The notion that stress and cancer are interlinked has dominated lay discourse for decades. More recent animal studies indicate that stress can substantially facilitate cancer progression through ...modulating most hallmarks of cancer, and molecular and systemic mechanisms mediating these effects have been elucidated. However, available clinical evidence for such deleterious effects is inconsistent, as epidemiological and stress-reducing clinical interventions have yielded mixed effects on cancer mortality. In this Review, we describe and discuss specific mediating mechanisms identified by preclinical research, and parallel clinical findings. We explain the discrepancy between preclinical and clinical outcomes, through pointing to experimental strengths leveraged by animal studies and through discussing methodological and conceptual obstacles that prevent clinical studies from reflecting the impacts of stress. We suggest approaches to circumvent such obstacles, based on targeting critical phases of cancer progression that are more likely to be stress-sensitive; pharmacologically limiting adrenergic-inflammatory responses triggered by medical procedures; and focusing on more vulnerable populations, employing personalized pharmacological and psychosocial approaches. Recent clinical trials support our hypothesis that psychological and/or pharmacological inhibition of excess adrenergic and/or inflammatory stress signalling, especially alongside cancer treatments, could save lives.
Background
Preclinical studies have implicated excess release of catecholamines and prostaglandins in the mediation of prometastatic processes during surgical treatment of cancer. In this study, we ...tested the combined perioperative blockade of these pathways in patients with colorectal cancer (CRC).
Methods
In a randomized, double‐blind, placebo‐controlled biomarker trial involving 34 patients, the β‐blocker propranolol and the COX2‐inhibitor etodolac were administered for 20 perioperative days, starting 5 days before surgery. Excised tumors were subjected to whole genome messenger RNA profiling and transcriptional control pathway analyses.
Results
Drugs were well‐tolerated, with minor complications in both the treatment group and the placebo group. Treatment resulted in a significant improvement (P < .05) of tumor molecular markers of malignant and metastatic potential, including 1) reduced epithelial‐to‐mesenchymal transition, 2) reduced tumor infiltrating CD14+ monocytes and CD19+ B cells, and 3) increased tumor infiltrating CD56+ natural killer cells. Transcriptional activity analyses indicated a favorable drug impact on 12 of 19 a priori hypothesized CRC‐related transcription factors, including the GATA, STAT, and EGR families as well as the CREB family that mediates the gene regulatory impact of β‐adrenergic– and prostaglandin‐signaling. Alterations observed in these transcriptional activities were previously associated with improved long‐term clinical outcomes. Three‐year recurrence rates were assessed for long‐term safety analyses. An intent‐to‐treat analysis revealed that recurrence rates were 12.5% (2/16) in the treatment group and 33.3% (6/18) in the placebo group (P = .239), and in protocol‐compliant patients, recurrence rates were 0% (0/11) in the treatment group and 29.4% (5/17) in the placebo group (P = .054).
Conclusions
The favorable biomarker impacts and clinical outcomes provide a rationale for future randomized placebo‐controlled trials in larger samples to assess the effects of perioperative propranolol/etodolac treatment on oncological clinical outcomes.
Simultaneous 20‐day perioperative inhibition of β‐adrenergic and COX2 signaling in patients with colorectal cancer has a favorable impact on tumor biomarkers associated with metastatic progression. Our results suggest scientific, medical, and safety justifications to conduct large‐scale clinical trials, assessing long‐term cancer outcomes.
Evidence suggests that excess perioperative activation of the sympathetic nervous system and the consequent release of catecholamines (ie, epinephrine and norepinephrine) in the context of cancer ...surgery and inflammation may significantly facilitate prometastatic processes. This review first presents biomedical processes that make the perioperative timeframe pivotal in determining long‐term cancer outcomes nonproportionally to its short duration (days to weeks). Then, it analyzes the various mechanisms via which the excess release of catecholamines can facilitate the progression of cancer metastases in this context by directly affecting the malignant tissues and by regulating, via indirect pathways, immunological and other mechanisms that affect metastatic progression in the tumor microenvironment and systemically. In addition, this review addresses the need to supplement β‐adrenoreceptor blockade with cyclooxygenase 2 inhibition, especially during surgery and shortly thereafter, because similar mechanisms are simultaneously activated by surgery‐induced inflammatory responses. Importantly, this review presents translational and clinical evidence showing that perioperative β‐adrenoreceptor blockade and cyclooxygenase 2 inhibition can reduce the prometastatic process and cancer recurrence, and the clinical feasibility and safety of this approach are demonstrated as well. Lastly, alternative psychophysiological approaches to the use of β‐adrenergic blockers are presented because a substantial portion of patients have medical contraindications to this pharmacological treatment. The adaptation of existing psychophysiological interventions to the perioperative period and principles for constructing new approaches are discussed and exemplified. Overall, pharmacobehavioral interventions, separately or in combination, could transform the perioperative timeframe from being a prominent facilitator of metastatic progression to an opportunity for arresting or eliminating residual disease, potentially improving long‐term survival rates in cancer patients.
Evidence based on animal models, retrospective clinical studies, and recently also randomized controlled trials indicates that simultaneous use of β‐blockers and cyclooxygenase 2 inhibitors can effectively reduce promalignant effects of perioperative stress‐inflammatory responses and may reduce patients’ recurrence rates and mortality. Hypothetically, perioperative psychological interventions may have similar benefits.
The immediate perioperative period (days before and after surgery) is hypothesized to be crucial in determining long-term cancer outcomes: during this short period, numerous factors, including excess ...stress and inflammatory responses, tumour-cell shedding and pro-angiogenic and/or growth factors, might facilitate the progression of pre-existing micrometastases and the initiation of new metastases, while simultaneously jeopardizing immune control over residual malignant cells. Thus, application of anticancer immunotherapy during this critical time frame could potentially improve patient outcomes. Nevertheless, this strategy has rarely been implemented to date. In this Perspective, we discuss apparent contraindications for the perioperative use of cancer immunotherapy, suggest safe immunotherapeutic and other anti-metastatic approaches during this important time frame and specify desired characteristics of such interventions. These characteristics include a rapid onset of immune activation, avoidance of tumour-promoting effects, no or minimal increase in surgical risk, resilience to stress-related factors and minimal induction of stress responses. Pharmacological control of excess perioperative stress-inflammatory responses has been shown to be clinically feasible and could potentially be combined with immune stimulation to overcome the direct pro-metastatic effects of surgery, prevent immune suppression and enhance immunostimulatory responses. Accordingly, we believe that certain types of immunotherapy, together with interventions to abrogate stress-inflammatory responses, should be evaluated in conjunction with surgery and, for maximal effectiveness, could be initiated before administration of adjuvant therapies. Such strategies might improve the overall success of cancer treatment.
Highlight ► Surgical stress, mostly through catecholamines and prostaglandins, suppresses newly discovered anti-metastatic CMI and promotes cancer recurrence.
Translational studies suggest that excess perioperative release of catecholamines and prostaglandins may facilitate metastasis and reduce disease-free survival. This trial tested the combined ...perioperative blockade of these pathways in breast cancer patients.
In a randomized placebo-controlled biomarker trial, 38 early-stage breast cancer patients received 11 days of perioperative treatment with a β-adrenergic antagonist (propranolol) and a COX-2 inhibitor (etodolac), beginning 5 days before surgery. Excised tumors and sequential blood samples were assessed for prometastatic biomarkers.
Drugs were well tolerated with adverse event rates comparable with placebo. Transcriptome profiling of the primary tumor tested
hypotheses and indicated that drug treatment significantly (i) decreased epithelial-to-mesenchymal transition, (ii) reduced activity of prometastatic/proinflammatory transcription factors (GATA-1, GATA-2, early-growth-response-3/EGR3, signal transducer and activator of transcription-3/STAT-3), and (iii) decreased tumor-infiltrating monocytes while increasing tumor-infiltrating B cells. Drug treatment also significantly abrogated presurgical increases in serum IL6 and C-reactive protein levels, abrogated perioperative declines in stimulated IL12 and IFNγ production, abrogated postoperative mobilization of CD16
"classical" monocytes, and enhanced expression of CD11a on circulating natural killer cells.
Perioperative inhibition of COX-2 and β-adrenergic signaling provides a safe and effective strategy for inhibiting multiple cellular and molecular pathways related to metastasis and disease recurrence in early-stage breast cancer.
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Evidence suggests that the perioperative period and the excision of the primary tumour can promote the development of metastases—the main cause of cancer-related mortality. This Review first presents ...the assertion that the perioperative timeframe is pivotal in determining long-term cancer outcomes, disproportionally to its short duration (days to weeks). We then analyse the various aspects of surgery, and their consequent paracrine and neuroendocrine responses, which could facilitate the metastatic process by directly affecting malignant tissues, and/or through indirect pathways, such as immunological perturbations. We address the influences of surgery-related anxiety and stress, nutritional status, anaesthetics and analgesics, hypothermia, blood transfusion, tissue damage, and levels of sex hormones, and point at some as probable deleterious factors. Through understanding these processes and reviewing empirical evidence, we provide suggestions for potential new perioperative approaches and interventions aimed at attenuating deleterious processes and ultimately improving treatment outcomes. Specifically, we highlight excess perioperative release of catecholamines and prostaglandins as key deleterious mediators of surgery, and we recommend blockade of these responses during the perioperative period, as well as other low-risk, low-cost interventions. The measures described in this Review could transform the perioperative timeframe from a prominent facilitator of metastatic progression, to a window of opportunity for arresting and/or eliminating residual disease, potentially improving long-term survival rates in patients with cancer.
The use of TLR agonists as an anti‐cancer treatment is gaining momentum given their capacity to activate various host cellular responses through the secretion of inflammatory cytokines and type‐I ...interferons. It is now also recognized that the perioperative period is a window of opportunity for various interventions aiming at reducing the risk of cancer metastases—the major cause of cancer related death. However, immune‐stimulatory approach has not been used perioperatively given several contraindications to surgery. To overcome these obstacles, in this study, we used the newly introduced, fully synthetic TLR‐4 agonist, Glucopyranosyl Lipid‐A (GLA‐SE), in various models of cancer metastases, and in the context of acute stress or surgery. Without exerting evident adverse effects, a single systemic administration of GLA‐SE rapidly and dose dependently elevated both innate and adaptive immunity in the circulation, lungs and the lymphatic system. Importantly, GLA‐SE treatment led to reduced metastatic development of a mammary adenocarcinoma and a colon carcinoma by approximately 40–75% in F344 rats and BALB/c mice, respectively, at least partly through elevating marginating‐pulmonary NK cell cytotoxicity. GLA‐SE is safe and well tolerated in humans, and currently is used as an adjuvant in phase‐II clinical trials. Given that the TLR‐4 receptor and its signaling cascade is highly conserved throughout evolution, our current results suggest that GLA‐SE may be a promising immune stimulatory agent in the context of oncological surgeries, aiming to reduce long‐term cancer recurrence.
What's new?
The use of active chemotherapeutic regimens immediately prior to, during, or after surgery may significantly reduce the risk of metastatic development in cancer patients. Generally excluded from such perioperative regimens are immunostimulators, which tend to exhibit pro‐inflammatory activity. This study shows, however, that in rats and mice with mammary adenocarcinomas or colon carcinomas, respectively, the toll‐like receptor 4 agonist glucopyranosyl lipid‐A (GLA‐SE) is capable of reducing metastatic development by increasing host resistance to metastasis without exerting adverse effects. GLA‐SE, currently under study clinically for other conditions, may be an effective perioperative immunostimulator, lacking adverse effects and lowering the risk of cancer recurrence.
Surgery is a crucial intervention in most cancer patients, but the perioperative period is characterized by increased risks for future outbreak of preexisting micrometastases and the initiation of ...new metastases-the major cause of cancer-related death. Here we argue that the short perioperative period is disproportionately critical in determining long-term recurrence rates, discuss the various underlying risk factors that act synergistically during this period, and assert that this time frame presents an unexplored opportunity to reduce long-term cancer recurrence. We then address physiologic mechanisms that underlie these risk factors, focusing on excess perioperative release of catecholamines and prostaglandins, which were recently shown to be prominent in facilitating cancer recurrence through their direct impact on the malignant tissue and its microenvironment, and through suppressing antimetastatic immunity. The involvement of the immune system is further discussed in light of accumulating evidence in cancer patients, and given the recent identification of endogenously activated unique leukocyte populations which, if not suppressed, can destroy autologous "immune-resistant" tumor cells. We then review animal studies and human correlative findings, suggesting the efficacy of blocking catecholamines and/or prostaglandins perioperatively, limiting metastasis and increasing survival rates. Finally, we propose a specific perioperative pharmacologic intervention in cancer patients, based on simultaneous β-adrenergic blockade and COX-2 inhibition, and discuss specific considerations for its application in clinical trials, including our approved protocol. In sum, we herein present the rationale for a new approach to reduce long-term cancer recurrence by using a relatively safe, brief, and inexpensive intervention during the perioperative period.
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