Aspirin and lung cancer in women

Evaluating the safety profile of calcineurin inhibitors: cancer risk in patients with systemic lupus erythematosus from the LUNA registry-a historical cohort study

BACKGROUND

Previous studies have shown conflicting evidence regarding the incidence of cancer in patients with systemic lupus erythematosus (SLE) compared with that in healthy individuals. Calcineurin inhibitors (CNIs) such as cyclosporine and tacrolimus have been widely used to treat SLE; however, their effects on cancer risk remain unclear. We aimed to investigate the incidence of cancer in patients with SLE and determine the potential association between CNI use and cancer risk.

METHODS

The standardized incidence ratio (SIR) of cancer among patients with lupus in the Lupus Registry of Nationwide Institutions (LUNA) was calculated based on the age-standardized incidence rate of cancer reported by Japan's Ministry of Health, Labour and Welfare. We also examined the association between CNI exposure and cancer risk, while considering potential confounding factors. The analysis accounted for confounding variables such as age, sex, smoking history, maximum glucocorticoid dose, treatment history with cyclophosphamide, ongoing hydroxychloroquine, Systemic Lupus International Collaboration Clinics/American College of Rheumatology Damage Index (SDI) value (excluding cancer occurrence), comorbidity of diabetes mellitus, and smoking history.

RESULTS

The study included 704 patients with SLE (625 females; 88.8%) with a median age of 44 years [interquartile range (IQR) = 34-55] years. The median past maximum glucocorticoid dose was 40 mg/day [IQR = 30-60 mg/day], and the SDI at registration was 1 [IQR = 0-2]. Among the patients, 246 (35.1%) had smoking histories, and 38 (5.4%) experienced cancer complications. Gynecological malignancies accounted for 63.2% of all cancers. The SIR of cancer in the LUNA cohort was 1.08 (95% confidence interval [CI] = 0.74-1.43). No statistically significant risks of cancer were found in relation to CNI treatment history; the odds ratio using multiple logistic regression was 1.12 (95% CI = 0.42-3.00), the risk ratio using standardization was 1.18 (95% CI = 0.47-2.16), and the risk ratio using inverse probability weighting was 1.8 (95% CI = 0.41-4.66).

CONCLUSIONS

The incidence of cancer in patients with SLE in the LUNA cohort did not significantly differ from that in the general population. These findings suggest that CNI treatment in this cohort did not pose a risk factor for cancer development.

Association between the use of aspirin and risk of lung cancer: results from pooled cohorts and Mendelian randomization analyses

PURPOSE

We aimed to elucidate the associations between aspirin use with risk of lung cancer, by conducting a meta-analysis and Mendelian randomization (MR) analyses from published Genome-Wide Association Studies (GWAS).

METHODS

Cohort studies, nested case-control studies, and randomized controlled trials (RCTs) investigating the impact of aspirin exposure and lung cancer incidence were included. Relative risk (RR) and its 95% confidence interval (CI) were evaluated in eligible studies. Subgroup analyses regarding gender, pathologic subtypes and smoking status were also executed. MR analyses were conducted using summary statistics obtained from two large consortia [Neale Lab and International Lung Cancer Consortium (ILCCO)] to assess the possible causal relationship of aspirin on lung cancer incidence.

RESULTS

Sixteen eligible studies involving 1,522,687 patients were included. The combined RR of aspirin use for the incidence of lung cancer was 0.95 (95% confidence interval (CI) 0.91-0.98). In subgroup meta-analyses, a significant protective effect was observed in squamous cell lung cancer (RR = 0.80; 95% CI 0.65-0.98). In terms of gender, the chemopreventive value was only observed among men (RR = 0.87; 95% CI 0.77-0.97). The MR risk analysis suggested a causal effect of aspirin on lung cancer incidence, with evidence of a decreased risk for overall lung cancer (OR = 0.042; 95% CI 0.003-0.564) and squamous cell lung cancer (OR = 0.002; 95% CI 1.21 × 10^-5-0.301).

CONCLUSION

Our study provided evidence for a causal protective effect of aspirin on the risk of lung cancer incidence among men, particularly on the squamous cell lung cancer risk.

Cancer and Systemic Lupus Erythematosus

Systemic lupus erythematosus is associated with a small overall increased cancer risk compared with the general population. This risk includes a 4-fold increased risk of non-Hodgkin lymphoma, but a decreased risk of other cancers (such as breast cancer). The pathophysiology underlying the increased risk of hematologic cancer is not fully understood, but many potential mechanisms have been proposed, including dysfunction of the tumor necrosis factor and other pathways. A decreased risk of breast, ovarian, and endometrial cancer might be driven by hormonal factors or lupus-related antibodies, but these links have not been proved.

Racial and Ethnic Differences in the Relationship between Aspirin Use and Non-Small Cell Lung Cancer Risk and Survival

BACKGROUND

African Americans (AA) experience higher incidence and mortality of lung cancer as compared with European Americans (EA). Inflammation is associated with lung cancer, many aspects of which differ between AA and EA. We investigated whether use, frequency, and duration of the anti-inflammatory drug aspirin were associated with lung cancer risk and survival, separately among AA and EA populations.

METHODS

Using data from the Maryland Non-Small Cell Lung Cancer (NSCLC) Case-Control Study (1,220 cases [404 AA and 816 EA] and 1,634 controls [1,004 EA and 630 AA]), we estimated the adjusted odds ratios (OR) and hazard ratios (HR) with 95% confidence intervals (CI) of the associations between aspirin use and NSCLC risk and survival, respectively.

RESULTS

Any aspirin use (OR: 0.66; 95% CI, 0.49-0.89), daily use of ≥ 1 tablet (OR: 0.68; 95% CI, 0.50-0.90), and use for ≥ 3 years (OR: 0.61; 95% CI, 0.44-0.85) was associated with lower NSCLC risk only among men, even after adjustment for covariates including body mass index and global genetic ancestry. These variables were also associated with improved survival, but only among AA (HR: 0.64; 95% CI, 0.46-0.91; HR: 0.61; 95% CI, 0.42-0.90; and HR: 0.60; 95% CI, 0.39-0.92, respectively). Tylenol and other NSAIDs were either associated with elevated or no NSCLC risk.

CONCLUSIONS

Aspirin use is associated with lower risk of NSCLC among men and improved survival among AA.

IMPACT

Preventive regular aspirin use could be considered among men and AA.

Associations between aspirin use and the risk of cancers: a meta-analysis of observational studies

Background

Epidemiological studies have clarified the potential associations between regular aspirin use and cancers. However, it remains controversial on whether aspirin use decreases the risk of cancers risks. Therefore, we conducted an updated meta-analysis to assess the associations between aspirin use and cancers.

Methods

The PubMed, Embase, and Web of Science databases were systematically searched up to March 2017 to identify relevant studies. Relative risks (RRs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

Results

A total of 218 studies with 309 reports were eligible for this meta-analysis. Aspirin use was associated with a significant decrease in the risk of overall cancer (RR = 0.89, 95% CI: 0.87–0.91), and gastric (RR = 0.75, 95% CI: 0.65–0.86), esophageal (RR = 0.75, 95% CI: 0.62–0.89), colorectal (RR = 0.79, 95% CI: 0.74–0.85), pancreatic (RR = 0.80, 95% CI: 0.68–0.93), ovarian (RR = 0.89, 95% CI: 0.83–0.95), endometrial (RR = 0.92, 95% CI: 0.85–0.99), breast (RR = 0.92, 95% CI: 0.88–0.96), and prostate (RR = 0.94, 95% CI: 0.90–0.99) cancers, as well as small intestine neuroendocrine tumors (RR = 0.17, 95% CI: 0.05–0.58).

Conclusions

These findings suggest that aspirin use is associated with a reduced risk of gastric, esophageal, colorectal, pancreatic, ovarian, endometrial, breast, and prostate cancers, and small intestine neuroendocrine tumors.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4156-5) contains supplementary material, which is available to authorized users.

Elevated plasma 8-iso-prostaglandin F2α levels in human smokers originate primarily from enzymatic instead of non-enzymatic lipid peroxidation

It is widely accepted that free radicals in tobacco smoke lead to oxidative stress and generate the popular lipid peroxidation biomarker 8-iso-prostaglandin F2α (8-iso-PGF2α). However, 8-iso-PGF2α can simultaneously be produced in vivo by the prostaglandin-endoperoxide synthases (PGHS) induced by inflammation. This inflammation-dependent mechanism has never been considered as a source of elevated 8-iso-PGF2α in tobacco smokers. The goal of this study is to quantify the distribution of chemical- and PGHS-dependent 8-iso-PGF2α formation in the plasma of tobacco smokers and non-smokers. The influences of gender and hormonal contraceptive use were accounted for. The distribution was determined by measuring the 8-iso-PGF2α/prostaglandin F2α (PGF2α) ratio. When comparing smokers (n = 28) against non-smokers (n = 30), there was a statistically significant increase in the 8-iso-PGF2α concentration. The source of this increased 8-iso-PGF2α was primarily from PGHS. When stratifying for gender, the increase in 8-iso-PGF2α in male smokers (n = 9) was primarily from PGHS. Interestingly, female smokers on hormonal contraceptives had increased 8-iso-PGF2α in both pathways, whereas those not on hormonal contraceptives did not have increased 8-iso-PGF2α. In conclusion, increased plasma 8-iso-PGF2α in tobacco smokers has complex origins, with PGHS-dependent formation as the primary source. Accounting for both pathways provides a definitive measurement of both oxidative stress and inflammation.

Meta-analysis of aspirin use and risk of lung cancer shows notable results

Aspirin is a promising agent for chemoprevention of lung cancer. We assessed the association of aspirin use and the development of lung cancer, with a focus on heterogeneity between studies. Databases were searched for relevant studies until September 2014. Studies evaluating the relationship of aspirin use and incidence of lung cancer were considered. Relative risks (RR) were extracted and a pooled estimate was calculated. Heterogeneity was assessed by the I measure, random-effects models, and finite-mixture models. Sources of heterogeneity were investigated using a meta-regression. A decreased risk of lung cancer was found including 20 studies [RR=0.87, 95% confidence interval (CI): 0.79-0.95] on the basis of a random-effects model. Strong heterogeneity was observed (τ=0.0258, I=74.4%). As a result, two subpopulations of studies were identified on the basis of a mixture model. The first subpopulation (42%) has an average RR of 0.64. The remaining subpopulation (58%) shows an RR of 1.04. Different results were found for case-control (RR=0.74, 95% CI: 0.60-0.90) and cohort studies (RR=0.99, 95% CI: 0.93-1.06) in a stratified analysis. In a subgroup analysis, use of aspirin was associated with a decreased risk of non-small-cell lung cancer in case-control studies (RR=0.74; 95% CI: 0.58-0.94). At first glance, our meta-analysis shows an average protective effect. A second glance indicates that there is strong heterogeneity. This leads to a subpopulation with considerable benefit and another subpopulation with no benefit. For further investigations, it is important to identify populations that benefit from aspirin use.

Aspirin use and lung cancer risk: a possible relationship? Evidence from an updated meta-analysis

Background and Purpose

Growing evidence has emerged and controversial results reported on possible relationship between aspirin use and lung cancer risk. We, therefore, conducted this updated and comprehensive meta-analysis to evaluate this issue, with focus on dose-risk and duration-risk relationships.

Methods

We searched electronic databases including PUBMED, EMBASE and Cochrane library to identify eligible studies. Relative risk (RR) and its 95% confidence interval (CI) were used for cohort studies, while odds ratio (OR) were employed for case-control studies. The random effects and fixed effects models were used for analyses.

Results

18 studies were identified including 19835 lung cancer cases, which were eligible for inclusion in the present meta-analysis. Pooled data from case-control studies showed a significant inverse association between regular aspirin use and lung cancer risk. But for cohort studies, insignificant association was detected with little evidence of heterogeneity (RR: 1.05, 95%CI: 0.95 – 1.16; I²: 10.3%, p value: 0.351). In case-control studies, standard aspirin use (>325mg) was related to lower lung cancer incidence, compared with low-dose aspirin use (75–100mg). A similar trend was observed in cohort studies. Besides, when analysis was restricted to long time regular aspirin use (>5 years), insignificant results were reported in both cohort and case-control studies. Finally, regular aspirin use might result in higher reduction of non-small cell lung cancer incidence among men.

Conclusions

Our findings do not support the protective effect of regular aspirin use on lung cancer risk. Long time aspirin use, sex, dose and type of lung cancer might alter the effect of aspirin use on lung cancer risk. More well-designed studies are needed to further clarify these associations.

Arsenic trioxide binding to serum proteins

Arsenic trioxide (ATO) also known as Trisenox, is an anticancer chemotherapeutic drug which has been used in treating diagnosed and relapsed patients with acute promyelocytic leukemia (APL). Serum albumin is the most abundant of the proteins in blood plasma and is the major transporter for delivering several drugs in vivo. The current study was designed to evaluate the potential ability of human and bovine serum albumin for delivering arsenic trioxide. Therefore, interaction of arsenic trioxide with HSA and BSA was investigated in aqueous solution at physiological conditions using a constant protein concentration and various drug contents. FTIR and UV-Vis spectroscopic methods were used to analyze arsenic trioxide and protein binding modes, the binding constants and the effect of drug complexation on HSA and BSA stability and conformation. Results of this study showed that drug complexation altered protein conformation by major reduction of α-helix and increase of turn structure which is indicative of a partial protein destabilization. Structural analysis revealed that arsenic trioxide bind HSA and BSA with overall binding constants of KATO-HSA=1.07 (±0.01)×10(4) M(-1) and KATO-BSA=1.27(±0.02)×10(4) M(-1). It could be concluded that serum albumins can be considered as good carriers for delivering arsenic trioxide to target tissue.

Chemoprevention of lung cancer: concepts and strategies

Lung cancer develops in a stepwise fashion, with an accumulation of molecular alterations progressing through preinvasive steps to invasive disease. This progression could be arrested or reversed through pharmacologic treatments, which are known as cancer chemoprevention. Preclinical and clinical findings relating to different classes of candidate chemopreventive agents provide support for this strategy as an active and promising approach for controlling this disease.

Prediagnostic nonsteroidal anti-inflammatory drug use and lung cancer survival in the VITAL study

INTRODUCTION

Inflammation is important for lung oncogenesis. Use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been shown to improve colorectal cancer survival. However, few studies have examined the association in lung cancer patients.

METHODS

The VITamins And Lifestyle (VITAL) cohort includes Washington State residents, aged 50 to 76 years, who completed a baseline questionnaire between 2000 and 2002. Participants responded on the frequency and duration of use of individual NSAIDs in the previous 10 years. Subjects of this study were 785 members of the cohort, who were identified with incident lung cancer from baseline through 2007 through linkage to a population-based cancer registry. Participants were followed for lung cancer death through linkage to state records of death through 2009. Adjusted proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI) for the association between NSAIDs and lung cancer death.

RESULTS

Five hundred and twenty-two participants (66%) died from lung cancer. Relative to nonuse, high (≥ 4 days/week and ≥ 4 years) prediagnostic use of regular-strength or low-dose aspirin (HR 0.99, 95% CI: 0.74-1.33 and HR 0.89, 95% CI: 0.67-1.17, respectively) or total nonaspirin NSAIDs (HR 1.20, 95% CI: 0.79-1.83) did not reduce lung cancer death. However, high use of ibuprofen was associated with a 62% increased risk of lung cancer death (HR 1.62, 95% CI: 1.01-2.58).

CONCLUSIONS

Long-term, prediagnostic NSAID use does not improve lung cancer survival overall. Use of ibuprofen may reduce survival from lung cancer. Our results underscore the need for further study of the mechanisms of action for individual NSAIDs with regard to cancer survival.

Cancer risk in systemic lupus: an updated international multi-centre cohort study

OBJECTIVE

To update estimates of cancer risk in SLE relative to the general population.

METHODS

A multisite international SLE cohort was linked with regional tumor registries. Standardized incidence ratios (SIRs) were calculated as the ratio of observed to expected cancers.

RESULTS

Across 30 centres, 16,409 patients were observed for 121,283 (average 7.4) person-years. In total, 644 cancers occurred. Some cancers, notably hematologic malignancies, were substantially increased (SIR 3.02, 95% confidence interval, CI, 2.48, 3.63), particularly non-Hodgkin's lymphoma, NHL (SIR 4.39, 95% CI 3.46, 5.49) and leukemia. In addition, increased risks of cancer of the vulva (SIR 3.78, 95% CI 1.52, 7.78), lung (SIR 1.30, 95% CI 1.04, 1.60), thyroid (SIR 1.76, 95% CI 1.13, 2.61) and possibly liver (SIR 1.87, 95% CI 0.97, 3.27) were suggested. However, a decreased risk was estimated for breast (SIR 0.73, 95% CI 0.61-0.88), endometrial (SIR 0.44, 95% CI 0.23-0.77), and possibly ovarian cancers (0.64, 95% CI 0.34-1.10). The variability of comparative rates across different cancers meant that only a small increased risk was estimated across all cancers (SIR 1.14, 95% CI 1.05, 1.23).

CONCLUSION

These data estimate only a small increased risk in SLE (versus the general population) for cancer over-all. However, there is clearly an increased risk of NHL, and cancers of the vulva, lung, thyroid, and possibly liver. It remains unclear to what extent the association with NHL is mediated by innate versus exogenous factors. Similarly, the etiology of the decreased breast, endometrial, and possibly ovarian cancer risk is uncertain, though investigations are ongoing.

Sex differences in effects and use of anti-inflammatory drugs

Gender accounts for important differences in the incidence, prevalence, and course of many immunoinflammatory diseases. However, similar treatment strategies, such as the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and tumor necrosis factor-α (TNF-α) inhibitors, have been advocated for both genders. Experimental studies found that molecular mechanisms of inflammation differ in males and females. In our chapter we summarize the data concerning gender-specific aspects about prevalence of use, drug survival, responsiveness, and adverse drug effects of NSAIDs and TNF-α inhibitors. Gender-related differences in the prevalence and course of many autoimmune diseases as well as differences in effects of anti-inflammatory drugs should be considered for the tailored treatment options for these patients.

Urotensin II contributes to the formation of lung adenocarcinoma inflammatory microenvironment through the NF-κB pathway in tumor-bearing nude mice

Urotensin II (UII), a somatostatin-like cyclic peptide, was originally isolated from the fish urophysis. Our previous study showed that UII stimulates the proliferation of A549 lung adenocarcinoma cells and promotes tumor growth in a nude mouse xenograft model, suggesting that UII may contribute to the pathogenesis of lung adenocarcinoma. In this study, the underlying mechanism for UII to promote lung adenocarcinoma growth was explored by observing the effect of UII on the tumor inflammatory microenvironment in tumor-bearing nude mice. Immunohistochemical analysis showed that UII promoted the infiltration of CD68(+) tumor-associated macrophages (TAMs) in the tumor micro-environment. Enzyme-linked immunosorbent assay (ELISA) demonstrated that UII promoted the release of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and matrix metalloproteinase-9 (MMP-9). Western blot analysis showed that UII promoted the activation of nuclear factor-κB (NF-κB). These findings suggest that the enhanced levels of IL-6, TNF-α and MMP-9 in the tumor microenvironment, which likely resulted from increased activation of NF-κB induced by UII, may be one of the important mechanisms by which UII promotes lung adenocarcinoma growth. These findings imply that antagonists of UII or urotensin II-receptor (UT-R) have potential for the prevention and treatment of lung adenocarcinoma.

Systemic lupus and malignancies

PURPOSE OF REVIEW

Individuals with systemic lupus erythematosus (SLE) have an increased susceptibility to certain types of cancer. Given concerns focused on this issue, we present a review of this important topic.

RECENT FINDINGS

In non-Hodgkin lymphoma (NHL), a several-fold increased risk is seen in SLE versus the general population. It has long been suspected that immunosuppressive drugs play a role in this risk, but there may be other important driving factors as well. Lupus disease activity may itself heighten the risk of lymphoma in diseases like SLE. Lung cancer risk also is increased in SLE; smoking appears to drive this risk. Additionally, cervical dysplasia risk is increased in SLE, particularly with immunosuppressive drug exposure. An altered clearance of cancer-related viral agents in SLE (due to the disease and/or immunosuppression) may contribute to this risk and may also drive the risk for other cancers (such as vulvovaginal and hepatic carcinomas) in SLE. On the positive side, one new and significant finding is that SLE patients seem to have a decreased risk of certain nonhematologic cancers (breast, ovarian, endometrial, and prostate).

SUMMARY

Though much has been learnt so far regarding the risk in SLE, much yet remains unknown.

Aspirin and non-aspirin non-steroidal anti-inflammatory drug use and risk of lung cancer

There is evidence that aspirin and non-aspirin non-steroidal anti-inflammatory drug (NSAID) have anti-carcinogenic properties, but their effect on lung cancer, in particular in never-smokers, is unclear. Information on past or current use of anti-inflammatory medication was obtained in 398 Chinese female primary lung cancer cases and 814 controls in a hospital-based study in Singapore. 65% of cases and 88% of controls were never-smokers. Controls were excluded if they had been admitted for conditions associated with aspirin or NSAID use (n=174). Regular aspirin use (twice a week or more, for a month or more) was associated with a reduced risk of lung cancer (adjusted odds ratio [OR] 0.50, 95% confidence intervals [95%CI] 0.31-0.81 in non-smokers; OR 0.38, 95%CI 0.16-0.93 in smokers). Regular use of non-aspirin NSAID, paracetamol, steroid creams and steroid pills was uncommon and no association with lung cancer was detected. Our results suggest that aspirin consumption may reduce lung cancer risk in Asian women and are consistent with current understanding of the role of cyclooxygenase in lung carcinogenesis.

Meta-analysis on the association between nonsteroidal anti-inflammatory drug use and lung cancer risk

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs), especially aspirin, have emerged as the most potential chemopreventive agents. However, epidemiologic studies reported a controversial association between NSAID use and lung cancer risk. We conducted a meta-analysis to summarize the evidence for such relationship.

METHODS

Eligible studies were identified by searching the electronic literature PubMed, Medline, Embase, and ScienceDirect databases for relevant reports and bibliographies. Studies were included if they designed as cohort study, case-control study, or clinical trial on the NSAID exposure and lung cancer with sufficient raw data to analyzes. Relative risk (RR) or odds ratio (OR) was used to evaluate the association between NSAIDs and lung cancer. Stratified analysis was also performed.

RESULTS

A total of 19 studies including 20,266 lung cancer cases met the inclusion criteria. To the effect of aspirin on lung cancer, the combined RR for cohort studies was 0.96 (95%confidence interval [CI]: 0.78-1.19) and OR for case-control studies was 0.87 (95%CI: 0.69-1.09). When restricted in exposure of aspirin use to 7 tablets per week, the OR was 0.80 (95%CI: 0.67-0.95). The summary risk estimates showed no significant association between non-aspirin NSAID or overall NSAID use and lung cancer risk.

CONCLUSIONS

Aspirin use with a dose of 7 tablets per week can significantly reduce lung cancer risk, whereas non-aspirin NSAIDs showed no chemopreventive value. Greater attention should be paid to identifying appropriate individuals for this new indication of aspirin and the optimal dose and duration as a chemopreventive agent.

Use of glucosamine and chondroitin and lung cancer risk in the VITamins And Lifestyle (VITAL) cohort

OBJECTIVE

Inflammation plays an important role in lung carcinogenesis. Epidemiologic studies have reported inverse associations of non-steroidal anti-inflammatory drug (NSAID) use and lung cancer risk. Previously, we found that ever use of glucosamine and chondroitin, which have anti-inflammatory properties, were inversely associated with lung cancer risk. After an additional year of follow-up, we further examined the association including frequency/duration of use, interaction with factors associated with inflammation, and lung cancer histology.

METHODS

Participants were members of the VITamins And Lifestyle cohort. Adults, aged 50-76 years, who were residents of western Washington State, completed a baseline questionnaire in 2000-2002 (n = 76,904). Participants were queried on their use of glucosamine and chondroitin, over the 10 years prior to baseline, and categorized as nonuser, low use < 4 days/week or < 3 years, or high use ≥ 4 days/week and ≥ 3 years. Lung cancer cases (n = 808) were ascertained through linkage to the Surveillance, Epidemiology, and End Results cancer registry.

RESULTS

High 10-year use of glucosamine [hazard ratio (HR), 0.77; 95% CI: 0.56-1.07; p trend = 0.04] but not chondroitin was associated with a reduction in lung cancer risk. The association with glucosamine was limited to adenocarcinoma (HR, 0.49; 95% CI: 0.27-0.90; p trend <0.01) and was not modified by NSAID use or smoking status.

CONCLUSIONS

Our results for glucosamine use are similar to the prior human studies of NSAID use and lung cancer, both in magnitude and the limitation of the association to adenocarcinoma. Unlike NSAIDs, glucosamine has no known adverse effects. Although confirmatory studies are needed, glucosamine is an attractive candidate for lung cancer chemoprevention.

Aspirin use and risk for lung cancer: a meta-analysis

BACKGROUND

Aspirin has received increasing attention owing to its potential as a chemopreventive agent against lung cancer. Previous observational studies have reported inconsistent findings on this issue. We investigated the association between aspirin use and risk for lung cancer by conducting a meta-analysis.

PATIENTS AND METHODS

Relevant studies were identified by searching Medline, EMBASE, and Cochrane Library to December 2009. We also reviewed relevant bibliographies from the retrieved articles. Two authors independently extracted data and assessed study quality. Disagreements were resolved by consensus.

RESULTS

Fifteen studies (six case-control studies and nine prospective cohort studies) were included in the final meta-analysis. When all studies were pooled, the odds ratio (OR) of aspirin use for lung cancer risk was 0.86 [95% confidence interval (CI) 0.76-0.98]. In subgroup meta-analyses, there was no association between aspirin use and lung cancer risk among cohort studies (relative risk, 0.97; 95% CI 0.87-1.08), while there was a significant association among case-control studies (OR, 0.74; 95% CI 0.57-0.99). In a subgroup meta-analysis by quality of study methodology, a significant protective effect of aspirin use on lung cancer was observed only among eight low-quality studies (OR, 0.82; 95% CI 0.68-0.99), but not among seven high-quality studies (OR, 0.90; 95% CI 0.76-1.07).

CONCLUSIONS

Overall, the findings of this meta-analysis support that there was no association between aspirin use and lung cancer risk. Our findings should be confirmed in future prospective cohort studies or randomized, controlled trials.

Suppressive effect of sulindac on branch duct-intraductal papillary mucinous neoplasms

BACKGROUND

When considering surgery for branch duct-intraductal papillary mucinous neoplasms (BD-IPMNs) with suspected malignancy, it should be recognized that these lesions are frequently multifocal and are usually found in elderly patients with potential comorbidities that could affect the outcome of surgery. Clinical trials of chemoprevention have been conducted for a wide variety of malignancies.

METHODS

Twenty-two BD-IPMN patients participated in the trial at our institution from June 2004 to January 2007. Ten of the 22 patients who rejected surgical therapy although their lesions or clinical symptoms met the criteria for surgical resection of the International Association of Pancreatology guidelines were assigned to the treatment group. Sulindac (150 mg twice daily) and omeprazole (20 mg once daily) were administered to these patients for 18 months. The remaining 12 patients comprised the control group. Branch duct diameter and mural nodule heights were monitored by either magnetic resonance cholangiopancreatography (MRCP) or computed tomography (CT) and by endoscopic ultrasonography (EUS).

RESULTS

Both branch duct diameter and mural nodule height of BD-IPMNs in the treatment group were significantly reduced, while those in the control group were unchanged. Immunohistochemical staining for cyclooxygenase-1 and -2 was negative in hyperplasia, adenoma and carcinoma portions of resected pancreatic specimens but was clearly positive for glutathione-S-transferase pi (GST-pi), suggesting that GST-pi is a putative target molecule for sulindac.

CONCLUSIONS

Although a larger scale randomized controlled study is needed in future, the present results suggest the promise of chemoprevention of carcinoma derived from BD-IPMNs by sulindac.

Reactive Oxygen Species And Lung Tumorigenesis By Mutant K-ras: A Working Hypothesis

Wild-type K-ras is tumor suppressive in mouse lung, but mutant K-ras is actively oncogenic. Thus, the mutant protein must acquire new, dominant protumorigenic properties. Generation of reactive oxygen species could be one such property. The authors demonstrate increased peroxides in lung epithelial cells (E10)-transfected with mutant hK-ras(va112). An associated increase in DNA damage (comet assay) correlates with increased cyclooxygenase-2 protein. This DNA damage is completely abrogated by a specific cyclooxygenase-2 inhibitor (SC58125) or by a cell-permeable modified catalase. Literature is reviewed regarding generation of reactive oxygen and cyclooxygenase-2 induction by ras, cyclooxygenase-2 release of DNA-damaging reactive oxygen, and involvement of cyclooxygenase-2 and reactive oxygen in lung cancer

Socioeconomic differences in lung cancer incidence: a systematic review and meta-analysis

OBJECTIVE

To investigate the associations between various socioeconomic indicators and lung cancer incidence.

METHODS

We searched PubMed and EMBASE databases for studies on socioeconomic position (SEP) and lung cancer incidence published through October 2007. Random-effect model was used to pool the risk estimates from the individual studies. We stratified the analysis by adjustment strategy to investigate the influence of smoking on socioeconomic gradient in lung cancer incidence.

RESULTS

Out of 3,288 citations, we identified 64 studies eligible for inclusion. Compared to the highest SEP level, we observed an overall increased risk in lung cancer incidence among people with low educational SEP (61%), low occupational SEP (48%), and low income-based SEP (37%). The negative social gradient for lung cancer incidence remained for most of the possible sets of pooled estimates obtained in subgroup analyses for occupational and educational SEP with less consistency for SEP based on income in studies adjusted and unadjusted for smoking. No evidence of publication bias was apparent.

CONCLUSION

Lung cancer incidence was associated with low educational, occupational, and income-based SEP. The association, adjusted or unadjusted for smoking, points out the importance of social position to be addressed in all discussions on cancer preventive measures.

Aspirin and cancer risk: a summary review to 2007

Aspirin has been associated with a reduced risk of colorectal cancer and--based on limited evidence--to cancers of the oesophagus, stomach, breast, ovary and lung. The role of aspirin on other cancers, such as pancreatic, prostate and bladder cancer and non-Hodgkin's lymphomas and myeloma is less clear, and an increase of risk has been suggested for kidney cancer. For most cancer sites, however, significant heterogeneity between studies, and particularly between study design, was found, with a reduction in risk generally stronger in case-control studies than in cohort ones.

Mechanisms Involved in A/J Mouse Lung Tumorigenesis Induced by Inhalation of an Environmental Tobacco Smoke Surrogate

Lung tumors have been reproducibly induced in A/J mice exposed to a surrogate for experimental environmental tobacco smoke (ETSS) in a 5-mo inhalation period followed by 4 mo without further exposure. In order to increase our mechanistic understanding of this model, male mice were whole-body exposed for 6 h/d, 5 d/wk to ETSS with a particulate matter concentration of 100 mg/m(3). Food restriction regimens were included to model or exceed the ETSS-related impairment of body weight development. Half of the mice were pretreated with a single ip injection of urethane to study the effect of the above treatments on lung tumor development induced by this substance. At 5 mo, the tumor response was statistically the same for all groups of non-pretreated mice; however, the expected urethane-induced lung tumorigenesis was significantly inhibited by approximately 25% by ETSS and food restriction. This inhibition was accompanied by a threefold increase in blood corticosterone as a common stress marker for both ETSS and food restriction. At 9 mo, in mice not pretreated, the lung tumor incidence and multiplicity were significantly increased by twofold in the ETSS group; in the urethane-treated groups, the same high tumor multiplicity was reached regardless of previous treatment. The predominant tumor type in all groups was bronchiolo-alveolar adenoma. There was no induction of a specific K-ras mutation pattern by ETSS exposure. These data suggest a stress-induced inhibition of lung tumorigenesis in this model, explaining the need for the posttreatment period.

Perspectives on Pulmonary Inflammation and Lung Cancer Risk in Cigarette Smokers

Cigarette mainstream smoke (MSS) inhaled by smokers is a complex aerosol composed of minute liquid droplets suspended within a mixture of combustion gases (CO, CO2, NOx, etc.) and semivolatile compounds. The minute liquid droplets represent the particulate or "tar" phase, while the combustion gases and semivolatiles comprise the vapor phase. For historical and technical reasons, the vast majority of studies on the carcinogenicity of MSS have focused on the particulate phase. The particulate phase is mutagenic and cytotoxic in vitro, proinflammatory, and promotes tumor formation in animal models. In addition to cytotoxic compounds found in the particulate phase, the vapor phase of MSS contains a number of cytotoxic constituents including reactive aldehydes and carbonyls capable of damaging cells and inducing pulmonary inflammation. A large body of evidence suggests that smoking-induced pulmonary inflammation may play an important role in increasing lung cancer risk in smokers. Use of aspirin and nonsteroidal anti-inflammatory drugs is associated with reduced cancer development in animal models and lower lung cancer rates in smokers. A number of benign nonpulmonary and pulmonary diseases characterized by chronic inflammation increase the risk of cancer at the affected site in the absence of chemical exposure. Animal models displaying tumorigenic responses following exposure to either whole smoke or smoke fractions show elevated rates of cellular proliferation. A relationship between pulmonary inflammation and lung cancer is mechanistically plausible because inflammatory cells secrete activated oxygen species, inflammatory mediators, and proteolytic enzymes that can both damage DNA and lead to increases in reparative cell proliferation rates.

Regular adult aspirin use decreases the risk of non-small cell lung cancer among women

BACKGROUND

Prior studies indicate that use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAID) is associated with a decreased risk of non-small cell lung cancer (NSCLC); however, results have been contradictory in part because of variation in study design. Few studies have examined the use of aspirin or other NSAIDs on risk of NSCLC in women.

METHODS

Through a case-control study of African American and Caucasian women with and without NSCLC, we examined the relationship between use of aspirin, NSAIDs, and acetaminophen and risk of NSCLC. Risk was estimated by calculating odds ratios and 95% confidence intervals for ever/never use, duration of use, and duration of use category (never, 1-5 years, >5 years) after adjusting for major risk factors for lung cancer. Risk estimates were stratified by race, age, smoking history, and body mass index.

RESULTS

Every use of adult-strength aspirin was associated with a significant reduction in risk of NSCLC (odds ratio, 0.66; 95% confidence interval, 0.46-0.94). Additionally, there was a significant trend toward a reduced risk of NSCLC in adult-strength aspirin users with increasing duration of use (P(trend) = 0.02). In stratified analyses, aspirin use was associated with a significantly reduced risk of lung cancer among Caucasians and 55- to 64-year-olds. Baby aspirin and NSAID use was associated with a significant reduction in risk of NSCLC only among 65- to 74-year-olds.

CONCLUSION

Our results suggest that long-term use of adult-strength aspirin may reduce the risk of NSCLC in women.

Selective COX-2 inhibitor celecoxib combined with EGFR-TKI ZD1839 on non-small cell lung cancer cell lines: in vitro toxicity and mechanism study

Constitutive expression of cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) occurs frequently in non-small cell lung cancer (NSCLC). Anticancer research targeting EGFR has got an extensive attention especially in NSCLC and COX-2 inhibitor also shown a certain anticancer activity in recent years. Simultaneously targeting COX-2 and EGFR may be a promising therapeutic way. We carried out the in vitro study using selective COX-2 inhibitor celecoxib combined with EGFR-tyrosine kinase inhibitor (EGFR-TKI) ZD1839 on NSCLC cell lines to investigate the anti proliferation effect and the cell molecular mechanism. MTT growth assay showed the synergistic therapeutic effect of certain concentration of celecoxib combined with ZD1839 and synergistic apoptosis effect was detected by Hoechest33258 fluorescence staining and flow cytometric analysis. In western blot analysis, ZD1839 single agent inhibited the activation of EGFR and downstream cell signal transduction AKT and extrocellular signal-regulated kinase (ERK) pathways, the transcription activity of nuclear factor-kappa B (NF-kappaB), and the expression of COX-2. Celecoxib single agent could also inhibit AKT and ERK pathway in NSCLC, even the EGFR expression under high concentration treatment. Celecoxib combined with ZD1839 led to stronger inhibition of related cell signal transduction pathways in NSCLC.

Use of NSAIDs, smoking and lung cancer risk

We investigated the risk of lung cancer in relation to non-steroidal anti-inflammatory drugs (NSAIDs) among 573 cases and 857 sex- and age-matched controls for whom we had information on use of NSAIDs, from a prescription database covering all pharmacies in Denmark since 1995, and self-reported NSAID use, smoking habits and other potential confounders. Associations were expressed as odds ratios, assessed by logistic regression in unmatched analyses. After controlling for smoking habits, length of education and concomitant use of acetaminophen, we found a slightly decreased relative risk of 0.86 (95% confidence intervals, 0.65–1.14) for lung cancer associated with any use of NSAIDs. The risk decreased significantly (P=0.02) with increasing numbers of dispensed prescriptions per year during the 1–3 years before the index date with a relative risk of 0.49 (0.28–0.84) among those with four or more prescriptions per year during this period. Our findings suggest that regular use of NSAIDs is associated with a slightly or moderately reduced risk for lung cancer.

Aspirin and lung cancer risk in a cohort study of women: dosage, duration and latency

Aspirin may reduce the risk of cancer at some sites but its effect at the lung is unclear. We prospectively examined associations between aspirin use and risk of lung cancer in 109,348 women in the Nurses' Health study from 1980 to 2004. During this time, 1,360 lung cancers were documented in participants 36-82 years of age. Aspirin use and smoking were assessed every 2 years. Risk of lung cancer was a non-significant 16% lower for regular aspirin users of one or two tablets per week and a significant 55% higher for users of 15 or more tablets per week compared with women who never regularly used aspirin. Results were similar when limited to never smokers. For both the low and high quantity aspirin users, risk of lung cancer did not decline or increase with longer durations of use, and associations attenuated as the latency period between aspirin assessment and lung cancer diagnosis was lengthened. Our findings, together with those from previous clinical trials and prospective studies, do not provide consistent evidence that aspirin influences the development of lung cancer and further investigation is required with adjustment for smoking.

Nonsteroidal anti-inflammatory drugs and lung cancer risk: a population-based case control study

BACKGROUND

It remains unknown whether nonsteroidal anti-inflammatory drugs (NSAIDs) confer a protective effect against lung cancer development. We examined the relationship between NSAID exposure and subsequent lung cancer development in a large statewide, population-based cohort.

DESIGN

Nested case-control study in the Tennessee Medicaid population from 1990 to 2000.

METHODS

Lung cancer cases were identified using a statewide computerized claims database. Each time a case was identified, age- and sex-matched controls were randomly selected from the available source population. A detailed pharmacy database quantified nonsteroidal anti-inflammatory drug (NSAID) exposure during the 5 years before cancer diagnosis, and conditional logistic regression was used to examine the relationship between NSAID exposure and lung cancer development. Identical analyses were repeated in a subpopulation of high-risk individuals with chronic obstructive pulmonary disease (COPD).

RESULTS

303,399 persons were enrolled in the study population. During 1.9 million person-years of follow-up (median 6.3 years per person), 3,370 lung cancer cases were identified. Among those ever using NSAIDs, the adjusted odds ratio of developing lung cancer was 1.03 (95% confidence interval: 0.94-1.12). Among those using >24 months of NSAIDs in the 5 years before lung cancer diagnosis, the adjusted odds ratio for lung cancer was 0.96 (95% confidence interval: 0.82-1.11), and no protective effect was demonstrated in any NSAID exposure stratum. Similarly, among the 2519 high-risk individuals with chronic obstructive pulmonary disease, no significant protective effect from NSAIDs was noted.

CONCLUSION

This large statewide, population-based study did not demonstrate a protective effect of NSAIDs on lung cancer development in either the general or high-risk chronic obstructive pulmonary disease populations.

Willow bark extract (BNO1455) and its fractions suppress growth and induce apoptosis in human colon and lung cancer cells

BACKGROUND

Recently, there have been extensive efforts to evaluate the chemopreventive role of substances present in natural products. The aim of this study was to examine the effects of the main groups of compounds (salicylalcohol derivates, flavonoids, proanthocyanidins), and salicin isolated from willow bark extract BNO 1455 on proliferation and apoptosis in human colon and cancer cells.

METHODS

We used human colon cyclooxygenase-2 (COX-2)-positive HT 29 and (COX-2)-negative HCT 116 or lung COX-2 proficient A 549 and low COX-2 expressing SW2 cells. After treatment for 72 h with various concentrations of single substances and acetylsalicylic acid (ASA) as control, inhibition of cell growth and cytotoxicity were measured by colorimetric WST-1 assay and propidium iodide uptake by flow cytometry, respectively. Apoptotic cells were identified by annexin V adhesion using flow cytometry.

RESULTS

Studies on dose-dependent effects of BNO 1455 and its fractions showed anti-proliferative activity of all compounds with 50% maximal growth inhibitory concentrations (GI(50)) between 33.3 and 103.3 microg/ml for flavonoids and proanthocyanidins fractions and 50.0-243.0 microg/ml for salicylalcohol derivates and extract. Apoptosis induction was confirmed by annexin V adherence and analysis of cell morphology based on light scattering characteristics using flow cytometry in all cell lines at GI(50).

CONCLUSIONS

We showed that willow bark extract BNO 1455 an its fractions inhibit the cell growth and promote apoptosis in human colon and lung cancer cell lines irrespective of their COX-selectivity.

Nonsteroidal anti-inflammatory drugs and risk of lung cancer

Regular aspirin and non-aspirin nonsteroidal anti-inflammatory drug (NSAID) use is associated with a reduced risk of colorectal cancer. The effect of NSAIDs on the risk of other cancers remains unclear. To evaluate whether use of aspirin or other specific NSAIDs protects against lung cancer, we conducted a case-control study nested in a cohort of subjects 40-84 years old in 1995-2004, without a diagnosis of cancer before the study start date, and with at least 2 years of enrollment with a general practitioner providing data to the The Health Improvement Network (THIN) database in the UK. Patients who had a first diagnosis of primary lung cancer during the study period were considered cases. A random sample of 10,000 controls was frequency-matched to the cases for age, sex and calendar year. The index date for exposure definition was 1 year before the date of diagnosis for cases and 1 year before a random date within the study period for controls. Relative risks and 95% confidence intervals were estimated using conditional logistic regression stratified for matching factors. Factors such as smoking, chronic obstructive pulmonary disease, cardiovascular diseases and body mass index were introduced in the model. We identified 4,336 cases with primary incident lung cancer (incidence rate 7.6 per 10,000 person-years). Compared with subjects with no prescription of non-aspirin NSAID prior to the index date, the risk of lung cancer was 0.76 (0.61-0.94) among those who received a prescription the previous year and had a treatment duration of at least 1 year. The corresponding relative risk was 1.15 (0.99-1.34) for aspirin. In conclusion, prescription of non-aspirin NSAIDs for at least 1 year might be associated with a slightly reduced risk of lung cancer. Aspirin was not associated with a risk reduction, perhaps due to residual confounding.

Association between Nonsteroidal Anti-inflammatory Drug Use and the Incidence of Lung Cancer in the Iowa Women's Health Study

BACKGROUND

Previous studies have suggested that use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) may be associated with reduced risk of lung cancer, but the data are inconsistent and are limited particularly with respect to the effects of aspirin, separate from other NSAIDs.

METHODS

The Iowa Women's Health Study is a prospective cohort of 41,836 Iowa women ages 55 to 69 years old at baseline in 1986. NSAID use was assessed in 1992. Over 10 years of follow-up, 403 incident cases of lung cancer were identified. The association of incident lung cancer with current use of aspirin or non-aspirin NSAIDs was analyzed after adjustment for lung cancer risk factors. Hazard ratios (HR) were estimated using multivariate COX proportional hazards regression.

RESULTS

There were 27,162 women in the analytic cohort. After controlling for age, education, alcohol intake, pack-years, smoking status, body mass index, and total fruit intake, the RR of women taking six or more aspirin weekly was 1.21 (95% confidence interval, 0.92-1.59). The HR was 1.23 for women taking six or more non-aspirin NSAIDs weekly (95% confidence interval, 0.92-1.65). There was no statistically significant trend by frequency of use for either aspirin (P(trend) = 0.22) or non-aspirin NSAIDs (P(trend) = 0.53). Analyses by histologic type and smoking status yielded similar null results. Information on dosage and duration of use were not available for this analysis.

CONCLUSION

These findings do not suggest that aspirin or other NSAIDs reduce risk of lung cancer in this cohort of postmenopausal women.

Aspirin and cancer risk: an updated quantitative review to 2005

Aspirin has been associated to a reduced risk of colorectal, and possibly of a few other common cancers. Epidemiological studies on aspirin and cancer risk published up to December 2005 have been reviewed, and pooled relative risks (RR) for several cancers have been provided. Besides a reduction in the risk of cancer of the colorectum (RR = 0.71, 95% confidence interval, CI: 0.67-0.75), there is evidence-although more limited, and mainly from case-control studies-that aspirin has a favourable effect on cancers of the esophagus (RR = 0.72, 95% CI: 0.62-0.84), stomach (RR = 0.84, 95% CI: 0.76-0.93), breast (RR = 0.91, 95% CI: 0.88-0.95), ovary (RR = 0.89, 95% CI: 0.78-1.02) and lung (RR = 0.94, 95% CI: 0.89-1.00). The role of aspirin on other cancers, such as pancreatic, prostate, bladder cancer, and non-Hodgkins' lymphomas is less clear, and an increase of risk has been suggested for kidney cancer. For most cancer sites, however, significant heterogeneity between studies, and particularly across study design, was found, with a reduction in risk generally stronger in case-control than in cohort studies. Further, notwithstanding the large amount of epidemiological evidence, substantial uncertainties remain about the proper aspirin dose and duration of treatment.

Sodium salicylate inhibits TNF-alpha-induced NF-kappaB activation, cell migration, invasion and ICAM-1 expression in human melanoma cells

We have previously shown that tumour necrosis factor-alpha (TNF-alpha) upregulates human melanoma cell integrin expression, migration and invasion in vitro. The aim of this study was to investigate the effect of the non-steroidal anti-inflammatory agent sodium salicylate on TNF-alpha-induced activation of the transcription factor nuclear factor-kappaB (NF-kappaB) and upregulation of intercellular adhesion molecule-1 (ICAM-1), and TNF-alpha-stimulated cell migration and invasion through fibronectin. HBL human melanoma cells were pre-incubated with sodium salicylate prior to stimulation with TNF-alpha for 24 h. NF-kappaB activation was measured using an assay that detects changes in the expression of a luciferase reporter gene under the direct control of NF-kappaB transcriptional activity. The effect of sodium salicylate and TNF-alpha on HBL cell invasion over 20 h and migration over 24 h was studied using fibronectin invasion and 'scratch wound' migration models in vitro, as described previously. Sodium salicylate inhibited TNF-alpha-stimulated NF-kappaB activation in melanoma cells in a concentration-dependent manner, and this was achieved with pre-incubation times as short as 15 min. TNF-alpha-stimulated ICAM-1 expression in HBL cells was also downregulated by sodium salicylate, although in a manner inversely related to the concentration of this agent. In functional assays, TNF-alpha stimulated migration and invasion, and sodium salicylate significantly reduced the extent of melanoma invasion and migration in both the presence and absence of TNF-alpha. In conclusion, sodium salicylate effectively inhibited TNF-alpha-induced upregulation of NF-kappaB, ICAM-1 expression, in-vitro migration and invasion in human melanoma cells, indicating that non-steroidal anti-inflammatory drugs may be a useful therapeutic approach to oppose inflammation-induced melanoma invasion and metastasis in vivo.

Relationship between cyclooxygenase 8473T>C polymorphism and the risk of lung cancer: a case-control study

BACKGROUND

Cyclooxygenase-2 (COX-2) plays an important role in the development of lung cancer. DNA sequence variations in the COX-2 gene may lead to altered COX-2 production and/or activity, and so they cause inter-individual differences in the susceptibility to lung cancer. To test this hypothesis, we investigated the association between the 8473T>C polymorphism in the 3'-untranslated region of the COX-2 gene and the risk of lung cancer in a Korean population.

METHODS

The COX-2 genotypes were determined using PCR-based primer-introduced restriction analysis in 582 lung cancer patients and in 582 healthy controls that were frequency-matched for age and gender.

RESULTS

The distribution of the COX-2 8473T>C genotypes was not significantly different between the overall lung cancer cases and the controls. However, when the cases were categorized by the tumor histology, the combined 8473 TC + CC genotype was associated with a significantly decreased risk of adenocarcinoma as compared with the 8473 TT genotype (adjusted OR = 0.64; 95% CI = 0.46-0.90, P = 0.01). On the stratification analysis, the protective effect of the combined 8473 TC + CC genotype against adenocarcinoma was statistically significant in the males, older individuals and ever-smokers (adjusted OR = 0.59; 95% CI = 0.39-0.91, P = 0.02; adjusted OR = 0.55; 95% CI = 0.33-0.93, P = 0.03; and adjusted OR = 0.57; 95% CI = 0.37-0.87, P = 0.01, respectively).

CONCLUSION

These findings suggest that the COX-2 8473T>C polymorphism could be used as a marker for the genetic susceptibility to adenocarcinoma of the lung.

alpha-Melanocyte stimulating hormone, inflammation and human melanoma

Alpha-melanocyte stimulating hormone (alpha-MSH) arises from the proteolytic cleavage of proopiomelanocortin (POMC) and is the most potent naturally occurring melanotropic peptide. The biological effects of alpha-MSH are mediated via melanocortin receptors (MCRs), which are expressed in virtually every cutaneous cell type. alpha-MSH has pleiotrophic functions including the modulation of a wide range of inflammatory stimuli such as proinflammatory cytokines, adhesion molecules and inflammatory transcription factors. All of the former would be consistent with a cytoprotective role for this hormone in protecting skin cells from exogenous stress, as would occur following UV exposure or exposure to agents inducing inflammation or oxidative stress. In addition to actions on normal skin cells it also modulates both cutaneous and uveal melanoma cell behavior. With respect to melanoma, alpha-MSH is intriguing as studies have shown that while alpha-MSH has the potential to retard metastatic spread (by reducing cell migration and invasion) it is also capable of reducing the ability of the immune system to detect tumor cells (by down regulating adhesion molecules that would normally assist in immune cell interaction with melanoma cells). This review considers the evolving biology of alpha-MSH and discusses its role in man that extend far beyond pigmentation of skin melanocytes, suggesting that the detoxifying role of alpha-MSH in inducing melanogenesis is only one aspect of the stress-coping role of this hormone. Indeed melanoma cells may owe at least some of their success to the 'protective' role of alpha-MSH.

A study of the effect of salicylic acetic acid on a lymphocyte cell model of cellular activation and proliferation

Salicylic acetic acid (SAA) is a drug that has formed part of the treatment of many diseases for many years. Its anti-inflammatory activity is well known, but recently its possible role in the interference in the oncogenesis mechanisms has become apparent. With the aim of supporting these yet preliminary observations, we studied the effect of salicylic acetic acid on a cellular activation and proliferation model. We used lymphocytes obtained from peripheral blood, which were later exposed to cellular activation and proliferation stimulus by the SEB antigen. Lymphocyte activation was determined by direct immunoflourescence through expression of the receptor IL-2 (CD25) alpha chain and proliferation through the incorporation of tritiated thymidine to the DNA in synthesis together with the determination of the cellular cycle by flow cytometry. We found that both processes, activation and proliferation, are inhibited by increasing doses of SAA.

Chemoprevention in lung carcinogenesis--an overview

Lung cancer ranks among the most commonly occurring malignancies and is currently the leading cause of cancer-related death worldwide. This is due to its late diagnosis and relative resistance to standard oncological treatment approaches. The heavy burden of lung cancer and its treatment resistance have elicited an intense interest in the promising approach of chemoprevention. Chemoprevention is defined as a pharmacologic intervention to suppress or reverse the carcinogenic process and the lung is one of the most studied sites for cancer chemoprevention. This review, with a short update on pulmonary carcinogenesis, will summarize the available knowledge of chemoprevention trials and agents with a preventive potential in the 'lung field'.

Dimethyl celecoxib as a novel non-cyclooxygenase 2 therapy in the treatment of non-small cell lung cancer

OBJECTIVES

The cyclooxygenase 2 enzyme has become a therapeutic target in cancer treatment. Cyclooxygenase 2 blockade with selective inhibitors increases apoptosis and decreases the metastatic potential of lung cancer cells. Some of the antitumor effects of these inhibitors may occur through both cyclooxygenase 2-dependent and independent pathways. Our goal was to investigate these pathways using celecoxib (selective cyclooxygenase 2 inhibitor) and 2,5-dimethyl celecoxib, a structural analog modified to eliminate cyclooxygenase 2 inhibitory activity, while potentially maintaining antineoplastic properties.

METHODS

2,5-dimethyl celecoxib was synthesized in the Department of Chemistry at the University of Southern California. With the use of non-small cell lung cancer cells (A549), prostaglandin E2 production was quantified by enzyme-linked immunosorbent assay to assess cyclooxygenase 2 activity. Cell proliferation was assessed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt assay. Cell migration was performed using transwell inserts that were matrigel coated for invasion experiments. Gelatin zymography was used to assess matrix-metalloproteinase activity.

RESULTS

2,5-dimethyl celecoxib did not inhibit interleukin-1beta-stimulated prostaglandin E2 production, whereas celecoxib did even at low doses. Both celecoxib and 2,5-dimethyl celecoxib decreased tumor cell viability and proliferation with IC50 for celecoxib and 2,5-dimethyl celecoxib of 73 and 53 micromol/L, respectively. Both drugs were also potent inducers of apoptosis, and both inhibited tumor cell migration and invasion. This was associated with down-regulation of matrix metalloproteinase activity.

CONCLUSIONS

2,5-dimethyl celecoxib is a structural analog of celecoxib that lacks cyclooxygenase 2 inhibitory activity but exhibits significant antineoplastic properties comparable to celecoxib. This suggests that the antineoplastic activities of celecoxib are, at least in part, cyclooxygenase independent and that therapeutic strategies can be developed without the side effects of global cyclooxygenase 2 blockade.

Evaluation of cyclooxygenase-2 inhibition in an orthotopic murine model of lung cancer for dose-dependent effect

OBJECTIVES

Cyclooxygenase-2 plays a role in growth, apoptosis, angiogenesis, and metastasis in lung cancer. Inhibition of cyclooxygenase-2 with celecoxib has been shown to inhibit tumor growth. We evaluated the effect of increasing doses of celecoxib in a murine model of human lung cancer.

METHODS

Human lung adenocarcinoma cells (A549) were implanted in the left lung upper lobe of mice with severe combined immunodeficiency syndrome. Mice were randomly assigned to 4 groups at implantation (n = 10 per group): control, 125 mg/kg chow, 500 mg/kg chow, 1000 mg/kg chow. After 3 weeks, mice were killed, and a blinded observer measured total tumor volume. The dose effect of celecoxib was examined in vitro by studying cell proliferation, expression of cyclooxygenase-2 (mRNA and protein), and production of prostaglandin E 2 in unstimulated and interleukin 1beta-stimulated cells.

RESULTS

All 40 mice survived for 3 weeks with no observed toxicities. Total tumor volume was inhibited in each celecoxib group ( P = .0038, Welch analysis of variance): 206.7 +/- 119.5 mm 3 (control group), 41.4 +/- 54.0 mm 3 (low-dose group), 34.5 +/- 39.3 mm 3 (medium-dose group), and 27.3 +/- 53.6 mm 3 (high-dose group). In vitro celecoxib was effective at inhibiting production of prostaglandin E 2 , even in stimulated cells, although little effect was seen on cyclooxygenase-2 protein levels. Inhibition of proliferation was evident only at doses that exceeded those used in the animal model.

CONCLUSION

Inhibition of cyclooxygenase-2 with low-dose celecoxib restricted the growth of lung cancer in this model. This might be mediated by prostaglandin E 2 . Higher doses of celecoxib afforded no additional benefit. Chronic therapy with low-dose cyclooxygenase-2 inhibition has the potential to influence tumor progression in non-small cell lung cancer.

Novel Strategies for the Early Detection and Prevention of Lung Cancer

Lung cancer is the leading cause of cancer death in the United States. Despite evidence of molecular abnormalities in biological specimens, progress in this disease is hampered by the lack of diagnostic markers useful for clinical practice. The majority of patients with lung cancer are still diagnosed at an advanced stage, when prognosis is poor. This article reviews new strategies being studied for the early detection of lung cancer. These strategies involve new methods of imaging (including low-dose computed tomography [CT] scanning), DNA analysis, and proteomic-based techniques. These strategies have not only improved our understanding of lung cancer but show promise in offering better survival to patients with this deadly disease. Of paramount importance in the search for methods of early detection is the need for the identification of the ideal population to screen, a multidisciplinary approach, and validation of promising techniques.

Nonsteroidal Antiinflammatory Drug Use and Lung Cancer

STUDY OBJECTIVE

Studies done both in laboratory animals and humans suggest that nonsteroidal antiinflammatory drug (NSAID) use may reduce the risk of developing lung cancer. Many epidemiologic studies exploring this association lacked sufficient power to draw definitive conclusions. We conducted a metaanalysis to examine the effect of NSAID use on the risk of lung cancer.

DESIGN

We searched the literature using MEDLINE, CANCERLIT, related conference abstracts, and bibliographies of selected studies. The estimators of relative risk (RR) and associated variances, adjusted for the greatest number of confounders, were abstracted and included in the metaanalysis. Combined estimators of RR were calculated using either fixed or random-effect models. Metaanalyses were performed on 14 studies (the number of cases ranged from 81 to 2,560) that examined the association between lung cancer and NSAIDs. Further, subgroup analyses were performed on the nine studies that had adjusted for the effects of smoking.

RESULTS

The combined estimate of RR was 0.79 (95% confidence interval [CI], 0.66 to 0.95) when all the studies were included in the analysis, and was 0.68 (95% CI, 0.55 to 0.85) when the analysis was limited to the subgroup of studies adjusted for smoking. The combined estimates for case-control studies and cohort studies within this subgroup were 0.63 (95% CI, 0.47 to 0.86) and 0.78 (95% CI, 0.62 to 0.98), respectively. We also observed that small cell lung cancer was more inversely associated with NSAID use (RR, 0.48; 95% CI, 0.30 to 0.75) than non-small cell lung cancer (RR, 0.66; 95% CI, 0.56 to 0.79).

CONCLUSION

The findings of this study support an inverse association between NSAID use and risk of lung cancer, but do not suggest a causal relationship.

Use of nonaspirin NSAIDs and risk of lung cancer

Epidemiologic evidence is conflicting regarding the potential for nonsteroidal antiinflammatory drugs (NSAIDs) to lower the risk of lung cancer. We thus determined the incidence of lung cancer among a cohort of over 242,000 adults in Denmark who had been issued NSAID prescriptions during 1991-2002 and calculated the relative risks of this cancer according to the numbers of prescriptions received. Similar analyses were conducted among a subset with chronic obstructive pulmonary disease, of whom the large majority was assumed to have been smokers, as an indirect control for smoking. Utilization of Danish registries ensured essentially complete and unbiased ascertainment of prescriptions and cancer outcomes. The relative risks of lung cancer among NSAID users redeeming 10 or more prescriptions vs. nonusers in the general population and among chronic obstructive pulmonary disease patients were 1.51 (95% CI = 1.33-1.71) and 1.55 (95% CI = 0.93-2.60) and tended to decline with decreasing numbers of NSAIDs prescribed. Separate analyses for adenocarcinoma and squamous cell carcinoma also failed to show reduced risks among NSAID users. Confounding by indication may have contributed to the increased risks, but the study provides no evidence to suggest that recent NSAID intake may be protective for lung cancer.

Chemoprevention of lung cancer: current status and future prospects

The statistics on lung cancer form a powerful argument to develop new methods to control this most deadly form of cancer. Chemoprevention is one of these new approaches. Carcinogens from cigarette smoke form the link between nicotine addiction and lung cancer. At the same time it has become increasingly clear that dietary and genetically determined factors play an important role in modulating the individual susceptibility and are linked to the chemoprevention approach. In spite of many positive pre-clinical observations, most of the experiences with potential chemopreventive agents such as retinoids and antioxidants in individuals at risk for lung cancer have been negative so far. Moreover, beta-carotene was associated with an increased lung cancer incidence in two large randomized studies, most likely due to negative interaction with cigarette smoke. The recent progress in diagnostic techniques and molecular biology has led to a new paradigm for chemoprevention and there is considerable optimism regarding the potential of new molecules and antibodies that target specific cellular receptors or mutations. This article reviews the lung cancer chemoprevention efforts of the last two decades and also gives prospects for the next coming years.