Surgical Stress Promotes the Development of Cancer Metastases by a Coagulation-Dependent Mechanism Involving Natural Killer Cells in a Murine Model

Survival Advantage of Laparoscopic Versus Open Resection For Colorectal Liver Metastases: A Meta-analysis of Individual Patient Data From Randomized Trials and Propensity-score Matched Studies

OBJECTIVE

To perform an individual participant data meta-analysis using randomized trials and propensity-score matched (PSM) studies which compared laparoscopic versus open hepatectomy for patients with colorectal liver metastases (CLM).

BACKGROUND

Randomized trials and PSM studies constitute the highest level of evidence in addressing the long-term oncologic efficacy of laparoscopic versus open resection for CLM. However, individual studies are limited by the reporting of overall survival in ways not amenable to traditional methods of meta-analysis, and violation of the proportional hazards assumption.

METHODS

Survival information of individual patients was reconstructed from the published Kaplan-Meier curves with the aid of a computer vision program. Frequentist and Bayesian survival models (taking into account random-effects and nonproportional hazards) were fitted to compare overall survival of patients who underwent laparoscopic versus open surgery. To handle long plateaus in the tails of survival curves, we also exploited "cure models" to estimate the fraction of patients effectively "cured" of disease.

RESULTS

Individual patient data from 2 randomized trials and 13 PSM studies involving 3148 participants were reconstructed. Laparoscopic resection was associated with a lower hazard rate of death (stratified hazard ratio = 0.853, 95% confidence interval: 0.754-0.965, P = 0.0114), and there was evidence of time-varying effects (P = 0.0324) in which the magnitude of hazard ratios increased over time. The fractions of long-term cancer survivors were estimated to be 47.4% and 18.0% in the laparoscopy and open surgery groups, respectively. At 10-year follow-up, the restricted mean survival time was 8.6 months (or 12.1%) longer in the laparoscopy arm (P < 0.0001). In a subgroup analysis, elderly patients (≥65 years old) treated with laparoscopy experienced longer 3-year average life expectancy (+6.2%, P = 0.018), and those who live past the 5-year milestone (46.1%) seem to be cured of disease.

CONCLUSIONS

This patient-level meta-analysis of high-quality studies demonstrated an unexpected survival benefit in favor of laparoscopic over open resection for CLM in the long-term. From a conservative viewpoint, these results can be interpreted to indicate that laparoscopy is at least not inferior to the standard open approach.

Current status of laparoscopic liver resection for the management of colorectal liver metastases

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide. The commonest site of spread is the liver, with up to 40% of patients developing colorectal liver metastasis (CLRM) during the course of their lifetime. Significant advances in surgical techniques, as well as breakthroughs in chemotherapy and biologic agents, have resulted in dramatic improvements in prognosis. A multimodal approach comprising of liver resection coupled with systemic therapy offers these patients the best chance of cure. The arrival of laparoscopic liver resection (LLR) within the last 3 decades has added a whole new dimension to the management of this condition. Today, CLRM is one of the most frequent indications for LLR globally. Meta-analyses of retrospective studies and two randomized trials have demonstrated superior short-term outcomes following LLR, with no differences in mortality rates. Oncologically, R0 resection rates are comparable to the open approach, while overall and disease-free survival rates are also similar. As surgeons gain confidence, boundaries are pushed even further. High-volume centers have published their early experiences with complex LLR of recurrent CLRM as well as totally laparoscopic synchronous resection of CRC and liver metastases, with very encouraging results. In the presence of extensive bilobar CLRM, two-stage hepatectomy (TSH) and associating liver partition with portal vein ligation (ALPPS) may be adopted to augment an inadequate future liver remnant to facilitate metastasectomy. Interestingly, the adoption of LLR for these techniques also seem to confer additional benefits. Despite the plethora of advantages, LLR comes with its own unique set of limitations such as a steep learning curve and high cost. The surgical world eagerly awaits the results of prospective trials currently underway in order to further advance the management of this disease.

Harnessing cancer immunotherapy during the unexploited immediate perioperative period

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.

The "Janus Face" of Platelets in Cancer

Besides their vital role in hemostasis and thrombosis, platelets are also recognized to be involved in cancer, where they play an unexpected central role: They actively influence cancer cell behavior, but, on the other hand, platelet physiology and phenotype are impacted by tumor cells. The existence of this platelet-cancer loop is supported by a large number of experimental and human studies reporting an association between alterations in platelet number and functions and cancer, often in a way dependent on patient, cancer type and treatment. Herein, we shall report on an update on platelet-cancer relationships, with a particular emphasis on how platelets might exert either a protective or a deleterious action in all steps of cancer progression. To this end, we will describe the impact of (i) platelet count, (ii) bioactive molecules secreted upon platelet activation, and (iii) microvesicle-derived miRNAs on cancer behavior. Potential explanations of conflicting results are also reported: Both intrinsic (heterogeneity in platelet-derived bioactive molecules with either inhibitory or stimulatory properties; features of cancer cell types, such as aggressiveness and/or tumour stage) and extrinsic (heterogeneous characteristics of cancer patients, study design and sample preparation) factors, together with other confounding elements, contribute to “the Janus face” of platelets in cancer. Given the difficulty to establish the univocal role of platelets in a tumor, a better understanding of their exact contribution is warranted, in order to identify an efficient therapeutic strategy for cancer management, as well as for better prevention, screening and risk assessment protocols.

Does delayed initiation of adjuvant chemotherapy following the curative resection affect the survival outcome of gastric cancer patients: A systematic review and meta-analysis

BACKGROUND

Adjuvant chemotherapy(AC) following the curative resection could improve the survival outcome of advanced gastric cancer(GC) patients. However, there is no specific timing interval from radical surgery to initiation of AC. Whether delayed initiation of AC could affect the survival outcome of these patients remains unclear. In this study, we performed a systematic review and meta-analysis to evaluate the relationship between delaying AC and the survival outcome of GC patients.

METHODS

PubMed, Embase and Cochrane Library databases were systematically searched for eligible studies that evaluated the relationship between time to AC and survival outcome. Survival data for HR and 95% CI were extracted and converted to a regression coefficient(β) corresponding to a continuous representation per 4-week delay of AC. Individual adjusted β were combined using a fixed-effects or random-effects model. Heterogeneity was assessed by I² statistic and publication bias was detected using standard error-based funnel plots.

RESULTS

A total of 11 eligible studies involving 6,017 patients were included in this meta-analysis. Eight studies evaluated the impact of delaying AC on overall survival(OS) and five evaluated the impact of delaying AC on disease-free survival(DFS). The pooled results demonstrated that the initiation of AC per 4-week delay was associated with a significant decrease in OS(HR:1.05, 95% CI: 1.03-1.08, P < 0.001; I² = 18.5%) and DFS (HR:1.06, 95% CI: 1.02-1.10, P = 0.001; I² = 40.6%).

CONCLUSION

The initiation of AC per 4-week delay was associated with worse survival outcomes in GC patients. If physical status and postoperative recovery were appropriated, GC patients should be recommended to receive adjuvant chemotherapy timely.

Pretreatment plasma fibrinogen level as a prognostic biomarker for patients with lung cancer

Many researchers have shown that pretreatment plasma fibrinogen levels are closely correlated with the prognosis of patients with lung cancer (LC). In this study, we thus performed a meta-analysis to systematically assess the prognostic value of pretreatment plasma fibrinogen levels in LC patients. A computerized systematic search in PubMed, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI) was performed up to March 15, 2018. Studies with available data on the prognostic value of plasma fibrinogen in LC patients were eligible for inclusion. The pooled hazard ratios (HRs) and odd ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the correlation between pretreatment plasma fibrinogen levels and prognosis as well as clinicopathological characteristics. A total of 17 studies with 6,460 LC patients were included in this meta-analysis. A higher pretreatment plasma fibrinogen level was significantly associated with worse overall survival (OS) (HR: 1.57; 95% CI: 1.39-1.77; p=0.001), disease-free survival (DFS) (HR: 1.53; 95% CI: 1.33-1.76; p=0.003), and progression-free survival (PFS) (HR: 3.14; 95% CI: 2.15-4.59; p<0.001). Furthermore, our subgroup and sensitivity analyses demonstrated that the pooled HR for OS was robust and reliable. In addition, we also found that a higher fibrinogen level predicted advanced TNM stage (III-IV) (OR=2.18, 95% CI: 1.79-2.66; p<0.001) and a higher incidence of lymph node metastasis (OR=1.74, 95% CI: 1.44-2.10; p=0.02). Our study suggested that higher pretreatment plasma fibrinogen levels predict worse prognoses in LC patients.

Study on the Effect of Ginsenosides Rb on Blood of Tumor Mice

Objective

The blood of cancer patients is in a state of hypercoagulability, easily leading to thrombosis. Anemia is also a complication of tumors. Anemia and thrombosis affect the treatment of tumor patients.

Methods

Ginsenosides Rb were extracted from the stems and leaves of American ginseng using water-saturated ethanol and ethyl acetate in silica gel column. Tumor mice model was established by injecting H₂₂ hepatocellular carcinoma cells into the axilla of mice. Mice were randomly divided into 6 groups: normal control group, model control group, positive control group, low dose group (7 mg/kg), middle dose group (14 mg/kg), and high dose group (35 mg/kg). After 18 days, the blood was obtained by picking the eyeball of mice. The levels of red blood cells (RBC), hemoglobin (HGB), neutrophils/lymphocytes radio (NLR), platelets (PLT), platelet distribution width (PDW), fibrinogen (FIB), and D-Dimer (D-D) were measured and compared in each group of mice.

Results

The content of obtained ginsenosides Rb reached 90.05%. This extraction process was simple and reliable. Middle dose of ginsenosides Rb could significantly increase RBC and HGB levels (P<0.05). Moreover, ginsenosides Rb could significantly reduce NLR, PLT, PDW, FIB, and D-D (P<0.01).

Conclusion

ginsenosides Rb could significantly improve anaemia and hypercoagulation of blood in cancer mice. Ginsenosides Rb are a potential anticoagulant and antianemia drug in treating cancer.

Surgical stress and cancer progression: the twisted tango

Surgical resection is an important avenue for cancer treatment, which, in most cases, can effectively alleviate the patient symptoms. However, accumulating evidence has documented that surgical resection potentially enhances metastatic seeding of tumor cells. In this review, we revisit the literature on surgical stress, and outline the mechanisms by which surgical stress, including ischemia/reperfusion injury, activation of sympathetic nervous system, inflammation, systemically hypercoagulable state, immune suppression and effects of anesthetic agents, promotes tumor metastasis. We also propose preventive strategies or resolution of tumor metastasis caused by surgical stress.

Lipid accumulation impairs natural killer cell cytotoxicity and tumor control in the postoperative period

BACKGROUND

Natural killer (NK) cell dysfunction following cancer surgery has been shown to promote metastases. Recent studies demonstrate an emerging role for lipids in the modulation of NK cell innate responses. However, the mechanisms involved in lipid modulation of NK cell postoperative anti-tumor function are unknown. This current study will determine whether the lipid accumulation via scavenger receptors on NK cells is responsible for the increase in postoperative metastasis.

METHODS

Lipid content in mouse and human NK cells was evaluated by flow cytometry. NK cell scavenger receptor (SR) expression was measured by microarray analysis, validated by qRT-PCR and flow cytometry. NK cell ex vivo and in vivo tumor killing was measured by chromium-release and adoptive transfer assays, respectively. The mediating role of surgery-expanded granulocytic myeloid derived suppressor cells (gMDSC) in SR induction on NK cells was evaluated using co-culture assays.

RESULTS

NK cells in surgery-treated mice demonstrated increased lipid accumulation, which occurred via up-regulation of MSR1, CD36 and CD68. NK cells with high lipid content had diminished ability to lyse tumor targets ex vivo. Adoptive transfer of lipid-laden NK cells into NK cell-deficient mice were unable to protect against a lung tumor challenge. Granulocytic MDSC from surgery-treated mice increased SR expression on NK cells. Colorectal cancer surgical patients showed increased NK cell lipid content, higher CD36 expression, decreased granzyme B and perforin production in addition to reduced cytotoxicity in the postoperative period.

CONCLUSIONS

Postoperative lipid accumulation promotes the formation of metastases by impairing NK cell function in both preclinical surgical models and human surgical colorectal cancer patient samples. Understanding and targeting the mechanisms underlying lipid accumulation in innate immune NK cells can improve prognosis in cancer surgical patients.

Postoperative Serum C-Reactive Protein Level Predicts Long-term Outcomes in Stage I Gastric Cancer

BACKGROUND

The aim of this study was to investigate the prognostic impact of postoperative systemic inflammation in patients with stage I gastric cancer.

METHODS

This study reviewed the medical records of 470 patients with stage I gastric cancer who underwent gastrectomy. The postoperative serum C-reactive protein (CRP) level on postoperative days (PODs) 1 and 3 and its peak value were evaluated as prognostic factors. A receiver operating characteristics curve analysis was performed to determine their cut-off values.

RESULTS

The CRP level on POD 3 (P = 0.001) and the peak CRP level (P = 0.007) were significantly associated with the overall survival rate. In the multivariate analysis, the CRP level on POD 3 (P = 0.002) and the peak CRP level (P = 0.008) were identified as independent predictors of the overall survival. The high CRP on POD3 group had significantly higher mortality rate from relapse of gastric cancer (P = 0.001) and infectious disease (P = 0.003) than the low CRP on POD 3 group. The CRP level on POD 3 was significantly associated with the patient sex, surgical procedure, duration of the operation, amount of blood loss, postoperative infectious complication, and peak CRP level.

CONCLUSIONS

The serum CRP level during the early postoperative period predicts the long-term outcomes in stage I gastric cancer. The present study suggests a significant influence of postoperative systemic inflammation on the survival of patients with stage I gastric cancer.

The Potential for Cancer Immunotherapy in Targeting Surgery-Induced Natural Killer Cell Dysfunction

Natural Killer (NK) cells are granular lymphocytes of the innate immune system that are able to recognize and kill tumor cells without undergoing clonal selection. Discovered over 40 years ago, they have since been recognized to possess both cytotoxic and cytokine-producing effector functions. Following trauma, NK cells are suppressed and their effector functions are impaired. This is especially important for cancer patients undergoing the removal of solid tumors, as surgery has shown to contribute to the development of metastasis and cancer recurrence postoperatively. We have recently shown that NK cells are critical mediators in the formation of metastasis after surgery. While research into the mechanism(s) responsible for NK cell dysfunction is ongoing, knowledge of these mechanisms will pave the way for perioperative therapeutics with the potential to improve cancer outcomes by reversing NK cell dysfunction. This review will discuss mechanisms of suppression in the postoperative environment, including hypercoagulability, suppressive soluble factors, the expansion of suppressive cell populations, and how this affects NK cell biology, including modulation of cell surface receptors, the potential for anergy, and immunosuppressive NK cell functions. This review will also outline potential immunotherapies to reverse postoperative NK dysfunction, with the goal of preventing surgery-induced metastasis.

Combining surgery and immunotherapy: turning an immunosuppressive effect into a therapeutic opportunity

Background

Cancer surgery is necessary and life-saving. However, the majority of patients develop postoperative recurrence and metastasis, which are the main causes of cancer-related deaths. The postoperative stress response encompasses a broad set of physiological changes that have evolved to safeguard the host following major tissue trauma. These stress responses, however, intersect with cellular mediators and signaling pathways that contribute to cancer proliferation.

Main

Previous descriptive and emerging mechanistic studies suggest that the surgery-induced prometastatic effect is linked to impairment of both innate and adaptive immunity. Existing studies that combine surgery and immunotherapies have revealed that this combination strategy is not straightforward and patients have experienced both therapeutic benefit and drawbacks. This review will specifically assess the immunological pathways that are disrupted by oncologic surgical stress and provide suggestions for rationally combining cancer surgery with immunotherapies to improve immune and treatment outcomes.

Short conclusion

Given the prevalence of surgery as frontline therapy for solid cancers, the emerging data on postoperative immunosuppression and the rapid development of immunotherapy for oncologic treatment, we believe that future targeted studies of perioperative immunotherapy are warranted.

Association between perioperative beta blocker use and cancer survival following surgical resection

BACKGROUND

Recent studies have demonstrated an association between beta-blocker exposure and improved survival in multiple cancer types. We sought to investigate the effects of beta-blockers at the time of index surgery for breast, lung, and colorectal cancer.

MATERIALS AND METHODS

Using linked data from a provincial cancer registry, we conducted a retrospective matched cohort study comparing disease-specific and overall survival between patients over age 64 exposed and not exposed to beta-blockers before and after index surgical resection for breast, lung and colorectal cancer between April 1st, 2002 and December 31st, 2010. A high-dimensional propensity score was used to match patients and Cox proportional hazard models were used to estimate relative risks of the outcomes.

RESULTS

30,020 patients were included in the final matched cohorts. Mean follow up time for breast, lung, and colorectal cancer was 57.6 ± 30.5, 43.1 ± 28.7, and 53.4 ± 31.0 months, respectively. The adjusted hazard ratio for disease-specific mortality for patients exposed to beta-blockers was 1.03 (0.83-1.29) for breast, 1.05 (0.92-1.20) for lung, and 1.10 (0.96-1.25) for the colorectal cancer cohort.

CONCLUSIONS

In this large population-based study, no association between perioperative beta-blocker exposure and improved cancer-specific survival for breast, lung, or colorectal cancer was demonstrated.

Sepsis increases perioperative metastases in a murine model

Background

Cancer surgery can promote tumour metastases and worsen prognosis, however, the effect of perioperative complications on metastatic disease remains unclear. In this study we sought to evaluate the effect of common perioperative complications including perioperative blood loss, hypothermia, and sepsis on tumour metastases in a murine model.

Methods

Prior to surgery, pulmonary metastases were established by intravenous challenge of CT26LacZ colon cancer cells in BALB/c mice. Surgical stress was generated through partial hepatectomy (PH) or left nephrectomy (LN). Sepsis was induced by puncturing the cecum to express stool into the abdomen. Hemorrhagic shock was induced by removal of 30% of total blood volume (i.e. stage 3 hemorrhage) via the saphenous vein. Hypothermia was induced by removing the heating apparatus during surgery and lowering core body temperatures to 30 °C. Lung tumour burden was quantified 3 days following surgery.

Results

Surgically stressed mice subjected to stage 3 hemorrhage or hypothermia did not show an additional increase in lung tumour burden. In contrast, surgically stressed mice subjected to intraoperative sepsis demonstrated an additional 2-fold increase in the number of tumour metastases. Furthermore, natural killer (NK) cell function, as assessed by YAC-1 tumour cell lysis, was significantly attenuated in surgically stressed mice subjected to intraoperative sepsis. Both NK cell-mediated cytotoxic function and lung tumour burden were improved with perioperative administration of polyI:C, which is a toll-like receptor (TLR)-3 ligand.

Conclusions

Perioperative sepsis alone, but not hemorrhage or hypothermia, enhances the prometastatic effect of surgery in murine models of cancer. Understanding the cellular mechanisms underlying perioperative immune suppression will facilitate the development of immunomodulation strategies that can attenuate metastatic disease.

Preoperative platelet to lymphocyte and neutrophil to lymphocyte ratios are independent prognostic factors for patients undergoing lung cancer radical surgery: A single institutional cohort study

BACKGROUND

The aim of this study was to assess the prognostic value for NSCLC patients who were scheduled to receive lung cancer radical resection.

METHODS

In this cohort study (Dec.2014-Feb.2016), patients with non-small cell lung cancer (NSCLC) who underwent radical lung cancer thoracotomy were enrolled and accessed at postoperative complications, one-year overall survival (OS) and relapse-free survival (RFS). The preoperative PLR and NLR of all patients were calculated based on preoperative complete blood counts. Univariate and multivariate Cox regression analyses were performed to determine the associations of PLR and NLR with OS and RFS.

RESULTS

A total of 174 NSCLC patients were studied. The results indicated that both high PLR (>148.6) and NLR (>2.9) were related to a high rate of postoperative pulmonary complications significantly (49.3%vs.29.1%, P = 0.007; 50.7% vs. 28.6%, P = 0.003). Moreover, NSCLC patients with a high PLR level (> 148.6) was significantly associated with a lower one-year OS (90.3% vs. 77.5%, P = 0.034).

CONCLUSIONS

Preoperative PLR and NLR were good prognostic factors for postoperative pulmonary complications and OS in NSCLC patients undergoing radical lung cancer surgery. Thus, blood PLR and NLR would be helpful as a prognostic tool before radical lung cancer surgery.

The coagulome and the oncomir: impact of cancer-associated haemostatic dysregulation on the risk of metastasis

Patients with cancer are at high risk of both thromboembolic and haemorrhagic events during the course of their disease. The pathogenesis of haemostatic dysfunction in cancer is complex and involves the interplay of multiple factors. There is growing evidence that interactions between malignancies and the coagulation system are not random but can represent coordinated and clinically-significant adaptations that enhance tumour cell survival, proliferation and metastatic potential. A detailed understanding of the interactions between the haemostatic systems and the pathophysiology of metastasis may not only provide insight into strategies that could potentially reduce the incidence of thrombohaemorrhagic events and complications, but could also help design strategies that are capable of modifying tumour biology, progression and metastatic potential in ways that could enhance anticancer therapies and thereby improve overall survival.

Impact of Malnutrition After Gastrectomy for Gastric Cancer on Long-Term Survival

BACKGROUND

Preoperative malnutrition can worsen morbidity and mortality; however, the role of postgastrectomy nutritional status remains unclear. Our purpose was to clarify whether malnutrition after gastrectomy could predict long-term survival.

METHODS

Patients with pathological stage I, II, and III gastric cancer who underwent gastrectomy between 2002 and 2013 were included. The nutrition risk index (NRI) was evaluated before and at 1, 3, 6 and 12 months after gastrectomy. The patients were divided into normal (NRI > 97.5) or malnutrition (NRI ≤ 97.5) groups, and we compared the correlations of clinicopathological characteristics, surgical treatment, and overall survival between the two groups.

RESULTS

Among the 760 participants, patients in the malnutrition group were significantly older and had higher incidences of comorbidity and advanced cancer than the patients in the normal group. Multivariate analysis showed that overall survival was poorer in the malnutrition group before gastrectomy [hazard ratio (HR) 1.68] and at 1 month (HR 1.77), 3 months (HR 2.18), 6 months (HR 1.81) and 12 months (HR 2.17) after gastrectomy (all p < 0.01). Malnutrition at 1 and 3 months after gastrectomy was significantly associated with poor cause-specific survival. Total gastrectomy, preoperative malnutrition, older age, and adjuvant chemotherapy were independent risk factors of postoperative malnutrition at 12 months postgastrectomy.

CONCLUSIONS

Malnutrition before gastrectomy and at 1, 3, 6 and 12 months after gastrectomy significantly and adversely affects overall survival. Nutritional interventions to lessen the impact of postoperative malnutrition offer hope for prolonged survival.

Surgical stress response and promotion of metastasis in colorectal cancer: a complex and heterogeneous process

Surgery remains the curative treatment modality for colorectal cancer in all stages, including stage IV with resectable liver metastasis. There is emerging evidence that the stress response caused by surgery as well as other perioperative therapies such as anesthesia and analgesia may promote growth of pre-existing micro-metastasis or potentially initiate tumor dissemination. Therapeutically targeting the perioperative period may therefore reduce the effect that surgical treatments have in promoting metastases, for example by combining β-adrenergic receptor antagonists and cyclooxygenase-2 (COX-2) inhibitors in the perioperative setting. In this paper, we highlight some of the mechanisms that may underlie surgery-related metastatic development in colorectal cancer. These include direct tumor spillage at the time of surgery, suppression of the anti-tumor immune response, direct stimulatory effects on tumor cells, and activation of the coagulation system. We summarize in more detail results that support a role for catecholamines as major drivers of the pro-metastatic effect induced by the surgical stress response, predominantly through activation of β-adrenergic signaling. Additionally, we argue that an improved understanding of surgical stress-induced dissemination, and more specifically whether it impacts on the level and nature of heterogeneity within residual tumor cells, would contribute to the successful clinical targeting of this process. Finally, we provide a proof-of-concept demonstration that ex-vivo analyses of colorectal cancer patient-derived samples using RGB-labeling technology can provide important insights into the heterogeneous sensitivity of tumor cells to stress signals. This suggests that intra-tumor heterogeneity is likely to influence the efficacy of perioperative β-adrenergic receptor and COX-2 inhibition, and that ex-vivo characterization of heterogeneous stress response in tumor samples can synergize with other models to optimize perioperative treatments and further improve outcome in colorectal and other solid cancers.

Surgery-induced tumor growth in (metastatic) colorectal cancer

Metastatic colorectal cancer (mCRC) is a devastating disease causing 700.000 deaths annually worldwide. Metastases most frequently develop in the liver. Partial hepatectomy has dramatically improved clinical outcome and is the only curative treatment option for eligible patients with mCRC. Pre-clinical studies have shown that surgical procedures can have tumor-promoting local 'side-effects' such as hypoxia and inflammation, thereby altering the behaviour of residual tumor cells. In addition, systemically released factors following (colon or liver) surgery can act as a wakeup-call for dormant tumor cells in distant organs and/or help establish a pre-metastatic niche. Tumor handling during resection may also increase the number of circulating tumor cells. Despite the overwhelming amount of pre-clinical data demonstrating the pro-tumorigenic side effects of surgery, clinical evidence is scarce. Indications for hepatic surgery are rapidly increasing due to a rise in the incidence of mCRC and a trend towards more aggressive surgical treatment. Therefore, it is increasingly important to understand the principles of surgery-induced tumor growth, in order to devise perioperative or adjuvant strategies to further enhance long-term tumor control. In the current study we review the evidence for surgery-stimulated tumor growth and suggest strategies to assess the clinical relevance of such findings.

Dysfunctional Natural Killer Cells in the Aftermath of Cancer Surgery

The physiological changes that occur immediately following cancer surgeries initiate a chain of events that ultimately result in a short pro-, followed by a prolonged anti-, inflammatory period. Natural Killer (NK) cells are severely affected during this period in the recovering cancer patient. NK cells play a crucial role in anti-tumour immunity because of their innate ability to differentiate between malignant versus normal cells. Therefore, an opportunity arises in the aftermath of cancer surgery for residual cancer cells, including distant metastases, to gain a foothold in the absence of NK cell surveillance. Here, we describe the post-operative environment and how the release of sympathetic stress-related factors (e.g., cortisol, prostaglandins, catecholamines), anti-inflammatory cytokines (e.g., IL-6, TGF-β), and myeloid derived suppressor cells, mediate NK cell dysfunction. A snapshot of current and recently completed clinical trials specifically addressing NK cell dysfunction post-surgery is also discussed. In collecting and summarizing results from these different aspects of the surgical stress response, a comprehensive view of the NK cell suppressive effects of surgery is presented. Peri-operative therapies to mitigate NK cell suppression in the post-operative period could improve curative outcomes following cancer surgery.

Perioperative Anesthesia Care and Tumor Progression

This narrative review discusses the most recent up-to-date findings focused on the currently available "best clinical practice" regarding perioperative anesthesia care bundle factors and their effect on tumor progression. The main objective is to critically appraise the current literature on local anesthetics, regional outcome studies, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs) and their ability to decrease recurrence in patients undergoing cancer surgery. A brief discussion of additional topical perioperative factors relevant to the anesthesiologist including volatile and intravenous anesthetics, perioperative stress and anxiety, nutrition, and immune stimulation is included. The results of several recently published systematic reviews looking at the association between cancer recurrences and regional anesthesia have yielded inconclusive data and provide insufficient evidence regarding a definitive benefit of regional anesthesia. Basic science data suggests an anti tumor effect induced by local anesthetics. New refined animal models show that opioids can safely be used for perioperative pain management. Preliminary evidence suggests that NSAIDs should be an essential part of multimodal analgesia. Volatile anesthetics have been shown to increase tumor formation, whereas preclinical and emerging clinical data from propofol indicate tumor protective qualities. The perioperative period in the cancer patient represents a unique environment where surgically mediated stress response leads to immune suppression. Regional anesthesia techniques when indicated in combination with multimodal analgesia that include NSAIDs, opioids, and local anesthetics to prevent the pathophysiologic effects of pain and neuroendocrine stress response should be viewed as an essential part of balanced anesthesia.

Natural killer cells as a promising tool to tackle cancer-A review of sources, methodologies, and potentials

Immune cell-based therapies are emerging as a promising tool to tackle malignancies, both solid tumors and selected hematological tumors. Vast experiences in literature have documented their safety and added survival benefits when such cell-based therapies are combined with the existing treatment options. Numerous methodologies of processing and in vitro expansion protocols of immune cells, such as the dendritic cells, natural killer (NK) cells, NKT cells, αβ T cells, so-called activated T lymphocytes, γδ T cells, cytotoxic T lymphocytes, and lymphokine-activated killer cells, have been reported for use in cell-based therapies. Among this handful of immune cells of significance, the NK cells stand apart from the rest for not only their direct cytotoxic ability against cancer cells but also their added advantage, which includes their capability of (i) action through both innate and adaptive immune mechanism, (ii) tackling viruses too, giving benefits in conditions where viral infections culminate in cancer, and (iii) destroying cancer stem cells, thereby preventing resistance to chemotherapy and radiotherapy. This review thoroughly analyses the sources of such NK cells, methods for expansion, and the future potentials of taking the in vitro expanded allogeneic NK cells with good cytotoxic ability as a drug for treating cancer and/or viral infection and even as a prophylactic tool for prevention of cancer after initial remission.

Early versus delayed initiation of adjuvant treatment for pancreatic cancer

Background

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor showing a tendency for early recurrence, even after curative resection. Although adjuvant treatment improves survival, it is unclear whether early adjuvant treatment initiation yields better outcomes in patients with PDAC.

Methods

We retrospectively enrolled 113 patients who underwent chemotherapy or chemoradiotherapy after curative resection of PDAC: Fifty-six and 57 patients were in the early and delayed groups, respectively based on the median time of treatment initiation (35 days [range, 20–83 days]).

Results

Patient baseline characteristics were comparable in both groups, except for grade III or IV postoperative complications (5.4% in the early group vs. 22.8% in the delayed group). With a median 20.3-month follow-up, the overall survival (OS) and disease-free survival (DFS) times were 29.5 and 14.7 months, respectively. The early group had significantly prolonged OS (39.1 vs. 21.1 months, p = 0.018) and DFS (18.8 vs. 10.0 months, p = 0.034), compared to the delayed group. Among 71 patients who completed planned adjuvant treatment, patients in the early group tended to have longer, though not statistically significant, OS and DFS times than those in the delayed group. In 67 patients without postoperative complications, patients in the early group had longer OS (42.8 vs. 20.5 months, p = 0.002) and DFS (19.6 vs. 9.1 months, p = 0.005) than those in the delayed group. By multivariate analysis, incompletion of treatment (hazard ratio [HR]: 4.039, 95% confidence interval [CI]: 2.334–6.992), delayed treatment initiation (HR: 1.822, 95% CI: 1.081–3.070), and positive angiolymphatic invasion (HR: 2.116, 95% CI: 1.160–3.862) were significantly associated with shorter OS.

Conclusions

Adjuvant treatment should be delivered earlier and completed for better outcomes in resected PDAC patients, especially without postoperative complications.

Microparticles and cancer thrombosis in animal models

Cancer-associated venous thromboembolism (VTE) constitutes the second cause of death after cancer. Many risk factors for cancer-associated VTE have been identified, among them soluble tissue factor and microparticles (MPs). Few data are available about the implication of MPs in cancer associated-VTE through animal model of cancer. The objective of the present review was to report the state of the current literature about MPs and cancer-associated VTE in animal model of cancer. Fourteen series have reported the role of MPs in cancer-associated VTE, through three main mouse models: ectopic or orthotopic tumor induction, experimental metastasis by intravenous injection of tumor cells into the lateral tail vein of the mouse. Pancreatic cancer is the most used animal model, due to its high rate of cancer-associated VTE. All the series reported that tumor cell-derived MPs can promote thrombus formation in TF-dependent manner. Some authors reported also the implication of phosphatidylserine and PSGL1 in the generation of thrombin. Moreover, MPs seem to be implicated in cancer progression through a coagulation-dependent mechanism secondary to thrombocytosis, or a mechanism implicating the regulation of the immune response. For these reasons, few authors have reported that antiplatelet and anticoagulant treatments may prevent tumor progression and the formation of metastases in addition of coagulopathy.

Sevoflurane attenuates platelets activation of patients undergoing lung cancer surgery and suppresses platelets-induced invasion of lung cancer cells

STUDY OBJECTIVE

Platelets play a pivotal role in metastasis of tumor cells. The aim of this study is to explore the effects of sevoflurane and isoflurane on platelets activation of patients undergoing lung cancer surgery, and the effects of sevoflurane and isoflurane on platelets-induced invasion of lung cancer cells.

DESIGN

Prospective and randomized study, and in vitro experiment.

SETTING

University-affiliated teaching hospital and laboratory.

PATIENTS

Forty-six patients scheduled for lung cancer radical surgery.

INTERVENTIONS

Patients were randomized to two groups of 23 patients each and were received sevoflurane (group SEV) or isoflurane (group ISO) during surgery, respectively. In vitro, lung cancer cells were treated with platelets in the presence or absence anesthetics.

MEASUREMENTS

Platelets activation were determined by detecting glycoproteinIIb/IIIa (GPIIb/IIIa), CD62P, and platelets aggregation rate (PAR) pre-, intra-, and postoperatively. Invasion ability of lung cancer cells were evaluated by Transwell assay.

RESULTS

The levels of GPIIb/IIIa, CD62P, and PAR were reduced markedly in group SEV during perioperative period compared with group ISO. In vitro, activated platelets contributed profoundly to the invasive ability of lung cancer cells. Sevoflurane, but not isoflurane, inhibited platelets-induced invasion of lung cancer cells. Furthermore, sevoflurane suppressed the platelets activity in vitro.

CONCLUSION

Sevoflurane attenuates platelets activation of patients undergoing lung cancer surgery. In vitro, sevoflurane suppresses platelets-induced invasion of lung cancer cells via decreasing platelets activity.

Adoptive transfer of natural killer cells promotes the anti-tumor efficacy of T cells

The density of NK cells in tumors correlates positively with prognosis in many types of cancers. The average number of infiltrating NK cells is, however, quite modest (approximately 30 NK cells/sq.mm), even in tumors deemed to have a "high" density of infiltrating NK cells. It is unclear how such low numbers of tumor-infiltrating NK cells can influence outcome. Here, we used ovalbumin-expressing tumor cell lines and TCR transgenic, OVA-specific cytotoxic T lymphocytes (OT-I-CTLs) to determine whether the simultaneous attack by anti-tumor CTLs and IL-2-activated NK (A-NK) cells synergistically increases the overall tumor cell kill and whether upregulation of tumor MHC class-I by NK cell-derived interferon-gamma (IFNγ) improves tumor-recognition and kill by anti-tumor CTLs. At equal E:T ratios, A-NK cells killed OVA-expressing tumor cells better than OT-I-CTLs. The cytotoxicity against OVA-expressing tumor cells increased by combining OT-I-CTLs and A-NK cells, but the increase was additive rather than synergistic. A-NK cells adenovirally-transduced to produce IL-12 (A-NK^IL-12) produced high amounts of IFNγ. The addition of a low number of A-NK^IL-12 cells to OT-I-CTLs resulted in a synergistic, albeit modest, increase in overall cytotoxicity. Pre-treatment of tumor cells with NK cell-conditioned medium increased tumor MHC expression and sensitivity to CTL-mediated killing. Pre-treatment of CTLs with NK cell-conditioned medium had no effect on CTL cytotoxicity. In vivo, MHC class-I expression by OVA-expressing B16 melanoma lung metastases increased significantly within 24-48h after adoptive transfer of A-NK^IL-12 cells. OT-I-CTLs and A-NK^IL-12 cells localized selectively and equally well into OVA-expressing B16 lung metastases and treatment of mice bearing 7-days-old OVA-B16 lung metastases with both A-NK^IL-12 cells and OT-I-CTLs lead to a significant prolongation of survival. Thus, an important function of tumor-infiltrating NK cells may be to increase tumor cell expression of MHC class-I through secretion of IFNγ, to prepare them for recognition by tumor-specific CTLs.

Surgical Stress Abrogates Pre-Existing Protective T Cell Mediated Anti-Tumor Immunity Leading to Postoperative Cancer Recurrence

Anti-tumor CD8+ T cells are a key determinant for overall survival in patients following surgical resection for solid malignancies. Using a mouse model of cancer vaccination (adenovirus expressing melanoma tumor-associated antigen (TAA)-dopachrome tautomerase (AdDCT) and resection resulting in major surgical stress (abdominal nephrectomy), we demonstrate that surgical stress results in a reduction in the number of CD8+ T cell that produce cytokines (IFNγ, TNFα, Granzyme B) in response to TAA. This effect is secondary to both reduced proliferation and impaired T cell function following antigen binding. In a prophylactic model, surgical stress completely abrogates tumor protection conferred by vaccination in the immediate postoperative period. In a clinically relevant surgical resection model, vaccinated mice undergoing a positive margin resection with surgical stress had decreased survival compared to mice with positive margin resection alone. Preoperative immunotherapy with IFNα significantly extends survival in surgically stressed mice. Importantly, myeloid derived suppressor cell (MDSC) population numbers and functional impairment of TAA-specific CD8+ T cell were altered in surgically stressed mice. Our observations suggest that cancer progression may result from surgery-induced suppression of tumor-specific CD8+ T cells. Preoperative immunotherapies aimed at targeting the prometastatic effects of cancer surgery will reduce recurrence and improve survival in cancer surgery patients.

Fundamental Principles of Cancer Biology: Does it have relevance to the perioperative period?

Malignant tumors are characterized by their ability to metastasize, which is the main cause of cancer-related mortality. Besides intrinsic alternations in cancer cells, the tumor microenvironment plays a pivotal role in tumor growth and metastasis. Ample evidence suggests that the perioperative period and the excision of the primary tumor can promote the development of metastases and can influence long-term cancer patient outcomes. The role of cancer biology and its impact on the perioperative period are of increasing interest. This review will present evidence regarding fundamental principles of cancer biology, especially tumor microenvironment, and discuss new therapeutic opportunities in the perioperative timeframe. We will also discuss the regulatory signaling that could be relevant to various aspects of surgery and surgical responses, which could facilitate the metastatic process by directly or indirectly affecting malignant tissues and the tumor microenvironment. We address the influences of surgery-related stress, anesthetic and analgesic agents, blood transfusion, hypothermia, and β-adrenergic blockade administration on tumor growth and metastasis. Through an improved understanding of these processes, we will provide suggestions for potential new perioperative approaches aimed at improving treatment outcomes of cancer patients.

The Impact of Perioperative Red Blood Cell Transfusions on Long-Term Outcomes after Hepatectomy for Colorectal Liver Metastases

BACKGROUND

Red blood cell transfusions (RBCTs) are associated with cancer recurrence following resection of colorectal cancer. Their impact after colorectal liver metastases (CRLM) resection remains debated. We sought to explore the association between perioperative RBCT and oncologic outcomes following resection of CRLM.

METHODS

We reviewed patients undergoing partial hepatectomy for CRLM from 2003 to 2012 at a single institution. Date of death was abstracted from a validated population-based cancer registry. Primary outcome was overall survival (OS). Secondary outcome was recurrence-free survival (RFS). Survivals were estimated using Kaplan-Meier methods and compared with log-rank test based on transfusion status. Cox regression analysis examined the association of RBCT with OS and RFS, while adjusting for age, preoperative chemotherapy, Clinical Risk Score, and period of treatment (2003-2007 vs. 2008-2012).

RESULTS

Among 483 patients, 27.5 % received RBCT. Ninety-day postoperative mortality was 4.8 %. At median follow-up of 33 (interquartile range 20.1-54.8) months, 5-year OS was inferior in transfused patients (45.9 vs. 61.0 %; p < 0.0001). Five-year RFS was decreased with RBCT (15.5 vs. 31.6 %; p < 0.0001). The difference persisted when considering only 90-day survivors for 5-year OS (53.1 vs. 61.9 %, p = 0.023) and RFS (15.6 vs. 31.6 %; p < 0.0001). After adjustment for prognostic factors, RBCT was independently associated with decreased OS (hazard ratio 2.24; 95 % confidence interval 1.60-3.15) and RFS (hazard ratio 1.71; 95 % confidence interval 1.28-2.28).

CONCLUSIONS

Perioperative RBCT is independently associated with decreased OS and RFS following hepatectomy for CRLM. Interventions to minimize and rationalize the use of RBCT for hepatectomy are warranted to mitigate this detrimental effect on long-term outcomes.

Attacking Postoperative Metastases using Perioperative Oncolytic Viruses and Viral Vaccines

Surgical resection of solid primary malignancies is a mainstay of therapy for cancer patients. Despite being the most effective treatment for these tumors, cancer surgery has been associated with impaired metastatic clearance due to immunosuppression. In preclinical surgery models and human cancer patients, we and others have demonstrated a profound suppression of both natural killer (NK) and T cell function in the postoperative period and this plays a major role in the enhanced development of metastases following surgery. Oncolytic viruses (OV) were originally designed to selectively infect and replicate in tumors, with the primary objective of directly lysing cancer cells. It is becoming increasingly clear, however, that OV infection results in a profound inflammatory reaction within the tumor, initiating innate and adaptive immune responses against it that is critical for its therapeutic benefit. This anti-tumor immunity appears to be mediated predominantly by NK and cytotoxic T cells. In preclinical models, we found that preoperative OV prevents postoperative NK cell dysfunction and attenuates tumor dissemination. Due to theoretical safety concerns of administering live virus prior to surgery in cancer patients, we characterized safe, attenuated versions of OV, and viral vaccines that could stimulate NK cells and reduce metastases when administered in the perioperative period. In cancer patients, we observed that in vivo infusion with oncolytic vaccinia virus and ex vivo stimulation with viral vaccines promote NK cell activation. These preclinical studies provide a novel and clinically relevant setting for OV therapy. Our challenge is to identify safe and promising OV therapies that will activate NK and T cells in the perioperative period preventing the establishment of micrometastatic disease in cancer patients.

Cumulative prognostic scores based on plasma fibrinogen and serum albumin levels in esophageal cancer patients treated with transthoracic esophagectomy: comparison with the Glasgow prognostic score

PURPOSE

The purpose of this study was to establish a prognostic indicator based on preoperative plasma fibrinogen and serum albumin levels (FA score) in esophageal cancer patients and to compare the correlation with survival to that of the Glasgow prognostic score.

METHODS

Patient characteristics, clinicopathological factors, and preoperative biochemical markers (fibrinogen, albumin, and C-reactive protein) were investigated in esophageal cancer patients who underwent transthoracic esophagectomy. Pretreatment fibrinogen and albumin levels were reviewed in patients who received neoadjuvant treatment. Patients with elevated fibrinogen and decreased albumin levels were allocated a score of 2, those with only one of these abnormalities were allocated a score of 1, and those with neither of these abnormalities were allocated a score of 0. The fibrinogen cut-off value was defined as 350 mg/dL according to our previous report, and the albumin cut-off value was defined as the lower quartile.

RESULTS

Among 199 consecutive patients, the interquartile range of preoperative albumin was 3.8-4.3 g/dL and the cut-off value was 3.8 g/dL. Thus, 108 (54 %), 68 (34 %), and 23 (12 %) patients had an FA score of 0, 1, and 2. The patients with a high preoperative FA score showed considerably shorter disease-free survival (DFS) and overall survival (OS). Multivariate analysis showed that pretreatment stage and preoperative FA score were independently associated with postoperative DFS and OS.

CONCLUSIONS

Preoperative FA score was significantly associated with postoperative survival in esophageal cancer patients, and the prognostic value is currently being validated in a prospective multicenter cohort study.

Maraba MG1 virus enhances natural killer cell function via conventional dendritic cells to reduce postoperative metastatic disease

This study characterizes the ability of novel oncolytic rhabdoviruses (Maraba MG1) to boost natural killer (NK) cell activity. Our results demonstrate that MG1 activates NK cells via direct infection and maturation of conventional dendritic cells. Using NK depletion and conventional dendritic cells ablation studies in vivo, we established that both are required for MG1 efficacy. We further explored the efficacy of attenuated MG1 (nonreplicating MG1-UV(2min) and single-cycle replicating MG1-Gless) and demonstrated that these viruses activate conventional dendritic cells, although to a lesser extent than live MG1. This translates to equivalent abilities to remove tumor metastases only at the highest viral doses of attenuated MG1. In tandem, we characterized the antitumor ability of NK cells following preoperative administration of live and attenuated MG1. Our results demonstrates that a similar level of NK activation and reduction in postoperative tumor metastases was achieved with equivalent high viral doses concluding that viral replication is important, but not necessary for NK activation. Biochemical characterization of a panel of UV-inactivated MG1 (2-120 minutes) revealed that intact viral particle and target cell recognition are essential for NK cell-mediated antitumor responses. These findings provide mechanistic insight and preclinical rationale for safe perioperative virotherapy to effectively reduce metastatic disease following cancer surgery.

A mouse tumor model of surgical stress to explore the mechanisms of postoperative immunosuppression and evaluate novel perioperative immunotherapies

Surgical resection is an essential treatment for most cancer patients, but surgery induces dysfunction in the immune system and this has been linked to the development of metastatic disease in animal models and in cancer patients. Preclinical work from our group and others has demonstrated a profound suppression of innate immune function, specifically NK cells in the postoperative period and this plays a major role in the enhanced development of metastases following surgery. Relatively few animal studies and clinical trials have focused on characterizing and reversing the detrimental effects of cancer surgery. Using a rigorous animal model of spontaneously metastasizing tumors and surgical stress, the enhancement of cancer surgery on the development of lung metastases was demonstrated. In this model, 4T1 breast cancer cells are implanted in the mouse mammary fat pad. At day 14 post tumor implantation, a complete resection of the primary mammary tumor is performed in all animals. A subset of animals receives additional surgical stress in the form of an abdominal nephrectomy. At day 28, lung tumor nodules are quantified. When immunotherapy was given immediately preoperatively, a profound activation of immune cells which prevented the development of metastases following surgery was detected. While the 4T1 breast tumor surgery model allows for the simulation of the effects of abdominal surgical stress on tumor metastases, its applicability to other tumor types needs to be tested. The current challenge is to identify safe and promising immunotherapies in preclinical mouse models and to translate them into viable perioperative therapies to be given to cancer surgery patients to prevent the recurrence of metastatic disease.

Optimal duration and timing of adjuvant chemotherapy after definitive surgery for ductal adenocarcinoma of the pancreas: ongoing lessons from the ESPAC-3 study

PURPOSE

Adjuvant chemotherapy improves patient survival rates after resection for pancreatic adenocarcinoma, but the optimal duration and time to initiate chemotherapy is unknown.

PATIENTS AND METHODS

Patients with pancreatic ductal adenocarcinoma treated within the international, phase III, European Study Group for Pancreatic Cancer-3 (version 2) study were included if they had been randomly assigned to chemotherapy. Overall survival analysis was performed on an intention-to-treat basis, retaining patients in their randomized groups, and adjusting the overall treatment effect by known prognostic variables as well as the start time of chemotherapy.

RESULTS

There were 985 patients, of whom 486 (49%) received gemcitabine and 499 (51%) received fluorouracil; 675 patients (68%) completed all six cycles of chemotherapy (full course) and 293 patients (30%) completed one to five cycles. Lymph node involvement, resection margins status, tumor differentiation, and completion of therapy were all shown by multivariable Cox regression to be independent survival factors. Overall survival favored patients who completed the full six courses of treatment versus those who did not (hazard ratio [HR], 0.516; 95% CI, 0.443 to 0.601; P < .001). Time to starting chemotherapy did not influence overall survival rates for the full study population (HR, 0.985; 95% CI, 0.956 to 1.015). Chemotherapy start time was an important survival factor only for the subgroup of patients who did not complete therapy, in favor of later treatment (P < .001).

CONCLUSION

Completion of all six cycles of planned adjuvant chemotherapy rather than early initiation was an independent prognostic factor after resection for pancreatic adenocarcinoma. There seems to be no difference in outcome if chemotherapy is delayed up to 12 weeks, thus allowing adequate time for postoperative recovery.

Perioperative influenza vaccination reduces postoperative metastatic disease by reversing surgery-induced dysfunction in natural killer cells

PURPOSE

Surgical removal of solid primary tumors is an essential component of cancer treatment. Surgery-induced dysfunction in natural killer (NK) cells has been linked to the development of metastases in animal models and patients with cancer. We investigated the activation of NK cells using influenza vaccine in the perioperative period to eradicate micrometastatic disease.

EXPERIMENTAL DESIGN

Both the B16lacZ and 4T1 tumor models in immunocompetent mice were used to assess the in vivo efficacy of perioperative influenza vaccine administration. In healthy human donors and cancer surgery patients, we assessed NK cell function pre- and post-influenza vaccination using both in vivo and ex vivo assays.

RESULTS

Using the TLR3 agonist poly(I:C), we showed as proof-of-principle that perioperative administration of a nonspecific innate immune stimulant can inhibit surgery-induced dysfunction in NK cells and attenuate metastases. Next, we assessed a panel of prophylactic vaccines for NK cell activation and determined that inactivated influenza vaccine was the best candidate for perioperative administration. Perioperative influenza vaccine significantly reduced tumor metastases and improved NK cytotoxicity in preclinical tumor models. Significantly, IFNα is the main cytokine mediator for the therapeutic effect of influenza vaccination. In human studies, influenza vaccine significantly enhanced NK cell activity in healthy human donors and cancer surgery patients.

CONCLUSION

These results provide the preclinical rationale to pursue future clinical trials of perioperative NK cell activation, using vaccination in cancer surgery patients. Research into perioperative immune therapy is warranted to prevent immune dysfunction following surgery and eradicate metastatic disease.