Antidepressants for the treatment of depression in people with cancer

Continuous flow synthesis of N,N-dimethyltryptamine (DMT) analogues with therapeutic potential

Herein, we describe the continuous flow synthesis and in-line extraction of N,N-dimethyltryptamine (DMT) and several of its analogues using a Fischer indole reaction, along with a larger gram scale synthesis (4.75 g) of the model compound. These products could then be quickly transformed into their respective fumarate salts, making them easier to handle and stable for long time storage using a straightforward batch procedure. Additionally, the commercially available drug rizatriptan benzoate could be synthesised with high purity using this setup. The presented method employs relatively green solvents both for the synthesis and purification of the target products.

Citalopram, an antipsychotic agent, induces G1/G0 phase cell cycle arrest and promotes apoptosis in human laryngeal carcinoma HEP-2 cells

Human laryngeal squamous carcinoma (LSCC) is a common malignant tumor in the head and neck. Despite the recently developed therapies for the treatment of LSCC, patients' overall survival rate still did not enhance remarkably; this highlights the need to formulate alternative strategies to develop novel treatments. The antitumor effects of antidepressant drugs such as citalopram have been reported on several cancer cells; however, they have yet to be investigated against LSCC. The current study was directed to explore the possible antitumor effects of citalopram on human laryngeal carcinoma cell lines (HEP-2). HEP-2 cells were cultured and treated with different doses of citalopram (50-400 µM) for 24, 48, and 72 h. The effects of citalopram on the viability of cancer cells were determined by the MTT assay. In addition, apoptosis and cell cycle analysis were performed by flow cytometry. Moreover, evaluation of the expression of proapoptotic and apoptotic proteins, such as cytochrome c, cleaved caspases 3 and 9, Bcl-2, and BAX, was performed by western blotting analysis. Our results revealed that citalopram significantly suppressed the proliferation of HEP-2 cells through the upregulation of p21 expression, resulting in the subsequent arrest of the cell cycle at the G0/G1 phase. Furthermore, citalopram treatment-induced HEP-2 cell apoptosis; this was indicated by the significant increase of cytochrome c, cleaved caspases 3 and 9, and BAX protein expression. On the contrary, Bcl-2 protein expression was significantly downregulated following treatment with citalopram. The ultrastructure studies were in accordance with the protein expression findings and showed clear signs of apoptosis with ring chromatin condensation upon treatment with citalopram. These findings suggest that citalopram's anti-tumor activities on HEP-2 cells entailed stimulation of the intrinsic apoptotic pathway, which was mediated via Bcl-2 suppression.

Antidepressants for the treatment of depression in people with cancer

BACKGROUND

Major depression and other depressive conditions are common in people with cancer. These conditions are not easily detectable in clinical practice, due to the overlap between medical and psychiatric symptoms, as described by diagnostic manuals such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) and International Classification of Diseases (ICD). Moreover, it is particularly challenging to distinguish between pathological and normal reactions to such a severe illness. Depressive symptoms, even in subthreshold manifestations, have a negative impact in terms of quality of life, compliance with anticancer treatment, suicide risk and possibly the mortality rate for the cancer itself. Randomised controlled trials (RCTs) on the efficacy, tolerability and acceptability of antidepressants in this population are few and often report conflicting results.

OBJECTIVES

To evaluate the efficacy, tolerability and acceptability of antidepressants for treating depressive symptoms in adults (aged 18 years or older) with cancer (any site and stage).

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was November 2022.

SELECTION CRITERIA

We included RCTs comparing antidepressants versus placebo, or antidepressants versus other antidepressants, in adults (aged 18 years or above) with any primary diagnosis of cancer and depression (including major depressive disorder, adjustment disorder, dysthymic disorder or depressive symptoms in the absence of a formal diagnosis).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was 1. efficacy as a continuous outcome. Our secondary outcomes were 2. efficacy as a dichotomous outcome, 3. Social adjustment, 4. health-related quality of life and 5. dropouts. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We identified 14 studies (1364 participants), 10 of which contributed to the meta-analysis for the primary outcome. Six of these compared antidepressants and placebo, three compared two antidepressants, and one three-armed study compared two antidepressants and placebo. In this update, we included four additional studies, three of which contributed data for the primary outcome. For acute-phase treatment response (six to 12 weeks), antidepressants may reduce depressive symptoms when compared with placebo, even though the evidence is very uncertain. This was true when depressive symptoms were measured as a continuous outcome (standardised mean difference (SMD) -0.52, 95% confidence interval (CI) -0.92 to -0.12; 7 studies, 511 participants; very low-certainty evidence) and when measured as a proportion of people who had depression at the end of the study (risk ratio (RR) 0.74, 95% CI 0.57 to 0.96; 5 studies, 662 participants; very low-certainty evidence). No studies reported data on follow-up response (more than 12 weeks). In head-to-head comparisons, we retrieved data for selective serotonin reuptake inhibitors (SSRIs) versus tricyclic antidepressants (TCAs) and for mirtazapine versus TCAs. There was no difference between the various classes of antidepressants (continuous outcome: SSRI versus TCA: SMD -0.08, 95% CI -0.34 to 0.18; 3 studies, 237 participants; very low-certainty evidence; mirtazapine versus TCA: SMD -4.80, 95% CI -9.70 to 0.10; 1 study, 25 participants). There was a potential beneficial effect of antidepressants versus placebo for the secondary efficacy outcomes (continuous outcome, response at one to four weeks; very low-certainty evidence). There were no differences for these outcomes when comparing two different classes of antidepressants, even though the evidence was very uncertain. In terms of dropouts due to any cause, we found no difference between antidepressants compared with placebo (RR 0.85, 95% CI 0.52 to 1.38; 9 studies, 889 participants; very low-certainty evidence), and between SSRIs and TCAs (RR 0.83, 95% CI 0.53 to 1.22; 3 studies, 237 participants). We downgraded the certainty of the evidence because of the heterogeneous quality of the studies, imprecision arising from small sample sizes and wide CIs, and inconsistency due to statistical or clinical heterogeneity.

AUTHORS' CONCLUSIONS

Despite the impact of depression on people with cancer, the available studies were few and of low quality. This review found a potential beneficial effect of antidepressants against placebo in depressed participants with cancer. However, the certainty of evidence is very low and, on the basis of these results, it is difficult to draw clear implications for practice. The use of antidepressants in people with cancer should be considered on an individual basis and, considering the lack of head-to-head data, the choice of which drug to prescribe may be based on the data on antidepressant efficacy in the general population of people with major depression, also taking into account that data on people with other serious medical conditions suggest a positive safety profile for the SSRIs. Furthermore, this update shows that the usage of the newly US Food and Drug Administration-approved antidepressant esketamine in its intravenous formulation might represent a potential treatment for this specific population of people, since it can be used both as an anaesthetic and an antidepressant. However, data are too inconclusive and further studies are needed. We conclude that to better inform clinical practice, there is an urgent need for large, simple, randomised, pragmatic trials comparing commonly used antidepressants versus placebo in people with cancer who have depressive symptoms, with or without a formal diagnosis of a depressive disorder.

Potential Drug Interactions Between Psychotropics and Intravenous Chemotherapeutics Used by Patients With Cancer

Introduction: Patients undergoing cancer treatment usually have comorbidities, and psychiatric disorders are commonly seen in these patients. For the treatment of these psychiatric disorders, the use of psychotropic drugs is common, turning these patients susceptible to untoward drug interactions. Therefore, the aim of this study was to estimate the prevalence of clinically relevant drug-drug interactions (DDI) between chemotherapeutic and psychotropic agents in patients with cancer treated at an oncology service in southern Brazil. Methods: An observational epidemiological study with a cross-sectional census-type design was carried out between October and December 2020. The drug-drug interactions were identified through consultation and analysis of the Medscape Drug Interaction Check and Micromedex databases. The interactions were classified as major, when the interaction can be fatal and/or require medical intervention to avoid or minimize serious adverse effects and moderate, when the interaction can exacerbate the patient's condition and/or requires changes in therapy. Results: A total of 74 patients was included in the study among the 194 patients seen in the oncology service during the period studied. A total of 24 (32.4%) DDIs were found, 21 (87.5%) of which were classified as being of major risk and 3 (12.5%) as moderate risk. According to the mechanism of action, 19 (79.1%) were classified as pharmacodynamic interactions and 5 (20.9%) as pharmacokinetic interactions. Conclusion: It was shown that a considerable percentage of patients undergoing intravenous chemotherapy are at risk of pharmacological interaction with psychotropic drugs. Thus, it is essential that the oncologist considers all psychotropic drugs and other drugs used by patients in order to avoid drug-drug interactions.

Complex Effects of Sertraline and Citalopram on In Vitro Murine Breast Cancer Proliferation and on In Vivo Progression and Anxiety Level

Some selective serotonin reuptake inhibitors (SSRIs), primarily sertraline, demonstrate anti-proliferative activity in malignant cell-lines and in xenografted mouse models of colorectal tumor. There is, however, a paucity of comparative studies on the anti-tumor effects of SSRIs. We compared the in vitro and in vivo effects of sertraline and citalopram on murine 4T1 breast cancer. Grafted mice were used to determine the rate of tumor growth and survival as well as the impact of stress and antidepressant treatment on tumor progression and mortality and on pro-inflammatory cytokines. Sertraline, in the micromolar range, but not citalopram, induced a significant in vitro concentration-dependent inhibition of murine 4T1 cell proliferation and splenocyte viability. In contrast, sertraline (10 mg/kg/d), enhanced in vivo tumor growth. Contrary to the study's hypothesis, chronic mild stress did not modify tumor growth in grafted mice. The in vitro effects of sertraline on tumor growth seem to be the opposite of its in vivo effects. The impact of sertraline treatment on humans with breast cancer should be further investigated.

Efficacy of expressive helping in adult hematologic cancer patients undergoing stem cell transplant: protocol for the Writing for Insight, Strength, and Ease (WISE) study's two-arm randomized controlled trial

Background

During, shortly after, and sometimes for years after hematopoietic stem cell transplant, a large proportion of hematological cancer patients undergoing transplant report significant physical and psychological symptoms and reduced health-related quality of life. To address these survivorship problems, we developed a low-burden, brief psychological intervention called expressive helping that includes two theory- and evidence-based components designed to work together synergistically: emotionally expressive writing and peer support writing. Building on evidence from a prior randomized control trial showing reductions in physical symptoms and distress in long-term transplant survivors with persistent survivorship problems, the Writing for Insight, Strength, and Ease (WISE) trial will evaluate the efficacy of expressive helping when used during transplant and in the early post-transplant period, when symptoms peak, and when intervention could prevent development of persistent symptoms.

Methods

WISE is a multi-site, two-arm randomized controlled efficacy trial. Adult hematological cancer patients scheduled for a hematopoietic stem cell transplant will complete baseline measures and then, after hospitalization but prior to transplant, they will be randomized to complete either expressive helping or a time and attention “neutral writing” task. Both expressive helping and neutral writing involve four brief writing sessions, beginning immediately after randomization and ending approximately 4 weeks after hospital discharge. Measures of symptom burden (primary outcome), distress, health-related quality of life, and fatigue (secondary outcomes) will be administered in seven assessments coinciding with medically relevant time points from baseline and to a year post-intervention.

Discussion

The steady and continuing increase in use of stem cell transplantation has created growing need for efficacious, accessible interventions to reduce the short- and long-term negative physical and psychosocial effects of this challenging but potentially life-saving treatment. Expressive helping is a psychological intervention that was designed to fill this gap. It has been shown to be efficacious in long-term transplant survivors but could have even greater impact if it is capable of reducing symptoms during and soon after transplant. The WISE study will evaluate these benefits in a rigorous randomized controlled trial.

Trial registration

Clinicaltrial.govNCT03800758. Registered January 11, 2019

Prevention of depression in adults with long-term physical conditions

BACKGROUND

Major depression is one of the world's leading causes of disability in adults with long-term physical conditions compared to those without physical illness. This co-morbidity is associated with a negative prognosis in terms of increased morbidity and mortality rates, increased healthcare costs, decreased adherence to treatment regimens, and a substantial decline in quality of life. Therefore, preventing the onset of depressive episodes in adults with long-term physical conditions should be a global healthcare aim. In this review, primary or tertiary (in cases of preventing recurrences in those with a history of depression) prevention are the focus. While primary prevention aims at preventing the onset of depression, tertiary prevention comprises both preventing recurrences and prohibiting relapses. Tertiary prevention aims to address a depressive episode that might still be present, is about to subside, or has recently resolved. We included tertiary prevention in the case where the focus was preventing the onset of depression in those with a history of depression (preventing recurrences) but excluded it if it specifically focused on maintaining an condition or implementing rehabilitation services (relapse prevention). Secondary prevention of depression seeks to prevent the progression of depressive symptoms by early detection and treatment and may therefore be considered a 'treatment,' rather than prevention. We therefore exclude the whole spectrum of secondary prevention.

OBJECTIVES

To assess the effectiveness, acceptability and tolerability of psychological or pharmacological interventions, in comparison to control conditions, in preventing depression in adults with long-term physical conditions; either before first ever onset of depressive symptoms (i.e. primary prevention) or before first onset of depressive symptoms in patients with a history of depression (i.e. tertiary prevention).

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO and two trials registries, up to 6 February 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of preventive psychological or pharmacological interventions, specifically targeting incidence of depression in comparison to treatment as usual (TAU), waiting list, attention/psychological placebo, or placebo. Participants had to be age 18 years or older, with at least one long-term physical condition, and no diagnosis of major depression at baseline (primary prevention). In addition, we included studies comprising mixed samples of patients with and without a history of depression, which explored tertiary prevention of recurrent depression. We excluded other tertiary prevention studies. We also excluded secondary preventive interventions. Primary outcomes included incidence of depression, tolerability, and acceptability. Secondary outcomes included severity of depression, cost-effectiveness and cost-utility.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 11 RCTs, with one trial on psychological interventions, and 10 trials on pharmacological interventions. Data analyses on the psychological intervention (problem-solving therapy compared to TAU) included 194 participants with age-related macular degeneration. Data analyses on pharmacological interventions included 837 participants comparing citalopram (one trial), escitalopram (three trials), a mixed sample of fluoxetine/nortriptyline (one trial), melatonin (one trial), milnacipran (one trial), and sertraline (three trials), each to placebo. Included types of long-term physical conditions were acute coronary syndrome (one trial), breast cancer (one trial), head and neck cancer (two trials), stroke (five trials), and traumatic brain injury (one trial). Psychological interventions Very low-certainty evidence of one study suggests that problem solving therapy may be slightly more effective than TAU in preventing the incidence of depression, immediately post-intervention (odds ratio (OR) 0.43, 95% confidence interval (CI) 0.20 to 0.95; 194 participants). However, there may be little to no difference between groups at six months follow-up (OR 0.71, 95% CI 0.36 to 1.38; 190 participants; one study; very low-certainty evidence). No data were available regarding incidence of depression after six months. Regarding acceptability (drop-outs due to any cause), slightly fewer drop-outs occurred in the TAU group immediately post-intervention (OR 5.21, 95% CI 1.11 to 24.40; 206 participants; low-certainty evidence). After six months, however, the groups did not differ (OR 1.67, 95% CI 0.58 to 4.77; 206 participants; low-certainty evidence). This study did not measure tolerability. Pharmacological interventions Post-intervention, compared to placebo, antidepressants may be beneficial in preventing depression in adults with different types of long-term physical conditions, but the evidence is very uncertain (OR 0.31, 95% CI 0.20 to 0.49; 814 participants; nine studies; I2 =0%; very low-certainty evidence). There may be little to no difference between groups both immediately and at six months follow-up (OR 0.44, 95% CI 0.08 to 2.46; 23 participants; one study; very low-certainty evidence) as well as at six to 12 months follow-up (OR 0.81, 95% CI 0.23 to 2.82; 233 participants; three studies; I2 = 49%; very low-certainty evidence). There was very low-certainty evidence from five studies regarding the tolerability of the pharmacological intervention. A total of 669 adverse events were observed in 316 participants from the pharmacological intervention group, and 610 adverse events from 311 participants in the placebo group. There was very low-certainty evidence that drop-outs due to adverse events may be less frequent in the placebo group (OR 2.05, 95% CI 1.07 to 3.89; 561 participants; five studies; I2 = 0%). There was also very low-certainty evidence that drop-outs due to any cause may not differ between groups either post-intervention (OR 1.13, 95% CI 0.73 to 1.73; 962 participants; nine studies; I2 = 28%), or at six to 12 months (OR 1.13, 95% CI 0.69 to 1.86; 327 participants; three studies; I2 = 0%).

AUTHORS' CONCLUSIONS

Based on evidence of very low certainty, our results may indicate the benefit of pharmacological interventions, during or directly after preventive treatment. Few trials examined short-term outcomes up to six months, nor the follow-up effects at six to 12 months, with studies suffering from great numbers of drop-outs and inconclusive results. Generalisation of results is limited as study populations and treatment regimes were very heterogeneous. Based on the results of this review, we conclude that for adults with long-term physical conditions, there is only very uncertain evidence regarding the implementation of any primary preventive interventions (psychological/pharmacological) for depression.

[Depression, anxiety, delirium and desire to die in palliative care : Recommendations of the S3 guideline on palliative care for patients with incurable cancer]

BACKGROUND

The aim of palliative care is to optimize the quality of life of patients with incurable advanced diseases. Adequate psychotherapeutic and psychiatric care is essential in this context.

OBJECTIVE

This article presents the recommendations of the S3 guideline on palliative care for patients with incurable cancer with regard to psychotherapeutic and psychiatric contents.

MATERIAL AND METHODS

The guideline was developed under the leadership of the German Society for Palliative Medicine (DGP) within the methodological framework of the German Guideline Program in Oncology. Systematic literature reviews were carried out to identify relevant publications in the databases Medline, Cochrane Library, PsycInfo and Embase. Based on the publications included and clinical experience, representatives of 61 professional associations developed and agreed on evidence-based and consensus-based recommendations.

RESULTS

Out of the total of 15 chapters in the guidelines, four have a special reference to psychiatry or psychotherapy; they cover the topics depression, anxiety, delirium in the dying phase and dealing with the desire to die. These chapters contain a total of 71 recommendations, almost one third of which are evidence-based. In view of the regularly undetected psychological symptoms in patients with incurable cancer, an early assessment is recommended. Optimal control of physical symptoms and support in social and existential matters are general measures that should be provided in addition to non-pharmacological and pharmacological procedures.

CONCLUSION

The guideline on palliative care deals with important mental issues that should be considered by all disciplines and professions. The need for research in palliative care remains high.

The Quality of Life of Patients with Suspected Lung Cancer before and after Bronchoscopy and the Effect of Mirtazapine on the Depressive Status

Objective Patients with suspected lung cancer often experience adverse side effects such as anxiety, depression, and a decreased appetite. These side effects influence the patients' quality of life and their ability to make decisions concerning appropriate treatment. This study examined the psychological status and quality of life of patients with suspected lung cancer before and after bronchoscopy treatment and evaluated the effect of mirtazapine prescribed to patients with depression. Methods To assess patient characteristics (e.g. age, gender, and medical history), a questionnaire including the Hospital Anxiety and Depression Scale - Japanese version and the Functional Assessment of Cancer Therapy-L was administered. Patients Forty-three patients admitted for bronchoscopy treatment between May 2017 and April 2018 were included. Results The results showed that patients with depression reported a worse quality of life than those without depression. Compared with no medication, the administration of mirtazapine alleviated depressive symptoms. Furthermore, the patients' depressive status was affected by their physical symptoms, including coughing, tightness of chest, and dyspnea. Conclusion Our results emphasize the importance of detecting depression in the early stages of a cancer diagnosis and have significant implications concerning pharmacological intervention in patients with cancer displaying signs of depression.

Interventions for Reducing Suicide Risk in Cancer Patients: A Literature Review

The suicide risk of people diagnosed with cancer is two times higher than the general population. The number of cases of diagnosed cancer is estimated to rise by 70% over the next two decades. Evidence-based prevention strategies are necessary to protect this vulnerable group of individuals. The purpose of this review was to find out the risk factors of suicide and which types of interventions can serve as prevention strategies. Psychosocial interventions, pharmacotherapy and physical activity can play a preventive role in reducing psychosocial and physical risk factors, such as mental disorders, poor social support, poor performance status and pain. Further research is needed to develop effective suicide prevention strategies for cancer patients.

The use of antidepressants in oncology: a review and practical tips for oncologists

Background

The use of psychotropic drugs, namely those with an antidepressant profile (ADs), is a mandatory part of an integrated treatment of psychiatric disorders among cancer patients. We aimed to synthetize the most relevant data emerging from published studies to provide tips about the use of ADs in oncology.

Design

A search was made of the major databases over the last 30 years (Embase/Medline, PsycLIT, PsycINFO, the Cochrane Library), including narrative reviews, systematic reviews and meta-analyses summarizing the results from observational studies and randomized clinical trials assessing effectiveness, safety profile, interactions, contraindications and use of ADs in oncology with regard to both psychiatric (depressive spectrum, stress-related, anxiety disorders) and cancer-related symptoms (e.g. pain, hot flashes and fatigue).

Results

The weight of evidence supports the efficacy of ADs for more severe major depression in individuals with cancer and as an adjuvant treatment in cancer-related symptoms, although the methodological limitations of reported randomized controlled trials do not permit definite conclusions. Data also indicate that there should be caution in the use of ADs in cancer patients in terms of their safety profile and potential clinically significant interactions with other prescribed medications. Practical recommendations that have been made for the use of ADs in cancer patients, in the context of a multimodal approach to depression treatment, have been summarized here.

Conclusions

ADs are a relatively safe and effective treatment for more severe major depression in cancer patients. However, more research is urgently needed regarding the efficacy of ADs in different cancer types and cancer settings, their interactions with anticancer agents and their additive benefit when integrated with psychosocial interventions.

Approaching to the Essence of Major Depressive Disorder

Major Depressive Disorder (MDD) is a serious neuropsychic disease. It destroys person’s family relationship and social connections seriously. Latest WHO investigation disclosed nearly 4.4% of the population worldwide (approximately 322 million people) were being affected by MDD extensively [1]. While in China, Dong M, et al. reported the occurrence rate of suicide attempt during hospitalization and after the onset of MDD were 17.3% (95% CI: 12.4-23.7%) and 42.1% (95% CI: 26.1-60.0%) respectively [2]. Another research made by Grupta S, et al. announced MDD in urban China might be under-diagnosed and untreated [3].

Health-Related Quality of Life: The Impact on Morbidity and Mortality

In the age of ever-expanding treatments and precision medicine, the hope for cure remains the ultimate goal for patients and providers. Equally important to many patients is the quality of life achieved during and after treatment. Evidence suggests that overall quality of life is important to patients and plays a role in determining outcomes in patients with cancer. This article examines components of health-related quality of life and cancer treatment, including physical, psychosocial, and financial burden, as well as how these components affect patients' overall wellbeing and survival.

Depression in Cancer Care

Depression is common among cancer patients and their families, and may lead to substantial clinical consequences. Clinicians should routinely screen cancer patients for comorbid depression and should provide appropriate care at both primary and specialized care levels. Good quality care is beneficial not only for cancer patients themselves but also for their family members. It includes good communication between patients and health providers, and addressing of unmet needs of cancer patients. Specialized care comprises pharmacotherapy and psychotherapy. The advancement of psychotherapy for cancer patients parallels the advancement of general psychotherapy. Among the many types of psychotherapies, mindfulness-based interventions have been attracting growing attention. Some relevant studies that have been conducted in Keio University Hospital are described herein.

Clinical Factors as a Component of the Personalized Treatment Approach to Advanced Pancreatic Cancer: a Systematic Literature Review

INTRODUCTION

Pancreatic cancer is often diagnosed at late stages, where disease is either locally advanced unresectable or metastatic. Despite advances, long-term survival is relatively non-existent.

DISCUSSION

This review article discusses clinical factors commonly encountered in practice that should be incorporated into the decision-making process to optimize patient outcomes, including performance status, nutrition and cachexia, pain, psychological distress, medical comorbidities, advanced age, and treatment selection.

CONCLUSION

Identification and optimization of these clinical factors could make a meaningful impact on the patient's quality of life.

Use of Antidepressant Medications Moderates the Relationship Between Depressive Symptoms and Hospital Length of Stay in Patients with Advanced Cancer

BACKGROUND

Among patients with cancer, depressive symptoms are associated with worse clinical outcomes, including greater health care utilization. As use of antidepressant medications can improve depressive symptoms, we sought to examine relationships among depressive symptoms, antidepressant medications, and hospital length of stay (LOS) in patients with advanced cancer.

MATERIALS AND METHODS

From September 2014 to May 2016, we prospectively enrolled patients with advanced cancer who had an unplanned hospitalization. We performed chart review to obtain information regarding documented depressive symptoms in the 3 months prior to admission and use of antidepressant medications at the time of admission. We compared differences in hospital LOS by presence or absence of depressive symptoms and used adjusted linear regression to examine if antidepressant medications moderated these outcomes.

RESULTS

Of 1,036 patients, 126 (12.2%) had depressive symptoms documented prior to admission, and 288 (27.8%) were taking antidepressant medications at the time of admission. Patients with depressive symptoms experienced longer hospital LOS (7.25 vs. 6.13 days; p = .036). Use of antidepressant medications moderated this relationship; among patients not on antidepressant medications, depressive symptoms were associated with longer hospital LOS (7.88 vs. 6.11 days; p = .025), but among those on antidepressant medications, depressive symptoms were not associated with hospital LOS (6.57 vs. 6.17 days; p = .578).

CONCLUSION

Documented depressive symptoms prior to hospital admission were associated with longer hospital LOS. This effect was restricted to patients not on antidepressant medications. Future studies are needed to investigate if use of antidepressant medications decreases LOS for patients hospitalized with advanced cancer and the mechanisms by which this may occur.

IMPLICATIONS FOR PRACTICE

This study investigated the prevalence of documented depressive symptoms in patients with advanced cancer in the 3 months prior to an unplanned hospitalization and the prevalence of use of antidepressant medications at time of hospital admission. The relationship of these variables with hospital length of stay was also examined, and it was found that documented depressive symptoms were associated with prolonged hospital length of stay. Interestingly, antidepressant medications moderated the relationship between depressive symptoms and hospital length of stay. These findings support the need to recognize and address depressive symptoms among patients with advanced cancer, with potential implications for optimizing health care utilization.

Persistent Post-Mastectomy Pain: Risk Factors and Current Approaches to Treatment

Persistent Post-Mastectomy Pain (PPMP) is a common condition that can follow surgeries for breast cancer, the most common cancer in women. Because of the frequency of PPMP and its potential severity, it has received increasing research attention. This manuscript reviews the recent research literature, beginning with a brief history and then relevant medical, surgical, demographic, and psychosocial risk factors. Subsequently, social, psychological, and functional sequelae that have been linked to PPMPS are considered, as is research on current pharmacological, psychological, and rehabilitative approaches to treatment. The review concludes with a discussion of directions for future research and treatment that might reduce the incidence and impact of PPMP on breast cancer survivors. PERSPECTIVE: This article describes current research literature involving mechanisms, risks, and treatments related to persistent post-mastectomy pain. Implications of research findings also are discussed for pre- and post-surgical approaches to pain management, current treatments, and promising research directions.

Antidepressants for the treatment of depression in people with cancer

BACKGROUND

Major depression and other depressive conditions are common in people with cancer. These conditions are not easily detectable in clinical practice, due to the overlap between medical and psychiatric symptoms, as described by diagnostic manuals such as the Diagnostic and Statistical Manual of Mental Disorders (DSM) and International Classification of Diseases (ICD). Moreover, it is particularly challenging to distinguish between pathological and normal reactions to such a severe illness. Depressive symptoms, even in subthreshold manifestations, have been shown to have a negative impact in terms of quality of life, compliance with anti-cancer treatment, suicide risk and likely even the mortality rate for the cancer itself. Randomised controlled trials (RCTs) on the efficacy, tolerability and acceptability of antidepressants in this population are few and often report conflicting results.

OBJECTIVES

To assess the efficacy, tolerability and acceptability of antidepressants for treating depressive symptoms in adults (aged 18 years or older) with cancer (any site and stage).

SEARCH METHODS

We searched the following electronic bibliographic databases: the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 6), MEDLINE Ovid (1946 to June week 4 2017), Embase Ovid (1980 to 2017 week 27) and PsycINFO Ovid (1987 to July week 4 2017). We additionally handsearched the trial databases of the most relevant national, international and pharmaceutical company trial registers and drug-approving agencies for published, unpublished and ongoing controlled trials.

SELECTION CRITERIA

We included RCTs comparing antidepressants versus placebo, or antidepressants versus other antidepressants, in adults (aged 18 years or above) with any primary diagnosis of cancer and depression (including major depressive disorder, adjustment disorder, dysthymic disorder or depressive symptoms in the absence of a formal diagnosis).

DATA COLLECTION AND ANALYSIS

Two review authors independently checked eligibility and extracted data using a form specifically designed for the aims of this review. The two authors compared the data extracted and then entered data into Review Manager 5 using a double-entry procedure. Information extracted included study and participant characteristics, intervention details, outcome measures for each time point of interest, cost analysis and sponsorship by a drug company. We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We retrieved a total of 10 studies (885 participants), seven of which contributed to the meta-analysis for the primary outcome. Four of these compared antidepressants and placebo, two compared two antidepressants, and one three-armed study compared two antidepressants and placebo. In this update we included one additional unpublished study. These new data contributed to the secondary analysis, while the results of the primary analysis remained unchanged.For acute-phase treatment response (6 to 12 weeks), we found no difference between antidepressants as a class and placebo on symptoms of depression measured both as a continuous outcome (standardised mean difference (SMD) -0.45, 95% confidence interval (CI) -1.01 to 0.11, five RCTs, 266 participants; very low certainty evidence) and as a proportion of people who had depression at the end of the study (risk ratio (RR) 0.82, 95% CI 0.62 to 1.08, five RCTs, 417 participants; very low certainty evidence). No trials reported data on follow-up response (more than 12 weeks). In head-to-head comparisons we only retrieved data for selective serotonin reuptake inhibitors (SSRIs) versus tricyclic antidepressants, showing no difference between these two classes (SMD -0.08, 95% CI -0.34 to 0.18, three RCTs, 237 participants; very low certainty evidence). No clear evidence of a beneficial effect of antidepressants versus either placebo or other antidepressants emerged from our analyses of the secondary efficacy outcomes (dichotomous outcome, response at 6 to 12 weeks, very low certainty evidence). In terms of dropouts due to any cause, we found no difference between antidepressants as a class compared with placebo (RR 0.85, 95% CI 0.52 to 1.38, seven RCTs, 479 participants; very low certainty evidence), and between SSRIs and tricyclic antidepressants (RR 0.83, 95% CI 0.53 to 1.30, three RCTs, 237 participants). We downgraded the certainty (quality) of the evidence because the included studies were at an unclear or high risk of bias due to poor reporting, imprecision arising from small sample sizes and wide confidence intervals, and inconsistency due to statistical or clinical heterogeneity.

AUTHORS' CONCLUSIONS

Despite the impact of depression on people with cancer, the available studies were very few and of low quality. This review found very low certainty evidence for the effects of these drugs compared with placebo. On the basis of these results, clear implications for practice cannot be deduced. The use of antidepressants in people with cancer should be considered on an individual basis and, considering the lack of head-to-head data, the choice of which agent to prescribe may be based on the data on antidepressant efficacy in the general population of individuals with major depression, also taking into account that data on medically ill patients suggest a positive safety profile for the SSRIs. To better inform clinical practice, there is an urgent need for large, simple, randomised, pragmatic trials comparing commonly used antidepressants versus placebo in people with cancer who have depressive symptoms, with or without a formal diagnosis of a depressive disorder.

Impact of physical exercise in cancer survivors during and after antineoplastic treatments

Cancer patients experience symptoms and adverse effects of treatments that may last even after the end of treatments. Exercise is a safe, non-pharmacological and cost-effective therapy that can provide several health benefits in cancer patient and survivors, reducing cancer symptoms and cancer treatment side effects. The purpose of this review is to describe how the physical exercise is capable to reduce cancer symptoms and cancer treatment side effects. We realized a pragmatic classification of symptoms, dividing them into physical, psychological and psycho-physical aspects. For each symptom we discuss causes, therapies, we analyse the effects of physical exercise and we summarize the most effective type of exercise to reduce the symptoms. This review also points out what are the difficulties that patients and survivors face during the practice of physical activity and provides some solutions to overcome these barriers. Related to each specific cancer, it emerges that type, frequency and intensity of physical exercise could be prescribed and supervised as a therapeutic program, like it occurs for the type, dose and duration of a drug treatment.

Herbal medicine for depression and anxiety: A systematic review with assessment of potential psycho-oncologic relevance

Anxiety and depression are prevalent among cancer patients, with significant negative impact. Many patients prefer herbs for symptom relief to conventional medications which have limited efficacy/side effects. We identified single-herb medicines that may warrant further study in cancer patients. Our search included PubMed, Allied and Complementary Medicine, Embase, and Cochrane databases, selecting only single-herb randomized controlled trials between 1996 and 2016 in any population for data extraction, excluding herbs with known potential for interactions with cancer treatments. One hundred articles involving 38 botanicals met our criteria. Among herbs most studied (≥6 randomized controlled trials each), lavender, passionflower, and saffron produced benefits comparable to standard anxiolytics and antidepressants. Black cohosh, chamomile, and chasteberry are also promising. Anxiety or depressive symptoms were measured in all studies, but not always as primary endpoints. Overall, 45% of studies reported positive findings with fewer adverse effects compared with conventional medications. Based on available data, black cohosh, chamomile, chasteberry, lavender, passionflower, and saffron appear useful in mitigating anxiety or depression with favorable risk-benefit profiles compared to standard treatments. These may benefit cancer patients by minimizing medication load and accompanying side effects. However, well-designed larger clinical trials are needed before these herbs can be recommended and to further assess their psycho-oncologic relevance.

Interventions to improve screening and appropriate referral of patients with cancer for psychosocial distress: systematic review

OBJECTIVES

The primary aim of the review was to determine the effectiveness of strategies to improve clinician provision of psychosocial distress screening and referral of patients with cancer.

DESIGN

Systematic review.

DATA SOURCES

Electronic databases (Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycINFO and Cumulative Index to Nursing and Allied Health Literature (CINAHL)) were searched until July 2016.

INCLUSION CRITERIA

Population: adult patients with cancer and clinical staff members.

INTERVENTION

any strategy that aimed to improve the rate of routine screening and referral for detected distress of patients with cancer. Comparison: no intervention controls, 'usual' practice or alternative interventions.

OUTCOME

(primary) any measure of provision of screening and/or referral for distress, (secondary) psychosocial distress, unintended adverse effects.

DESIGN

trials with or without a temporal comparison group, including randomised and non-randomised trials, and uncontrolled pre-post studies.

DATA EXTRACTION AND ANALYSIS

Two review authors independently extracted data. Heterogeneity across studies precluded quantitative assessment via meta-analysis and so a narrative synthesis of the results is presented.

RESULTS

Five studies met the inclusion criteria. All studies were set in oncology clinics or departments and used multiple implementation strategies. Using the Grades of Recommendation, Assessment, Development and Evaluation, the overall rating of the certainty of the body of evidence reported in this review was assessed as very low. Three studies received a methodological quality rating of weak and two studies received a rating of moderate. Only one of the five studies reported a significant improvement in referrals.

CONCLUSIONS

The review identified five studies of predominantly poor quality examining the effectiveness of strategies to improve the routine implementation of distress screening and referral for patients with cancer. Future research using robust research designs, including randomised assignment, are needed to identify effective support strategies to maximise the potential for successful implementation of distress screening and referral for patients with cancer.

PROSPERO REGISTRATION NUMBER

CRD42015017518.

Psychosocial Issues in Patients with Head and Neck Cancer: an Updated Review with a Focus on Clinical Interventions

PURPOSE OF REVIEW

There are frequent and diverse psychosocial issues that afflict patients with head and neck cancer (HNC) across the illness trajectory, prompting a focus on clinical interventions to prevent and mitigate psychosocial distress. We sought to characterize current understanding on the cause, effects, and interplay of various psychosocial factors in HNC and summarize updated, evidence-based interventions.

RECENT FINDINGS

The psychosocial experience of patients with HNC is characterized by a disproportionately high incidence of depression, suicide, continued substance dependence/abuse, and distress related to relationship conflict, social isolation, disfigurement, and damage to self-image. As we move towards a more thorough understanding and greater appreciation of the relationship between HNC and patient quality of life (QoL), future research focuses on implementation of effective, accessible clinical interventions to alleviate psychosocial distress in this population.

Survivorship: Morbidity, Mortality, Malignancy

Survivorship encompasses the entire therapeutic, psychosocial, functional, and financial experience of living with and through a cancer diagnosis. The period of survivorship starts on the day of the cancer diagnosis and lasts until the end of the survivor's life, regardless of the cause of death. The National Cancer Institute's Office of Cancer Survivorship expands the term "survivor" to include, importantly, caregivers, family, and friends close to the survivor who also live through this period.

Cancer at the Dinner Table: Experiences of Psilocybin-Assisted Psychotherapy for the Treatment of Cancer-Related Distress

Recent randomized controlled trials of psilocybin-assisted psychotherapy for patients with cancer suggest that this treatment results in large-magnitude reductions in anxiety and depression as well as improvements in attitudes toward disease progression and death, quality of life, and spirituality. To better understand these findings, we sought to identify psychological mechanisms of action using qualitative methods to study patient experiences in psilocybin-assisted psychotherapy. Semistructured interviews were conducted with 13 adult participants with clinically elevated anxiety associated with a cancer diagnosis who received a single dose of psilocybin under close clinical supervision. Transcribed interviews were analyzed using interpretative phenomenological analysis, which resulted in 10 themes, focused specifically on cancer, death and dying, and healing narratives. Participants spoke to the anxiety and trauma related to cancer, and perceived lack of available emotional support. Participants described the immersive and distressing effects of the psilocybin session, which led to reconciliations with death, an acknowledgment of cancer’s place in life, and emotional uncoupling from cancer. Participants made spiritual or religious interpretations of their experience, and the psilocybin therapy helped facilitate a felt reconnection to life, a reclaiming of presence, and greater confidence in the face of cancer recurrence. Implications for theory and clinical treatment are discussed.

Depressive Spectrum Disorders in Cancer: Diagnostic Issues and Intervention. A Critical Review

Depressive spectrum disorders, including major depression, persistent depression, minor and sub-syndromal depression, and other forms of depressive conditions, such as demoralization, are among the most common psychiatric consequences of cancer patients, affecting up to 60% of patients. In spite of the negative effects and the burden for cancer patients and their families, these disorders often remain under-recognized and undertreated. The present review aims at summarizing the relevant data concerning the diagnostic challenges within the depressive spectrum disorders among cancer patients. Also, the most relevant data relative to integrated intervention, including psychopharmacological and psychosocial treatment, for depression in cancer patients are critically evaluated. It is mandatory that health care professionals working in oncology (e.g., oncologists, surgeons, radiation oncologists, primary care physicians, nurses, social workers, psychologists) receive training in the diagnosis and integrated management of the different types of disorder within the spectrum of clinical depression.

Cell autonomous expression of CXCL-10 in JAK2V617F-mutated MPN

PURPOSE

Myeloproliferative neoplasms (MPN) are clonal disorders of hematopoietic stem- and progenitor cells. Mutation of Janus-Kinase 2 (JAK2) is the most frequent genetic event detected in Philadelphia-negative MPN. In advanced phases, the clinical hallmark of the disease is a striking inflammatory syndrome. So far, the cellular and molecular basis of inflammation is not fully understood. We, therefore, sought to investigate the relationship of activating JAK2 mutation and aberrant cytokine expression in MPN.

METHODS

Cytokine array was performed to identify Jak2V617F-related cytokine expression and secretion. CXCL10 mRNA expression was analyzed by qPCR in peripheral blood cells. To exclude paracrine/autocrine stimulation as a potential mechanism, we generated Ba/F3-EpoR-JAK2WT or EpoR-JAK2V617F cells lacking CXCL10 receptor. Pharmacologic inhibition of JAK2 kinase was achieved by JAK-Inhibitor treatment. Signaling pathways and downstream effectors were characterized by Western blotting, immunofluorescence microscopy, luciferase reporter assays, qPCR, and chromatin-immunoprecipitation studies.

RESULTS

We identified CXCL10 as the most highly induced cytokine in JAK2-mutated cell lines. In MPN patients, CXCL10 is highly expressed in JAK2V617F but not JAK2WT MPN or healthy donor controls. Moreover, CXCL10 expression correlates with JAK2V617F allelic burden. High CXCL10 correlates with the presence of clinical risk factors but not with clinical symptoms and quality of life. Pharmacologic inhibition of mutated JAK2 kinase inhibits CXCL10 expression. NFκB signaling is activated downstream of JAK2V617F receptor and directly induces CXCL10 expression.

CONCLUSIONS

Our data provide first evidence for a link between oncogenic JAK2V617F signaling and cell intrinsic induction of CXCL10 induced by activated NFkB signaling.

Behavioural Effects of Using Sulfasalazine to Inhibit Glutamate Released by Cancer Cells: A Novel target for Cancer-Induced Depression

Despite the lack of robust evidence of effectiveness, current treatment options for cancer-induced depression (CID) are limited to those developed for non-cancer related depression. Here, anhedonia-like and coping behaviours were assessed in female BALB/c mice inoculated with 4T1 mammary carcinoma cells. The behavioural effects of orally administered sulfasalazine (SSZ), a system x_c⁻ inhibitor, were compared with fluoxetine (FLX). FLX and SSZ prevented the development of anhedonia-like behaviour on the sucrose preference test (SPT) and passive coping behaviour on the forced swim test (FST). The SSZ metabolites 5-aminosalicylic acid (5-ASA) and sulfapyridine (SP) exerted an effect on the SPT but not on the FST. Although 5-ASA is a known anti-inflammatory agent, neither treatment with SSZ nor 5-ASA/SP prevented tumour-induced increases in serum levels of interleukin-1β (IL-1β) and IL-6, which are indicated in depressive disorders. Thus, the observed antidepressant-like effect of SSZ may primarily be attributable to the intact form of the drug, which inhibits system x_c⁻. This study represents the first attempt at targeting cancer cells as a therapeutic strategy for CID, rather than targeting downstream effects of tumour burden on the central nervous system. In doing so, we have also begun to characterize the molecular pathways of CID.

Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial

BACKGROUND

Clinically significant anxiety and depression are common in patients with cancer, and are associated with poor psychiatric and medical outcomes. Historical and recent research suggests a role for psilocybin to treat cancer-related anxiety and depression.

METHODS

In this double-blind, placebo-controlled, crossover trial, 29 patients with cancer-related anxiety and depression were randomly assigned and received treatment with single-dose psilocybin (0.3 mg/kg) or niacin, both in conjunction with psychotherapy. The primary outcomes were anxiety and depression assessed between groups prior to the crossover at 7 weeks.

RESULTS

Prior to the crossover, psilocybin produced immediate, substantial, and sustained improvements in anxiety and depression and led to decreases in cancer-related demoralization and hopelessness, improved spiritual wellbeing, and increased quality of life. At the 6.5-month follow-up, psilocybin was associated with enduring anxiolytic and anti-depressant effects (approximately 60-80% of participants continued with clinically significant reductions in depression or anxiety), sustained benefits in existential distress and quality of life, as well as improved attitudes towards death. The psilocybin-induced mystical experience mediated the therapeutic effect of psilocybin on anxiety and depression.

CONCLUSIONS

In conjunction with psychotherapy, single moderate-dose psilocybin produced rapid, robust and enduring anxiolytic and anti-depressant effects in patients with cancer-related psychological distress.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00957359.

Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial

Cancer patients often develop chronic, clinically significant symptoms of depression and anxiety. Previous studies suggest that psilocybin may decrease depression and anxiety in cancer patients. The effects of psilocybin were studied in 51 cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety. This randomized, double-blind, cross-over trial investigated the effects of a very low (placebo-like) dose (1 or 3 mg/70 kg) vs. a high dose (22 or 30 mg/70 kg) of psilocybin administered in counterbalanced sequence with 5 weeks between sessions and a 6-month follow-up. Instructions to participants and staff minimized expectancy effects. Participants, staff, and community observers rated participant moods, attitudes, and behaviors throughout the study. High-dose psilocybin produced large decreases in clinician- and self-rated measures of depressed mood and anxiety, along with increases in quality of life, life meaning, and optimism, and decreases in death anxiety. At 6-month follow-up, these changes were sustained, with about 80% of participants continuing to show clinically significant decreases in depressed mood and anxiety. Participants attributed improvements in attitudes about life/self, mood, relationships, and spirituality to the high-dose experience, with >80% endorsing moderately or greater increased well-being/life satisfaction. Community observer ratings showed corresponding changes. Mystical-type psilocybin experience on session day mediated the effect of psilocybin dose on therapeutic outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00465595.

Neurocognitive Deficits and Neurocognitive Rehabilitation in Adult Brain Tumors

OPINION STATEMENT

Neurocognitive deficits are common with brain tumors. If assessed at presentation using detailed neurocognitive tests, problems are detected in 80 % of cases. Neurocognition may be affected by the tumor, its treatment, associated medication, mood, fatigue, and insomnia. Interpretation of neurocognitive problems should be considered in the context of these factors. Early post-operative neurocognitive rehabilitation for brain tumor patients will produce rehabilitation outcomes (e.g., quality of life, improved physical function, subjective neurocognition) equivalent to stroke, multiple sclerosis, and head injury, but the effect size and duration of benefit needs further research. In stable patients treated with radiotherapy +/- chemotherapy, the most frequent causes of distress include neurocognitive problems, psychological factors of anxiety, depression, fatigue, and sleep. Exercise, neurocognitive training, neurocognitive behavioral therapy, and medications to treat fatigue, behavior, memory, mood, and removal of drugs that may be associated with neurocognitive side effects (e.g., anti-epileptic drugs) all show promise in helping patients to manage the effects of their neurocognitive impairments better. As these are complex symptoms, multidisciplinary expertise is necessary to evaluate the influence of each variable to plan appropriate support and intervention. Neurocognitive rehabilitation should therefore occur in parallel with disease-centered, medical management from the outset. It should not occur in series, as a restricted phase in a patient's pathway. It should be considered in the pre- and post-operative period where there are good prospects of recovery, as one would for any brain-injured patient, so that the person may reach their optimal physical, sensory, intellectual, psychological, and social functional level. Yet the identification and selection of patients for early neurological rehabilitation and routine evaluation of cognition is uncommon in neurosurgical wards.

Interventions to improve screening and appropriate referral of patients with cancer for distress: systematic review protocol

INTRODUCTION

It is estimated that 35-40% of patients with cancer experience distress at some stage during their illness. Distress may affect functioning, capacity to cope, treatment compliance, quality of life and survival of patients with cancer. Best practice clinical guidelines recommend routine psychosocial distress screening and referral for further assessment and/or psychosocial support for patients with cancer. However, evidence suggests this care is not provided consistently.

METHODS AND ANALYSIS

We developed our methods following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. The review is registered with PROSPERO and any amendments to the protocol will be tracked. The primary aim of this systematic review is to examine the impact of interventions delivered in healthcare settings that are aimed at (1) improving routine screening of patients for psychosocial distress and (2) referral of distressed patients with cancer for further assessment and/or psychosocial support. The effectiveness of such interventions in reducing psychosocial distress, and any unintended adverse effect of the intervention will also be assessed in patients with cancer. Data sources will include the bibliographic databases Cochrane Central Register of Controlled trials (CENTRAL) in the Cochrane Library, MEDLINE, EMBASE, PsycINFO and CINAHL. Eligible studies must compare an intervention (or two or more interventions) in a healthcare setting to improve the rate of screening for psychosocial distress and/or referral for further assessment and/or psychosocial support for patients with cancer with no intervention or 'usual' practice. Two investigators will independently review titles and abstracts, followed by full article reviews and data extraction. Disagreements will be resolved by consensus and if necessary, a third reviewer. Where studies are sufficiently homogenous, trial data will be pooled and meta-analyses performed.

ETHICS AND DISSEMINATION

No ethical issues are foreseen. The findings of this study will be disseminated widely via peer-reviewed publications and conference presentations.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD4 2015017518.