Effect of Pre-Operative Short Course Famotidine on Tumor Infiltrating Lymphocytes in Colorectal Cancer: A Double Blind, Placebo Controlled, Prospective Randomized Study

H2 antihistamines: May be useful for combination therapies in cancer?

Cancer morbimortality is still a great concern despite advances in research and therapies. Histamine and its receptors' ligands can modulate different biological responses according to the cell type and the receptor subtype involved. Besides the wide variety of histamine functions in normal tissues, diverse roles in the acquisition of hallmarks of cancer such as sustained proliferative signaling, resistance to cell death, angiogenesis, metastasis, altered immunity and modified microenvironment have been described. This review summarizes the present knowledge of the various roles of histamine H2 receptor (H2R) ligands in neoplasias. A bioinformatic analysis of human tumors showed dissimilar results in the expression of the H2R gene according to tumor type when comparing malignant versus normal tissues. As well, the relationship between patients' survival parameters and H2R gene expression levels also varied, signaling important divergences in the role of H2R in neoplastic progression in different cancer types. Revised experimental evidence showed multiple effects of H2R antihistamines on several of the cited hallmarks of cancer. Interventional and retrospective clinical studies evaluated different H2R antihistamines in cancer patients with two main adjuvant uses: improving antitumor efficacy (which includes regulation of immune response) and preventing toxic adverse effects produced by chemo or radiotherapy. While there is a long path to go, research on H2R antihistamines may provide new opportunities for developing more refined combination therapeutic strategies for certain cancer types to improve patients' survival and health-related quality of life.

A novel pharmacological mechanism of anti-cancer drugs that induce pyroptosis

Pyroptosis is an inflammasome-induced lytic form of programmed cell death, and its main effect involves the release of inflammatory mediators when a cell dies, resulting in an inflammatory response in the body. The key to pyroptosis is the cleavage of GSDMD or other gasdermin families. Some drugs can cause cleavage GSDMD or other gasdermin members cause pyroptosis and suppress cancer growth and development. This review explores several drugs that may induce pyroptosis, thereby contributing to tumor treatment. Pyroptosis-inducing drugs, such as arsenic, platinum, and doxorubicin, were used originally in cancer treatment. Other pyroptosis-inducing drugs, such as metformin, dihydroartemisinin, and famotidine, were used to control blood glucose, treat malaria, and regulate blood lipid levels and are effective tumor treatments. By summarizing drug mechanisms, we provide a valuable basis for treating cancers by inducing pyroptosis. In future, the use of these drugs may contribute to new clinical treatments.

Association between use of antacid medications (proton pump inhibitors and histamine-2 receptor antagonists) and the incidence of lung cancer: A population-based cohort analysis

This study investigated the association between antacid administration and lung cancer incidence in a real-world setting. This was a nationwide, retrospective cohort study. The cohort comprised random samples (n = 1,031,392) from the entire South Korean population in 2002. The duration of antacid administration between January 2006 and December 2010 was recorded for each participant. Newly developed lung cancers were counted during the 5-year observation period (January 1, 2006 to December 31, 2010). A total of 437,370 participants aged ≥ 40 years were included, of whom 301,201 (68.9%) had antacid exposure before the diagnosis of lung cancer. A total of 1230 (0.28%) antacid-exposed patients developed lung cancer. Among patients with no antacid exposure or underexposure (n = 136,171), 597 (0.44%) developed lung cancer. In the multivariable analysis, antacid exposure before the diagnosis of lung cancer was independently associated with a reduced incidence of lung cancer (hazard ratio: 0.64; 95% confidence interval: 0.55-0.74; P < .001). Antacid use might be independently associated with a decreased risk of lung cancer development in this cohort study.

Expression pattern and prognostic potential of histamine receptors in epithelial ovarian cancer

PURPOSE

Despite recent advances in the treatment of ovarian cancer (OC), long-term remissions remain scarce. For a targeted approach, prognostic markers are indispensable for predicting survival and treatment response. Given their association with multiple hallmarks of cancer, histamine receptors (HR) are emerging as promising candidates. Here, we investigate their expression pattern and prognostic value in OC.

METHODS

Specimens of 156 epithelial OC patients were collected during cytoreductive surgery at the Department of Obstetrics and Gynecology, LMU, between 1990 and 2002 and combined in a tissue microarray. Immunohistochemical staining of the HR H1, H2, H3 and H4 was quantified by an immunoreactive score and linked with clinico-pathological data by Spearman's correlation. Via ROC curve analysis, optimal cut-off values for potential prognostic markers were defined. Overall survival (OS) was visualized in Kaplan-Maier curves and significances determined by log-rank testing. A Cox regression model was applied for multivariate analysis.

RESULTS

HR H3 and H4 expression was restricted to the cytosol of OC cells, while H1 was also present in the nucleus. A significant association between HR H1, H3 and H4 expression with several clinico-pathological parameters was revealed. In addition, HR H1 and H3 expression correlated positively, HR H4 expression negatively with OS. In addition, HR H3 was identified as independent prognostic marker for OS. HR H2 expression had no prognostic value.

CONCLUSIONS

HR H1, H3 and H4 could serve as potential predictors for OS of OC patients. Further research is warranted to elucidate their pathophysiologic role and their predictive and therapeutic potential in OC.

Pathophysiological Roles of Histamine Receptors in Cancer Progression: Implications and Perspectives as Potential Molecular Targets

High levels of histamine and histamine receptors (HRs), including H1R~H4R, are found in many different types of tumor cells and cells in the tumor microenvironment, suggesting their involvement in tumor progression. This review summarizes the latest evidence demonstrating the pathophysiological roles of histamine and its cognate receptors in cancer biology. We also discuss the novel therapeutic approaches of selective HR ligands and their potential prognostic values in cancer treatment. Briefly, histamine is highly implicated in cancer development, growth, and metastasis through interactions with distinct HRs. It also regulates the infiltration of immune cells into the tumor sites, exerting an immunomodulatory function. Moreover, the effects of various HR ligands, including H1R antagonists, H2R antagonists, and H4R agonists, on tumor progression in many different cancer types are described. Interestingly, the expression levels of HR subtypes may serve as prognostic biomarkers in several cancers. Taken together, HRs are promising targets for cancer treatment, and HR ligands may offer novel therapeutic potential, alone or in combination with conventional therapy. However, due to the complexity of the pathophysiological roles of histamine and HRs in cancer biology, further studies are warranted before HR ligands can be introduced into clinical settings.

Histamine receptors and cancer pharmacology: an update

In the present review, we will discuss the recent advances in the understanding of the role of histamine and histamine receptors in cancer biology. The controversial role of the histaminergic system in different neoplasias including gastric, colorectal, oesophageal, oral, pancreatic, liver, lung, skin, blood and breast cancers will be reviewed. The expression of histamine receptor subtypes, with special emphasis on the histamine H4 receptor, in different cell lines and human tumours, the signal transduction pathways and the associated biological responses as well as the in vivo treatment of experimental tumours with pharmacological ligands will be described. The presented evidence demonstrates that histamine regulates cancer-associated biological processes during cancer development in multiple cell types, including neoplastic cells and cells in the tumour micro-environment. The outcome will depend on tumour cell type, the level of expression of histamine receptors, signal transduction associated with these receptors, tumour micro-environment and histamine metabolism, reinforcing the complexity of cancer disease. Findings show the pivotal role of H4 receptors in the development and progression of many types of cancers, and considering its immunomodulatory properties, the H4 receptor appears to be the most promising molecular therapeutic target for cancer treatment within the histamine receptor family. Furthermore, the H4 receptor is differentially expressed in tumours compared with normal tissues, and in most cancer types in which data are available, H4 receptor expression is associated with clinicopathological characteristics, suggesting that H4 receptors might represent a novel cancer biomarker. LINKED ARTICLES: This article is part of a themed section on New Uses for 21st Century. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.3/issuetoc.

The Effect of Perioperative Cimetidine Administration on Time to Colorectal Cancer Recurrence

BACKGROUND

Studies have reported that the perioperative use of cimetidine, a histamine type 2 receptor antagonist, in addition to chemotherapy in patients with lymph node-positive colorectal cancer (CRC) improves the survival.

STUDY QUESTION

To determine if time to CRC recurrence could be prolonged with cimetidine.

STUDY DESIGN

Cimetidine was prescribed to American Joint on Cancer Committee (AJCC) stage III CRC patients perioperatively. Tumor recurrence was defined as the time (in days) between tumor resection and CRC recurrence. Medical charts of patients diagnosed with CRC between 1996 and 2006 were reviewed. Inclusion criteria were patients with (a) AJCC stage III CRC, (b) who had undergone surgical resection of the tumor, and (c) who received chemotherapy (5-fluorouracil).

MEASURES AND OUTCOMES

AJCC stage III CRC patients who did and did not receive cimetidine as part of the treatment regimen were compared with respect to their clinical outcomes using univariate analysis and Kaplan-Meier modeling.

RESULTS

Between 1996 and 2006, 38 patients met our inclusion criteria. Twenty-six percent (10/38) received perioperative cimetidine (mean daily dose, 750 mg; mean duration, 369 days; mean total cumulative cimetidine dose, 274,070 mg/d) in addition to chemotherapy. Time to recurrence and cancer deaths were prolonged in the chemotherapy plus cimetidine group compared with the group that received chemotherapy alone (mean ± SD: 1078 ± 290 vs. 446 ± 62; P = 0.03). In addition, we found a significant positive relationship between the duration of cimetidine therapy (days) and survival duration (correlation coefficient = 0.94, P = 0.02) and time until cancer recurrence (correlation coefficient = 0.99, P = 0.04). Moreover, there was a significant positive relationship between the total cumulative cimetidine dose and survival duration (correlation coefficient = 0.92, P = 0.03).

CONCLUSIONS

Prolonged duration of cimetidine may be superior to shorter courses in prolonging recurrence of CRC and thus survival.

Whole Blood Gene Expression Profiling in patients undergoing colon cancer surgery identifies differential expression of genes involved in immune surveillance, inflammation and carcinogenesis

INTRODUCTION

Cancer surgery may represent a potential risk of enhanced growth and metastatic ability of residual cancer cells due to post-operative immune dysfunction. This study identifies changes in transcription of genes involved in immune surveillance, immune suppression and carcinogenesis in the post-operative period of laparoscopic colon-cancer surgery within an ERAS regime.

METHODS

Patients undergoing elective, curatively intended laparoscopic surgery for colon cancer stage I-III UICC were included in the study. Patients followed standard of care in an ERAS setting. Whole blood gene expression profiling (WBGP) was performed on the day prior to surgery and 1, 2, 3 and 10-14 days after surgery. Samples were collected in Paxgene tubes and Labeled cDNA was fragmented and hybridized to Affymetrix GeneChip™ 2.0. Results were corrected for multiple hypothesis testing using the false discovery rate. Pathway analysis was performed through the Molecular Signature Database. Paired fold changes of gene expression were calculated for post-operative compared to pre-operative samples. A mixed effect model was used to test differential gene expression by repeated-measures ANOVA.

RESULTS

WBGP of 33,804 genes at five timepoints in six patients showed 302 significantly differentially expressed genes between samples from the day prior to surgery and the day after surgery. Pathway gene enrichment analysis showed a downregulation of immunologically relevant pathways. There was a significant downregulation of genes involved in T-cell receptor signaling, antigen presentation and NK-cell activity after surgery. Furthermore, there was an upregulation of cytokines related to metastatic ability, growth and angiogenesis.

CONCLUSION

Whole blood gene expression profiling revealed dysregulation of genes involved in immune surveillance, inflammation and carcinogenesis, after laparoscopic colon cancer surgery.

Reduction in radiation-induced lymphocytopenia by famotidine in patients undergoing radiotherapy for prostate cancer

BACKGROUND

Ionizing radiation causes a series of hematological alterations especially profound lymphocytopenia during and after the radiotherapy course. To investigate whether famotidine can reduce hematologic toxicity in patients treated with radiotherapy for prostate cancer.

METHODS

A total of 36 patients undergoing radiotherapy for prostate cancer were randomized to receive either placebo or famotidine tablets. Participants were pretreated with 40 mg of oral famotidine or placebo tablets twice daily, 4 and 3 hr before each radiotherapy fraction. The patients received external-beam radiotherapy up to 70 Gy. Complete blood counts with differential, platelet counts, and hemoglobin levels were obtained at baseline, biweekly during the treatment and once 4 weeks after the end of radiotherapy course. Magnitude of changes from baseline in the hematological parameters was determined and compared using Repeated Measures ANOVA.

RESULTS

Famotidine was well tolerated. A total of 112 blood samples were evaluated. A significant reduction in radiation-induced lymphocytopenia was noted in patients receiving famotidine than in patients receiving placebo (P = 0.006). No significant difference was observed between two groups for the decline in platelets, erythrocytes and leucocytes. For both groups, neutrophil, monocyte, eosinophil, and hemoglobin levels did not change significantly during the treatment.

CONCLUSIONS

Our results indicate that famotidine could result in a significant reduction in radiation-induced lymphocytopenia and may consequently increase radiotherapy efficacy as well as survival times. This radioprotective effect may be chiefly associated with its antioxidant and radical scavenging properties. Further studies are required to confirm these encouraging results.

Histamine type 2 receptor antagonists as adjuvant treatment for resected colorectal cancer

BACKGROUND

Anecdotal reports of tumour regression with histamine type 2 receptor antagonists (H(2)RAs) have lead to a series of trials with this class of drug as adjuvant therapy to try and improve outcomes in patients with resected colorectal cancers. There was a plausible scientific rationale suggesting merit in this strategy. This included improved immune surveillance (by way of increasing tumour infiltrating lymphocytes), inhibiting the direct proliferative effect of histamine as a growth factor for colorectal cancer and, in the case of cimetidine, inhibiting endothelial expression of E-selectin (a cell adhesion molecule thought to be critical for metastatic spread).

OBJECTIVES

To determine if H(2)RAs improve overall survival when used as pre- and/or postoperative therapy in colorectal cancer patients who have had surgical resection with curative intent. We also stratified the results to see if there was an improvement in overall survival in terms of the specific H(2)RA used.

SEARCH METHODS

Randomised controlled trials were identified using a sensitive search strategy in the following databases: MEDLINE (1964 to present), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2009), EMBASE (1980 to present) and Cancerlit (1983 to present).

SELECTION CRITERIA

Criteria for study selection included: patients with colorectal cancer surgically resected with curative intent; H(2)RAs used i) at any dose, ii) for any length of time, iii) with any other treatment modality and iv) in the pre-, peri- or post-operative period. The results were stratified for the H(2)RA used.

DATA COLLECTION AND ANALYSIS

The literature search retrieved 142 articles. There were six studies included in the final analysis, published from 1995 to 2007, including a total of 1229 patients. All patients were analysed by intention to treat according to their initial allocation. Log hazard ratios and standard errors of treatment effects (on overall survival) were calculated using the Cochrane statistical package RevMan Version 5. Hazard ratios and standard errors were recorded from trial publications or, if not provided, were estimated from published actuarial survival curves using a spreadsheet designed for this purpose (http://www.biomedcentral.com/content/supplementary/1745-6215-8-16-S1.xls).

MAIN RESULTS

Of the six identified trials, five used cimetidine as the experimental H(2)RA, whereas one used ranitidine. There was a trend towards improved survival when H(2)RAs were utilised as adjuvant therapy in patients having curative-intent surgery for colorectal cancer (HR 0.70; 95% CI 0.48-1.03, P = 0.07). Analysis of the five cimetidine trials (n = 421) revealed a statistically significant improvement in overall survival (HR 0.53; 95% CI 0.32 to 0.87).

AUTHORS' CONCLUSIONS

Of the H(2)RAs evaluated cimetidine appears to confer a survival benefit when given as an adjunct to curative surgical resection of colorectal cancers. The trial designs were heterogeneous and adjuvant therapy has evolved since these trials were performed. Further prospective randomised studies are warranted.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Histamine receptors and cancer pharmacology

Considerable evidence has been collected indicating that histamine can modulate proliferation of different normal and malignant cells. High histamine biosynthesis and content together with histamine receptors have been reported in different human neoplasias including melanoma, colon and breast cancer, as well as in experimental tumours in which histamine has been postulated to behave as an important paracrine and autocrine regulator of proliferation. The discovery of the human histamine H(4) receptor in different tissues has contributed to our understanding of histamine role in numerous physiological and pathological conditions revealing novel functions for histamine and opening new perspectives in histamine pharmacology research. In the present review we aimed to briefly summarize current knowledge on histamine and histamine receptor involvement in cancer before focusing on some recent evidence supporting the novel role of histamine H(4) receptor in cancer progression representing a promising molecular target and avenue for cancer drug development.

Cytokine responses of intraepithelial lymphocytes are regulated by histamine H(2) receptor

BACKGROUND

Histamine participates in the immune regulation of several gastrointestinal diseases. However, the effect of histamine on intestinal intraepithelial lymphocytes (IELs), the front line of the intestinal mucosal immune system, is not well understood. We examined whether histamine has a direct effect on cytokine production by IELs and the involvement of histamine receptor subtypes.

METHODS

Murine IELs were activated by PMA plus ionomycin with/without histamine. Secreted cytokines were measured and compared with those of splenocytes. Intracellular cytokines were detected by flow cytometry. Expression of histamine receptor subtypes in IELs was examined by RT-PCR.

RESULTS

Histamine H(1) receptor (H(1)R), H(2)R, and H(4)R, but not H(3)R mRNA were expressed on IELs. Histamine significantly decreased Th1-cytokine (IFN-gamma, TNF-alpha, and IL-2) and also IL-4 production in IELs as well as splenocytes. The selective H(2)R antagonist famotidine, but not the H(1)R antagonist pyrilamine nor the H(3)R/H(4)R antagonist thioperamide, competes with the inhibitory effect of histamine on these cytokine production in IELs. These suppressive effects of histamine were mimicked by a selective H(2)R/H(4)R agonist dimaprit. Further, these suppressive effects of histamine for Th1-cytokine and IL-4 did not accompany the enhancement of IL-10 production or IL-10 mRNA level in IELs. Intracellular cytokine analysis revealed that the number of IFN-gamma-producing alphabeta T cells was significantly reduced by histamine in IELs.

CONCLUSIONS

Histamine has a direct suppressive effect on IEL-derived cytokines via H(2)R, which would have a crucial role in the suppression of local immunoregulation in the intestinal epithelium.

The perioperative period is an underutilized window of therapeutic opportunity in patients with colorectal cancer

OBJECTIVE

In this review, we address the underlying mechanisms by which surgery augments metastases outgrowth and how these insights can be used to develop perioperative therapeutic strategies for prevention of tumor recurrence.

SUMMARY BACKGROUND DATA

Surgical removal of the primary tumor provides the best chance of long-term disease-free survival for patients with colorectal cancer (CRC). Unfortunately, a significant part of CRC patients will develop metastases, even after successful resection of the primary tumor. Paradoxically, it is now becoming clear that surgery itself contributes to development of both local recurrences and distant metastases.

METHODS

Data for this review were identified by searches of PubMed and references from relevant articles using the search terms "surgery," "CRC," and "metastases."

RESULTS

Surgical trauma and concomitant wound-healing processes induce local and systemic changes, including impairment of tissue integrity and production of inflammatory mediators and angiogenic factors. This can lead to immune suppression and enhanced growth or adhesion of tumor cells, all of which increase the chance of exfoliated tumor cells developing into secondary malignancies.

CONCLUSIONS

Because surgery remains the appropriate and necessary means of treatment for most CRC patients, new adjuvant therapeutic strategies that prevent tumor recurrence after surgery need to be explored since the perioperative therapeutic window of opportunity offers promising means of improving patient outcome but is unfortunately underutilized.

Adjuvant therapy for completely resected stage II colon cancer

BACKGROUND

Colon cancer is potentially curable by surgery. Although adjuvant chemotherapy benefits patients with stage III disease, there is uncertainty of such benefit in stage II colon cancer. A systematic review of the literature was performed to better define the potential benefits of adjuvant therapy for patients with stage II colon cancer.

OBJECTIVES

To determine the effects of adjuvant therapy on overall survival and disease-free survival in patients with stage II colon cancer.

SEARCH STRATEGY

Ovid MEDLINE (1986-2007), EMBASE (1980-2007), and EBM Reviews - Cochrane Central Register of Controlled Trials ( to 2007) were searched using the medical headings "colonic neoplasms", "colorectal neoplasms", "adjuvant chemotherapy", "adjuvant radiotherapy" and "immunotherapy", and the text words "colon cancer" and "colonic neoplasms". In addition, proceedings from the annual meetings of the American Society of Clinical Oncology and the European Society of Medical Oncology (1996 to 2004) as well as personal files were searched for additional information.

SELECTION CRITERIA

Randomized trials or meta-analyses containing data on stage II colon cancer patients undergoing adjuvant therapy versus surgery alone.

DATA COLLECTION AND ANALYSIS

:Three reviewers summarized the results of selected studies. The main outcomes of interest were overall and disease-free survival, however, data on toxicity and treatment delivery were also recorded.

MAIN RESULTS

With regards to the effect of adjuvant therapy on stage II colon cancer, the pooled relative risk ratio for overall survival was 0.96 (95% confidence interval 0.88, 1.05). With regards to disease-free survival, the pooled relative risk ratio was 0.83 (95% confidence interval 0.75, 0.92).

AUTHORS' CONCLUSIONS

Although there was no improvement in overall survival in the pooled analysis, we did find that disease-free survival in patients with stage II colon cancer was significantly better with the use of adjuvant therapy. It seems reasonable to discuss the benefits of adjuvant systemic chemotherapy with those stage II patients who have high risk features, including obstruction, perforation, inadequate lymph node sampling or T4 disease. The co-morbidities and likelihood of tolerating adjuvant systemic chemotherapy should be considered as well. There exists a need to further define which high-risk features in stage II colon cancer patients should be used to select patients for adjuvant therapy. Also, researchers must continue to search for other therapies which might be more effective, shorter in duration and less toxic than those available today.

Saccharomyces cerevisiae, the Baker's Yeast, suppresses the growth of Ehrlich carcinoma-bearing mice

This study was undertaken to evaluate the effectiveness and mechanisms of anti-tumor activity of Baker's yeast, Saccharomyces cerevisiae, in immunocompetent mice. Swiss albino mice were inoculated intramuscularly in the right thigh with Ehrlich Ascites Carcinoma (EAC) cells. At day 8, mice bearing Solid Ehrlich Carcinoma tumor (SEC) were intratumorally (IT) injected with killed S. cerevisiae (10 x 10(6) and 20 x 10(6) cells) for 35 days. Histopathology of yeast-treated mice showed extensive tumor degeneration, apoptosis, and ischemic (coagulative) and liquefactive necrosis. These changes are associated with a tumor growth curve that demonstrates a significant antitumor response that peaked at 35 days. Yeast treatment (20 x 10(6) cells) three times a week resulted in a significant decrease in tumor volume (TV) (67.1%, P < 0.01) as compared to PBS-treated mice. The effect was determined to be dependent on dose and frequency. Yeast administered three and two times per week induced significant decrease in TV as early as 9 and 25 days post-treatment, respectively. Administration of yeast significantly enhanced the recruitment of leukocytes, including macrophages, into the tumors and triggered apoptosis in SEC cells as determined by flow cytometry (78.6%, P < 0.01) at 20 x 10(6) cells, as compared to PBS-treated mice (42.6%). In addition, yeast treatment elevated TNF-alpha and IFN-gamma plasma levels and lowered the elevated IL-10 levels. No adverse side effects from the yeast treatment were observed, including feeding/drinking cycle and life activity patterns. Indeed, yeast-treated mice showed significant final body weight gain (+21.5%, P < 0.01) at day 35. These data may have clinical implications for the treatment of solid cancer with yeast, which is known to be safe for human consumption.

Decreased expression of histamine H1 and H4 receptors suggests disturbance of local regulation in human colorectal tumours by histamine

Production of histamine in colon tumours has been described earlier. Histamine-mediated signals have been shown to be implicated in tumour growth, and the effects of histamine are largely determined locally by the histamine receptor expression pattern. We analysed histamine receptor expression in human colorectal cancer, adenoma and normal mucosa by quantitative reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis and immunostaining. Real-time RT-PCR results revealed significantly decreased (p<0.001) H1R and H4R mRNA levels in tumours compared to normal colonic mucosa, without any significant change in H2R mRNA expression. H3R was absent in most samples; it was detected at low levels in 7.9% of the cases. Protein analysis showed a similar decrease in histamine receptor expression in carcinoma and adenoma compared to normal mucosa controls. Based on these results, we performed further Western blot analysis on Dukes-classified and -selected tumour samples. We found significantly decreased H4R levels in neoplastic samples compared to normal colonic tissue, but there was no significant correlation between histamine receptor expression profile and the Dukes stage of tumours. Immunohistochemical staining revealed expression patterns of H1R, H2R and H4R similar to those suggested by the mRNA and Western blot results. In the present study, we demonstrate that H1R, H2R and H4R are expressed in colon carcinoma and the adjacent normal mucosa. The results suggest a dramatic alteration in the distribution of histamine receptors in colon cancer. These findings raise the perspective of targeted pharmacological studies with selective histamine receptor antagonists or agonists in the therapy of colorectal tumours.

Review article: immune suppression and colorectal cancer

BACKGROUND

Advances in immunology and molecular biology have shown that colorectal cancer is potentially immunogenic and that host immune responses influence survival. However, immune surveillance and activation is frequently ineffective in preventing and/or controlling tumour growth.

AIM

To discuss potential ways in which colorectal cancer induces immune suppression, its effect upon prognosis and avenues for therapeutic development.

METHOD

A literature review was undertaken for evidence of colorectal cancer-induced immune suppression using PubMed and Medline searches. Further studies were identified from the reference lists of identified papers.

RESULTS

Immune suppression occurs at a molecular and cellular level and can result in a shift from cellular to humoral immunity. Several mechanisms for immune suppression have been described affecting innate and adaptive immunity with suppression linked to poorer clinical outcome.

CONCLUSIONS

Colorectal cancer causes direct inhibition of the host's immune response with a detrimental effect upon prognosis. Immunotherapy offers a therapeutic strategy to counteract these effects with promising results seen particularly in precancerous conditions and early tumours. This review strongly suggests that immunotherapy should be incorporated into adjuvant therapeutic trials for stage 2 tumours and be considered as adjuvant treatment in conjunction with standard chemotherapy regimes for advanced disease.

Perioperative blood transfusions for the recurrence of colorectal cancer

BACKGROUND

The improvement of renal allograft survival by pre-transplantation transfusions alerted the medical community to the potential detrimental effect of transfusions in patients being treated for cancer.

OBJECTIVES

The present meta-analysis aims to evaluate the role of perioperative blood transfusions (PBT) on colorectal cancer recurrence. This is accomplished by validating the results of a previously published meta-analysis (Amato 1998); and by updating it to December 2004.

SEARCH STRATEGY

Published papers were retrieved using Medline, EMBASE, the Cochrane Library, controlled trials web-based registries, or the CCG Trial Database. The search strategy used was: {colon OR rectal OR colorectal} WITH {cancer OR tumor OR neoplasm} AND transfusion. The tendency not to publish negative trials was balanced by inspecting the proceedings of international congresses.

SELECTION CRITERIA

Patients undergoing curative resection of colorectal cancer (classified either as Dukes stages A-C, Astler-Coller stages A-C2, or TNM stages T1-3a/N0-1/M0) were included if they had received any amount of blood products within one month of surgery. Excluded were patients with distant metastases at surgery, and studies with short follow-up or with no data.

DATA COLLECTION AND ANALYSIS

A specific form was developed for data collection. Data extraction was cross-checked, using the most recent publication in case of repetitive ones. Papers' quality was ranked using the method by Evans and Pollock. Odds ratios (OR, with 95% confidence intervals) were computed for each study, and pooled estimates were generated by RevMan (version 4.2). When available, data were stratified for risk factors of cancer recurrence.

MAIN RESULTS

The findings of the 1998 meta-analysis were confirmed, with small variations in some estimates. Updating it through December 2004 led to the identification of 237 references. Two-hundred and one of them were excluded because they analyzed survival (n=22), were repetitive (n=26), letters/reviews (n=66) or had no data (n=87). Thirty-six studies on 12,127 patients were included: 23 showed a detrimental effect of PBT; 22 used also multivariable analyses, and 14 found PBT to be an independent prognostic factor. Pooled estimates of PBT effect on colorectal cancer recurrence yielded overall OR of 1.42 (95% CI, 1.20 to 1.67) against transfused patients in randomized controlled studies. Stratified meta-analyses confirmed these findings, also when stratifying patients by site and stage of disease. The PBT effect was observed regardless of timing, type, and in a dose-related fashion, although heterogeneity was detected. Data on surgical techniques was not available for further analysis.

AUTHORS' CONCLUSIONS

This updated meta-analysis confirms the previous findings. All analyses support the hypothesis that PBT have a detrimental effect on the recurrence of curable colorectal cancers. However, since heterogeneity was detected and conclusions on the effect of surgical technique could not be drawn, a causal relationship cannot still be claimed. Carefully restricted indications for PBT seems necessary.