Neural-endocrine-immune complex in the central modulation of tumorigenesis: facts, assumptions, and hypotheses

Role of the parasympathetic nervous system in cancer initiation and progression

The nervous system plays an important role in cancer initiation and progression. Accumulated evidences clearly show that the sympathetic nervous system exerts stimulatory effects on carcinogenesis and cancer growth. However, the role of the parasympathetic nervous system in cancer has been much less elucidated. Whereas retrospective studies in vagotomized patients and experiments employing vagotomized animals indicate the parasympathetic nervous system has an inhibitory effect on cancer, clinical studies in patients with prostate cancer indicate it has stimulatory effects. Therefore, the aim of this paper is a critical evaluation of the available data related to the role of the parasympathetic nervous system in cancer.

Stress and cancer. Part I: Mechanisms mediating the effect of stressors on cancer

Observations indicating a link between psychosocial stress and cancer can be traced back almost 2 millennia. However, the pathways and mechanisms interconnecting them has only been elucidated in more detail since the end of the 20th century. Importantly, recently accumulated evidences have confirmed the ability of stress to promote the induction and progression of cancer. The main aim of this review is to describe the pathways and mechanisms mediating the stimulatory effects of the neuroendocrine stress response on the induction of cancer, potentiation of cancer growth, and the development of metastases.

Role of the brain-gut axis in gastrointestinal cancer

Several studies have largely focused on the significant role of the nervous and immune systems in the process of tumorigenesis, including tumor growth, proliferation, apoptosis, and metastasis. The brain-gut-axis is a new paradigm in neuroscience, which describes the biochemical signaling between the gastrointestinal (GI) tract and the central nervous system. This axis may play a critical role in the tumorigenesis and development of GI cancers. Mechanistically, the bidirectional signal transmission of the brain-gut-axis is complex and remains to be elucidated. In this article, we review the current findings concerning the relationship between the brain-gut axis and GI cancer cells, focusing on the significant role of the brain-gut axis in the processes of tumor proliferation, invasion, apoptosis, autophagy, and metastasis. It appears that the brain might modulate GI cancer by two pathways: the anatomical nerve pathway and the neuroendocrine route. The simulation and inactivation of the central nervous, sympathetic, and parasympathetic nervous systems, or changes in the innervation of the GI tract might contribute to a higher incidence of GI cancers. In addition, neurotransmitters and neurotrophic factors can produce stimulatory or inhibitory effects in the progression of GI cancers. Insights into these mechanisms may lead to the discovery of potential prognostic and therapeutic targets.

Secondary outcomes of a behavioral sleep intervention: A randomized clinical trial

OBJECTIVE

Nearly 80% of cancer patients struggle with insomnia, which is associated with decreased heart rate variability (HRV) and quality of life (QOL). The aim of this secondary analysis was to evaluate the possible effects of Brief Behavioral Therapy for Cancer-Related Insomnia (BBT-CI), delivered during chemotherapy visits, on QOL and HRV in patients with breast cancer (BC).

METHOD

QOL and HRV data were obtained during a pilot clinical trial assessing the feasibility and effects of BBT-CI on insomnia. A total of 71 BC patients (mean age = 52.5 years) were randomly assigned to either BBT-CI or a healthy-eating control intervention (HEAL). BBT-CI and HEAL were delivered over 6 weeks (2 face-to-face sessions plus 4 phone calls) by trained staff at 4 National Cancer Institute-funded Community Oncology Research Program clinics. QOL was measured with the Functional Assessment of Cancer Therapy (FACT-G) and HRV with the Firstbeat device at baseline and after intervention.

RESULTS

There were significant improvements in QOL after intervention for BBT-CI (FACT-G, p = .009; FACT-B, p = .016; ANCOVA) and 5-min supine HRV measures (SDNN, p = .005; rMSSD, p = .004; HF, p = .009; ANCOVA) compared with HEAL.

CONCLUSIONS

Patients randomized to BBT-CI showed improvements in QOL and HRV, providing support for BBT-CI's possible benefit when delivered in the community oncology setting by trained staff. A more definitive efficacy trial of BBT-CI is currently being planned with sufficient statistical power to evaluate the intervention's clinical utility. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Human acute myeloid leukemia cells express Neurokinin-1 receptor, which is involved in the antileukemic effect of Neurokinin-1 receptor antagonists

The substance P/neurokinin-1 receptor system has been implicated in tumor cell proliferation. Neurokinin-1 receptor has been identified in different solid tumors but not frequently in hematopoietic malignant cells. We investigated the presence of the Neurokinin-1 receptor in acute myeloid leukemia cell lines (KG-1 and HL-60), demonstrating that acute myeloid leukemia cell lines overexpress the truncated Neurokinin-1 receptor isoform compared with lymphocytes from healthy donors. Using the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) method, we demonstrated that substance P induced cell proliferation in both acute myeloid leukemia cell lines. We also observed that four different Neurokinin-1 receptor antagonists (L-733,060, L-732,138, CP 96-345 and aprepitant) elicited inhibition of acute myeloid leukemia cell growth lines in a concentration-dependent manner, while growth inhibition was only marginal in lymphocytes; the specific antitumor action of Neurokinin-1 receptor antagonists occurs via the Neurokinin-1 receptor, and leukemia cell death is due to apoptosis. Finally, administration of high doses of daily intraperitoneal fosaprepitant to NOD scid gamma mice previously xenografted with the HL60 cell line increased the median survival from 4 days (control group) to 7 days (treated group) (p = 0.059). Taken together, these findings suggest that Neurokinin-1 receptor antagonists suppress leukemic cell growth and may be considered to be potential antitumor drugs for the treatment of human acute myeloid leukemia.

Vasovagal tonus index (VVTI) as an indirect assessment of remission status in canine multicentric lymphoma undergoing multi-drug chemotherapy

Vasovagal tonus index (VVTI) is an indirect measure of heart rate variability and may serve as a marker of disease severity. Higher heart rate variability has predicted lower tumour burden and improved survival in humans with various tumour types. The purpose of this pilot study was to evaluate VVTI as a biomarker of remission status in canine lymphoma. The primary hypothesis was that VVTI would be increased in dogs in remission compared to dogs out of remission. Twenty-seven dogs were prospectively enrolled if they had a diagnosis of intermediate to high-grade lymphoma and underwent multidrug chemotherapy. Serial electrocardiogram data were collected under standard conditions and relationships between VVTI, remission status and other clinical variables were evaluated. VVTI from dogs in remission (partial or complete) did not differ from dogs with fulminant lymphoma (naive or at time of relapse). Dogs in partial remission had higher VVTI than dogs in complete remission (p = 0.021). Higher baseline VVTI was associated with higher subsequent scores (p < 0.001). VVTI also correlated with anxiety level (p = 0.03). Based on this pilot study, VVTI did not hold any obvious promise as a useful clinical biomarker of remission status. Further investigation may better elucidate the clinical and prognostic utility of VVTI in dogs with lymphoma.

Exercise training improves heart rate recovery in women with breast cancer

PURPOSE

To determine whether exercise training improves autonomic function in women with breast cancer (BC).

METHODS

Fifty-one patients (aged between 39 and 72 years) with a history of primary invasive BC within the previous 5 years and enrolled in the Mediterranean diet-based DIANA (Diet and Androgens)-5 Trial were subdivided in two groups: a ET group (n = 25) followed a formal ET program of moderate intensity (3 session/week on a bicycle at 60-70% VO2peak for 3 months, followed by one session/week until 1-year follow-up), while a control group (n = 26) did not perform any formal ET. At baseline and after 1-year, all patients underwent cardiopulmonary exercise stress test (CPET). Heart rate recovery (HRR) was calculated as the difference between heart rate at peak exercise and heart rate at first minute of the cool-down period.

RESULTS

There were no significant differences between groups in baseline anthropometrical, BC characteristics, metabolic profile, CPET parameters and HRR. Compared to controls, at 1-year follow-up ET group showed a significant improvement in VO2peak (from 12.6 ± 3.0 to 14.5 ± 3.3 ml/kg/min, p < 0.001; p < 0.001 between groups); and in HRR (from 17.6 ± 6.4 to 23.0 ± 8.3 beats/min, p < 0.001; p < 0.001 between groups). In ET group the changes in HRR directly correlated with changes in VO2peak (r = 0.58, p = 0.002).

CONCLUSIONS

Moderate intensity exercise training in BC survivors is associated with improvement of autonomic function. Whether the improvement of sympatho-vagal balance may favorably modulate some of the pathophysiological mechanisms implied in cancer evolution need further investigation.

Higher vagal activity as related to survival in patients with advanced breast cancer: an analysis of autonomic dysregulation

OBJECTIVE

High levels of high-frequency heart rate variability (HF-HRV), related to parasympathetic-nervous-system functioning, have been associated with longer survival in patients with myocardial infarction and acute trauma and in patients undergoing palliative care. From animal studies linking higher vagal activity with better immune system functioning and reduced metastases, we hypothesized that higher HF-HRV would predict longer survival in patients with metastatic or recurrent breast cancer (MRBC).

METHODS

Eighty-seven patients with MRBC participated in a laboratory task including a 5-minute resting baseline electrocardiogram. HF-HRV was computed as the natural logarithm of the summed power spectral density of R-R intervals (0.15-0.50 Hz). In this secondary analysis of a study testing whether diurnal cortisol slope predicted survival, we tested the association between resting baseline HF-HRV on survival using Cox proportional hazards models.

RESULTS

A total of 50 patients died during a median follow-up of 7.99 years. Higher baseline HF-HRV predicted significantly longer survival, with a hazard ratio of 0.75 (95% confidence interval = 0.60-0.92, p = .006). Visceral metastasis status and baseline heart rate were related to both HF-HRV and survival. However, a combination of HF-HRV and heart rate further improved survival prediction, with a hazard ratio of 0.64 (95% confidence interval = 0.48-0.85, p = .002).

CONCLUSIONS

Vagal activity of patients with MRBC strongly predicted their survival, extending the known predictive window of HF-HRV in cancer beyond palliative care. Vagal activity can be altered by behavioral, pharmacological, and surgical interventions and may be a promising target for extending life expectancy in patients with metastasizing cancer.

Review of psychotherapeutic interventions on depression in cancer patients and their impact on disease progression

Depression, ranging from mild to severe, is the most frequently found psychological symptom among individuals with cancer. Depression in cancer patients has been known to mitigate emotional distress, quality of life, adherence to medical treatment, and overall health outcomes. Specifically, depression has been associated with impaired immune response and with poorer survival in patients with cancer. Various studies have found that psychotherapeutic interventions are effective in reducing symptoms of depression, which in turn could affect disease progression and mortality. This paper provides updated information on psychotherapeutic interventions geared towards cancer patients suffering from depressive disorders, and its impact on disease progression. PubMed, Cochrane Library database, PsycINFO and PsycARTICLES databases were searched from January 1980 through August 2013 using key words: psychotherapy, treatment, oncology, cancer, psycho-oncology, psychosocial issues, psychosocial stress, depression, mood disorder, and psychoneuroimmunology.

The time-course of hindbrain neuronal activity varies according to location during either intraperitoneal or subcutaneous tumor growth in rats: single Fos and dual Fos/dopamine β-hydroxylase immunohistochemistry

Neuronal activity in the nucleus of the solitary tract, ventrolateral medulla, area postrema, and parabrachial nucleus was studied in rats with intraperitoneal or subcutaneous tumors on the 7th, 14th, 21st, and 28th day after injection of fibrosarcoma tumor cells. We found that the number of Fos and dopamine β-hydroxylase immunopositive neurons differs between animals with intraperitoneal and subcutaneous tumors and also between tumor-bearing rats at different times following injection. Our data indicate that responses of the brainstem structures to peripheral tumor growth depend on the localization as well as the stage of the tumor growth.

Efeitos comportamentais e imunológicos da fluoxetina em ratos submetidos ao nado forçado

No presente trabalho, os efeitos comportamentais e imunomoduladores da fluoxetina foram avaliados num modelo animal de depressão, o nado forçado. Nesse, o comportamento de flutuar é sensível a antidepressivos e é usado como índice de desespero comportamental. Foram utilizados dois grupos experimentais, sendo um grupo controle tratado com salina e outro grupo teste tratado com a fluoxetina, ambos administrados por via intra-peritoneal. Os animais foram tratados três vezes ao dia por 12 dias. Adicionalmente, a resposta imune humoral a uma imunoestimulação (hemácias de carneiro) foi avaliada. A fluoxetina provocou aumento no tempo em flutuação, queda na massa corporal e menor produção total de anticorpos. Os resultados indicam uma modulação simultânea do comportamento e do sistema imunológico pela fluoxetina.

Decrease in depression symptoms is associated with longer survival in patients with metastatic breast cancer: a secondary analysis

PURPOSE

Numerous studies have examined the comorbidity of depression with cancer, and some have indicated that depression may be associated with cancer progression or survival. However, few studies have assessed whether changes in depression symptoms are associated with survival.

METHODS

In a secondary analysis of a randomized trial of supportive-expressive group therapy, 125 women with metastatic breast cancer (MBC) completed a depression symptom measure (Center for Epidemiologic Studies-Depression Scale [CES-D]) at baseline and were randomly assigned to a treatment group or to a control group that received educational materials. At baseline and three follow-up points, 101 of 125 women completed a depression symptom measure. We used these data in a Cox proportional hazards analysis to examine whether decreasing depression symptoms over the first year of the study (the length of the intervention) would be associated with longer survival.

RESULTS

Median survival time was 53.6 months for women with decreasing CES-D scores over 1 year and 25.1 months for women with increasing CES-D scores. There was a significant effect of change in CES-D over the first year on survival out to 14 years (P = .007) but no significant interaction between treatment condition and CES-D change on survival. Neither demographic nor medical variables explained this association.

CONCLUSION

Decreasing depression symptoms over the first year were associated with longer subsequent survival for women with MBC in this sample. Further research is necessary to confirm this hypothesis in other samples, and causation cannot be assumed based on this analysis.

Brain mapping of patients with lung cancer and controls: inquiry into tumor-to-brain communication

Recent converging evidence suggests that the brain may receive stimuli and possibly modulate tumor progression via the vagus nerve. The present study aimed to compare brain metabolism in patients with and without lung cancer and to assess if significant differences exist in regions associated with the vagus nerve.

METHODS

Eighteen patients with lung malignancy and 19 controls underwent (18)F-FDG PET of the brain. Brain metabolism was compared using statistical parametric mapping.

RESULTS

Patients with lung malignancy showed a statistically significantly higher right cerebellar metabolism.

CONCLUSION

This finding may be related to the role of the cerebellum in immune regulation, because of its proximity to the nucleus tractus solitarius innervated by the vagus and its connections with the hypothalamus. This higher metabolism in the right cerebellum may reflect an attempt to reinstate homeostasis in functions such as respiration and immunity pertinent to lung malignancy.

Psychosocial factors, biological mediators, and cancer prognosis: a new look at an old story

PURPOSE OF REVIEW

The present article briefly reviews the prognostic role of psychosocial factors in cancer and concentrates on biological markers that may mediate such relationships. We focus on specific markers that show promising mediating roles.

RECENT FINDINGS

The article reviews the prognostic role of psychosocial factors as shown in longitudinal studies and in previous reviews. We present the general stress response and its relevance to cancer progression. The main focus of the article is on the prognostic roles of specific biomarkers that had to meet three criteria for being accepted as biomarkers - being related to a psychosocial factor at the level of the brain, the circulation, and the tissue/cellular level. We review studies supporting the mediating roles of neurohormones and neurotransmitters (e.g., cortisol, norepinephrine), the vagal nerve and inflammation, interleukin-1, DNA damage, and the hormone oxytocin.

SUMMARY

These biomarkers may mediate the relationships between certain psychosocial factors (e.g., hopelessness, social support) and cancer progression. Future studies should test the effects of altering such biomarkers on the prognosis of patients scoring high/low on their associated psychosocial factors. Clinical implications that need to be tested are provided.