatment sequence for a large majority of patients.

Association of Fatigue and Outcomes in Advanced Cancer: An Analysis of Four SWOG Treatment Trials

PURPOSE

Patient-reported outcomes may be associated with cancer outcomes. We evaluated clinically significant fatigue (CSF), overall survival, adverse events (AEs), and quality of life (QOL) during cancer treatment.

METHODS

We compared outcomes in four phase II or III chemotherapy trials, two advanced non-small-cell lung cancer and two advanced hormone-refractory prostate cancer, with or without baseline CSF. CSF was defined as a rating of two or greater on the Functional Assessment of Cancer Therapy fatigue question or a European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 fatigue symptom score of 50% or greater. Survival was compared according to CSF using Kaplan-Meier estimates and Cox regression models. Differences in AE rates by CSF were assessed via chi-squared tests, and QOL changes from baseline to 3 months via linear regression.

RESULTS

Of 1,994 participants, 1,907 (median age 69 years, range: 32-91) had complete baseline QOL survey data, with 52% reporting CSF at baseline. For the two hormone-refractory prostate cancer studies, baseline CSF was associated with higher mortality rates, with adjusted hazard ratios of (95% CI, P value) 1.32 (1.13 to 1.55, P < .001) and 1.31 (1.02 to 1.67, P = .03) and with increased incidence of grade 3-5 constitutional (16.5% v 9.4%, P = .002; 13.9% v 6.3%, P = .002) and neurologic (11.7% v 6.1%, P = .006; 9.0% v 3.9%, P = .01) AEs, respectively. Baseline CSF was associated with a higher mortality rate in one non-small-cell lung cancer study: hazard ratio 1.44 and 1.04 to 2.00, P = .03.

CONCLUSION

Oncology trial participants with baseline CSF had poorer survival and experienced more AEs than participants without CSF. This indicates fatigue as an important baseline prognostic factor in oncology treatment trials.

A Phase II Study of Durvalumab in Combination with Tremelimumab in Patients with Rare Cancers

LESSONS LEARNED

Disease control with signals of response were demonstrated, which should lead to future validating clinical trials using checkpoint inhibitors in this underserved rare malignancy population. Although the study of single types of rare cancers is practically challenging, clinical trial designs that aggregate such patients into cohorts treated similarly are feasible, even in the community setting.

BACKGROUND

Patients with rare cancers are an underserved population with limited access to clinical trials aside from phase I trials in the refractory setting. Treatment of these patients is often based on collections of anecdotes and small denominator review articles. Despite broad evidence of efficacy of combined immune checkpoint blockade across multiple tumor types, patients with rare tumors have not been afforded the opportunity for these therapies.

METHODS

A phase II, investigator-initiated, single institution trial using durvalumab (1,500 mg every [Q]4 weeks × 13) and tremelimumab (75 mg Q4 weeks × 7, then Q12 weeks × 2) is reported. The population included 50 patients with advanced rare solid tumors (incidence <6/100,000 per year). The phase II dose and safety profile were defined in prior phase I trials. All patients had exhausted standard therapy options and all had received at least one prior line of systemic therapy (n = 49) unless a standard treatment option did not exist (n = 1).

RESULTS

A complete response was demonstrated in one patient with anal cancer. Striking partial responses were seen in four patients. Prolonged disease stability was noted in 18 patients. Thirteen patients experienced disease progression. Patients were considered unevaluable if unable to initiate therapy (n = 6) or unable to complete two cycles of therapy (n = 8). In all cases, patients were unevaluable because of clinical deterioration. The toxicity profile paralleled prior published studies. Toxicities were manageable and without new signals. There were two events of grade 4 immune-mediated hepatitis and one death from pneumonitis.

CONCLUSION

This single-cohort basket trial demonstrated clinical activity from combined checkpoint blockade in 23 of the 36 evaluable patients. Patients with rare cancers, not eligible for immunotherapy via conventional clinical trial mechanisms, should be considered for this therapy through compassionate use, further clinical trials, and national registry programs.

The pathogenic role of dendritic cells in non-infectious anterior uveitis

BACKGROUND

Anterior uveitis (AU) is characterised by infiltration of immune cells into the anterior chamber of the eye. Dendritic cells (DC) are professional antigen presenting cells that initiate and promote inflammation. This study aims to characterise DC in AU and to examine the effects of aqueous humor (AqH) on DC maturation and function.

METHODS

The frequency and phenotype of AU and healthy control (HC) circulating DC was examined. AU and HC AqH was immunostained and assessed by flow cytometry. The effect of AU and HC AqH on DC activation and maturation was examined and subsequent effects on CD4⁺ T cell proliferation assessed.

RESULTS

AU peripheral blood demonstrated decreased circulating myeloid and plasmacytoid DC. Within AU AqH, three populations of CD45⁺ cells were significantly enriched compared to HC; DCs (CD11c⁺ HLA-DR⁺), neutrophils (CD15⁺ CD11c⁺) and T cells (CD4⁺ and CD8⁺). A significant increase in IFNγ, IL8 and IL6 was observed in the AU AqH, which was also significantly higher than that of paired serum. AU AqH induced expression of CD40 and CD80 on DC, which resulted in increased T cell proliferation and the production of GM-CSF, IFNγ and TNFα.

CONCLUSION

DC are enriched at the site of inflammation in AU. Our data demonstrate an increase in inflammatory mediators in the AU inflamed microenvironment. AU AqH can activate DC, leading to subsequent proliferation and activation of effector T cells. Thus, the AU microenvironment contributes to immune cell responses and intraocular inflammation.

Abstract P4-04-07: Characterization of the effects of estrogen receptor alpha Y537S and D538G mutations on receptor function and pharmacology

The frontline therapy for estrogen receptor alpha (ERα) positive Breast Cancer (ER+BC) involves various forms of endocrine therapy, consisting of either Selective Estrogen Receptor Modulators (SERMs) or aromatase inhibitors. An emerging mechanism of ER+BC resistance to endocrine therapy, and consequently disease relapse, has been associated with a set of “hotspot” mutations in and near to helix-12 of the ERα ligand binding domain. Selective Estrogen Receptor Degraders/Down-regulators (SERDs), such as GDC-0810, AZD9496 and GDC-0927, represent a current major pharmacological strategy being applied to develop treatments for such resistant ER+BC. Here, we compare 2 of the most frequent ERα hotspot mutations (Y537S and D538G), with ERα wildtype (WT) and the ability of a set of ERα ligands (including GDC-0810, AZD9496 and GDC-0927) to bind, antagonize and degrade ERα. The concentration of each drug required to bind, antagonize or degrade ERα Y537S or ERα D538G was typically higher than that required for ERα WT. Importantly, ERα Y537S is resistant to estradiol stimulated protein degradation and 4-hydroxy-tamoxifen (a major active metabolite of tamoxifen) stabilizes ERα Y537S protein. This represents a potential mechanism of resistance of ERα Y537S ER+BC to Tamoxifen therapy.

Citation Format: Blake RA, Hartman SJ, Kleinheinz TL, White J, Daly S, Goodwin R, Zhou W, Liang J, Wang X, O'Rourke M, Metcalfe C, Friedman L. Characterization of the effects of estrogen receptor alpha Y537S and D538G mutations on receptor function and pharmacology [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-04-07.

Abstract 4834: 3D modeling of immune cell interactions in breast cancer and prediction of immunotherapy response

While breast cancer has an overall 5-year survival rate of 89%, the rate for patients with stage 4 metastatic disease is only 26%. Immunotherapies have the potential to improve the prognosis for these patients while also providing better treatment options for all breast cancer patients since they have fewer side effects enabling longer treatment times and the use of combination therapies and reduced chances of developing resistance. Currently these treatments are tested in standard 2D cell cultures that are inaccurate in mimicking in vivo drug response or animal models where the immune system differs from humans in numerous ways including T-cell subsets, cytokine receptors, and costimulatory molecule expression. We have developed 3D models of human breast cancer that span the subtypes, ER+, HER2+, and triple negative, incorporate numerous stromal cell types, fibroblasts and adipocytes, and include different immune cells, macrophages and T-cells under either static or perfusion culture systems. These models have been used to examine how tumor cells influence macrophage differentiation using undifferentiated peripheral blood mononuclear cells (PBMCs), how M1 and M2 macrophages influence tumor cell survival and proliferation, how the combination of these cell types influence cytokine secretion, and how the microenvironment affects macrophage invasion. We have also used these complex models to examine response of tumor cells and T-cells to checkpoint inhibitors through standard viability assays and flow cytometry. These models have several potential uses which include the ability to quickly answer whether a particular immunotherapy agent is effective for that particular patient-specific manner and to screen potential novel immunotherapeutic candidates and/or combinations prior to clinical use.

Citation Format: Qi Guo, Stephen Shuford, Brian McKinley, Mary Rippon, Wendy Cornett, Mark O'Rourke, David Schammel, Jeff Edenfield, David L. Kaplan, Hal E. Crosswell, Teresa Desrochers. 3D modeling of immune cell interactions in breast cancer and prediction of immunotherapy response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4834. doi:10.1158/1538-7445.AM2017-4834

The at-risk medical student--what more can we do?

Securing a place in medical school is extremely difficult-students who are successful all have similar high levels of academic achievement. So why do some students, and not others, have difficulty with the course, and in some cases, leave the programme? Studies on medical school attrition offer valuable insight into why medical students under-perform. Identification of the 'at-risk' student can trigger additional support and early remediation, helping some students remain in their chosen profession.

Gemcitabine, Cisplatin, and sunitinib for metastatic urothelial carcinoma and as preoperative therapy for muscle-invasive bladder cancer

BACKGROUND

Data support chemotherapy combined with antiangiogenic therapy in metastatic urothelial cancer (mUC) and muscle-invasive bladder cancer (MIBC). We investigated the efficacy and safety of gemcitabine, cisplatin, and sunitinib (GCS) in mUC and MIBC in parallel phase II trials.

PATIENTS AND METHODS

Trial 1 enrolled 36 patients with mUC who were chemotherapy naive; trial 2 enrolled 9 patients with MIBC. The primary endpoints for trials 1 and 2 were response rate and pathologic complete response, respectively. GCS was given as first-line treatment for patients with mUC and as neoadjuvant therapy for patients with MIBC. The Simon minimax 2-stage design was used for an objective response rate in trial 1 and for the pathologic complete response rate in trial 2.

RESULTS

The initial trial 1 GCS dose was gemcitabine 1000 mg/m(2) intravenously, days 1 and 8; cisplatin 70 mg/m(2) intravenously, day 1; and sunitinib 37.5 mg orally daily, days 1 to 14 of a 21-day cycle. These doses proved intolerable. The doses of gemcitabine and cisplatin were subsequently reduced to 800 and 60 mg/m(2), respectively, without an improvement in drug delivery, and the trial was closed. This lower-dose regimen was applied in trial 2, which was stopped early due to excess toxicity. Grade 3 to 4 hematologic toxicities occurred in 70% (23/33) of patients in trial 1 and 22% (2/9) of patients in trial 2. In trial 1, the response rate was 49% (95% CI, 31%-67%); in trial 2, the pathologic complete response was 22% (2/9). Due to early closure secondary to toxicity, the sample sizes of both trials were small.

CONCLUSIONS

Delivery of GCS was hampered by excessive toxicity in both advanced and neoadjuvant settings.

Documenting the natural history of patients with resected stage II adenocarcinoma of the colon after random assignment to adjuvant treatment with edrecolomab or observation: results from CALGB 9581

PURPOSE

We conducted a randomized trial comparing adjuvant treatment with edrecolomab versus observation in patients with resected, low-risk, stage II colon cancer. This study also prospectively studied patient- and tumor-specific markers of treatment outcome.

PATIENTS AND METHODS

After surgical resection, patients with stage II colon cancer were randomly assigned to either five infusions of edrecolomab at 28-day intervals or observation without adjuvant therapy.

RESULTS

Final accrual included 1,738 patients; 865 patients received edrecolomab, and 873 patients were observed without adjuvant treatment. Median follow-up time was 7.9 years. There were no significant outcome differences between study arms (overall survival [OS], P = .71; disease-free survival, P = .64). The combined 5-year all-cause OS was 0.86 (95% CI, 0.84 to 0.88), and the combined 5-year disease-specific OS was 0.93 (95% CI, 0.91 to 0.94). The relationships between demographic and histopathologic factors and survival differed for all-cause and disease-specific survival outcomes, but no combined prognostic factor model was found to adequately classify patients at higher risk of recurrence or death as a result of colon cancer.

CONCLUSION

Edrecolomab did not prolong survival. Consequently, this large study with a long duration of follow-up provided unique data concerning the natural history of resected stage II colon cancer. Prognostic factors identified in previous retrospective and pooled analyses were associated with survival outcomes in this stage II patient cohort. Results from ongoing molecular marker studies may enhance our ability to determine the risk profile of these patients.

A phase I study of the chinese herbal medicine PHY906 as a modulator of irinotecan-based chemotherapy in patients with advanced colorectal cancer

PHY906 is a novel Chinese herbal preparation that has been used in the Orient for over 1800 years to treat a wide range of gastrointestinal side effects including diarrhea, abdominal cramps, vomiting, fever, and headache. Preclinical and clinical studies were conducted to further investigate the biologic and clinical activities of this herbal medicine. To ensure standardization and maintain interbatch reliability of PHY906, high performance liquid chromatography (HPLC) was used to establish a "chemical fingerprint" of PHY906. In vivo preclinical studies using the murine Colon 39 tumor model showed that PHY906 protected against the weight loss associated with irinotecan treatment. In the presence of PHY906, mice were able to tolerate otherwise lethal doses of irinotecan. Significantly improved antitumor activity and overall survival were observed in animals treated with the combination of irinotecan and PHY906 versus irinotecan alone. The combination of PHY906 with irinotecan, 5-fluorouracil (5-FU), and leucovorin (LV) also resulted in at least additive antitumor activity with no increased host toxicity. Based on these in vivo studies, a phase I multicenter, double-blind, randomized, placebo-controlled, dose escalation, cross-over study of PHY906 as a modulator of the weekly, bolus regimen of irinotecan, 5-FU, and LV (IFL) in the first-line treatment of patients with advanced colorectal cancer (CRC) was conducted. The specific objectives of this clinical trial were to determine the safety and tolerability of PHY906 when administered concomitantly with the bolus, weekly IFL regimen. Treatment with PHY906 did not alter the pharmacokinetics of 5-FU, irinotecan, or the irinotecan metabolite SN-38.

Results of a Phase II Study of Weekly Paclitaxel Plus Carboplatin in Advanced Carcinoma of Unknown Primary Origin: A Reasonable Regimen for the Community-Based Clinic?

Optimal treatment for cancer of unknown primary (CUP) can challenge clinicians. This study sought to determine the efficacy and toxicity of weekly paclitaxel and carboplatin in CUP. Forty-two subjects enrolled. Treatment was intravenous paclitaxel (80 mg/m2) plus carboplatin (AUC = 2) on Days 1, 8, and 15 every 28 days. Seven (18 percent) responded (complete = 2, partial = 5); median survival was 8.5 months; estimated survival (12 and 24-month) was 33 and 17 percent, respectively. Median time to progression was 3.7 months, and estimated progression-free survival (12 and 24 months) was 14 and 7 percent, respectively. Median duration of response was 17.3 months. This combination produced modest antitumor activity in advanced CUP.

Welcome to Serbia: feel free to smoke

This paper reviews tobacco use and control policies in Serbia. Tobacco contributes significantly to the burden of disease in Serbia, and it has one of the highest age standardised lung cancer incidence rates in Europe. Until recently there were few restrictions on smoking or tangible tobacco control policies. Serbia has, however, now embarked on a legislative and regulatory path towards greater tobacco control, but implementation and enforcement are still lax. Increased government interventions are needed to reduce the prevalence of smoking in the population.

Ecological separation and genetic isolation of Neisseria gonorrhoeae and Neisseria meningitidis

BACKGROUND

Classifying bacteria into species is problematic. Most microbiologists consider species to be groups of isolates that share some arbitrary degree of relatedness of biochemical or molecular (such as DNA sequence) features and that, ideally, are clearly delineated from all other groups of isolates. The main problem in applying to bacteria a biological concept of species based on the ability or inability of their genes to recombine, is that recombination appears to be rare in bacteria in nature, as indicated by the strong linkage disequilibrium between alleles found in most bacterial populations. However, there are some naturally transformable bacteria in which assortative recombination appears to be so frequent that alleles are in, or close to, linkage equilibrium. For these recombining populations a biological concept of species might be applicable.

RESULTS

Populations of Neisseria gonorrhoeae and Neisseria meningitidis from Spain were analysed by multilocus enzyme electrophoresis. The data indicate that assortative recombination occurs frequently within populations, but not between populations. Similarly, the sequences of two house-keeping genes show no evidence of intragenic recombination between N. gonorrhoeae and N. meningitidis.

CONCLUSIONS

N. gonorrhoeae and N. meningitidis represent extremely closely related 'sexual' populations that appear to be genetically isolated in nature, and thus conform to the biological concept of species. The extreme uniformity of N. gonorrhoeae house-keeping genes suggests that this species may have arisen recently as a clone of N. meningitidis that could colonize the genital tract. Ecological isolation - of populations that can colonize the genital tract from those that can colonize the nasopharynx - may have been an important component in speciation, leading to a lower frequency of recombination between species than within species.

Alpha-2 adrenergic receptor development in rat CNS: an autoradiographic study

During development norepinephrine plays a role in determining the morphologic organization of the CNS and the density and future responsiveness of adrenergic receptors. alpha-2 Adrenergic receptors, one of three adrenergic receptor types, regulate important adult CNS functions and may have a distinct role during development. We examined alpha-2 receptor distribution and density in the rat brain at postnatal days 1, 5, 10, 15, 21, 28 and in adults using the antagonist [(3)H]RX821002 for autoradiography. Binding kinetics and pharmacology for alpha-2 adrenergic receptors were the same in adults and neonates. There was an overall increase in alpha-2 receptor levels during postnatal development with great variability in pattern and timing of receptor density changes among brain regions. Three major patterns were apparent. First, in many regions receptor density increased during postnatal development, generally reaching adult levels around postnatal day 15. Within this group there was variability in timing between regions and there were several regions with receptor densities higher than adult levels during the postnatal period. Second, there were regions with very high levels of receptors at birth and little or no change in density during the postnatal period. Third, some regions demonstrated decreasing or transient expression of alpha-2 adrenergic receptors in the course of postnatal development, including white matter regions, cerebellum and many brainstem nuclei, suggesting specific roles for alpha-2 receptors during development. This study investigates the development of alpha-2 adrenergic receptors in the rat CNS. It demonstrates there is region-specific regulation of alpha-2 receptor development and identifies brain regions where these receptors may play a specific and critical role in the regulation normal development.

Essential Bacillus subtilis genes

To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among approximately 4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were predicted to be essential. The vast majority of essential genes were categorized in relatively few domains of cell metabolism, with about half involved in information processing, one-fifth involved in the synthesis of cell envelope and the determination of cell shape and division, and one-tenth related to cell energetics. Only 4% of essential genes encode unknown functions. Most essential genes are present throughout a wide range of Bacteria, and almost 70% can also be found in Archaea and Eucarya. However, essential genes related to cell envelope, shape, division, and respiration tend to be lost from bacteria with small genomes. Unexpectedly, most genes involved in the Embden-Meyerhof-Parnas pathway are essential. Identification of unknown and unexpected essential genes opens research avenues to better understanding of processes that sustain bacterial life.

Phase II multicenter trial of a weekly paclitaxel and carboplatin regimen in patients with advanced breast cancer

PURPOSE

To determine the activity of weekly paclitaxel plus carboplatin as first-line therapy in patients with advanced breast cancer (ABC) by assessing response rate, survival, and safety.

PATIENTS AND METHODS

One hundred patients with ABC received paclitaxel 135 mg/m(2) (group 1, n = 20) and carboplatin area under the concentration-time curve (AUC) of 2. Paclitaxel was subsequently reduced to 100 mg/m(2) (group 2, n = 80) because of toxicity. The median age was 58.5 years, and most patients had an Eastern Cooperative Oncology Group performance status of <or= 2. Estrogen and progesterone receptor status were evenly distributed among both groups. Sixty-one patients received prior chemotherapy, 37 (61%) of whom received prior doxorubicin. Among 47 patients who received prior hormonal therapy, 43 received tamoxifen.

RESULTS

The overall response rate (ORR) among 95 assessable patients was 62%, including 8% complete responses and 54% partial responses. The median time to response was 1.8 months, and the median duration of response was 13.3 months. The median time to progression was 4.8 months. The median survival was 16 months. Neutropenia and leukopenia were the most common grade 3 and 4 toxicities. In group 1, neutropenia (50%) and leukopenia (35%) necessitated dose reductions for 50% of patients during the first three cycles, prompting the reduction in paclitaxel dose to 100 mg/m(2). Grade 3 and 4 nonhematologic toxicities for all patients included peripheral neuropathy (11%), infection (6%), anemia (5%), weakness (6%), and paresthesia (3%).

CONCLUSION

The 62% ORR achieved with weekly paclitaxel plus carboplatin is among the highest achieved with chemotherapy for ABC. This high response rate and the lack of cardiotoxicity suggest that the regimen should be considered as a nonanthracycline regimen for future adjuvant therapy.

Ease of access is a principal factor in the frequency of paracetamol overdose

BACKGROUND

In Ireland, 30% of non-fatal overdoses involve paracetamol.

AIMS

To determine how and where patients obtained paracetamol, to assess awareness of toxicity and examine the relationship between dose and suicidal intent.

METHODS

A prospective study of patients admitted following a paracetamol overdose recording their reasons for using paracetamol, their knowledge of its toxicity and their suicidal intent scale (SIS).

RESULTS

Of 100 patients, 66% obtained paracetamol in non-pharmacy outlets, 82% cited ease of availability as the reason, 55% were aware of its toxicity, 31% of liver damage and 68% did not read the warning on packets. The mean number of tablets taken was 51.3 for males and 37.2 for females (p < 0.01). Males presented later than females for medical attention (12.5 versus seven hours [p < 0.02]) and more males than females took alcohol (p < 0.03). The mean SIS score was 14.71 for males and 12.38 for females. There was a significant correlation between the SIS and the amount of paracetamol consumed (r = 0.28; p < 0.01).

CONCLUSION

The majority obtained paracetamol in local shops or at home. Knowledge of toxicity and the need for early antidote was poor. There was a significant relationship between suicidal intent and number of tablets consumed. Limiting availability could reduce number of overdoses.

Mongolia's system-wide health reforms: lessons for other developing countries

Mongolia is a poor country that lost 30% of its GDP when the Soviet Bloc collapsed in 1990. Its health care system had the typical weaknesses of centrally planned economies--quantity rather than quality, excessive medical specialisation, dominance of the hospital sector, weak policy and management capabilities, little community participation in decision making, and so on. This paper describes Mongolia's attempts to resolve these problems through a radical program of reform that began in 1998. There have been significant successes in spite of almost overwhelming difficulties, and this may be a consequence of the strong sense of community that has been present for five hundred years and re-emerged intact at the end of 70 years of Soviet dominance. We argue, however, that good design and skillful implementation of the reform program may have made a contribution. Its notable features have included the use of a comprehensive and integrated model rather than piecemeal reform, the generation of political support for change through social marketing campaigns, a team approach using local and international experts, and co-ordination of international donor activities. Some of these features may be relevant to other transitional and developing countries.

Determining the efficacy of glucosamine and chondroitin for osteoarthritis

Glucosamine sulfate and chondroitin sulfate are being used by many patients for the treatment of osteoarthritis. Despite a number of studies supporting efficacy of these agents for palliation of joint pain in patients with osteoarthritis, the American College of Rheumatology Subcommittee on Osteoarthritis believes that it is too early to issue recommendations for use. Currently, the National Institute of Arthritis and Musculoskeletal and Skin Diseases in collaboration with the National Center for Complementary and Alternative Medicine have begun a pivotal study to thoroughly evaluate these agents.

A new articulated elbow external fixation technique for difficult elbow trauma

Articulated external fixation of the elbow allows aggressive elbow range of motion while protecting the joint and periarticular structures from excessive forces. A technique for aligning a monolateral-hinged fixator to the rotational axis of the elbow without the use of an invasive axis pin has been developed. Thirteen patients with acute and chronic post-traumatic elbow problems were treated over a four year period with this technique. An average arc of motion of 84 degrees was achieved in the frame. Frames were removed at an average of 7.6 weeks. Complications were confined to pin tract infections. In 11 patients followed for an average of 35 weeks the average arc of motion was 81 degrees. Further experience is required to determine the role of this device and to identify which elbows achieve the most benefit compared to conventional techniques.

Pulse wave analysis in the assessment of patients with left ventricular assist device

Central aortic pressure determines perfusion of vital organs, and its precise determination is particularly important in low-output syndromes. Because peripheral pressure values are not equal to the corresponding pressures in the aorta, we used a validated system that employs the principle of applanation tonometry for non-invasive recording of radial arterial pulse and determination of central aortic pressure waveform in patients who underwent implantation of left ventricular assist device. We observed significant improvement after assist device implantation; however, a discrepancy between peripheral and central pressure values was evident both before and after implantation. This non-invasive technique may prove particularly useful in repeat evaluation of patients in long-term follow-up and may provide valuable insights for coupling between the assist device and the vascular system.

Modification of vascular tone using iNOS under the control of a radiation-inducible promoter

It may be therapeutically advantageous to alter tumour blood supply specifically. Nitric oxide is a potent vasodilator which is produced in many tissues by the enzyme nitric oxide synthase (NOS). We have transfected cDNA for the inducible isoform of this enzyme (iNOS), under the control of the radiation-inducible promoter WAF1. The activity of the promoter was initially assessed using green fluorescent protein (GFP) in both endothelial cells and rat tail artery segments. Induction of protein expression by 9.5- and 4.5-fold respectively, was observed after a radiation dose of 4 Gy. Artery sections were then transfected with the WAF1/iNOS construct; this gave five-fold induction of iNOS protein after a dose of 4 Gy. The transfected artery was also tested functionally for relaxation, indicative of NO production. One hour after exposure to 4 Gy there was a significant (65%) relaxation of artery segments that had been preconstricted with phenylephrine. This could be partially reversed by the NOS inhibitor nitro-L-arginine. This study demonstrates that we can regulate vascular tone using an X-ray inducible promoter.

Diastolic pressure, systolic pressure, or pulse pressure?

Diastolic pressure, systolic pressure, and pulse pressure have all been assigned the role of the best predictor of cardiovascular events during the 20th century. At the dawn of the new millennium, concepts that draw attention to vascular mechanics reconcile the seemingly conflicting results of epidemiologic studies, better define the hypertensive patient, evaluate more accurately the risk and set its markers, and ultimately optimize treatment through a logical approach that aims at the mechanism and not at the manifestation. Pulse wave analysis and measurement of arterial stiffness are valuable tools in the assessment and management of the hypertensive patient.

Prospective randomized trial of docetaxel versus best supportive care in patients with non-small-cell lung cancer previously treated with platinum-based chemotherapy

PURPOSE

To evaluate whether treatment with single-agent docetaxel would result in longer survival than would best supportive care in patients with non-small-cell lung cancer who had previously been treated with platinum-based chemotherapy. Secondary end points included assessment of response (docetaxel arm only), toxicity, and quality of life.

PATIENTS AND METHODS

Patients with performance statuses of 0 to 2 and stage IIIB/IV non-small-cell lung cancer with either measurable or evaluable lesions were eligible for entry onto the study if they had undergone one or more platinum-based chemotherapy regimens and if they had adequate hematology and biochemistry parameters. They were excluded if they had symptomatic brain metastases or if they had previously been treated with paclitaxel. Patients were stratified by performance status and best response to cisplatin chemotherapy and were then randomized to treatment with docetaxel 100 mg/m(2) (49 patients) or 75 mg/m(2) (55 patients) or best supportive care. Patients in both arms were assessed every 3 weeks.

RESULTS

One hundred four patients (103 of whom were eligible for entry onto the study) were well balanced for prognostic factors. Of 84 patients with measurable lesions, six (7. 1%) achieved partial responses (three patients at each dose level). Time to progression was longer for docetaxel patients than for best supportive care patients (10.6 v 6.7 weeks, respectively; P <.001), as was median survival (7.0 v 4.6 months; log-rank test, P =.047). The difference was more significant for docetaxel 75 mg/m(2) patients, compared with corresponding best supportive care patients (7.5 v 4.6 months; log-rank test, P =.010; 1-year survival, 37% v 11%; chi(2) test, P =.003). Febrile neutropenia occurred in 11 patients treated with docetaxel 100 mg/m(2), three of whom died, and in one patient treated with docetaxel 75 mg/m(2). Grade 3 or 4 nonhematologic toxicity, with the exception of diarrhea, occurred at a similar rate in both the docetaxel and best supportive care groups.

CONCLUSION

Treatment with docetaxel is associated with significant prolongation of survival, and at a dose of 75 mg/m(2), the benefits of docetaxel therapy outweigh the risks.

The effect of dose and route of oestradiol benzoate administration on plasma concentrations of oestradiol and FSH in long-term ovariectomised heifers

Oestradiol (E(2)) suppresses FSH and affects follicle wave dynamics in cattle. However, neither the optimum dose of ODB required to suppress FSH nor the effect of route of ODB administration on blood concentrations of E(2) are known; hence, the aim of this experiment was to answer these questions. Ovariectomised heifers received Progesterone Releasing Intravaginal Device (PRID) for 7 days, and 4 days later heifers received one of eight ODB treatments at second PRID insertion as follows; (1) 0.0 mg (Control; n=3), (2) 0.5 mg (n=4), (3) 1.0 mg (n=4), (4) 2.5 mg (n=6), (5) 5.0 mg (n=4), (6) 10. 0 mg (n=4), (7) 5.0 mg (n=4), and (8) 10.0 mg (n=5). For treatments 2-6 inclusive, ODB was administered intramuscularly in oil, while for treatments 7 and 8, the ODB in powder form was administered topically in the vagina by gelatine capsule attached to the PRID. Blood samples were collected every 6 h for the first 48 h, every 12 h for the next 48 h, and twice daily for a further 6 days. The interval from ODB administration to peak E(2) concentration was similar (P0.05) for treatments 2-6 where ODB was administered intramuscularly (mean 13.4+/-1.24 h), and was longer (P<0.05) for the intravaginal capsule treatments (mean 25.5+/-2.84 h). Plasma concentrations of E(2) increased with increasing intramuscular dose of ODB injected, (plasma E(2)=-0.237+16.109 (dose)-0.74 (dose)(2), R(2)=0.75; P<0.05). Peak plasma concentrations of E(2) following the 5- and 10-mg capsules were similar to each other and to those following the 0.5-mg injection (P0.05), but were lower than concentrations obtained following injection of 1.0-5.0 mg (P<0.05). Across all treatments, both the maximum percentage decline in FSH and the interval to FSH nadir were related to the peak plasma concentrations of E(2) (maximum % decline in FSH=11.17+1.564 (peak E(2))-0.009 (peak E(2))(2), R(2)=0.75; P<0.01), (hours to FSH nadir=10.628+1.486(hours to peak E(2))-0.0282(hours to peak E(2))(2), R(2)=0.22; P<0.05). Concentrations of FSH increased as E(2) declined from its peak value, irrespective of maximum value achieved. It was concluded that the intramuscular administration of ODB in oil to ovariectomised heifers given a PRID results in higher plasma concentrations of E(2) and causes a greater reduction in FSH than administration topically by intravaginal gelatine capsule. E(2) transiently suppresses FSH in ovariectomised heifers, and the magnitude of the suppression is dose-dependent; however FSH concentrations begin to increase 1-2 days after ODB administration while concentrations of E(2) were declining but still high.

A multicenter phase II study of a five-day regimen of oral 5-fluorouracil plus eniluracil with or without leucovorin in patients with metastatic colorectal cancer

PURPOSE

To evaluate the safety and efficacy of a five-day regimen of oral 5-fluorouracil (5-FU) plus eniluracil (776C85) in patients with metastatic colorectal cancer (CRC).

PATIENTS AND METHODS

Seventy-five patients with metastatic CRC that was previously untreated or refractory to 5-FU-leucovorin (LV) were enrolled and divided into two strata based upon their treatment history. Twenty-four had not previously received chemotherapy or had received adjuvant chemotherapy that ended > 6 months prior to enrollment on study (previously untreated stratum). Fifty-one patients had disease refractory to intravenous (i.v.) 5-FU-LV (previously treated stratum). All patients received seven consecutive daily doses of eniluracil (20 mg/day) with once daily oral 5-FU given on days 2-6, repeated every four weeks. One-half of the patients in each stratum also received 50 mg/day oral LV on days 2-6. The 5-FU dose was 25 mg/m2 when administered without LV and 20 mg/m2 when administered with LV.

RESULTS

Partial response (PR) was noted in 2 of 12 patients receiving eniluracil-5-FU and in 3 of 12 patients receiving eniluracil-5-FU-LV in the previously untreated stratum. No responses were observed in the refractory disease stratum, however, 15 patients (30%) demonstrated stable disease over 2-18+ courses of therapy. Non-hematologic toxicities were mild; only 7% of patients experienced grade 3 diarrhea. Myelosuppression was frequent and dose limiting. Neutropenic sepsis was reported in 13.5% of patients.

CONCLUSIONS

Eniluracil with 5-FU administered orally with or without LV on a five-day schedule is active and well tolerated when given as primary therapy to patients with metastatic CRC.

Regulation of follicle waves to maximize fertility in cattle

Cattle have recurrent follicular waves every 7-10 days in most physiological situations; an FSH increase is associated with emergence of the wave and LH pulse frequency determines the fate of the dominant follicle. To control oestrus with hormones it is necessary to ensure that either induced corpus luteum regression or the termination of a progestogen treatment coincides with the selection of the dominant follicle during the wave, to give a precise onset of oestrus and high fertility. The exogenous administration of progesterone or progestagen blocks the normal turnover of the dominant follicle once the corpus luteum regresses. Thus, the effects of duration of dominance of the preovulatory follicle on onset of oestrus and fertility were examined. The variation in onset of oestrus was reduced but occurred 5-9 h later after 4 versus 8 days of dominance; pregnancy rate was also affected with dominance periods of 2-4, 4-8 and > 10 days resulting in 0, 10-15% or 20-50% reduction in pregnancy rates, respectively. The necessity for short duration of dominance of the preovulatory follicle means that to ensure high fertility the follicular wave needs to be regulated when using hormones to control oestrus. Two approaches were examined, namely the use of GnRH or oestradiol at time of progesterone intravaginal releasing device insertion. The effect of 250 micrograms of synthetic GnRH on the fate of an existing follicle wave was to ovulate the dominant follicle (20/20 cows) and a new wave emerged 1.6 +/- 0.3 days later; however, there was no effect of GnRH on the wave if administered before dominant follicle selection. The effect of oestradiol concentrations on suppression of FSH in ovariectomized heifers showed that increasing oestradiol to 10-15 pg ml-1 caused a 37 +/- 6.9% decrease in FSH for 24 h, with a subsequent increase to pretreatment values by 57 +/- 13 h. In cyclic heifers, increasing oestradiol to > 10 pg ml-1 in conjunction with progesterone treatment at emergence of the first wave of the cycle affected the current follicle wave by either preventing dominant follicle selection or decreasing diameter of the dominant follicle, without consistently affecting the interval to new wave emergence. Increase of oestradiol after dominance, however, delayed new wave emergence by 2-5 days. A better understanding of the hormonal control of follicle waves will lead to development of improved hormonal regimens to control oestrus sufficiently to give high pregnancy rates to a single AI without recourse to detection of oestrus.

Privatising general practice in Mongolia: a trial of needs-adjusted capitation

Mongolia's family doctors have long been salaried government employees. The crisis caused by the break-up of the Soviet Bloc required the government to seek a balance between command and market economies, and this influenced the decision to introduce capitated private practice for family doctor services on a trial basis. This article explains why and how a risk-adjusted capitation model was developed by a blend of empirical analysis and expert judgement, which comprises ten classes of clients defined by age-sex and poverty groupings. Payment relativities across the classes were set in proportion to a desirable (or target) number of contacts per year. Separate processes were used to set the targets for patient-initiated and active (health promotion and illness prevention) contacts. The model is intended to lead to greater equity of service access and provision. It should also encourage a greater concern for health outcomes, sensitivity to clients' views, and operational efficiency.

Improvements in clinical benefit with vinorelbine in the treatment of hormone-refractory prostate cancer: a phase II trial

BACKGROUND

Clinical activity is difficult to assess by traditional response endpoints in patients with advanced prostate cancer. We used clinical benefit response to assess the activity of vinorelbine (Navelbine) in patients with hormone-refractory prostate cancer.

PATIENTS AND METHODS

Forty-nine men with hormone-refractory prostate cancer received vinorelbine weekly for eight weeks followed by every-other-week dosing. Clinical benefit response was defined by improvement in 1 of the following categories for at least 12 weeks and stable response or better in the other 2: pain index (analgesic consumption and pain intensity), Karnofsky performance status, and tumor status.

RESULTS

Of 37 evaluable patients, 14 (39%) achieved clinical benefit for a median duration of 6 months (range 3-24 months). Toxicities consisted primarily of brief neutropenia and mild nausea.

CONCLUSION

These findings indicate that vinorelbine is well tolerated in men with hormone-refractory prostate cancer and produces durable clinical benefit as defined by improvement in pain index and performance status.