Timing and specificity of the cognitive changes induced by interleukin-2 and interferon-alpha treatments in cancer patients

Functional biomarkers of depression: diagnosis, treatment, and pathophysiology

Major depressive disorder (MDD) is a heterogeneous illness for which there are currently no effective methods to objectively assess severity, endophenotypes, or response to treatment. Increasing evidence suggests that circulating levels of peripheral/serum growth factors and cytokines are altered in patients with MDD, and that antidepressant treatments reverse or normalize these effects. Furthermore, there is a large body of literature demonstrating that MDD is associated with changes in endocrine and metabolic factors. Here we provide a brief overview of the evidence that peripheral growth factors, pro-inflammatory cytokines, endocrine factors, and metabolic markers contribute to the pathophysiology of MDD and antidepressant response. Recent preclinical studies demonstrating that peripheral growth factors and cytokines influence brain function and behavior are also discussed along with their implications for diagnosing and treating patients with MDD. Together, these studies highlight the need to develop a biomarker panel for depression that aims to profile diverse peripheral factors that together provide a biological signature of MDD subtypes as well as treatment response.

An Evolutionary Hypothesis of Suicide: Why it Could be Biologically Adaptive and is so Prevalent in Certain Occupations

From an evolutionary perspective, suicide is a puzzle, because it has serious adverse effects, yet is remarkably common and heritable. An hypothesis is proposed to explain this puzzle, by explaining how suicide could be adaptive through reducing risk that individuals will transmit infections to kin. Empirical evidence supports four predictions from the hypothesis. There are well-established mechanisms by which infections and immune factors increase risk for mental disorders that contribute to suicide. Suicide is more prevalent in occupations with greater exposure to infection and immune-compromising factors and at higher latitudes, where key environmental factors increase vulnerability to infection. In several other highly social species, suicide-like behaviors have evolved to reduce transmission of infections. If the hypothesis is correct, detection and treatment of underlying infections and immune dysfunction should help predict and prevent suicidal behavior, while also combating spread of infectious diseases.

The Attentional Function Index--a self-report cognitive measure

OBJECTIVE

Cognitive assessment in individuals with cancer requires both measured performance on neuropsychological tests and self-report of effectiveness in functioning. Few instruments are available to assess the perceived impact of cognitive alterations on daily functioning in individuals treated for cancer. In this study, we investigated the psychometric properties of a theoretically based instrument, and the Attentional Function Index (AFI), designed to measure perceived effectiveness in common activities requiring attention and working memory, particularly the ability to formulate plans, carry out tasks, and function effectively in daily life.

METHODS

Women (N=172), ages 27-86 years, completed the questionnaire before primary treatment for early stage breast cancer. Construct validity was established using exploratory principal component factor analysis with varimax rotation.

RESULTS

A 13-item instrument emerged with 3 subscales, namely effective action, attentional lapses, and interpersonal effectiveness, which explained 74.69% of total variance. The internal consistency coefficients (Cronbach's α) were 0.92 for the total instrument, and ranged from 0.80 to 0.92 for the 3 subscales. Further examination of validity indicated that the scores on the AFI (1) showed expected correlations with established measures of ability to concentrate, cognitive failures, states of confusion, and mental fatigue, and (2) could distinguish differences in perceived cognitive functioning between younger and older age groups. AFI scores were not significantly associated with years of education or presence of comorbid conditions.

CONCLUSION

The brief AFI has demonstrated usefulness for assessment of perceived cognitive functioning in populations with life-threatening and chronic illness, such as breast cancer.

Common Respiratory Tract Infections as Psychological Entities: A Review of the Mood and Performance Effects of Being Ill

The clinical manifestations associated with colds and influenza overshadow the equally important mood and performance impairments. While decreased alertness and increased anxiety can be considered side effects of symptomatology, symptoms alone may not be responsible for the psychomotor and attention deficits of colds and influenza, respectively. An alternative hypothesis, as proposed in this review, suggests that the immune response, in the form of a cytokine cascade, may be responsible for both the physical and psychological symptoms. In particular, patterns of cytokine production for each infection will dictate the symptoms and performance deficits both within and between viruses. This hypothesis can be extended to incorporate infectious mononucleosis, as well as colds and influenza. The efficacy of symptom‐based overthe‐counter medications is then called into question.

Is systemic anti-cancer therapy neurotoxic? Does chemo brain exist? And should we rename it?

The existence of chemo brain has become almost universally accepted, although many details of the concept are controversial. Data about the different types of cognitive impairment and their duration are not always consistent in the literature. We still do not know which cytotoxic agents are responsible, which characteristics make patients vulnerableand which biologic mechanisms are involved. This chapter reviews the recent literature and provides an actualized definition of chemo brain, including recent functional imaging data and discusses its controversial aspects. Potential underlying mechanisms and their future possible clinical applications in the prevention and treatment of chemo brain are also discussed. These issues are of clinical importance given the prevalence of breast carcinoma, the increased use of chemotherapy as adjuvant therapy, the increasing use of more aggressive dosing schedules and the increasing survival rates. Better-designed future trials should lead to a better definition and understanding of chemo brain and to future therapies.

Neuroimmune pharmacology of neurodegenerative and mental diseases

Neuroimmune pharmacology is a newly emerging field that intersects with neuroscience, immunology, and pharmacology and that is seeking avenues for translational research and better understanding of disease mechanisms. It focuses on the immunity of the central nervous system (CNS) which is greatly influenced by endogenous effectors, such as cytokines and neurotransmitters, and by exogenous substances, including therapeutic compounds, infectious pathogens, and drugs of abuse. In this article, we attempt to raise awareness of the pivotal discovery of how those mediators affect the immunity of the CNS in both physiological conditions and processes of certain mental illnesses, including psychiatric disorders, neurodegenerative diseases, and cerebral dysfunctions due to drugs of abuse. The abnormality in cytokine networks, neurotransmitter homeostasis, and other immune responses may be involved in the neuropathology associated with those mental illnesses, and the therapeutic effects of the potential treatments can be attributed, at least partially, to their immunomodulatory activities. However, the resulting inflammatory cytokines from certain treatments frequently cause psychiatric complications. In addition, the poor neuropathological outcomes frequently found among drug abusers with HIV-1 infection appear to be related to the neurotoxic and immunomodulatory effects of the drugs used. Importantly, glial cells, especially microglia and astrocytes, are key players in the immunomodulatory activities in the CNS, and the functioning CNS is largely dependent upon the reciprocal interactions between neurons and glial cells. Therefore, glia-neuron interactions have become a critical issue for further understanding the disease mechanism. From this review, readers will gain insights into the new field of neuroimmune pharmacology, with a focus on the impacts of CNS immunity on the mental illnesses.

Methodologic issues in the measurement of cytokines to elucidate the biological basis for cancer symptoms

Multiple concurrent symptoms are highly prevalent in patients with cancer. However, little is known about the relationships among these symptoms and their underlying mechanisms. A number of cytokines that are involved in the development of sickness behavior are hypothesized to be a mechanism for symptom clusters. Measurement of these cytokines would provide valuable information that could be used to elucidate mechanisms underlying the development of symptom clusters and the identification of potential targets for intervention studies. In this article, the authors explore several issues that warrant careful consideration when designing a research study involving the use of a cytokine as a biomarker in symptom cluster research. These issues include which molecules to measure, which specimens to collect, the timing of specimen collection and processing, and which technologies to use to measure the biomarker and the sensitivity and specificity of the assay system. The article begins with a brief discussion of cytokines and sickness behavior and the role of the cytokines in cancer-related symptoms.

Attention-deficit hyperactivity disorder (ADHD) and glial integrity: an exploration of associations of cytokines and kynurenine metabolites with symptoms and attention

Background

In contrast to studies of depression and psychosis, the first part of this study showed no major differences in serum levels of cytokines and tryptophan metabolites between healthy children and those with attention-deficit/hyperactivity disorder of the combined type (ADHD). Yet, small decreases of potentially toxic kynurenine metabolites and increases of cytokines were evident in subgroups. Therefore we examined predictions of biochemical associations with the major symptom clusters, measures of attention and response variability.

Methods

We explored systematically associations of 8 cytokines (indicators of pro/anti-inflammatory function) and 5 tryptophan metabolites with symptom ratings (e.g. anxiety, opposition, inattention) and continuous performance test (CPT) measures (e.g. movement, response time (RT), variability) in 35 ADHD (14 on medication) and 21 control children. Predictions from linear regressions (controlled by the false discovery rate) confirmed or disconfirmed partial correlations accounting for age, body mass and socio-economic status.

Results

(1) Total symptom ratings were associated with increases of the interleukins IL-16 and IL-13, where relations of IL-16 (along with decreased S100B) with hyperactivity, and IL-13 with inattention were notable. Opposition ratings were predicted by increased IL-2 in ADHD and IL-6 in control children. (2) In the CPT, IL-16 related to motor measures and errors of commission, while IL-13 was associated with errors of omission. Increased RT variability related to lower TNF-α, but to higher IFN-γ levels. (3) Tryptophan metabolites were not significantly related to symptoms. But increased tryptophan predicted errors of omission, its breakdown predicted errors of commission and kynurenine levels related to faster RTs.

Conclusions

Many associations were found across diagnostic groups even though they were more marked in one group. This confirms the quantitative trait nature of these features. Conceptually the relationships of the pro- and antiinflammatory cytokines distinguished between behaviours associated more with cognitive or more with motor control respectively. Further study should extend the number of immunological and metabolic markers to confirm or refute the trends reported here and examine their stability from childhood to adolescence in a longitudinal design.

Management of Psychiatric Disease in Hepatitis C Treatment Candidates

Depression and other influences on mental health can impact antiviral response rates during chronic hepatitis C treatment, the quality of life for these patients, and the risk for adverse outcomes such as suicide. Enhanced treatment outcomes for patients who are receiving interferon-α requires 1) addressing preexisting mental health problems, 2) alleviating psychiatric conditions that emerge during treatment, and 3) prediction and prevention of these conditions. Accumulating evidence indicates that these three goals are feasible. Collaborative involvement of psychiatric management may often be critical in this regard.

Cancer protection of soy resembles cancer protection during pregnancy

It has been established that carrying a pregnancy to full-term at an early age can protect against contracting cancer by up to 50% in later life. The trophoblast theory of cancer states that trophoblast and cancer tissue are very similar. New findings suggest that the loss of fetal cells during pregnancy resemble those cells responsible for causing metastasis in cancer. Fetal cells and spreading cancer cells are highly proliferative. They are similar to stem cells, exhibiting no or low hormone receptor expression, and require a hormone receptor independent mechanism for control. Control of membrane stability during pregnancy is of vital importance for a successful pregnancy and is mediated by androstenediol and 2-methoxyestradiol. 2-Methoxyestradiol has no hormone receptor affinity and elicits strong anticancer effects particularly against cancer stem cells and fetal cells, for which currently no treatment has yet been established. There is a discussion whether pregnancy reduces cancer stem cells in the breast. Soy isoflavones are structurally similar to both hormones, and elicit strong anticancer effects and antiangiogenesis via inhibition of NF-κB, even in hormone receptor independent breast cancers seen in epidemiologic studies. The trophoblast theory of cancer could help to explain why soy baby nutrition formulas have no effect on baby physiology, other than the nutritional aspect, although soy elicits many effects on the adult immune system. To survive the immune system of the mother, the immune system of the fetus has to be separated; otherwise, the reduction of the immune system in the mother, a necessary feature for the blastocyst to grow, would immediately reduce the immunity for the fetus and endanger its survival. Similar to a fetus, newly born babies show immune insensitive to Th1 and Th2 cytokines, which are necessary and crucial for regulating the immune system of the mother, thus raising the risk of the baby of developing allergies and neurodermatitis. Gene expression studies in vitro as well as in circulating tumor cells from patients consuming a fermented soy product support the antiangiogenic as well as antiproliferative effects of soy.

Does cytokine-induced depression differ from idiopathic major depression in medically healthy individuals?

BACKGROUND

Cytokines of the innate immune response may contribute to behavioral alterations that resemble major depression as manifested in medically healthy individuals.

METHODS

To explore potential similarities and differences between cytokine-induced depression and idiopathic major depression in healthy subjects, dimensional analyses comparing specific symptom dimensions of depression were conducted in 20 patients with malignant melanoma administered the innate immune cytokine, interferon (IFN)-alpha, and 28 medically healthy subjects with major depression of similar age and gender distribution. The Hamilton Rating Scale for Depression was used to assess severity of individual depressive symptoms.

RESULTS

Severity of symptoms of anxiety, depressed mood, and impaired work/activities were comparable between patients with IFN-alpha-induced depression and medically healthy depressed patients. Interestingly, however, compared to medically healthy patients with major depression, patients with IFN-alpha-induced depression reported significantly greater psychomotor retardation and weight loss and significantly less severe feelings of guilt.

LIMITATIONS

The relatively small sample size limited statistical power to detect small differences in symptom expression among groups.

CONCLUSIONS

The data suggest that there is considerable overlap in symptom expression between cytokine-induced depression and idiopathic depression in medically healthy subjects. Nevertheless, differences in isolated symptom domains suggest that cytokines may preferentially target neurocircuits relevant to psychomotor activity (e.g. basal ganglia), while having a limited effect on cognitive distortions regarding self-appraisal.

A potential role for pro-inflammatory cytokines in regulating synaptic plasticity in major depressive disorder

A growing body of data suggests that hyperactivation of the immune system has been implicated in the pathophysiology of major depressive disorder (MDD). Several pro-inflammatory cytokines, such as tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) have been found to be significantly increased in patients with MDD. This review focuses on these two cytokines based on multiple lines of evidence from genetic, animal behaviour, and clinical studies showing that altered levels of serum TNF-alpha and IL-1 are associated with increased risk of depression, cognitive impairments, and reduced responsiveness to treatment. In addition, recent findings have shown that centrally expressed TNF-alpha and IL-1 play a dual role in the regulation of synaptic plasticity. In this paper, we review and critically appraise the mechanisms by which cytokines regulate synaptic and neural plasticity, and their implications for the pathophysiology and treatment of MDD. Finally, we discuss the therapeutic potential of anti-inflammatory-based approaches for treating patients with severe mood disorders. This is a promising field for increasing our understanding of the mechanistic interaction between the immune system, synaptic plasticity, and antidepressants, and for the ultimate development of novel and improved therapeutics for severe mood disorders.

Norman Cousins Lecture. Mechanisms of cytokine-induced behavioral changes: psychoneuroimmunology at the translational interface

Work in our laboratory has focused on the mechanisms by which cytokines can influence the brain and behavior in humans and non-human primates. Using administration of interferon (IFN)-alpha as a tool to unravel these mechanisms, we have expanded upon findings from the basic science literature implicating cytokine-induced changes in monoamine metabolism as a primary pathway to depression. More specifically, a role for serotonin metabolism has been supported by the clinical efficacy of serotonin reuptake inhibitors in blocking the development of IFN-alpha-induced depression, and the capacity of IFN-alpha to activate metabolic enzymes (indolamine 2,3 dioxygenase) and cytokine signaling pathways (p38 mitogen activated protein kinase) that can influence the synthesis and reuptake of serotonin. Our data also support a role for dopamine depletion as reflected by IFN-alpha-induced changes in behavior (psychomotor slowing and fatigue) and regional brain activity, which implicate the involvement of the basal ganglia, as well as the association of IFN-alpha-induced depressive-like behavior in rhesus monkeys with decreased cerebrospinal fluid concentrations of the dopamine metabolite, homovanillic acid. Neuroimaging data in IFN-alpha-treated patients also suggest that activation of neural circuits (dorsal anterior cingulate cortex) associated with anxiety and alarm may contribute to cytokine-induced behavioral changes. Taken together, these effects of cytokines on the brain and behavior appear to subserve competing evolutionary survival priorities that promote reduced activity to allow healing, and hypervigilance to protect against future attack. Depending on the relative balance between these behavioral accoutrements of an activated innate immune response, clinical presentations may be distinct and warrant individualized therapeutic approaches.

Cancer, cognitive impairment, and meditation

BACKGROUND AND OBJECTIVES

Cancer-related cognitive impairment has been acknowledged as a substantial limiting factor in quality of life among cancer patients and survivors. In addition to deficits on behavioral measures, abnormalities in neurologic structure and function have been reported. In this paper, we review findings from the literature on cognitive impairment and cancer, potential interventions, meditation and cognitive function, and meditation and cancer. In addition, we offer our hypotheses on how meditation practice may help to alleviate objective and subjective cognitive function, as well as the advantages of incorporating a meditation program into the treatment of cancer patients and survivors for cancer-related cognitive deficits.

FINDINGS

Various factors have been hypothesized to play a role in cancer-related cognitive impairment including chemotherapy, reduced hormone levels, proinflammatory immune response, fatigue, and distress. Pharmacotherapies such as methylphenidate or modafinil have been suggested to alleviate cognitive deficits. While initial reports suggest they are effective, some pharmacotherapies have side effects and may not relieve other symptoms associated with multimodal cancer treatment including sleep disturbance, nausea and pain. Several recent studies investigating the effects of meditation programs have reported behavioral and corresponding neurophysiological modulations that may be particularly effective in alleviating cancer-related cognitive impairment. Such programs also have been shown to reduce stress, fatigue, nausea and pain, and improve mood and sleep quality.

CONCLUSIONS

With the increasing success of cancer treatment and the ability to return to previous family, social, and work activities, symptom management and quality of life are an essential part of survivorship. We propose that meditation may help to improve cancer-related cognitive dysfunction, alleviate other cancer-related sequelae, and should be fully investigated as an adjuvant to cancer treatment.

Cytokines and their relationship to the symptoms and outcome of cancer

Tumours contain immune cells and a network of pro- and anti-inflammatory cytokines, which collaborate in the development and progression of cancer. Cytokine profiles might prove to be prognostic. The systemic effects of pro-inflammatory cytokines are associated with fatigue, depression and cognitive impairment, and can affect quality of life before, during and after treatment. In people with advanced cancer, pro-inflammatory cytokines are additionally associated with anorexia and cachexia, pain, toxicity of treatment and resistance to treatment. However, physical activity might modify cytokine levels and decrease fatigue in patients with cancer, and might also improve their prognosis.

Malaise in the water maze: untangling the effects of LPS and IL-1beta on learning and memory

It has been widely described that immune activation, such as that induced by bacterial endotoxin (lipopolysaccharide, LPS) or by interleukin-1beta (IL-1beta) causes deficits in learning and memory. These studies have been performed in a limited number of paradigms and have often failed in their experimental design to account for features of sickness behaviour and have thus introduced potential confounding factors. As such, this literature provides an oversimplified view of the issues. A detailed reading of the literature reveals that rodents treated with LPS or IL-1beta, whether systemically or centrally, do not reproducibly show clear impairments in spatial reference memory in the Morris Water Maze. Latency to find the platform is almost invariably increased, consistent with sickness and reduced locomotor speed in these animals. In studies where distance travelled or route to the platform have been examined there have been either very modest or no differences between treated groups, or stress-induced, thigmotaxic, strategies employed by the sick animals. This suggests that emotional and performance changes are more significant than cognitive impairments. There is better evidence for a deficit in contextual fear conditioning experiments induced by LPS and IL-1beta and these effects are clearly dose-dependent, with facilitation at low doses and impairment at higher doses. We propose that the field should be more cautious and more specific in its description of these cognitive effects and that new tasks be employed in these studies, that are not susceptible to confounding factors such as locomotor speed and elevated stress responses. Emerging data suggests that systemic insults induce more robust memory impairments in aged rodents or those with pre-exisiting neurodegenerative disease and these effects are consistent with the mild effects of infection on cognitive processes in young or healthy adults and the more severe effects, such as delirium, in the elderly and demented population.

Cerebral immune activation in chronic hepatitis C infection: a magnetic resonance spectroscopy study

BACKGROUND/AIMS

Abnormal cerebral metabolism and cognitive impairments have been reported in patients with chronic hepatitis C (HCV) but studies have failed to demonstrate a relationship between these findings.

METHODS

Twenty-five HCV-positive patients with histologically-mild liver disease were studied with cerebral proton magnetic resonance spectroscopy (MRS), using acquisition parameters to quantify myo-inositol (mI) and other metabolites in frontal white matter (FWM). Patients underwent automated attention and working memory tests (Cognitive Drug Research test system).

RESULTS

The mean mI/ creatine ratio in the HCV+ve patients (0.64, SD 0.21) was significantly higher (p=0.02) than in healthy controls (0.52, SD 0.10). On cognitive testing, the HCV+ve patients showed impairments in 2/4 composite scores, reflecting working memory and attention, compared to normative data from healthy volunteers (p<0.005) and HCV-ve controls (p=0.03). There was a significant association between elevated FWM mI/creatine and prolonged working memory reaction times (R=0.72, p=0.002).

CONCLUSIONS

Elevated FWM mI/ creatine is a feature of HIV-related minor cognitive-motor disorder. It is associated with infection and immune activation of microglial cells. The similar findings in this study suggest that cerebral immune activation may also occur in HCV infection. This may underlie the mild neurocognitive impairment and neuropsychological symptoms observed in a proportion of patients.

IFN-alpha-induced motor slowing is associated with increased depression and fatigue in patients with chronic hepatitis C

Interferon (IFN)-alpha has been used to investigate pathways by which innate immune cytokines influence the brain and behaviour. Previous studies suggest that altered basal ganglia function may contribute to IFN-alpha-induced neuropsychological and behavioural changes. To further examine IFN-alpha effects on neuropsychological functions related to basal ganglia (as well as other brain regions), and explore the relationship between altered neuropsychological function and IFN-alpha-induced depression and fatigue, a selected subset of the Cambridge Neuropsychological Test Automated Battery was administered to 32 hepatitis C patients at baseline (Visit 1) and following approximately 12 weeks (Visit 2) of either no treatment (n=12) or treatment with IFN-alpha plus ribavirin (n=20). Symptoms of depression and fatigue were assessed using the Montgomery-Asberg Depression Rating Scale and the Multidimensional Fatigue Inventory. Compared to control subjects, patients treated with IFN-alpha/ribavirin exhibited significant decreases in motor speed as measured in the simple and five-choice movement segments of the CANTAB reaction time task and slower response times in the rapid visual information processing task, a task of sustained attention. Decreased motor speed on the five-choice movement segments of the reaction time task was in turn correlated with increased symptoms of depression and fatigue (R=0.47, p<0.05 and R=0.48, p<0.05, respectively). IFN-alpha/ribavirin treatment had no effects on executive function, decision time in the reaction time task, or target detection accuracy in the sustained attention task. Motor slowing and its correlation with psychiatric symptoms suggest that altered basal ganglia function may contribute to the pathogenesis of IFN-alpha-induced behavioural changes.

Interferon-alpha-induced deficits in novel object recognition are rescued by chronic exercise

The anti-viral drug interferon-alpha (IFN-alpha) is widely-known to induce psychiatric and cognitive effects in patients. Previous work has shown that physical exercise can have a positive effect against brain insult. We investigated the effects of a clinically-comparable treatment regime of IFN-alpha on cognitive function in male Wistar rats and assessed the impact of chronic treadmill running on the deficits generated by IFN-alpha. We found that IFN-alpha induced significant impairments in performance on both spatial novelty and object novelty recognition. Chronic forced exercise did not protect against IFN-alpha-induced learning deficits in reactivity to spatial change, but did restore the capacity for novel object recognition in IFN-alpha-treated animals.

Cancer fatigue: a review for psychiatrists

OBJECTIVE

Cancer-related fatigue (CRF) is a ubiquitous and debilitating phenomenon for patients both during and after treatment for cancer of all types. This review will outline the complex neurobiological mechanisms underlying CRF and their relevance to various treatment routes. It will cover aspects of screening, diagnosis and treatment, including both pharmacological and behavioral interventions for CRF. The goal of the article was not to perform a comprehensive literature review or meta-analysis, but rather to integrate clinically relevant information from different areas of research related to cancer fatigue, including etiology, diagnosis and management for a nonspecialist audience.

METHOD

The methodology used involved broadly surveying the literature available on Medline using such search terms as "cancer," "fatigue," "cytokine" and "depression," exploring relevant articles over the past 15 years and relevant citations from these articles and focusing on recent advances in the study of CRF.

RESULTS

CRF occurs at high prevalence rates during and subsequent to cancer treatment. Multidisciplinary approaches are available for the assessment and management of fatigue including underlying contributory factors.

CONCLUSIONS

An increasing base for evidence is present to guide the management of CRF. Additional research is warranted to understand the neurobiological mechanisms, etiology and risk factors for fatigue.

Neuroendocrine-immune mechanisms of behavioral comorbidities in patients with cancer

Patients with cancer experience a host of behavioral alterations that include depression, fatigue, sleep disturbances, and cognitive dysfunction. These behavioral comorbidities are apparent throughout the process of diagnosis and treatment for cancer and can persist well into the survivorship period. There is a rich literature describing potential consequences of behavioral comorbidities in patients with cancer including impaired quality of life, reduced treatment adherence, and increased disease-related morbidity and mortality. Medical complications of cancer and its treatment such as anemia, thyroid dysfunction, and the neurotoxicity of cancer chemotherapeutic agents account in part for these behavioral changes. Nevertheless, recent advances in the neurosciences and immunology/oncology have revealed novel insights into additional pathophysiologic mechanisms that may significantly contribute to the development of cancer-related behavioral changes. Special attention has been focused on immunologic processes, specifically activation of innate immune inflammatory responses and their regulation by neuroendocrine pathways, which, in turn, influence CNS functions including neurotransmitter metabolism, neuropeptide function, sleep-wake cycles, regional brain activity, and, ultimately, behavior. Further understanding of these immunologic influences on the brain provides a novel conceptual framework for integrating the wide spectrum of behavioral alterations that occur in cancer patients and may reveal a more focused array of translational targets for therapeutic interventions and future research. Such developments warrant complementary advances in identification of cancer patients at risk as well as those currently suffering, including an increased emphasis on the status of behavior as a "sixth vital sign" to be assessed in all cancer patients throughout their disease encounter.

Comparative analysis of the expression of c-Fos and interleukin-2 proteins in hypothalamus cells during various treatments

The aim of the present work was to perform a combined analysis of the degree of activation of the anterior hypothalamus of the rat and expression of the interleukin-2 gene during treatments of different types: mild stress ("handling") and adaption to it, as well as intranasal administration of physiological saline and the peptides Vilon (Lys-Glu) and Epitalon (Ala-Glu-Asp-Gly). Changes in the numbers of c-Fos-and IL-2-positive cells in structures of the lateral area (LHA) and anterior (AHN), supraoptic (SON), and paraventricular (PVN) nuclei of the hypothalamus in Wistar rats. Ratios of the quantities of c-Fos-and IL-2-positive cells were determined in intact animals and after activation of brain cells initiated by different treatments; the influences of adaptation to handling on the nature of changes in the expression of these proteins was also studied. Combined analysis of the intensity of expression of these two proteins - c-Fos, a marker of neuron activation and a trans-factor for the IL-2 cytokine gene and other inducible genes, and IL-2 - in intact animals and after various treatments showed that the process of cell activation in most of the hypothalamic structures studied correlated with decreases in the quantity of IL-2-positive cells in these structures; different patterns of changes in the numbers of c-Fos-and IL-2-positive cells were seen in response to different treatments in conditions of stress and adaptation to it.

Memory impairments with adjuvant anastrozole versus tamoxifen in women with early-stage breast cancer

OBJECTIVE

Hormones have been implicated as modulators of cognitive functioning. For instance, results of our previous work in women with breast cancer showed that cognitive impairment was more severe and involved more memory domains in those who received adjuvant tamoxifen therapy compared with women who received chemotherapy alone or no adjuvant therapy. Recently aromatase inhibitors such as anastrozole have been used in lieu of tamoxifen for the adjuvant treatment of postmenopausal women with hormone receptor-positive, early-stage breast cancer. Plasma estrogen levels are significantly lower in women who receive anastrozole compared with those who receive tamoxifen. We hypothesized, therefore, that anastrozole would have a more profound effect on cognitive function than tamoxifen, a mixed estrogen agonist/antagonist.

DESIGN

To test this hypothesis we compared cognitive function in women with early-stage breast cancer who received tamoxifen with those who received anastrozole therapy in a cross-sectional study. We evaluated cognitive function, depression, anxiety, and fatigue in 31 postmenopausal women with early-stage breast cancer who were between the ages of 21 and 65 years and treated with tamoxifen or anastrozole for a minimum of 3 months.

RESULTS

The results showed that women who received anastrozole had poorer verbal and visual learning and memory than women who received tamoxifen.

CONCLUSIONS

Additional, prospective studies are needed to validate and confirm the changes in cognitive function associated with hormone therapy for breast cancer.

Cognitive dysfunction in chronic hepatitis C: a review

The hepatitis C virus (HCV) is a common blood-borne illness that affects up to 2% of the world's population and almost 4 million Americans. Cognitive impairment, or difficulty with thinking, has become a well-established symptom in persons with end stage liver disease. It was previously assumed that cognitive impairment was a consequence of cirrhosis-associated hepatic encephalopathy. Recent evidence, however, suggests that approximately one-third of people with chronic HCV experience cognitive impairment even in the absence of cirrhosis and that its occurrence is unrelated to other indices of liver function, such as laboratory values, viral load, and genotype. In the present review, evidence outlining the presence of cognitive deficits associated with HCV, possible etiological factors, effects of antiviral therapy, and co-infection with human immunodeficiency virus (HIV) is presented. Implications of these findings and directions for future work are discussed.

Basal ganglia hypermetabolism and symptoms of fatigue during interferon-alpha therapy

Interferon (IFN)-alpha is a cytokine of the innate immune response that is well known for inducing behavioral alterations and has been used to study effects of cytokines on the nervous system. Limited data, however, are available on the sites of action of IFN-alpha within the brain and their relationship with specific IFN-alpha-induced symptoms. Using a longitudinal design, whole-brain metabolic activity as assessed by fluorine-18-labeled fluorodeoxyglucose uptake and positron emission tomography was examined before and 4 weeks after IFN-alpha administration in patients with malignant melanoma. Changes in metabolic activity in relevant brain regions were then correlated with IFN-alpha-induced behavioral changes. IFN-alpha administration was associated with widespread bilateral increases in glucose metabolism in subcortical regions including the basal ganglia and cerebellum. Decreases in dorsal prefrontal cortex glucose metabolism were also observed. Prominent IFN-alpha-induced behavioral changes included lassitude, inability to feel, and fatigue. Correlational analyses revealed that self-reported fatigue (specifically as assessed by the 'energy' subscale of the Visual Analog Scale of Fatigue) was associated with increased glucose metabolism in the left nucleus accumbens and putamen. These data indicate that IFN-alpha as well as other cytokines of the innate immune response may target basal ganglia nuclei, thereby contributing to fatigue-related symptoms in medically ill patients.

Cancer and cancer-therapy related cognitive dysfunction: an international perspective from the Venice cognitive workshop

A subset of survivors has cognitive impairment after cancer treatment. This is generally subtle, but may be sustained. In October 2006, the second international cognitive workshop was held in Venice. The workshop included neuropsychologists, clinical and experimental psychologists, medical oncologists, imaging experts, and patient advocates. The main developments since the first Cognitive Workshop in 2003 have been the following. (i) studies evaluating cognitive function in patients receiving chemotherapy for cancers other than breast cancer, and in patients receiving hormonal therapy for cancer. (ii) The publication of longitudinal prospective studies which have shown that some patients already exhibit cognitive impairment on neuropsychological testing before receiving chemotherapy, and some patients have deterioration in cognitive functioning from pre- to postchemotherapy. (iii) Studies of the underlying mechanisms of cognitive impairment both in patients and in animal models. (iv) Use of structural and functional imaging techniques to study changes in brain morphology and activation patterns associated with chemotherapy. (v) At present cognitive research in cancer is limited by methodological challenges and the lack of standardization in neuropsychological studies. The current workshop addressed many of these issues and established an international task force to provide guidelines for future research and information on how best to manage these symptoms.

Cholinergic status modulations in human volunteers under acute inflammation

Cholinergic Status, the total soluble circulation capacity for acetylcholine hydrolysis, was tested for putative involvement in individual variabilities of the recruitment of immune cells in response to endotoxin challenge. Young (average age 26) and elderly (average age 70) volunteers injected with either Escherichia coli endotoxin or saline on two different occasions were first designated Enhancers and Suppressors if they showed increase or decrease, respectively, in plasma acetylcholinesterase (AChE) activity 1.5 h after endotoxin administration compared to saline. Enhancers showed significant co-increases in plasma butyrylcholinesterase (BChE) and paraoxonase (PON1) activities, accompanied by rapid recovery of lymphocyte counts. Young Enhancers alone showed pronounced post-exposure increases in the pro-inflammatory cytokine interleukin-6 (IL-6), and upregulation of the normally rare, stress-induced AChE-R variant, suggesting age-associated exhaustion of the cholinergic effects on recruiting innate immune reactions to endotoxin challenge. Importantly, IL-6 injected to young volunteers or administered in vitro to primary mononuclear blood cells caused upregulation of AChE, but not BChE or PON1, excluding it from being the sole cause for this extended response. Interestingly, Suppressors but not Enhancers showed improved post-exposure working memory performance, indicating that limited cholinergic reactions may be beneficial for cognition. Our findings establish Cholinergic Status modulations as early facilitators and predictors of individual variabilities in the peripheral response to infection.

The social and emotional toll of chemotherapy - patients' perspectives

The aim of this paper is to briefly describe the unique methodology employed by nine nurse researchers who conducted research into the social and emotional effects of chemotherapy from the patient's perspective, and to present four dominant themes. The research developed from discussions at a local UK Nurses Oncology Forum, during which nurses voiced their concern about the social and emotional implications for people receiving chemotherapy. It was anticipated that understanding the issues from the patient's perspective would assist nurses to reconsider and reshape the care provided, particularly in the chemotherapy clinic. Using principles of phenomenology, the nurse researchers collected data from participants using conversational-style interviews. Some participants kept diaries of chemotherapy experiences. These data were subsequently analysed using a modified phenomenological analysis framework. Nineteen people were recruited to the study, resulting in 98 interviews and seven diaries. Eight major themes emerged from the data: striving for normality, the role of significant others, feeling up - feeling down, flagging, being sociable, anxiety, the chemotherapy process, and participating in the research. Relationship dynamics, the perceived role of significant others and the frustrations associated with lack of concentration and memory loss are important findings that should influence nursing care and management.

Interferon-induced depression in hepatitis C: an update

Hepatitis C is a global epidemic, and its costs in both lives and health care expenditures continue to rise. The only approved treatment for this disease, interferon-alpha (IFN), causes treatment-emergent depression in more than one quarter of all patients who take it. Newer preparations of IFN have been developed to increase its antiviral efficacy, but the incidence of treatment-emergent depression has not decreased. The data on the epidemiology and risk factors for interferon-induced depression are reviewed in an effort to delineate its standing as a unique psychiatric disorder. In addition, evidence-based treatment approaches are outlined, including the potential efficacy of preinterferon prophylactic treatment with antidepressants.

Candidate mechanisms for chemotherapy-induced cognitive changes

The mechanism(s) for chemotherapy-induced cognitive changes are largely unknown; however, several candidate mechanisms have been identified. We suggest that shared genetic risk factors for the development of cancer and cognitive problems, including low-efficiency efflux pumps, deficits in DNA-repair mechanisms and/or a deregulated immune response, coupled with the effect of chemotherapy on these systems, might contribute to cognitive decline in patients after chemotherapy. Furthermore, the genetically modulated reduction of capacity for neural repair and neurotransmitter activity, as well as reduced antioxidant capacity associated with treatment-induced reduction in oestrogen and testosterone levels, might interact with these mechanisms and/or have independent effects on cognitive function.

Delirium in Older Adults With Cancer: Implications for Practice and Research

PURPOSE/OBJECTIVES

To provide a comprehensive review of the literature and existing evidence-based findings on delirium in older adults with cancer.

DATA SOURCES

Published articles, guidelines, and textbooks.

DATA SYNTHESIS

Although delirium generally is recognized as a common geriatric syndrome, a paucity of empirical evidence exists to guide early recognition and treatment of this sequelae of cancer and its treatment in older adults. Delirium probably is more prevalent than citations note because the phenomenon is under-recognized in clinical practice across varied settings of cancer care.

CONCLUSIONS

Extensive research is needed to formulate clinical guidelines to manage delirium. A focus on delirium in acute care and at the end of life precludes identification of this symptom in ambulatory care, where most cancer therapies are used. Particular emphasis should address the early recognition of prodromal signs of delirium to reduce symptom severity.

IMPLICATIONS FOR NURSING

Ongoing assessment opportunities and close proximity to patients' treatment experiences foster oncology nurses' mastery of this common exemplar of altered cognition in older adults with cancer. Increasing awareness of and knowledge delineating characteristics of delirium in older patients with cancer can promote early recognition, optimum treatment, and minimization of untoward consequences associated with the historically ignored example of symptom distress.

Neurocognitive functioning and HAART in HIV and hepatitis C virus co-infection

OBJECTIVES

This study examined the effects of HAART on neurocognitive functioning in persons with hepatitis C virus (HCV) and HIV co-infection.

DESIGN

A prospective study examining neurocognitive performance before and after HAART initiation.

METHOD

Participant groups included a mono-infected group (45 HIV+/HCV- participants) and a co-infected group (20 HIV+/HCV+ participants). A neuropsychological battery (attention/concentration, psychomotor speed, executive functioning, verbal memory, visual memory, fine motor, and gross motor functioning) was used to evaluate all participants. After 6 months of HAART, 31 HIV+ mono-infected and 13 HCV+/HIV+ co-infected participants were reevaluated.

RESULTS

Neurocognitive functioning by domain revealed significantly worse performance in the co-infected group when compared to the monoinfected group on domains of visual memory and fine motor functioning. Assessment of neurocognitive functioning after antiretroviral therapy revealed that the co-infected group was no longer performing worse than the monoinfected group.

CONCLUSIONS

The findings of the current study suggest that persons with HCV+/HIV+ co-infection may have greater neurocognitive declines than persons with HIV infection alone. HCV+/HIV+ co-infection may accelerate the progression of HIV related neurocognitive decline.

Interferon-induced depression in chronic hepatitis C: a review of its prevalence, risk factors, biology, and treatment approaches

Hepatitis C viral infection is a global health problem that affects approximately 4 million people in the United States. Combination treatment with pegylated interferon (IFN)-alpha plus ribavirin has been shown to be most effective in treating patients with chronic hepatitis C (CHC). Despite its efficacy, one of the most common side effects of this regimen is depression. Whereas IFN-alpha has been found to induce depression in chronic myelogenous leukemia, melanoma, and renal cell carcinoma, CHC patients may be especially prone to develop IFN-induced depression. This review includes a summary of differences between IFN-alpha and IFN-beta and addresses whether pegylation of IFN (versus nonpegylated IFN) gives rise to a treatment with reduced potential to induce depressive symptoms. Consideration is also given to evidence showing that treatment with ribavirin may contribute to IFN-induced depression. Thyroid disorders and anemia (as well as other medical conditions) have also been associated with IFN exposure and may account for some incidences of depression in CHC patients. Evidence is reviewed indicating that prior psychiatric and mood disorders (especially previous episodes of major depressive disorder), just prior to IFN treatment, contribute to the propensity to develop depression during treatment. In addition, a brief description is provided of potential biological mechanisms of IFN-induced depression (ie, monoamines, hypothalamic-pituitary-adrenocortical [HPA] axis, proinflammatory cytokines, peptidases, intercellular adhesion molecule-1, and nitric oxide). Finally, a discussion is provided on the use of antidepressants as a preventative versus restorative treatment, including a commentary on risks of using antidepressants in this patient population.

Hepatitis C Treatment for People With Severe Mental Illness

Over 4 million people in the United States are chronically infected with hepatitis C virus (HCV), and, if untreated, over 20% of these will progress to more serious disease. Persons with severe mental illness (SMI) have markedly elevated rates of HCV infection, but treatment of persons with SMI and HCV has been controversial. Effective antiviral treatment is available, but side effects include depression and other neuropsychiatric symptoms. This article reviews the available data on neuropsychiatric side effects of interferon (IFN) treatment, discusses the limitations of the current research, and makes recommendations regarding HCV treatment in persons with SMI.

Anterior cingulate activation and error processing during interferon-alpha treatment

BACKGROUND

There has been increasing interest in the role of immunologic processes, notably cytokines, in the development of behavioral alterations, especially in medically ill patients. Interferon (IFN)-alpha is notorious for causing behavioral symptoms, including depression, fatigue, and cognitive dysfunction, and has been used to investigate the effects of cytokines on the brain.

METHODS

In the present study we assessed the effects of low-dose IFN-alpha on brain activity, using functional magnetic resonance imaging during a task of visuospatial attention in patients infected with hepatitis C virus (HCV).

RESULTS

Despite endorsing symptoms of impaired concentration and fatigue, IFN-alpha-treated patients (n = 10) exhibited task performance and activation of parietal and occipital brain regions similar to that seen in HCV-infected control subjects (n = 11). Interestingly, however, in contrast to control subjects, IFN-alpha-treated patients exhibited significant activation in the dorsal part of the anterior cingulate cortex (ACC), which highly correlated with the number of task-related errors. No such correlation was found in control subjects.

CONCLUSIONS

Consistent with the role of the ACC in conflict monitoring, ACC activation during IFN-alpha administration suggests that cytokines might increase processing conflict or reduce the threshold for conflict detection, thereby signaling the need to exert greater mental effort to maintain performance. Such alterations in ACC activity might in turn contribute to cytokine-induced behavioral changes.

Pathways for psychosocial care of cancer survivors

Today, the growing number of survivors from many sites of cancer necessitates that thought be given to ways that ensure follow-up psychosocial care and its integration into ongoing medical surveillance. The establishment of standards of care together with evidence- and consensus-based clinical practice guidelines have provided a highly effective method of enhancing quality care for treatment of cancer. There remain, however, major problems in dissemination and application of these guidelines on the clinical level. The National Comprehensive Cancer Network (NCCN) formed a Panel on Distress Management that developed the first set of consensus-based standards for psychosocial care and clinical practice guidelines specific to cancer illnesses. This article proposes the extension of their concepts to cancer survivors. A model is presented that can assist oncologists and multidisciplinary teams in busy ambulatory settings to more readily identify those survivors who are distressed, whose quality of life is impaired, and who may benefit from further psychological evaluation and treatment. Three groups of cancer survivors are identified for whom pathways for psychosocial care should be defined and developed: 1) survivors with physical sequelae, often resulting in significant neuropsychologic and physical consequences; 2) survivors with psychological sequelae or psychiatric disorders that interfere with functioning and quality of life; and 3) survivors with subsyndromal symptoms who have no identified physical or psychiatric sequelae, but who may nonetheless need help integrating the cancer experience into their lives to increase a sense of purpose, direction, and well being. A rapid screening tool for distress could be used at the time of follow-up visits to oncologists or physicians to identify patients with psychological, social, or spiritual concerns and could serve as a pathway for evaluation and referral for psychosocial counseling. Treating distress in these areas is to be viewed as an integral part of surveillance for survivors, and pathways to ensure integration are important.

Major depression and risk of depressive symptomatology associated with short-term and low-dose interferon-alpha treatment

OBJECTIVE

The objective of this study is to identify early patients who are at-risk for major depression (MD) induced by interferon-alpha (IFN-alpha) and evaluate the response of depressive symptoms to antidepressants.

METHODS

Thirty-six consecutive patients were treated with IFN-alpha. Psychiatric evaluations were performed prior to, and at 1 and 2 months after onset of therapy and upon completion of the study. Diagnoses were made according to DSM-IV criteria, and the severity of depressive symptoms was determined by the Hamilton Depression Rating Scale score (HDRSS).

RESULTS

Of the 36 patients studied, 7 (19%) had MD before IFN-alpha treatment, 6 of which manifested a worsening of the depressive symptomatology during treatment. Of the remaining 29 patients, 9 (31%) developed MD during treatment. The median time required for the appearance or worsening of the depressive symptoms was 15 days (range 7-25). The median HDRSS before IFN-alpha in the 36 patients was 3 (range 1-20), whereas after 1 month of therapy, it was 10 (range 1-24; P=.000004). There was a strong positive correlation in the HDRSS before and 1 month after the initiation of treatment (r=.863). Of the 14 patients with a HDRSS of 1-2 before IFN-alpha treatment, only 1 (7%) developed MD, whereas of the 15 patients with a score >3, 8 (53%) developed MD. Antidepressants resulted in a decrease of the HDRSS to the IFN-alpha pretreatment values.

CONCLUSION

One third of those treated with IFN-alpha developed MD. The HDRSS before treatment reveals the high- and low-risk patients for developing MD. Psychiatric evaluation should be performed prior to IFN-alpha treatment.

Mood, cognition and EEG changes during interferon alpha (alpha-IFN) treatment for chronic hepatitis C

BACKGROUND

This study is aim to investigate concurrent long-term psychiatric, cognitive and neurophysiological measures of alpha-IFN neurotoxicity in the treatment of chronic viral hepatitis.

METHODS

Twenty patients with HCV hepatitis were enrolled while treated with alpha-IFN (3-6 MU t.i.w. for 6-12 months). Neurotoxicity was evaluated by psychiatric [Hamilton Depression Rating Scale (HAM-D), Hamilton Scale for Anxiety (HAM-A), Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI-Y)], complete cognitive and neurophysiological assessments (EEG spectral analysis, P300). Patients were assessed at baseline (t0), 2 (t1) and 6 months (t2) since the beginning of therapy.

RESULTS

Depression scores significantly increased (HAM-D: t0=4.4+/-2.6; t1=8.9+/-3.9, p<0.001; and t2=7.7+/-3.8, p<0.001). A concurrent increase was shown also for anxiety (HAM-A: t0=6.0+/-3.2; t1=9.6+/-4.5, p<0.005; and t2=9.1+/-4.5, p<0.005). Significant neurophysiological effects were also detected: increase of alpha power (p<0.05) in frontal derivations, reduction of the mean dominant frequency (p<0.005) and increase of theta power (p<0.05) in parietal derivations. In contrast, no significant cognitive changes occurred.

LIMITATIONS

The study was performed on a relative small sample of patients mainly with observational intentions. Biological data (e.g. blood cytokines samples) are not available: they could have given useful information about biological mechanisms related to the alterations observed.

CONCLUSIONS

Alpha-IFN treatment caused a time-dependent induction of symptoms of mild depression, concurrent anxiety and EEG changes. These psychiatric and neurophysiological changes can better explain the pharmacological profile of alpha-IFN and could help to address research on at risk population and, particularly, during pegylated-IFN therapy.

Mild acute inflammatory stimulation induces transient negative mood

OBJECTIVE

This study aims to assess the mood changes induced by mild acute inflammatory stimulation (typhoid vaccination).

METHODS

Using a double blind study design, 26 healthy volunteers underwent baseline assessments of mood, financial strain and work stress and were randomised to injection of Salmonella typhi vaccine or placebo injection. Mood, symptoms and body temperature was assessed by a modified version of the Profile of Mood States at 1, 2, 3, 4, 6 and 8 h post injection.

RESULTS

Typhoid vaccination induces no increases in physical symptoms or temperature. Mood improved over the day in the placebo but not in the vaccine condition. Negative changes in mood following injection were correlated with chronic stress (financial strain) in the vaccination condition (r=-.65, P<.025).

CONCLUSION

A mild acute inflammatory stimulus induces transient negative mood, and responses were modulated by chronic stress. Implications for depressed mood in physical illness are discussed.

Neuropsychological dysfunction associated with cancer and cancer therapies: a conceptual review of an emerging target

Neuropsychological dysfunction associated with cancer and cancer treatment is a growing concern. Methodological limitations permeate the corpus of research in this area and have limited our understanding of the multifactorial nature of this process. The following review provides a summary of the current state of knowledge and highlights future directions.

What is the effect of systemic anticancer treatment on cognitive function?

Treatment regimens for solid tumours have been extensively investigated for their physical toxic effects, but far less is known about the potential impairment of cognitive function by anticancer treatment regimens. Here, we review published studies that examined cognitive function in adult patients receiving systemic therapy for solid tumours. Our review suggests that patients can experience cognitive changes related to their treatment. However, several studies had methodological limitations, such as use of a limited sample size, lack of baseline assessment, and lack of control for potential confounding factors. Better designed clinical trials are required so that the difficulties patients face in terms of reduced cognitive function as a result of anticancer treatment can be fully elucidated. These trials should have sufficient statistical power and, importantly, should also be prospective.

Central nervous system toxicity from cancer treatment

Neurologic complications of cancer therapy are an increasingly important concern in patient management. Improvements in systemic therapies and increasing use of local treatments to target such specific tumor sites as brain or leptomeningeal metastases have resulted in increased incidence of treatment toxicity in the central nervous system (CNS). Recognition of specific treatment-related toxicities, and more importantly, differentiation of treatment toxicity from reversible causes of neurologic dysfunction, are critical. This article reviews the evaluation and treatment of major CNS toxicities related to cancer treatment and conditions that present with similar signs and symptoms. The three most common of these, alterations in cognition and consciousness, seizures, and cerebellar dysfunction, are discussed. Prompt recognition of these problems and their causes will have an impact on patient care in all areas of oncology.

Neuropsychological effects of treatments for adults with cancer: a meta-analysis and review of the literature

A meta-analysis was conducted to evaluate possible neuropsychological effects of treatments for cancer in adults. A search revealed 30 studies, encompassing 29 eligible samples, and leading to inclusion of a total of 838 patients and control participants. A total of 173 effect sizes (Cohen's d) were extracted across 7 cognitive domains and as assessed in the literature via 3 methods of comparison (post-treatment compared with normative data, controls, or baseline performance). Statistically significant negative effect sizes were found consistently across both normative and control methods of comparison for executive function, verbal memory, and motor function. The largest effects were for executive function and verbal memory normative comparisons (-.93 and -.91, respectively). When limiting the sample of studies in the analyses to only those with relatively "less severe" diagnoses and treatments, the effects remained. While these results point toward some specific cognitive effects of systemic cancer therapies in general, no clear clinical implications can yet be drawn from these results. More research is needed to clarify which treatments may produce cognitive decrements, the size of those effects, and their duration, while ruling out a wide variety of possible mediating or moderating variables.

Depression in cancer: new developments regarding diagnosis and treatment

Considerable data demonstrate the high prevalence of symptoms of depression in patients with a wide variety of neoplastic disorders. Moreover, the dire consequences of these depressive symptoms in cancer patients have been well documented. Recent conceptual developments in the potential contributing mechanisms include increasing appreciation of the possibility that behavioral alterations in cancer patients may represent a "sickness syndrome" that results from activation of the inflammatory cytokine network. This sickness syndrome, which has been well documented in patients and laboratory animals exposed to inflammatory cytokines, includes symptoms that overlap with those seen in major depression. Conceptualizing these symptoms as components of cytokine-mediated sickness behavior has several important, and potentially novel, implications, including 1) an expansion of the neurobehavioral symptoms that are relevant to diagnosis and treatment; and 2) an increased appreciation of the potential diagnostic utility of peripheral markers of inflammation, as well as cytokine-related neurocircuitry alterations as defined by brain imaging. Treatment implications focus on the pathways by which inflammatory cytokines influence behavior, including therapeutic targets such as the inflammatory cytokines themselves, corticotropin-releasing hormone, and monoaminergic neurotransmitters and their precursors. Finally, recent data suggest that aggressive treatment strategies initiated before inflammation-inducing cancer treatments might prevent behavioral alterations, including depression, before they occur.