Aspirin and the prevention of colorectal cancer

Targeting cyclooxygenase-2 for chemoprevention of inflammation-associated intestinal carcinogenesis: An update

Mounting evidence from preclinical and clinical studies suggests that persistent inflammation functions as a driving force in the journey to cancer. Cyclooxygenase-2 (COX-2) is a key enzyme involved in inflammatory signaling. While being transiently upregulated upon inflammatory stimuli, COX-2 has been found to be consistently overexpressed in human colorectal cancer and several other malignancies. The association between chronic inflammation and cancer has been revisited: cancer can arise when inflammation fails to resolve. Besides its proinflammatory functions, COX-2 also catalyzes the production of pro-resolving as well as anti-inflammatory metabolites from polyunsaturated fatty acids. This may account for the side effects caused by long term use of some COX-2 inhibitory drugs during the cancer chemopreventive trials. This review summarizes the latest findings highlighting the dual functions of COX-2 in the context of its implications in the development, maintenance, and progression of cancer.

Aspirin and nonaspirin nonsteroidal antiinflammatory drug use and occurrence of colorectal adenoma in Black American women

Evidence suggests that aspirin use reduces the occurrence of colorectal neoplasia. Few studies have investigated the association among Black Americans, who are disproportionately burdened by the disease. We assessed aspirin use in relation to colorectal adenoma among Black women. The Black Women's Health Study is a prospective cohort of self-identified Black American women established in 1995. Participants reported regular aspirin use on baseline and follow-up questionnaires. Beginning in 1999, participants reported undergoing a colonoscopy or sigmoidoscopy, the only procedures through which colorectal adenomas can be diagnosed. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for associations between aspirin use and colorectal adenoma among 34 397 women who reported at least 1 colonoscopy or sigmoidoscopy. From 1997 through 2018, 1913 women were diagnosed with an adenoma. Compared to nonaspirin users, regular users had 14% (OR = 0.86, 95% CI: 0.78-0.95) lower odds of adenoma. The odds of adenoma decreased with increasing duration of aspirin use (≥10 years: OR = 0.80, 95% CI: 0.66-0.96). Initiating aspirin at a younger age was associated with a reduced adenoma occurrence (age < 40 years at initiation: OR = 0.69, 95% CI: 0.55-0.86). Regular aspirin use was associated with a decreased odds of colorectal adenoma in our study of Black women. These findings support evidence demonstrating a chemopreventive impact of aspirin on colorectal neoplasia and suggest that aspirin may be a useful prevention strategy among US Black women.

Antiplatelet agents aspirin and dipyridamole, and the risk of different carcinoma in patients with type 2 diabetes mellitus: A Taiwan retrospective cohort study

Studies have shown aspirin decreases the risk of some cancers. However, the evidence reported the association between aspirin and cancer risk in the diabetic population. In this study, we investigate whether aspirin and dipyridamole decrease the risk of cancer in patients with type 2 diabetes. A total of 5308 patients with type 2 diabetes were identified by the National Health Insurance from 1998 to 2000 and followed up until 2013. The demographic characteristics among nondipyridamole nor aspirin, aspirin, and dipyridamole users were analyzed by using the χ(2) test. Cox proportional hazard regression models were used to determine the independent effects of no aspirin nor dipyridamole, aspirin, and dipyridamole users on the risk of different cancer. After adjustment with multiple covariates, both low and high doses of aspirin and dipyridamole decrease liver cancer with risk ratios of 0.56 (95% CI, 0.37-0.83), 0.14 (95% CI, 0.05-0.39), 0.61 (95% CI, 0.38-0.99), and 0.28 (95% CI, 0.12-0.66), respectively. Both low and high doses of aspirin decrease any types of cancer with risk ratios of 0.79 (95% CI, 0.64-0.98) and 0.49 (95% CI, 0.34-0.70), respectively. Therefore, we conclude aspirin may decrease any types of cancer and liver cancer, and dipyridamole may decrease the risk of liver cancer in patients with type 2 diabetes.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

Superior Overall Survival in Patients with Colorectal Cancer, Regular Aspirin Use, and Combined Wild-Type PIK3CA and KRAS-Mutated Tumors

Simple Summary

The impact of aspirin use after the diagnosis of colorectal cancer is unknown. Among others, PIK3CA mutational status was proposed as a molecular biomarker for the response to adjuvant aspirin therapy. The aim of this study was to retrospectively analyze whether the PIK3CA and KRAS mutational status had an impact on overall survival in patients with colorectal cancer and aspirin use. In a retrospective study, we obtained KRAS and PIK3CA mutational status in a cohort of 153 patients with a first diagnosis of colorectal cancer receiving tumor surgery with curative intent. Clinicopathological data and survival data were assessed using patient records and reporting registers. We observed a significant 10-year overall survival benefit in patients with aspirin use and combined wild-type PIK3CA and mutated-KRAS tumors (HR = 0.38; 95% CI = 0.17–0.87; p = 0.02). Our data indicated a benefit of aspirin usage particularly for patients with combined wild-type PIK3CA and mutated-KRAS tumor characteristics.

Abstract

The impact of aspirin use after the diagnosis of colorectal cancer is unknown. Among others, PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha) mutational status was proposed as a molecular biomarker for the response to adjuvant aspirin therapy. However, prognostic data on aspirin use after a colorectal cancer diagnosis in relation to KRAS mutational status is limited. In a single-center retrospective study, we obtained KRAS and PIK3CA mutational status in a cohort of 153 patients with a first diagnosis of colorectal cancer receiving tumor surgery with curative intent. PIK3CA mutational status was determined by pyrosequencing, and KRAS mutational status was determined by next-generation sequencing. Clinicopathological data and survival data were assessed using patient records and reporting registers. We observed a significant 10-year overall survival benefit in patients with aspirin use and combined wild-type PIK3CA and mutated-KRAS tumors (HR = 0.38; 95% CI = 0.17–0.87; p = 0.02), but not in patients without aspirin use. Our data indicate a benefit of aspirin usage particularly for patients with combined wild-type PIK3CA and mutated-KRAS tumor characteristics.

Aspirin enhances the therapeutic efficacy of cisplatin in oesophageal squamous cell carcinoma by inhibition of putative cancer stem cells

BACKGROUND

Cancer stem cells (CSCs) are related to the patient's prognosis, recurrence and therapy resistance in oesophageal squamous cell carcinoma (ESCC). Although increasing evidence suggests that aspirin (acetylsalicylic acid, ASA) could lower the incidence and improve the prognosis of ESCC, the mechanism(s) remains to be fully understood.

METHODS

We investigated the role of ASA in chemotherapy/chemoprevention in human ESCC cell lines and an N-nitrosomethylbenzylamine-induced rat ESCC carcinogenesis model. The effects of combined treatment with ASA/cisplatin on ESCC cell lines were examined in vitro and in vivo. Sphere-forming cells enriched with putative CSCs (pCSCs) were used to investigate the effect of ASA in CSCs. Assay for Transposase-Accessible Chromatin with high-throughput sequencing (ATAC-seq) was performed to determine the alterations in chromatin accessibility caused by ASA in ESCC cells.

RESULTS

ASA inhibits the CSC properties and enhances cisplatin treatment in human ESCC cells. ATAC-seq indicates that ASA treatment results in remarkable epigenetic alterations on chromatin in ESCC cells, especially their pCSCs, through the modification of histone acetylation levels. The epigenetic changes activate Bim expression and promote cell death in CSCs of ESCC. Furthermore, ASA prevents the carcinogenesis of NMBzA-induced ESCC in the rat model.

CONCLUSIONS

ASA could be a potential chemotherapeutic adjuvant and chemopreventive drug for ESCC treatment.

Acetylsalicylic Acid Governs the Effect of Sorafenib in RAS-Mutant Cancers

Purpose: Identify and characterize novel combinations of sorafenib with anti-inflammatory painkillers to target difficult-to-treat RAS-mutant cancer.Experimental Design: The cytotoxicity of acetylsalicylic acid (aspirin) in combination with the multikinase inhibitor sorafenib (Nexavar) was assessed in RAS-mutant cell lines in vitro The underlying mechanism for the increased cytotoxicity was investigated using selective inhibitors and shRNA-mediated gene knockdown. In vitro results were confirmed in RAS-mutant xenograft mouse models in vivoResults: The addition of aspirin but not isobutylphenylpropanoic acid (ibruprofen) or celecoxib (Celebrex) significantly increased the in vitro cytotoxicity of sorafenib. Mechanistically, combined exposure resulted in increased BRAF/CRAF dimerization and the simultaneous hyperactivation of the AMPK and ERK pathways. Combining sorafenib with other AMPK activators, such as metformin or A769662, was not sufficient to decrease cell viability due to sole activation of the AMPK pathway. The cytotoxicity of sorafenib and aspirin was blocked by inhibition of the AMPK or ERK pathways through shRNA or via pharmacologic inhibitors of RAF (LY3009120), MEK (trametinib), or AMPK (compound C). The combination was found to be specific for RAS/RAF-mutant cells and had no significant effect in RAS/RAF-wild-type keratinocytes or melanoma cells. In vivo treatment of human xenografts in NSG mice with sorafenib and aspirin significantly reduced tumor volume compared with each single-agent treatment.Conclusions: Combination sorafenib and aspirin exerts cytotoxicity against RAS/RAF-mutant cells by simultaneously affecting two independent pathways and represents a promising novel strategy for the treatment of RAS-mutant cancers. Clin Cancer Res; 24(5); 1090-102. ©2017 AACR.

The role of aspirin in preventing colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers in the developed world and is the second leading cause of cancer-related mortality in the UK and USA. Regular use of aspirin can reduce cancer incidence, recurrence, metastasis and cancer-related mortality.

SOURCES OF DATA

Peer-reviewed journals, governmental and professional society publications.

AREAS OF AGREEMENT

There is a wide body of evidence from observational studies and randomized trials that aspirin reduces risk of CRC. There is a delay of several years between initiation and effect. There is interpersonal variation in aspirin metabolism but pharmacogenetic testing is not yet sufficiently sensitive or specific to justify routine use.

AREAS OF DISAGREEMENT

There is uncertainty about the optimal dose and the duration of aspirin. There is debate around use for the general population but there is growing consensus on use in those at increased risk of developing cancer.

GROWING POINTS

Understanding is growing of the possible mechanisms by which aspirin exerts its anticancer effects. Large-scale meta-analyses are quantifying the cost-benefit ratio in the general population. International trials are underway to assess the optimal dose in high-risk individuals and the role of aspirin as an adjuvant in those who present with a malignancy.

Aspirin inhibits glucose‑6‑phosphate dehydrogenase activity in HCT 116 cells through acetylation: Identification of aspirin-acetylated sites

Glucose-6-phosphate dehydrogenase (G6PD) catalyzes the first reaction in the pentose phosphate pathway, and generates ribose sugars, which are required for nucleic acid synthesis, and nicotinamide adenine dinucleotide phosphate (NADPH), which is important for neutralization of oxidative stress. The expression of G6PD is elevated in several types of tumor, including colon, breast and lung cancer, and has been implicated in cancer cell growth. Our previous study demonstrated that exposure of HCT 116 human colorectal cancer cells to aspirin caused acetylation of G6PD, and this was associated with a decrease in its enzyme activity. In the present study, this observation was expanded to HT-29 colorectal cancer cells, in order to compare aspirin-mediated acetylation of G6PD and its activity between HCT 116 and HT-29 cells. In addition, the present study aimed to determine the acetylation targets of aspirin on recombinant G6PD to provide an insight into the mechanisms of inhibition. The results demonstrated that the extent of G6PD acetylation was significantly higher in HCT 116 cells compared with in HT-29 cells; accordingly, a greater reduction in G6PD enzyme activity was observed in the HCT 116 cells. Mass spectrometry analysis of aspirin-acetylated G6PD (isoform a) revealed that aspirin acetylated a total of 14 lysine residues, which were dispersed throughout the length of the G6PD protein. One of the important amino acid targets of aspirin included lysine 235 (K235, in isoform a) and this corresponds to K205 in isoform b, which has previously been identified as being important for catalysis. Acetylation of G6PD at several sites, including K235 (K205 in isoform b), may mediate inhibition of G6PD activity, which may contribute to the ability of aspirin to exert anticancer effects through decreased synthesis of ribose sugars and NADPH.

Heme Iron Intake, Dietary Antioxidant Capacity, and Risk of Colorectal Adenomas in a Large Cohort Study of French Women

BACKGROUND

Nitrosylated and non-nitrosylated heme iron from red processed and nonprocessed meat have been associated with increased colorectal carcinogenesis. Mechanisms include oxidative processes. It has been hypothesized that dietary antioxidants could counteract the effects of heme iron. We investigated the relationships between heme iron intake and the risk of colorectal adenomas, and a potential interaction with the dietary antioxidant capacity, in the E3N prospective cohort study.

METHODS

The study included 17,397 women, who underwent at least one colonoscopy. Among them, 1,409 were diagnosed with at least one first colorectal adenoma during the 103,253 person-years of follow-up. Dietary intake was measured by a semiquantitative food history questionnaire. HR estimates and 95% confidence intervals (CI) were obtained from Cox proportional hazards models, adjusted for potential confounders.

RESULTS

Heme iron intake was positively associated with colorectal and colon adenoma risks [HR for the fourth vs. first quartile: HR4 = 1.36 (1.13-1.65), Ptrend = 0.001 and HR4 = 1.49; 95% CI, 1.19-1.87; Ptrend = 0.0003, respectively]. Nonnitrosylated and nitrosylated heme iron intakes were, respectively, associated with advanced distal and proximal adenoma risks. There was a dose-effect relationship between the heme iron to total dietary antioxidant capacity ratio and colorectal adenoma risk.

CONCLUSION

In this prospective cohort study, the association between heme iron and colorectal adenoma risk was found to depend on site, nitrosylation or not, and the ratio with the NEAC.

IMPACT

These results emphasize the need for a global assessment of diet when considering nutritional prevention of colorectal carcinogenesis. Cancer Epidemiol Biomarkers Prev; 25(4); 640-7. ©2016 AACR.

Chemoprevention of colorectal neoplasia

BACKGROUND

Colorectal cancer is a common and often fatal malignancy. Currently, the modifications that alter disease outcome include early symptom recognition, population screening as well as improved surgical and adjuvant treatments. Preventative strategies have been limited with little evidence that lifestyle changes significantly alter risk. There is however a growing awareness of a potential role for chemoprevention in some patient groups. This study aimed to review the literature associated with chemoprevention in colorectal cancer.

METHODS

An electronic literature search of MEDLINE and Embase databases was performed on PubMed for studies detailing the use of chemoprevention agents in colon and rectal cancer. The search was limited to clinical trials on adult humans (>16 years of age) published in English since 1990.

RESULTS

The strongest evidence is for non-steroidal anti-inflammatory drugs slowing polyp progression, notably Sulindac and aspirin in patients with familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer, respectively. There is also increasing evidence that continuing use of low-dose aspirin reduces long-term incidence of colorectal cancers. Cyclooxygenase 2 inhibitors also have a potential role but cardiac toxicity currently limits their use. Folic acid, statins, antioxidants, calcium and 5-aminosalicylic acid lack evidence to support their use at present.

CONCLUSIONS

Currently, there is not enough evidence to support the implementation of a chemopreventative agent for general use. However, there appears to be a role for aspirin in selected subgroups.

Geographic differences in low-dose aspirin-associated gastroduodenal mucosal injury

Aspirin, even at low doses, has been known to cause upper gastro-intestinal complications, such as gastroduodenal ulcers, despite the definite benefits from its antithrombotic effects. Helicobacter pylori (H. pylori) is major pathogen responsible for gastroduodenal ulcer formation. There have been conflicting results about the potential interaction between these two ulcerogenic factors and the geographic areas involved. In Western countries, the prevalence of gastroduodenal ulcers is consistently higher in H. pylori-positive low-dose aspirin (LDA) users than in H. pylori-negative ones, suggesting that H. pylori infection exacerbates LDA-induced gastroduodenal mucosal injury in these geographic areas. Meanwhile, previous studies from Japan have generally reported a similar prevalence of LDA-induced gastroduodenal mucosal injury regardless of the presence of H. pylori infection, indicating that the infection is not an overall exacerbating factor for drug-induced injury. H. pylori infection could have a synergistic or antagonistic interaction with LDA use in adverse gastroduodenal events depending on gastric acid secretion. It is well-recognized that the net effect of H. pylori infection on gastric acid secretion shows considerable geographic variation at the population level. While gastric acid secretion levels were not decreased and were well-preserved in most patients with H. pylori infection from Western countries, the majority of Japanese patients with H. pylori infection exhibited decreased gastric acid secretion. Such large geographic differences in the net effect of H. pylori infection on gastric acid secretion could be at least partly responsible for the geographically distinct interaction between LDA use and H. pylori infection on adverse gastroduodenal lesions.

Choosing the optimal method in programmatic colorectal cancer screening: current evidence and controversies

Colorectal cancer (CRC) is an important health problem all over the world, being the third most common cancer and the second leading cause of cancer-related death in Western countries. The most important strategy for CRC prevention is screening (i.e. secondary prevention). Since it is widely accepted that adenomas and serrated polyps are the precursors of the vast majority of CRC, early detection and removal of these lesions is associated with a reduction of CRC incidence and, consequently, mortality. Moreover, cancers detected by screening are usually diagnosed at early stages and, therefore, curable by endoscopic or surgical procedures. This review will be address CRC screening strategies in average-risk population, which is defined by those individuals, men and women, 50 years of age or older, without any additional personal or familial predisposing risk factor. In order to maximize the impact of screening and ensure high coverage and equity of access, only organized screening programs (i.e. programmatic screening) should be implemented, as opposed to case-finding or opportunistic screening. For that reason and considering that the optimal approach for colorectal screening may differ depending on the scenario, this review will be focused on the advantages and limitations of each screening strategy in an organized setting.

Non-melanoma skin cancer and NSAID use in women with a history of skin cancer in the Women's Health Initiative

OBJECTIVE

Evidence for the effect of non-steroidal anti-inflammatory drugs (NSAIDs) on non-melanoma skin cancer (NMSC) risk is inconsistent. We prospectively examined whether regular, inconsistent, or no/low-use of NSAIDs is associated with lower NMSC risk among 54,728 postmenopausal Caucasian women in the Women's Health Initiative Observational Study enrolled between 1993 and 1998.

METHODS

Logistic regression models were used to assess odds of NMSC after adjusting for skin type, sun exposure history and indication for NSAID use.

RESULTS

There were 7652 incident cases of NMSC (median follow-up: 6.9years). There was no association between regular NSAID-use and NMSC risk relative to no/low-users. However, in a subgroup analysis of 5325 women with a history of skin cancer (incident NMSC: 1897), odds of NMSC were lower among regular NSAID users whether <5years (OR 0.82, 95% CI: 0.70-0.95) or ≥5years (OR 0.82, 95% CI: 0.69-0.98) of use compared to no/low-users. Inconsistent NSAID use and acetaminophen use were not associated with NMSC risk.

CONCLUSION

Overall, NSAID use was not associated with NMSC risk. However, in women with a history of skin cancer, regular NSAID use was associated with 18% lower odds of NMSC. Future studies on potential chemopreventative effects of NSAIDs should focus on subjects with prior history of NMSC.

Systematic review: interactions between aspirin, and other nonsteroidal anti-inflammatory drugs, and polymorphisms in relation to colorectal cancer

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) include aspirin (acetylsalicylic acid, ASA). Long-term use of NSAIDs has been associated with lowered risk of colorectal cancer (CRC), but the use is hampered by adverse effects. Also, the anti-carcinogenic effects of NSAIDs are incompletely understood. Understanding biological effects of NSAIDs may help developing new preventive medical strategies.

AIM

To identify gene-environment interactions between genetic variation and NSAID use in relation to risk of CRC.

METHODS

We performed a PubMed literature search and all studies reporting original data on interactions between NSAIDs and polymorphisms in relation to CRC were evaluated.

RESULTS

We found indications that aspirin interacted with rs6983267 close to MYC (encoding a transcription factor involved in cell cycle progression, apoptosis and cellular transformation) and NSAIDs interacted with rs3024505 and rs1800872 in or close to IL10 (encoding IL-10) in preventing CRC. Homozygous carriers of the variant allele of rs6983267 (ca. 25% of the population) halved their risk for CRC by aspirin use compared to homozygous wildtype carriers who did not benefit from aspirin intake. No interaction between use of NSAIDs and PTGS-2 (encoding COX-2) in relation to CRC risk was detected. Other findings of interactions between genes in inflammatory and oncogenic pathways and NSAIDs were considered suggestive.

CONCLUSIONS

Knowledge of underlying biological effects of NSAIDs in relation to CRC is scarce and the basis for stratifying the patients for preventive treatment is not yet available. Further studies assessing interactions between long-term NSAID exposure and genetic variation in relation to CRC are warranted in large well-characterised prospective cohorts.

Molecular targets of aspirin and cancer prevention

Salicylates from plant sources have been used for centuries by different cultures to treat a variety of ailments such as inflammation, fever and pain. A chemical derivative of salicylic acid, aspirin, was synthesised and mass produced by the end of the 19th century and is one of the most widely used drugs in the world. Its cardioprotective properties are well established; however, recent evidence shows that it can also act as a chemopreventive agent. Its antithrombotic and anti-inflammatory actions occur through the inhibition of cyclooxygenases. The precise mechanisms leading to its anticancer effects are not clearly established, although multiple mechanisms affecting enzyme activity, transcription factors, cellular signalling and mitochondrial functions have been proposed. This review presents a brief account of the major COX-dependent and independent pathways described in connection with aspirin's anticancer effects. Aspirin's unique ability to acetylate biomolecules besides COX has not been thoroughly investigated nor have all the targets of its primary metabolite, salicylic acid been identified. Recent reports on the ability of aspirin to acetylate multiple cellular proteins warrant a comprehensive study to investigate the role of this posttranslational modification in its anticancer effects. In this review, we also raise the intriguing possibility that aspirin may interact and acetylate cellular molecules such as RNA, and metabolites such as CoA, leading to a change in their function. Research in this area will provide a greater understanding of the mechanisms of action of this drug.

Aspirin and other NSAIDs as chemoprevention agents in melanoma

Melanoma incidence is increasing and, despite recent therapeutic advances, the prognosis for patients with metastatic disease remains poor. Thus, early detection and chemoprevention are promising strategies for improving patient outcomes. Aspirin (acetylsalicylic acid) and other nonsteroidal anti-inflammatory drugs (NSAID) have demonstrated chemoprotective activity in several other cancers, and have been proposed as chemopreventive agents for melanoma. Throughout the last decade, however, a number of case-control, prospective, and interventional studies of NSAIDs and melanoma risk have yielded conflicting results. These inconsistent findings have led to uncertainty about the clinical utility of NSAIDs for melanoma chemoprevention. This mini-review highlights current knowledge of NSAID mechanisms of action and rationale for use in melanoma, provides a comparative review of outcomes and limitations of prior studies, and discusses the future challenges in demonstrating that these drugs are effective agents for mitigating melanoma risk.

Does regional anaesthesia and analgesia or opioid analgesia influence recurrence after primary cancer surgery? An update of available evidence

Cancer continues to be a key cause of morbidity and mortality worldwide and its overall incidence continues to increase. Anaesthetists are increasingly faced with the challenge of managing cancer patients, for surgical resection to debulk or excise the primary tumour, or for surgical emergencies in patients on chemotherapy or for the analgesic management of disease- or treatment-related chronic pain. Metastatic recurrence is a concern. Surgery and a number of perioperative factors are suspected to accelerate tumour growth and potentially increase the risk of metastatic recurrence. Retrospective analyses have suggested an association between anaesthetic technique and cancer outcomes, and anaesthetists have sought to ameliorate the consequences of surgical trauma and minimise the impact of anaesthetic interventions. Just how anaesthesia and analgesia impact cancer recurrence and consequent survival is very topical, as understanding the potential mechanisms and interactions has an impact on the anaesthetist's ability to contribute to the successful outcome of oncological interventions. The outcome of ongoing, prospective, randomized trials are awaited with interest.

MMP1, MMP9, and COX2 expressions in promonocytes are induced by breast cancer cells and correlate with collagen degradation, transformation-like morphological changes in MCF-10A acini, and tumor aggressiveness

Tumor-associated immune cells often lack immune effector activities, and instead they present protumoral functions. To understand how tumors promote this immunological switch, invasive and noninvasive breast cancer cell (BRC) lines were cocultured with a promonocytic cell line in a Matrigel-based 3D system. We hypothesized that if communication exists between tumor and immune cells, coculturing would result in augmented expression of genes associated with tumor malignancy. Upregulation of proteases MMP1 and MMP9 and inflammatory COX2 genes was found likely in response to soluble factors. Interestingly, changes were more apparent in promonocytes and correlated with the aggressiveness of the BRC line. Increased gene expression was confirmed by collagen degradation assays and immunocytochemistry of prostaglandin 2, a product of COX2 activity. Untransformed MCF-10A cells were then used as a sensor of soluble factors with transformation-like capabilities, finding that acini formed in the presence of supernatants of the highly aggressive BRC/promonocyte cocultures often exhibited total loss of the normal architecture. These data support that tumor cells can modify immune cell gene expression and tumor aggressiveness may importantly reside in this capacity. Modeling interactions in the tumor stroma will allow the identification of genes useful as cancer prognostic markers and therapy targets.

Protumor activities of the immune response: insights in the mechanisms of immunological shift, oncotraining, and oncopromotion

Experimental and clinical studies indicate that cells of the innate and adaptive immune system have both anti- and pro-tumor activities. This dual role of the immune system has led to a conceptual shift in the role of the immune system's regulation of cancer, in which immune-tumor cell interactions are understood as a dynamic process that comprises at least five phases: immunosurveillance, immunoselection, immunoescape, oncotraining, and oncopromotion. The tumor microenvironment shifts immune cells to perform functions more in tune with the tumor needs (oncotraining); these functions are related to chronic inflammation and tissue remodeling activities. Among them are increased proliferation and survival, increased angiogenesis and vessel permeability, protease secretion, acquisition of migratory mesenchymal characteristics, and self-renewal properties that altogether promote tumor growth and metastasis (oncopromotion). Important populations in all these pro-tumor processes are M2 macrophages, N2 neutrophils, regulatory T cells, and myeloid derived suppressor cells; the main effectors molecules are CSF-1, IL-6, metalloproteases, VEGF, PGE-2, TGF- β , and IL-10. Cancer prognosis correlates with densities and concentrations of protumoral populations and molecules, providing ideal targets for the intelligent design of directed preventive or anticancer therapies.