β-Blocker usage and colorectal cancer mortality: a nested case-control study in the UK Clinical Practice Research Datalink cohort

Nerve-tumor crosstalk in tumor microenvironment: From tumor initiation and progression to clinical implications

The autonomic nerve system (ANS) innervates organs and tissues throughout the body and maintains functional balance among various systems. Further investigations have shown that excessive activation of ANS not only causes disruption of homeostasis, but also may promote tumor formation. In addition, the dynamic interaction between nerve and tumor cells in the tumor microenvironment also regulate tumor progression. On the one hand, nerves are passively invaded by tumor cells, that is, perineural invasion (PNI). On the other hand, compared with normal tissues, tumor tissues are subject to more abundant innervation, and nerves can influence tumor progression through regulating tumor proliferation, metastasis and drug resistance. A large number of studies have shown that nerve-tumor crosstalk, including PNI and innervation, is closely related to the prognosis of patients, and contributes to the formation of cancer pain, which significantly deteriorates the quality of life for patients. These findings suggest that nerve-tumor crosstalk represents a potential target for anti-tumor therapies and the management of cancer pain in the future. In this review, we systematically describe the mechanism by which nerve-tumor crosstalk regulates tumorigenesis and progression.

Trial watch: beta-blockers in cancer therapy

Compelling evidence supports the hypothesis that stress negatively impacts cancer development and prognosis. Irrespective of its physical, biological or psychological source, stress triggers a physiological response that is mediated by the hypothalamic-pituitary-adrenal axis and the sympathetic adrenal medullary axis. The resulting release of glucocorticoids and catecholamines into the systemic circulation leads to neuroendocrine and metabolic adaptations that can affect immune homeostasis and immunosurveillance, thus impairing the detection and eradication of malignant cells. Moreover, catecholamines directly act on β-adrenoreceptors present on tumor cells, thereby stimulating survival, proliferation, and migration of nascent neoplasms. Numerous preclinical studies have shown that blocking adrenergic receptors slows tumor growth, suggesting potential clinical benefits of using β-blockers in cancer therapy. Much of these positive effects of β-blockade are mediated by improved immunosurveillance. The present trial watch summarizes current knowledge from preclinical and clinical studies investigating the anticancer effects of β-blockers either as standalone agents or in combination with conventional antineoplastic treatments or immunotherapy.

Vagus innervation in the gastrointestinal tumor: Current understanding and challenges

The vagus nerve (VN) is the main parasympathetic nerve of the autonomic nervous system. It is widely distributed in the gastrointestinal tract and maintains gastrointestinal homeostasis with the sympathetic nerve under physiological conditions. The VN communicates with various components of the tumor microenvironment to positively and dynamically affect the progression of gastrointestinal tumors (GITs). The intervention in vagus innervation delays GIT progression. Developments in adeno-associated virus vectors, nanotechnology, and in vivo neurobiological techniques have enabled the creation of precisely regulated "tumor neurotherapies". Furthermore, the combination of neurobiological techniques and single cell sequencing may reveal more insights into VN and GIT. The present review aimed to summarize the mechanisms of communication between the VN and the gastrointestinal TME and to explore the potential and challenges of VN-based tumor neurotherapy in GITs.

Cancer Metastasis and Treatment Resistance: Mechanistic Insights and Therapeutic Targeting of Cancer Stem Cells and the Tumor Microenvironment

Cancer metastasis and treatment resistance are the main causes of treatment failure and cancer-related deaths. Their underlying mechanisms remain to be fully elucidated and have been attributed to the presence of cancer stem cells (CSCs)-a small population of highly tumorigenic cancer cells with pluripotency and self-renewal properties, at the apex of a cellular hierarchy. CSCs drive metastasis and treatment resistance and are sustained by a dynamic tumor microenvironment (TME). Numerous pathways mediate communication between CSCs and/or the surrounding TME. These include a paracrine renin-angiotensin system and its convergent signaling pathways, the immune system, and other signaling pathways including the Notch, Wnt/β-catenin, and Sonic Hedgehog pathways. Appreciation of the mechanisms underlying metastasis and treatment resistance, and the pathways that regulate CSCs and the TME, is essential for developing a durable treatment for cancer. Pre-clinical and clinical studies exploring single-point modulation of the pathways regulating CSCs and the surrounding TME, have yielded partial and sometimes negative results. This may be explained by the presence of uninhibited alternative signaling pathways. An effective treatment of cancer may require a multi-target strategy with multi-step inhibition of signaling pathways that regulate CSCs and the TME, in lieu of the long-standing pursuit of a 'silver-bullet' single-target approach.

Long-term use of antihypertensive medications, hypertension and colorectal cancer risk and mortality: a prospective cohort study

BACKGROUND

Hypertension and the use of antihypertensive medications have been intensively investigated in relation to colorectal cancer (CRC). Prior epidemiologic studies have not been able to examine this topic with adequate confounding control and follow-up time, or disentangle the effects of antihypertensive agents and hypertension.

METHODS

Eligible participants in the Nurses' Health Study and Health Professionals Follow-up Study were followed for up to 28 years, with repeat assessments of exposures. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals.

RESULTS

In fully adjusted analyses based on both new-user and prevalent-user designs, there was no association between the use of beta-blockers, calcium-channel blockers, thiazide diuretics, angiotensin-converting enzyme inhibitors, furosemide, other antihypertensive drugs and CRC risk and mortality reached the statistically significant threshold after Bonferroni correction. The results remained similar in sensitivity analyses among participants with hypertension. Before Bonferroni correction, suggestive associations between beta-blocker use and CRC risk and between furosemide use and CRC-specific mortality were observed specifically in analyses using a new-user design. Hypertension was not associated with CRC risk in analyses based on both new-user and prevalent-user designs.

CONCLUSIONS

Hypertension and long-term use of major classes of antihypertensive medications are unlikely to be associated with CRC risk and mortality.

Advances in understanding cancer-associated neurogenesis and its implications on the neuroimmune axis in cancer

Nerves and immunologic mediators play pivotal roles in body homeostasis by interacting with each other through diverse mechanisms. The spread of nerves in the tumor microenvironment increases tumor cell proliferation and disease progression, and this correlates with poor patient outcomes. The effects of sympathetic and parasympathetic nerves on cancer regulation are being investigated. Recent findings demonstrate the possibility of developing therapeutic strategies that target the tumor microenvironment and its components such as immune cells, neurotransmitters, and extracellular vesicles. Therefore, examining and understanding the mechanisms and pathways associated with the sympathetic and parasympathetic nervous systems, neurotransmitters, cancer-derived mediators and their interactions with the immune system in the tumor microenvironment may lead to the development of new cancer treatments. This review discusses the effects of nerve cells, immune cells, and cancer cells have on each other that regulate neurogenesis, cancer progression, and dissemination.

Antidiabetics, Anthelmintics, Statins, and Beta-Blockers as Co-Adjuvant Drugs in Cancer Therapy

Over the last years, repurposed agents have provided growing evidence of fast implementation in oncology treatment such as certain antimalarial, anthelmintic, antibiotics, anti-inflammatory, antihypertensive, antihyperlipidemic, antidiabetic agents. In this study, the four agents of choice were present in our patients’ daily treatment for nonmalignant-associated pathology and have known, light toxicity profiles. It is quite common for a given patient’s daily administration schedule to include two or three of these drugs for the duration of their treatment. We chose to review the latest literature concerning metformin, employed as a first-line treatment for type 2 diabetes; mebendazole, as an anthelmintic; atorvastatin, as a cholesterol-lowering drug; propranolol, used in cardiovascular diseases as a nonspecific inhibitor of beta-1 and beta-2 adrenergic receptors. At the same time, certain key action mechanisms make them feasible antitumor agents such as for mitochondrial ETC inhibition, activation of the enzyme adenosine monophosphate-activated protein kinase, amelioration of endogenous hyperinsulinemia, inhibition of selective tyrosine kinases (i.e., VEGFR2, TNIK, and BRAF), and mevalonate pathway inhibition. Despite the abundance of results from in vitro and in vivo studies, the only solid data from randomized clinical trials confirm metformin-related oncological benefits for only a small subset of nondiabetic patients with HER2-positive breast cancer and early-stage colorectal cancer. At the same time, clinical studies confirm metformin-related detrimental/lack of an effect for lung, breast, prostate cancer, and glioblastoma. For atorvastatin we see a clinical oncological benefit in patients and head and neck cancer, with a trend towards radioprotection of critical structures, thus supporting the role of atorvastatin as a promising agent for concomitant association with radiotherapy. Propranolol-related increased outcomes were seen in clinical studies in patients with melanoma, breast cancer, and sarcoma.

Pan-Cancer Characterization of Intratumoral Autonomic Innervation in 32 Cancer Types in the Cancer Genome Atlas

Simple Summary

There have been growing interests in the roles of intratumoral innervation of the autonomic nervous system (ANS) as a mechanism linking psychosocial stress, β-adrenergic signaling pathways, and poor cancer outcomes, and a potential target for therapeutic purpose. Our current knowledge is being limited by the few cancer types where intratumoral ANS have been studied; it remains to be determined the extent of this mechanism existing in different cancer types. Our study provided the first pan-cancer characterization of intratumoral innervation across 32 cancer types, and further, their relationships with tumor histopathological and molecular characteristics and survival outcomes. We found wide variations in intratumoral ANS expression both within and across cancer types. The association of ANS signatures with tumor histopathological characteristics and survival outcomes also varied by cancer type. Our findings suggest that the potential benefits of cancer therapies targeting β-adrenergic receptor-mediated stress signaling pathways are likely dependent on cancer type.

Abstract

Over the past two decades, multiple studies have demonstrated the important role that the autonomic nervous system (ANS) plays in tumorigenesis and cancer progression. However, the mechanisms by which this process occurs have only recently begun to be elucidated. Further, the extent of autonomic innervation in various cancer types and its effects on tumor molecular, immunological, and histopathological features, as well as on patient outcomes, are not yet fully characterized. In this study, we analyzed intratumoral ANS gene expression signatures, including overall intratumoral neuron growth and sympathetic and parasympathetic markers, across 32 cancer types using tumor transcriptomic and clinical annotation data available from The Cancer Genome Atlas (TCGA). Our analysis revealed wide variations in intratumoral ANS expression both within and across cancer types. The association of ANS signatures with tumor histopathological characteristics and survival outcomes also varied by cancer type. We found intratumoral ANS expression to be commonly correlated with angiogenesis, TGF-β signaling, and immunosuppression in the tumor microenvironment of many cancer types, which provide mechanistic insights into the involvement of intratumoral innervation in cancer development and progression. Our findings suggest that the potential benefits of cancer therapies targeting β-adrenergic receptor-mediated stress signaling pathways are likely dependent on cancer type.

Antitumor Anesthetic Strategy in the Perioperatory Period of the Oncological Patient: A Review

The stress response triggered by the surgical aggression and the transient immunosuppression produced by anesthetic agents stimulate the inadvertent dispersion of neoplastic cells and, paradoxically, tumor progression during the perioperative period. Anesthetic agents and techniques, in relation to metastatic development, are investigated for their impact on long-term survival. Scientific evidence indicates that inhaled anesthetics and opioids benefit immunosuppression, cell proliferation, and angiogenesis, providing the ideal microenvironment for tumor progression. The likely benefit of reducing their use, or even replacing them as much as possible with anesthetic techniques that protect patients from the metastatic process, is still being investigated. The possibility of using "immunoprotective" or "antitumor" anesthetic techniques would represent a turning point in clinical practice. Through understanding of pharmacological mechanisms of anesthetics and their effects on tumor cells, new perioperative approaches emerge with the aim of halting and controlling metastatic development. Epidural anesthesia and propofol have been shown to maintain immune activity and reduce catecholaminergic and inflammatory responses, considering the protective techniques against tumor spread. The current data generate hypotheses about the influence of anesthesia on metastatic development, although prospective trials that determinate causality are necessary to make changes in clinical practice.

Nerve Dependence in Colorectal Cancer

Cancerous invasion of nerves has been reported in a list of malignant tumors as a high-risk pathological feature and marker of poor disease outcome especially in neurotrophic cancers (such as in pancreas and prostate), indicating that although once neglected, nerves could have played a pivotal role in tumorigenesis and cancer progression. In colorectal cancer, perineural invasion, a specific form of tumor-nerve interaction referring to the identification of tumor cells in proximity to the nerve, has been recognized as a strong and independent prognosis predictor; denervation of autonomic nerves and enteric nerves have shown that the existence of these nerves in the gut are accompanied by promoted cancer proliferation, further supporting that nerve is a potential accomplice to shield and nurture tumor cells. However, the precise role of nerve in CRC and the pattern of interaction between CRC cells and nerve has not been unveiled yet. Here we aim to review some basic knowledge of the importance of nerves in CRC and attempt to depict a mechanistic view of tumor-nerve interaction during CRC development.

Effects of Antihypertensive Drugs Use on Risk and Prognosis of Colorectal Cancer: A Meta-Analysis of 37 Observational Studies

Background: Antihypertensive drugs might play a key role in the risk and poor prognosis of colorectal cancer. However, current epidemiologic evidence remains inconsistent. The aim of this study is to quantify the association between antihypertensive drugs and colorectal cancer. Methods: To identify available studies, we systematically searched electronic databases: PubMed, Web of Science, Embase, Cochrane Library. The risk estimates and their corresponding 95% confidence intervals (CIs) were collected and analyzed by using random-effects models. Heterogeneity test and sensitivity analysis were also performed. Results: Overall, 37 observational studies were included in this analysis (26 studies with cohort design, three studies with nested case-control design, and 8 studies with case-control design). Antihypertensive drugs did not present a significant effect on the risk or overall survival of patients with colorectal cancer [Risk ratio (RR) = 1.00, 95% CI: 0.95-1.04; Hazard ratio (HR) = 0.93, 95% CI: 0.84-1.02]. In the subgroup analysis, diuretics use was significantly associated with a worse overall survival of patients with colorectal cancer (HR = 1.27; 95% CI: 1.14-1.40). However, use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers was associated with improved progression-free survival of patients who suffered from colorectal cancer (HR = 0.83; 95% CI: 0.72-0.95). Conclusion: Antihypertensive drug usage did not influence the risk and overall survival of patients with colorectal cancer in general. Further investigation reminded us that diuretics use might reduce the overall survival time in colorectal cancer patients, whereas those who took Angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers had a longer progression-free survival.

Biobehavioral Pathways and Cancer Progression: Insights for Improving Well-Being and Cancer Outcomes

The relationship between psychosocial factors and cancer has intrigued people for centuries. In the last several decades there has been an expansion of mechanistic research that has revealed insights regarding how stress activates neuroendocrine stress-response systems to impact cancer progression. Here, we review emerging mechanistic findings on key pathways implicated in the effect of stress on cancer progression, including the cellular immune response, inflammation, angiogenesis, and metastasis, with a primary focus on the mediating role of the sympathetic nervous system. We discuss converging findings from preclinical and clinical cancer research that describe these pathways and research that reveals how these stress pathways may be targeted via pharmacological and mind-body based interventions. While further research is required, the body of work reviewed here highlights the need for and feasibility of an integrated approach to target stress pathways in cancer patients to achieve comprehensive cancer treatment.

Sympathetic and parasympathetic innervation in cancer: therapeutic implications

PURPOSE

The autonomic nervous system, consisting of sympathetic and parasympathetic/vagal nerves, is known to control the functions of any organ, maintaining whole-body homeostasis under physiological conditions. Recently, there has been increasing evidence linking sympathetic and parasympathetic/vagal nerves to cancers. The present review aimed to summarize recent developments from studies addressing the relationship between sympathetic and parasympathetic/vagal nerves and cancer behavior.

METHODS

Literature review.

RESULTS

Human and animal studies have revealed that sympathetic and parasympathetic/vagal nerves innervate the cancer microenvironment and alter cancer behavior. The sympathetic nerves have cancer-promoting effects on prostate cancer, breast cancer, and melanoma. On the other hand, while the parasympathetic/vagal nerves have cancer-promoting effects on prostate, gastric, and colorectal cancers, they have cancer-suppressing effects on breast and pancreatic cancers. These neural effects may be mediated by β-adrenergic or muscarinic receptors and can be explained by changes in cancer cell behavior, angiogenesis, tumor-associated macrophages, and adaptive antitumor immunity.

CONCLUSIONS

Sympathetic nerves innervating the tumor microenvironment promote cancer progression and are related to stress-induced cancer behavior. The parasympathetic/vagal nerves have variable (promoting or suppressing) effects on different cancer types. Approaches directed toward the sympathetic and parasympathetic/vagal nerves can be developed as a new cancer therapy. In addition to existing pharmacological, surgical, and electrical approaches, a recently developed virus vector-based genetic local neuroengineering technology is a powerful approach that selectively manipulates specific types of nerve fibers innervating the cancer microenvironment and leads to the suppression of cancer progression. This technology will enable the creation of "cancer neural therapy" individually tailored to different cancer types.

Incidental Use of Beta-Blockers Is Associated with Outcome of Metastatic Colorectal Cancer Patients Treated with Bevacizumab-Based Therapy: A Single-Institution Retrospective Analysis of 514 Patients

Background: Beta-adrenergic signalling plays an important role in several cancer-related processes, including angiogenesis. The impact of beta-blocker use on prognosis of cancer patients treated with antiangiogenic agents is unclear. The aim of this study was to evaluate the association between the incidental use of beta-blockers and the outcomes of patients with metastatic colorectal cancer (mCRC) treated with bevacizumab-based therapy. Methods: Clinical data from 514 mCRC patients treated with bevacizumab between 2005 and 2019 were analysed retrospectively. The association of progression-free survival (PFS) and overall survival (OS) with the incidental use of beta-blockers and other common antihypertensive drugs was assessed. Results: The median PFS and OS for patients using beta-blockers was 11.40 (95% confidence interval (CI) 10.10–13.61) months and 26.8 (95% CI 22.2–32.2) months compared with 8.30 (95% CI 7.80–9.57) and 21.0 (95% CI 17.8–23.8) months for patients not using beta-blockers (p = 0.006 and p = 0.009, respectively). In the Cox multivariate analysis, the use of beta-blockers was a significant factor predicting both PFS (hazard ratio (HR) = 0.763 (95% CI 0.606–0.960), p = 0.021) and OS (HR = 0.730 (95% CI 0.560–0.951), p = 0.020). Conclusions: The results of the present retrospective study suggest that there is a significant association between the use of beta-blockers and favourable outcomes of mCRC patients treated with bevacizumab-based therapy.

Association between Resting Heart Rate and Colorectal Cancer: Results from a Case-Controlled Study

Previous studies evaluating associations between resting heart rate (RHR) and cancer-related mortality/prognosis have yielded conflicting results. We investigated whether elevations in RHR are associated with colorectal cancer (CRC). We conducted a case-controlled study involving 1241 CRC patients and 5909 cancer-free controls from the Korean National Health and Nutrition Examination Survey. After propensity score (PS) matching, 1207 CRC patients and 1207 matched controls were analyzed. Associations between RHR and CRC, colon, and rectal cancer were analyzed in appropriate patient subgroups using multiple and conditional logistic regression. Receiver operating characteristics analysis yielded the optimal RHR cut-point to predict CRC. RHR was significantly higher in CRC, colon, and rectal cancer patients than in controls (72.7 bpm in CRC, 72.8 bpm in colon cancer, 72.3 bpm in rectal cancer, and 68.7 bpm in controls; all p < 0.001). Analysis of data prior to PS matching yielded the following odds ratios (ORs) per RHR increment for CRC, colon, and rectal cancer: 1.043 (95% confidence intervals (CIs): 1.036–1.049), 1.045 (95% CI: 1.037–1.053), and 1.040 (95% CI: 1.030–1.051), respectively, in unadjusted models, and 1.043 (95% CI: 1.034–1.051), 1.046 (95% CI: 1.037–1.055), and 1.040 (95% CI: 1.027–1.052), respectively, in multivariable adjusted models. Patients with CRC, colon, and rectal cancer have a significantly higher RHR compared to cancer-free controls.

Genetic manipulation of autonomic nerve fiber innervation and activity and its effect on breast cancer progression

The effects of autonomic innervation of tumors on tumor growth remain unclear. Here we developed a series of genetic techniques to manipulate autonomic innervation in a tumor- and fiber-type-specific manner in mice with human breast cancer xenografts and in rats with chemically induced breast tumors. Breast cancer growth and progression were accelerated following stimulation of sympathetic nerves in tumors, but were reduced following stimulation of parasympathetic nerves. Tumor-specific sympathetic denervation suppressed tumor growth and downregulated the expression of immune checkpoint molecules (programed death-1 (PD-1), programed death ligand-1 (PD-L1), and FOXP3) to a greater extent than with pharmacological α- or β-adrenergic receptor blockers. Genetically induced simulation of parasympathetic innervation of tumors decreased PD-1 and PD-L1 expression. In humans, a retrospective analysis of breast cancer specimens from 29 patients revealed that increased sympathetic and decreased parasympathetic nerve density in tumors were associated with poor clinical outcomes and correlated with higher expression of immune checkpoint molecules. These findings suggest that autonomic innervation of tumors regulates breast cancer progression.

The effect of propranolol on the prognosis of hepatocellular carcinoma: A nationwide population-based study

Background

Beta-blockers can reduce recurrence, metastasis, and mortality in various cancers. In this study, we investigated the effect of propranolol, a non-selective beta-blocker on overall survival (OS) in unresectable/metastatic hepatocellular carcinoma (HCC) and on recurrence-free survival (RFS) in resectable, curable HCC.

Methods

Data were retrieved from the Taiwan National Health Insurance Research Database between January 2000 and December 2013. Propranolol users (for >1 year) and non-propranolol users were matched using a 1:2 propensity score in both cohorts.

Results

The unresectable/metastatic HCC cohort comprised 1,560 propranolol users and 3,120 non-propranolol users (control group). On multivariate Cox regression analysis of HCC mortality, propranolol significantly reduced the mortality risk by 22% (hazard ratio [HR] = 0.78, 95% confidence interval [CI] 0.72–0.84, P <0.001). On stratified Cox regression analysis, propranolol also reduced the mortality risk in HCC patients with hepatitis B (HR = 0.92, 95% CI 0.85–0.99, P = 0.045), hepatitis C (HR = 0.85, 95% CI = 0.78–0.92, P = 0.001), liver cirrhosis (HR = 0.78, 95% CI = 0.72–0.85, P <0.001), and diabetes mellitus (HR = 0.87, 95% CI = 0.81–0.94, P = 0.008). The resectable, curable HCC cohort comprised 289 propranolol users and 578 non-propranolol users (control group), but there was no significant difference in RFS (P = 0.762) between propranolol and non-propranolol users.

Conclusion

This study revealed that propranolol could improve OS in unresectable/metastatic HCC.

Effect of Propranolol Treatment on the Incidence of Hepatocellular Carcinoma in Patients Waiting for Liver Transplant With Cirrhosis: A Retrospective, Surveillance Study in a Tertiary Center

OBJECTIVES

Hepatocellular carcinoma is the most frequent primary malignant tumor of the liver and the third most common cause of all cancer-related mortalities. There is a need to develop new strategies to prevent hepatocellular carcinoma, as the incidence of this cancer continues to increase despite all advancements. In this study, our aim was to determine the effects of propranolol treatment on the incidence of hepatocellular carcinoma in cirrhotic patients waiting for liver transplant.

MATERIALS AND METHODS

We retrospectively reviewed the data of patients waiting for liver transplant with cirrhosis due to various causes registered at the Hepatocellular Carcinoma Surveillance Program between June 2011 and December 2017 in our center. These data were compared between patients using propranolol and those not using propranolol.

RESULTS

Of the 231 patients, 135 (58.4%) were male and 96 (41.6%) were female. The mean age was 58.1 ± 14 years. We noted that 153 of total patients (66.2%) were using propranolol. Three patients (2%) were using 20 mg propranolol, 125 (81.7%) were using 40 mg propranolol, 10 (6.5%) were using 60 mg propranolol, and 15 (9.8%) were using 80 mg propranolol. Of total patients, 36 (15.6%) developed hepatocellular carcinoma, including in 12 patients (7.8%) using propranolol and 24 patients (30.8%) who did not use this agent (P < .001). Thus, the hepatocellular carcinoma frequency was 5.22 times lower in patients receiving propranolol than in those not receiving propranolol.

CONCLUSIONS

Although causes of cirrhosis and initial stages were similar in both groups using and not using propranolol, incidence of hepatocellular carcinoma was significantly lower in the propranolol group than in the group without propranolol. This result showed that propranolol treatment has a protective effect for hepatocellular carcinoma in patients waiting for liver transplant with cirrhosis.

Tamoxifen and CYP2D6: A Controversy in Pharmacogenetics

Tamoxifen reduces the rate of breast cancer recurrence by about one-half. It is converted to more active metabolites by enzymes encoded by polymorphic genes, including cytochrome P450 2D6 (CYP2D6) and transported by ATP-binding cassette transporters. Genetic polymorphisms that confer reduced CYP2D6 activity or concurrent use of CYP2D6-inhibiting drugs may reduce the clinical efficacy of tamoxifen. The issue of the clinical utility of CYP2D6 genotype testing is subject to considerable and ongoing academic and clinical controversy. In this chapter, we outline tamoxifen's clinical pharmacology and give an overview of the research to date on the association between CYP2D6 inhibition and tamoxifen effectiveness. Based on the evidence to date, the impact of drug-induced and/or gene-induced inhibition of CYP2D6 activity is likely to be null or small, or at most moderate in subjects carrying two reduced function alleles. Future research should examine the effect of polymorphisms in genes encoding enzymes in tamoxifen's complete metabolic pathway, should comprehensively evaluate other biomarkers that affect tamoxifen effectiveness, such as the transport enzymes, and focus on subgroups of patients, such as premenopausal breast cancer patients, for whom tamoxifen is the only guideline approved endocrine therapy.

Adrenergic Signaling: A Targetable Checkpoint Limiting Development of the Antitumor Immune Response

An immune response must be tightly controlled so that it will be commensurate with the level of response needed to protect the organism without damaging normal tissue. The roles of cytokines and chemokines in orchestrating these processes are well known, but although stress has long been thought to also affect immune responses, the underlying mechanisms were not as well understood. Recently, the role of nerves and, specifically, the sympathetic nervous system, in regulating immune responses is being revealed. Generally, an acute stress response is beneficial but chronic stress is detrimental because it suppresses the activities of effector immune cells while increasing the activities of immunosuppressive cells. In this review, we first discuss the underlying biology of adrenergic signaling in cells of both the innate and adaptive immune system. We then focus on the effects of chronic adrenergic stress in promoting tumor growth, giving examples of effects on tumor cells and immune cells, explaining the methods commonly used to induce stress in preclinical mouse models. We highlight how this relates to our observations that mandated housing conditions impose baseline chronic stress on mouse models, which is sufficient to cause chronic immunosuppression. This problem is not commonly recognized, but it has been shown to impact conclusions of several studies of mouse physiology and mouse models of disease. Moreover, the fact that preclinical mouse models are chronically immunosuppressed has critical ramifications for analysis of any experiments with an immune component. Our group has found that reducing adrenergic stress by housing mice at thermoneutrality or treating mice housed at cooler temperatures with β-blockers reverses immunosuppression and significantly improves responses to checkpoint inhibitor immunotherapy. These observations are clinically relevant because there are numerous retrospective epidemiological studies concluding that cancer patients who were taking β-blockers have better outcomes. Clinical trials testing whether β-blockers can be repurposed to improve the efficacy of traditional and immunotherapies in patients are on the horizon.

β-Blocker use and mortality in cancer patients: systematic review and meta-analysis of observational studies

A number of epidemiologic studies have attempted to link the use of β blockers to mortality in cancer patients, but their findings have been inconclusive. A meta-analysis was carried out to derive a more precise estimation. Relevant studies were identified by searching PubMed and EMBASE to May 2015. We calculated the summary hazard ratios (HRs) and 95% confidence intervals (CIs) using random-effects models. Twenty cohort studies and four case-control studies involving 76 538 participants were included. The overall results showed that patients who used β blockers after diagnosis had an HR of 0.89 (95% CI 0.81-0.98) for all-cause mortality compared with nonusers. Those who used β blockers after diagnosis (vs. nonusers) had an HR of 0.89 (95% CI 0.79-0.99) for cancer-specific mortality. Prediagnostic use of β blockers showed no beneficial effect on all-cause mortality or cancer-specific mortality. Stratifying by cancer type, only breast cancer patients who used β blockers after diagnosis had a prolonged overall survival. A linear but nonsignificant trend was found between postdiagnostic β-blocker use and mortality of cancer patients. In conclusion, the average effect of β-blocker use after diagnosis but not before diagnosis is beneficial for the survival of cancer patients.

Pre- and post-diagnostic beta-blocker use and prognosis after colorectal cancer: Results from a population-based study

Recent experimental and epidemiological studies have suggested that beta-blocker use might be associated with better cancer prognosis, but results were inconclusive and only few studies have investigated the association specifically for colorectal cancer (CRC) patients. We investigated this hypothesis using a linked dataset of the Eindhoven area of the Netherlands Cancer Registry and the PHARMO record linkage, including patients diagnosed with CRC between 1998 and 2011. Eligible patients were matched on propensity scores to control for potential confounders such as socio-demographic factors, comorbidity, cancer treatment and use of other medications. Controls were subsequently restricted to active comparators. The association between pre-diagnostic and time-dependent post-diagnostic beta-blocker use and overall survival was estimated using Cox proportional hazard regression models. Subgroup analyses by cancer site and stage and by beta-blocker type were conducted. Of 8,100 CRC patients with a median follow-up of 6.6 years, 1,813 (22%) used beta-blockers prior to diagnosis. In multivariate analysis, we observed no significant association in overall mortality for pre-diagnostic [hazard ratio 1.07, 95% confidence interval (0.96-1.19)] and post-diagnostic [1.10 (0.98-1.23)] beta-blocker use, respectively. Analyses by beta-blocker type, by cancer site, cancer stage and by cumulative dose showed no significant survival improvements for beta-blocker users. However, there was a significant association between cumulative duration of use of 1-12 months and increased overall mortality [1.20 (1.03-1.39)]. Thus, our results do not support the hypothesis of a beneficial effect of pre- or post-diagnostic beta-blocker intake on CRC prognosis, neither for specific patient subgroups nor for specific types of beta-blockers.

Postdiagnostic use of β-blockers and other antihypertensive drugs and the risk of recurrence and mortality in head and neck cancer patients: an observational study of 10,414 person-years of follow-up

INTRODUCTION

Growing evidence indicates that norepinephrine promotes cancer growth and metastasis whereas β-blockers decrease these risks. This study aimed to examine the clinical impact of β-blockers and other hypertensive drugs on disease recurrence and survival in patients with head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

This study analyzed a cohort of 1274 consecutive patients who received definitive treatments for previously untreated HNSCC at our tertiary referral center between January 2001 and December 2012. Antihypertensive use was considered positive if patients were on medication from HNSCC diagnosis to at least 1 year after treatment initiation. Cox proportional hazard models were utilized to determine associations between antihypertensive drugs and recurrence, survival, and second primary cancer (SPC) occurrence.

RESULTS

Hypertension itself was not a significant variable of recurrence and survival and no antihypertensive drug use affected SPC occurrence (all P > 0.1). After controlling for clinical factors, calcium-channel blocker use remained an independent variable for index cancer recurrence, and β-blocker use was significantly associated with poor cancer-specific mortality, competing mortality, and all-cause mortality (all P < 0.05). β-blocker use significantly affected competing and all-cause mortalities in normotensive patients, and calcium-channel blocker use affected index cancer recurrence in normotensive patients (all P < 0.05).

CONCLUSIONS

Our data show that β-blocker use is associated with decreased survival and calcium-channel blockers is associated with increased cancer recurrence in patients of HNSCC.

The Impact of Housing Temperature-Induced Chronic Stress on Preclinical Mouse Tumor Models and Therapeutic Responses: An Important Role for the Nervous System

In the last 10-15 years, there has been a recognition that the catecholamines (norepinephrine, NE, and epinephrine, Epi) released by the sympathetic nervous system under stressful conditions promote tumor growth through a variety of mechanisms. Tumors recruit autonomic nerves during their development and NE is then released locally in the tumor microenvironment (TME). Acting through adrenergic receptors present on a variety of cells in the TME, NE and Epi induce proliferation, resistance to apoptosis, epithelial to mesenchymal transition, metastasis of tumor cells, angiogenesis, and inflammation in the TME. These pre-clinical studies have been conducted in mouse models whose care and housing parameters are outlined in "The Guide for the Care and Use of Laboratory Animals [1]. In particular, the Guide mandates that mice be housed at standardized sub-thermoneutral temperatures; however, this causes a state of chronic cold-stress and elevated levels of NE. Although mice are able to maintain a normal body temperature when kept at these cool temperatures, it is becoming clear that this cold-stress is sufficient to activate physiological changes which affect experimental outcomes. We find that when mice are housed under standard, sub-thermoneutral temperatures (~22 °C, ST), tumor growth is significantly greater than when mice are housed at thermoneutrality (~30 °C TT). We also find that the anti-tumor immune response is suppressed at ST and this immunosuppression can be reversed by housing mice at TT or by administration of propranolol (a β-adrenergic receptor antagonist) to mice housed at ST. Furthermore, at ST tumors are more resistant to therapy and can also be sensitized to cytotoxic therapies by housing mice at TT or by treating mice with propranolol. The implications of these observations are particularly relevant to the way in which experiments conducted in preclinical models are interpreted and the findings implemented in the clinic. It may be that the disappointing failure of many new therapies to fulfill their promise in the clinic is related to an incomplete preclinical assessment in mouse models. Further, an expanded understanding of the efficacy of a therapy alone or in combination obtained by testing under a wider range of conditions would better predict how patients, who are under various levels of stress, might respond in a clinical setting. This may be particularly important to consider since we now appreciate that long term outcome of many therapies depends on eliciting an immune response.It is clear that the outcome of metabolic experiments, immunological investigations and therapeutic efficacy testing in tumors of mice housed at ST is restricted and expanding these experiments to include results obtained at TT may provide us with valuable information that would otherwise be overlooked.

The impact of perioperative β blocker use on patient outcomes after primary cytoreductive surgery in high-grade epithelial ovarian carcinoma

OBJECTIVE

To quantify the impact of perioperative β blocker use on survival after primary cytoreductive surgery for epithelial ovarian cancer.

METHODS

We conducted a multi-center retrospective study of all women who underwent primary cytoreductive surgery for ovarian cancer (2000-2010). One institution had routinely used perioperative β blockers for patients "at risk" for coronary events. The other institution did not routinely use perioperative β blockers. Demographic, operative, and follow up data were collected. Cox proportional hazards models were used to assess the effect of β blockers on progression-free interval (PFI) as well as overall survival (OS).

RESULTS

Out of 185 eligible patients, 70 received β blockers and 115 underwent cytoreductive surgery without perioperative β blockers. Both groups were similar in demographics. A history of hypertension was present more often in the β blocker group compared to the group that did not receive β blockers (22% and 6%, p=0.002). PFI in β blocker group was greater at 18.2 vs. 15.8months (p=0.66). The OS in the β blocker group was significantly higher at 44.2 vs. 39.3months (p=0.01). In multivariate analysis, perioperative β blocker use was associated with significant improvement in OS (HR 0.68 (0.46-0.99); p=0.046).

CONCLUSION

Our study showed an association between perioperative β blocker use and longer overall survival in patients undergoing primary ovarian cancer cytoreductive surgery. A prospective randomized clinical trial in this population would further validate these results.

Beta blockers and cancer prognosis - The role of immortal time bias: A systematic review and meta-analysis

BACKGROUND

Findings from experimental and observational studies have suggested beneficial effects of beta blocker (BB) use on cancer survival. Nevertheless, results have been inconclusive and there have been concerns that the observed associations might have resulted from immortal time bias (ITB). We conducted a systematic review and meta-analysis to summarize existing evidence, paying particular attention to this potential source of bias.

METHODS

A systematic literature search was performed in PubMed and Web of Science. Studies investigating the association between BB use and overall or cancer-specific survival were included. Summary estimates were derived from meta-analyses using random effects models. The potential influence of ITB was investigated.

RESULTS

We identified 30 eligible studies including 88,026 cancer patients in total. We deemed 11 studies to be at high or unclear risk of ITB. Including all studies in the meta-analysis, BB users had a significantly better overall (hazard ratio (HR) 0.88, 95% CI 0.79-0.97) and cancer-specific (HR 0.75, 95% CI 0.64-0.88) survival. Excluding the studies deemed to be prone to ITB resulted in HRs (95% CIs) of 1.00 (0.93-1.07) and 0.90 (0.83-0.98), respectively. Analyses on cancer site and BB type did not show beneficial associations besides overall survival among melanoma patients. However, melanoma-specific survival was not improved.

CONCLUSION

We found no clinically meaningful evidence for an association between BB use and survival after excluding studies with a possible ITB. Our results support suggestions that the proposed beneficial effect of BBs on cancer survival might be based on ITB.

The potential anticancer effect of beta-blockers and the genetic variations involved in the interindividual difference

β-ARs are extensively spread in different tissues of our body, which could be activated by neurotransmitters norepinephrine and epinephrine to mediate physiological function and abnormal states including cancer. Recently, β-AR blockers could have significant implications in cancer therapy. But the precise molecular mechanisms are far from being fully understood. Through identifying the β-AR system signal pathways relevant to cancer, we can understand the mechanisms of β-blockers used for cancer treatment. What's more, retrospective clinical data made β-blockers jump out of the traditional field of cardiovascular disease and strengthened our confidence in cancer therapy. At last, genetic studies of β-adrenergic system offered crucial genes to analyze the effects of polymorphisms on cancer susceptibility, therapy response and prognosis of cancer patients.

Effect of Chronic Psychological Stress on Liver Metastasis of Colon Cancer in Mice

Metastasis to the liver is a main factor in colorectal cancer mortality. Previous studies suggest that chronic psychological stress is important in cancer progression, but its effect on liver metastasis has not been investigated. To address this, we established a liver metastasis model in BALB/c nude mice to investigate the role of chronic stress in liver metastasis. Our data suggest that chronic stress elevates catecholamine levels and promotes liver metastasis. Chronic stress was also associated with increased tumor associated macrophages infiltration into the primary tumor and increased the expression of metastatic genes. Interestingly, β-blocker treatment reversed the effects of chronic stress on liver metastasis. Our results suggest the β-adrenergic signaling pathway is involved in regulating colorectal cancer progression and liver metastasis. Additionally, we submit that adjunctive therapy with a β-blocker may complement existing colorectal cancer therapies.

Propranolol Reduces Cancer Risk: A Population-Based Cohort Study

β-Blockers have been reported to exhibit potential anticancer effects in cancer cell lines and animal models. However, clinical studies have yielded inconsistent results regarding cancer outcomes and cancer risk when β-blockers were used. This study investigated the association between propranolol and cancer risk.Between January 1, 2000 and December 31, 2011, a patient cohort was extracted from the Longitudinal Health Insurance Database 2000, a subset of the Taiwan National Health Insurance Research Database. A propranolol cohort (propranolol usage >6 months) and nonpropranolol cohort were matched using a propensity score. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) of cancer associated with propranolol treatment.The study sample comprised 24,238 patients. After a 12-year follow-up period, the cumulative incidence for developing cancer was low in the propranolol cohort (HR: 0.75; 95% CI: 0.67-0.85; P < 0.001). Patients with propranolol treatment exhibited significantly lower risks of cancers in head and neck (HR: 0.58; 95% CI: 0.35-0.95), esophagus (HR: 0.35; 95% CI: 0.13-0.96), stomach (HR: 0.54; 95% CI: 0.30-0.98), colon (HR: 0.68; 95% CI: 0.49-0.93), and prostate cancers (HR: 0.52; 95% CI: 0.33-0.83). The protective effect of propranolol for head and neck, stomach, colon, and prostate cancers was most substantial when exposure duration exceeded 1000 days.This study supports the proposition that propranolol can reduce the risk of head and neck, esophagus, stomach, colon, and prostate cancers. Further prospective study is necessary to confirm these findings.

Neural regulation of hematopoiesis, inflammation, and cancer

Although the function of the autonomic nervous system (ANS) in mediating the flight-or-fight response was recognized decades ago, the crucial role of peripheral innervation in regulating cell behavior and response to the microenvironment has only recently emerged. In the hematopoietic system, the ANS regulates stem cell niche homeostasis and regeneration and fine-tunes the inflammatory response. Additionally, emerging data suggest that cancer cells take advantage of innervating neural circuitry to promote their progression. These new discoveries outline the need to redesign therapeutic strategies to target this underappreciated stromal constituent. Here, we review the importance of neural signaling in hematopoietic homeostasis, inflammation, and cancer.

Can analyses of electronic patient records be independently and externally validated? Study 2--the effect of β-adrenoceptor blocker therapy on cancer survival: a retrospective cohort study

OBJECTIVES

To conduct a fully independent, external validation of a research study based on one electronic health record database using a different database sampling from the same population.

DESIGN

Retrospective cohort analysis of β-blocker therapy and all-cause mortality in patients with cancer.

SETTING

Two UK national primary care databases (PCDs): the Clinical Practice Research Datalink (CPRD) and Doctors' Independent Network (DIN).

PARTICIPANTS

CPRD data for 11,302 patients with cancer compared with published results from DIN for 3462 patients; study period January 1997 to December 2006.

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause mortality: overall; by treatment subgroup (β-blockers only, β-blockers plus other blood pressure lowering medicines (BPLM), other BPLMs only); and by cancer site.

RESULTS

Using CPRD, β-blocker use was not associated with mortality (HR=1.03, 95% CI 0.93 to 1.14, vs patients prescribed other BPLMs only), but DIN β-blocker users had significantly higher mortality (HR=1.18, 95% CI 1.04 to 1.33). However, these HRs were not statistically different (p=0.063), but did differ for patients on β-blockers alone (CPRD=0.94, 95% CI 0.82 to 1.07; DIN=1.37, 95% CI 1.16 to 1.61; p<0.001). Results for individual cancer sites differed by study, but only significantly for prostate and pancreas cancers. Results were robust under sensitivity analyses, but we could not be certain that mortality was identically defined in both databases.

CONCLUSIONS

We found a complex pattern of similarities and differences between databases. Overall treatment effect estimates were not statistically different, adding to a growing body of evidence that different UK PCDs produce comparable effect estimates. However, individually the two studies lead to different conclusions regarding the safety of β-blockers and some subgroup effects differed significantly. Single studies using even internally well-validated databases do not guarantee generalisable results, especially for subgroups, and confirmatory studies using at least one other independent data source are strongly recommended.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone promotes esophageal squamous cell carcinoma growth via beta-adrenoceptors in vitro and in vivo

Cigarette smoke is a risk factor for esophageal squamous cell carcinoma (ESCC). It contains several carcinogens known to initiate and promote tumorigenesis as well as metastasis. The nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is one of the strongest carcinogens in tobacco and our previous studies have shown its proliferation-promoting role in the progression of ESCC. Recently, NNK was identified as an agonist for both beta1- and beta2-adrenoceptors. Thus, we hypothesized that the cancer-promoting effect of NNK was likely mediated through beta-adrenoceptors in ESCC. Therefore, we investigated the comprehensive role of NNK in ESCC in vitro and in vivo, and found that NNK promoted many oncogenic features including ESCC cell proliferation and xenograft tumor growth as well as ESCC cell migration and invasion. Western blotting showed that NNK induced significant up-regulation of phosphorylated ERK1/2, cyclin D1, Bcl-2, and vascular endothelial growth factor as well as down-regulation of Bax. Importantly, the oncogenic effects of NNK in ESCC and the altered protein expression were reversed to some extent by down-regulation of beta1- and beta2-adrenoceptors with the beta2-adrenoceptor showing a greater rescue effect. Taken together, our in vitro and in vivo results demonstrate that NNK plays an oncogenic role in ESCC through beta-adrenoceptors. Furthermore, beta2-adrenoceptor might play a more important role in this process. Our findings might provide a chemoprevention and therapy strategy for cigarette smoke-related ESCC carcinogenesis.

Role of adrenergic receptor signaling pathway in colorectal cancer

Colorectal cancer is one of the most common malignancies. During the past decades, studies have continued to shed light on the role of adrenergic receptor signaling in cancer. Preclinical studies have shown that adrenergic receptor signaling is involved in colon cancer progression and metastasis and have implicated that stress hormones or behavioral changes are highly associated with tumor formation and progression. Therefore, further understanding of the role of the adrenergic receptor (AR) signaling pathway in colorectal cancer progression and metastasis will be of great value in developing therapeutic strategies for this malignancy.

Prevention of skin carcinogenesis by the β-blocker carvedilol

The stress-related catecholamine hormones and the α- and β-adrenergic receptors (α- and β-AR) may affect carcinogenesis. The β-AR GRK/β-arrestin biased agonist carvedilol can induce β-AR-mediated transactivation of the EGFR. The initial purpose of this study was to determine whether carvedilol, through activation of EGFR, can promote cancer. Carvedilol failed to promote anchorage-independent growth of JB6 P(+) cells, a skin cell model used to study tumor promotion. However, at nontoxic concentrations, carvedilol dose dependently inhibited EGF-induced malignant transformation of JB6 P(+) cells, suggesting that carvedilol has chemopreventive activity against skin cancer. Such effect was not observed for the β-AR agonist isoproterenol and the β-AR antagonist atenolol. Gene expression, receptor binding, and functional studies indicate that JB6 P(+) cells only express β2-ARs. Carvedilol, but not atenolol, inhibited EGF-mediated activator protein-1 (AP-1) activation. A topical 7,12-dimethylbenz(α)anthracene (DMBA)-induced skin hyperplasia model in SENCAR mice was utilized to determine the in vivo cancer preventative activity of carvedilol. Both topical and oral carvedilol treatment inhibited DMBA-induced epidermal hyperplasia (P < 0.05) and reduced H-ras mutations; topical treatment being the most potent. However, in models of established cancer, carvedilol had modest to no inhibitory effect on tumor growth of human lung cancer A549 cells in vitro and in vivo. In conclusion, these results suggest that the cardiovascular drug carvedilol may be repurposed for skin cancer chemoprevention, but may not be an effective treatment of established tumors. More broadly, this study suggests that β-ARs may serve as a novel target for cancer prevention.

A role for cAMP-driven transactivation of EGFR in cancer aggressiveness - therapeutic implications

In many common cancers, production of cAMP boosts cancer proliferation, survival, and aggressiveness, reflecting the fact that, through mechanisms that require further clarification, cAMP can promote tyrosine phosphorylation, notably transactivation of the epidermal growth factor receptor (EGFR). Hormones which activate adenylate cyclase in many cancers include PGE2 - often produced by cox-2 activity within tumors - and adrenergic hormones, acting on beta2 receptors. NSAID cyclooxygenase inhibitors, including low-dose aspirin, clearly reduce risk for many adenocarcinomas, but the impact of cox-2 inhibitors in clinical cancer therapy remains somewhat equivocal. There is increasing evidence that increased sympathetic drive, often reflecting psychic stress or tobacco usage, increases risk for, and promotes the aggressiveness of, many cancers. The non-specific beta antagonist propranolol shows cancer-retardant activity in pre-clinical rodent studies, especially in stressed animals, and a limited amount of epidemiology concludes that concurrent propranolol usage is associated with superior prognosis in breast cancer, ovarian cancer, and melanoma. Epidemiology correlating increased resting heart rate with increased total cancer mortality can be interpreted as compelling evidence that increased sympathetic drive encourages the onset and progression of common cancers. Conversely, hormones which inhibit adenylate cyclase activity in cancers may have potential for cancer control; GABA, which can be administered as a well-tolerated nutraceutical, has potential in this regard. Combination regimens intended to down-regulate cancer cAMP levels, perhaps used in conjunction with EGFR inhibitors, may have considerable potential for suppressing the contribution of cAMP/EGFR to cancer aggressiveness. This model also predicts that certain other hormones which activate adenylate cylase in various tissue may play a yet-unsuspected role in cancer induction and spread.