Circulating levels of coagulation and inflammation markers and cancer risks: individual participant analysis of data from three long-term cohorts

Higher Risk of Recurrence in Patients Treated for Head and Neck Cancer with Low BMI and Elevated Levels of C-Reactive Protein

Simple Summary

Head and neck cancer (HNC) treatment poses several challenges in clinical practice, and treatment side effects can be debilitating due to the close proximity of important anatomical structures. Cancer recurrence post-treatment presents some of the most challenging HNC management issues. This prospective study identifies high-risk groups for recurrence of head and neck cancer, based on commonly accessible clinical parameters. In this study with 272 HNC patients, elevated pre- and post-treatment CRP levels, low BMI and advanced stage at admission indicate higher risk for recurrence of disease. Using these parameters, a risk model is proposed which may be useful for estimating the probability of cancer recurrence and allow the identification of high and low-risk patients.

Abstract

This prospective study identifies high-risk groups for recurrence of head and neck cancer by BMI and circulating inflammatory response markers. Head and neck cancer patients from three Swedish hospitals were included (n = 272). Leukocyte and thrombocyte counts, CRP levels, and BMI were measured pre-treatment and post-treatment. Associations between the four factors and treatment failure (residual tumor, loco-regional failure, general failure/distant metastasis) were assessed using a Cox proportional hazards model adjusted for sex, age at the initial visit, smoking status, cancer stage, and hemoglobin count. CRP level was the only significant single variable, with an average increase in risk of recurrence of 74% (p = 0.018) for every doubling. The predictive power of a combined model using all variables was highest during the initial months after treatment, with AUC under the ROC curve 0.75 at the 0–3 month timepoints. Patients with elevated pre- and post-treatment CRP levels are at higher risk for recurrence of disease. Male patients with low post-treatment BMI, advanced stage, and high CRP at any time post treatment are at high risk for recurrence. The combined model may be useful for stratifying post-treatment patients into low and high-risk groups, to enable more detailed follow-up or additional treatment regimens.

Methylation-derived inflammatory measures and lung cancer risk and survival

BACKGROUND

Examining immunity-related DNA methylation alterations in blood could help elucidate the role of the immune response in lung cancer etiology and aid in discovering factors that are key to lung cancer development and progression. In a nested, matched case-control study, we estimated methylation-derived NLR (mdNLR) and quantified DNA methylation levels at loci previously linked with circulating concentrations of C-reactive protein (CRP). We examined associations between these measures and lung cancer risk and survival.

RESULTS

Using conditional logistic regression and further adjusting for BMI, batch effects, and a smoking-based methylation score, we observed a 47% increased risk of non-small cell lung cancer (NSCLC) for one standard deviation (SD) increase in mdNLR (n = 150 pairs; OR: 1.47, 95% CI 1.08, 2.02). Using a similar model, the estimated CRP Scores were inversely associated with risk of NSCLC (e.g., Score 1 OR: 0.57, 95% CI: 0.40, 0.81). Using Cox proportional hazards models adjusting for age, sex, smoking status, methylation-predicted pack-years, BMI, batch effect, and stage, we observed a 28% increased risk of dying from lung cancer (n = 145 deaths in 205 cases; HR: 1.28, 95% CI: 1.09, 1.50) for one SD increase in mdNLR.

CONCLUSIONS

Our study demonstrates that immunity status measured with DNA methylation markers is associated with lung cancer a decade or more prior to cancer diagnosis. A better understanding of immunity-associated methylation-based biomarkers in lung cancer development could provide insight into critical pathways.

Biomarkers and Lung Cancer Early Detection: State of the Art

Simple Summary

Lung cancer is the leading cause of cancer death worldwide. Detecting lung malignancies promptly is essential for any anticancer treatment to reduce mortality and morbidity, especially in high-risk individuals. The use of liquid biopsy to detect circulating biomarkers such as RNA, microRNA, DNA, proteins, autoantibodies in the blood, as well as circulating tumor cells (CTCs), can substantially change the way we manage lung cancer patients by improving disease stratification using intrinsic molecular characteristics, identification of therapeutic targets and monitoring molecular residual disease. Here, we made an update on recent developments in liquid biopsy-based biomarkers for lung cancer early diagnosis, and we propose guidelines for an accurate study design, execution, and data interpretation for biomarker development.

Abstract

Lung cancer burden is increasing, with 2 million deaths/year worldwide. Current limitations in early detection impede lung cancer diagnosis when the disease is still localized and thus more curable by surgery or multimodality treatment. Liquid biopsy is emerging as an important tool for lung cancer early detection and for monitoring therapy response. Here, we reviewed recent advances in liquid biopsy for early diagnosis of lung cancer. We summarized DNA- or RNA-based biomarkers, proteins, autoantibodies circulating in the blood, as well as circulating tumor cells (CTCs), and compared the most promising studies in terms of biomarkers prediction performance. While we observed an overall good performance for the proposed biomarkers, we noticed some critical aspects which may complicate the successful translation of these biomarkers into the clinical setting. We, therefore, proposed a roadmap for successful development of lung cancer biomarkers during the discovery, prioritization, and clinical validation phase. The integration of innovative minimally invasive biomarkers in screening programs is highly demanded to augment lung cancer early detection.

Hemostatic biomarkers in occult cancer and cancer risk prediction

Cancer patients present with abnormalities of coagulation tests, reflecting a hypercoagulable state, often asso- ciated with a high incidence of thrombotic complications and poor disease prognosis. Different degrees of blood clotting abnormalities are described in diverse cancers, depending on tumor types and stage. The mechanisms of hemostasis that are critically involved in thrombosis are also implicated in tumor progression, angiogenesis, and metastatic spread. In this review, we summarize the results of published studies and focus on ongoing research and future directions of clotting factors and clotting activation bioproducts as biomarkers for cancer disease diagnosis and in cancer risk prediction.

Chronic inflammation towards cancer incidence: A systematic review and meta-analysis of epidemiological studies

This systematic review and meta-analysis provides epidemiological data on the relationship between chronic inflammation, as measured by inflammatory blood parameters, and cancer incidence. Two independent researchers searched PubMed, Web Of Science and Embase databases until October 2020. In vitro studies, animal studies, studies with chronically-ill subjects or cross-sectional studies were excluded. Quality was assessed with the Newcastle-Ottawa scale. The 59 nested case-control, 6 nested case-cohort and 42 prospective cohort studies considered 119 different inflammatory markers (top three: CRP, fibrinogen and IL6) and 26 cancer types (top five: colorectal, lung, breast, overall and prostate cancer). Nineteen meta-analyses resulted in ten significant positive associations: CRP-breast (OR = 1.23[1.05-1.43];HR = 1.14[1.01-1.28)), CRP-colorectal (OR = 1.34[1.11-1.60]), CRP-lung (HR = 2.03[1.59-2.60]), fibrinogen-lung (OR = 2.56[1.86-3.54]), IL6-lung (OR = 1.41[1.12-1.78]), CRP-ovarian (OR = 1.41[1.10-1.80]), CRP-prostate (HR = 1.09[1.03-1.15]), CRP-overall (HR = 1.35[1.16-1.57]) and fibrinogen-overall (OR = 1.22[1.07-1.39]). Study quality improvements can be done by better verification of inflammatory status (more than one baseline measurement of one parameter), adjusting for important confounders and ensuring long-term follow-up.

Fibrinogen is associated with EGFR mutation status and lymphatic metastasis in non-small cell lung cancer

In the previous decade, tyrosine kinase inhibitors (TKIs) have demonstrated significant effects in patients with non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. However, sufficient tumor tissue for genetic testing cannot always be obtained in clinical settings. The present study evaluated whether fibrinogen may assist in predicting the EFGR mutation status in patients with NSCLC. Between January 2010 to December 2013, 303 patients with NSCLC underwent EGFR mutation testing. Plasma fibrinogen was acquired prior to treatment, and the associations between fibrinogen, EGFR mutation status and clinical features were assessed. A multivariate analysis and a receiver operator characteristic curve analysis were performed to identify the potential value of fibrinogen in predicting EGFR mutation status. The proportion of patients with hyperfibrinogenemia was significantly higher in N2 and N3 stages compared with N0 and N1 stages, 45.2 and 56.5 vs. 29.2 and 36.0%, respectively (P=0.001), and higher in the M1 stage compared with the M0 stage, 47.9 vs. 35.2%, respectively (P=0.025) (Stages according to the American Joint Committee of Cancer, 7th edition). Plasma fibrinogen levels were significantly lower in patients with EGFR mutations compared with the wild-type EGFR gene, 2.95 g/l (range, 0.84 −8.61 g/l) vs. 3.57 g/l (range, 1.38–7.44 g/l), respectively (P<0.001). In the multivariate analysis, logistic regression was utilized and the fibrinogen odds ratio (OR), 2.5, confidence intervals (CI) 1.53–4.51 (P<0.001) and smoking status OR 5.07, CI 3.01–8.53 (P<0.001), for which the area under the curve was 0.75, were revealed to be independent predictive factors. Hyperfibrinogenemia is associated with metastasis of the distant organs, but also metastasis of the lymphatic tissue. In addition, a multivariate model based on fibrinogen and smoking history may be used as a predictive marker of EGFR mutation status in patients with NSCLC.

Chronic inflammation and risk of lung cancer in older adults in the health, aging and body composition cohort study

OBJECTIVES

We examined the association between three inflammatory markers (Interleukin (IL)-6, C-reactive protein (CRP), tumor necrosis factor (TNF)-α) and incident lung cancer using baseline, updated, and averaged inflammatory measures in older adults.

METHODS

We fitted multivariable Cox models to assess whether circulating levels of inflammation markers were associated with incident lung cancers in the Health Aging, Body and Composition (HealthABC) prospective cohort of 3075 older adults aged 70-79 years at baseline. IL-6 and CRP were measured biennially, whereas TNF-α was measured at baseline.

RESULTS

Baseline levels of IL-6 were significantly associated with incident lung cancer risk in a model that adjusted for age, gender, race, and site (Model 1) (Hazard Ratio_{T3 vs. T1}: 3.34, 95% Confidence Interval: 1.91, 5.85) and in a model adjusted for health factors linked to chronic inflammation (Model 2) (HR _{T3 vs. T1}: 2.57, 95% CI: 1.41, 4.65). The associations observed in time-updated IL-6 (HR _{T3 vs. T1}: 2.47, 95% CI: 1.43, 4.28), cumulatively averaged IL-6 (HR _{T3 vs. T1}: 2.47, 95% CI: 1.43, 4.35), and baseline CRP levels (HR _{T3 vs. T1}: 1.85, 95% CI: 1.11, 3.08) with incident lung cancer in Model 1 were not statistically significant in Model 2.

CONCLUSIONS

Baseline CRP and IL-6 levels were associated with increased risk of lung cancer in Model 1 and both models, respectively. Chronic IL-6 inflammation, as quantified by repeated measures was associated with incident lung cancer in Model 1, but not Model 2. Further research is needed to understand the role of CRP and IL-6 in lung carcinogenesis.

Inflammatory biomarkers and risk of cancer in 84,000 individuals from the general population

Inflammation and cancer are tightly linked. This study tests the hypothesis that an inflammatory score based on plasma levels of C-reactive protein (CRP) and fibrinogen and whole blood leukocyte count is associated with risk of colorectal, lung, breast and prostate cancer. A score ranging from none through three elevated biomarkers was constructed in 84,000 individuals from the Danish general population. During a median follow-up time of 4.8 years, 4,081 incident cancers occurred. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) of incident cancer. Multifactor-adjusted HRs for colorectal cancer were 1.28 (95% CI, 1.01 to 1.62), 1.79 (95% CI, 1.41 to 2.27) and 2.18 (95% CI, 1.67 to 2.86) for individuals with elevated levels of one, two and three inflammatory biomarkers compared to individuals with none elevated biomarkers. A similar stepwise increasing risk was observed for lung and breast cancer with HRs of 3.03 (95% CI, 2.25 to 4.08) and 1.42 (95% CI, 1.11 to 1.80) for three versus none elevated biomarkers. HRs were highest within the first years of follow-up. Absolute 5-year risk of lung cancer was 7.8 (95% CI, 6.1 to 10)% among older smokers with three elevated biomarkers compared to 3.8 (95% CI, 2.6 to 5.6)% among those with none elevated biomarkers. In conclusion, simultaneously elevated CRP, fibrinogen and leukocyte count are associated with an increased risk of colorectal, lung and breast cancer. Cancer as a promoter of inflammation may be more likely to account for our findings than low-grade inflammation promoting cancer development.

Inflammatory biomarker score and cancer: A population-based prospective cohort study

BACKGROUND

Inflammation is associated with cancer but there are conflicting reports on associations of biomarkers of inflammation with cancer risk and mortality. We investigated the associations of C-reactive protein (CRP) and leukocyte count with cancer risk and mortality using individual biomarkers, and an inflammatory score derived from both biomarkers.

METHODS

We conducted this analysis among 2,570 men enrolled in the population-based, prospective Kuopio Ischemic Heart Disease Risk Factor Study in Finland. During an average follow-up period of 26 years, 653 cancer cases and 287 cancer deaths occurred. We computed a z-score for each participant, with the combined z-score being the sum of each individual's CRP and leukocyte z-scores. Multivariable-adjusted Cox proportional hazard model was used to evaluate associations with cancer risk and mortality.

RESULTS

Using individual biomarkers, elevated leukocyte count was associated with an increased risk of cancer (RR = 1.31, 95% CI 1.04-1.66), and cancer mortality (RR=, 95% CI 1.39, 0.98-1.97). The corresponding results for CRP were (RR = 1.23, 95% CI 0.97-1.55) for risk and (RR = 1.15, 95% CI 0.81-1.64) for cancer mortality. Associations of the biomarkers with cancer appeared to be more robust using the combined z-score. HRs comparing men within the highest z-score quartile to those within the lowest z-score quartiles were 1.47 (95% CI 1.16-1.88, p-trend < 0.01) for cancer risk, and 1.48 (95% CI 1.03-2.14, p-trend = 0.09) for cancer mortality.

CONCLUSION

Our study suggests that inflammation is associated with cancer risk and mortality, and combining inflammatory biomarkers into a score is a robust method of elucidating this association.

Evaluation of neutrophil-to-lymphocyte ratio prior to prostate biopsy to predict biopsy histology: Results of 1836 patients

INTRODUCTION

We evaluate the role of NLR prior to prostate biopsy to predict biopsy histology and Gleason score in patients with prostate cancer.

METHODS

In this retrospective study, we evaluated data of patients underwent prostate biopsy between May 2005 and March 2015. We collected the following data: age, prostate-specific antigen (PSA), biopsy histology, Gleason score (GS) in prostate cancer patients, neutrophil counts, and lymphocyte counts. Patients were grouped as benign prostatic hyperplasia (BPH), prostate cancer, and prostatitis. The Chi square test was used to compare categorical variables and analysis of variance (ANOVA) was applied for continuous variables.

RESULTS

Data of 1836 patients were investigated. The mean age, total PSA and neutrophil-lymphocyte ratio (NLR) of the population were 66.8 ± 8.17 years, 9.38 ± 4.7 ng/dL, and 3.11 ± 1.71, respectively. Patients were divided as follows: 625 in the group with BPH history, 600 in the prostatitis group, and 611 in the prostate cancer histology group. The mean NLR of the prostatitis group was higher compared to the prostate cancer and BPH groups (p = 0.0001). The mean NLR of the prostate cancer group was significantly higher compared to the BPH group (p = 0.002). The GS 8-10 group had a significantly higher mean NLR compared to GS 5-6 (3.64 vs. 2.54, p = 0.0001) and GS 7 (3.64 vs. 2.58, p = 0.0001) patients.

CONCLUSIONS

NLR was found to differ with regard to histology of prostate biopsy and higher GS was associated with higher NLR in patients with prostate cancer. However prostatitis prevents the use of NLR in predicting prostate cancer before a prostate biopsy. Also, the retrospective nature and lack of multivariate analysis in this study somewhat limits the relevance of these results.

Biological Marker Analysis as Part of the CIBERES-RTIC Cancer-SEPAR Strategic Project on Lung Cancer

The aim of the Clinical and Molecular Staging of Stage I-IIp Lung Cancer Project is to identify molecular variables that improve the prognostic and predictive accuracy of TMN classification in stage I/IIp non-small cell lung cancer (NSCLC). Clinical data and lung tissue, tumor and blood samples will be collected from 3 patient cohorts created for this purpose. The prognostic protein signature will be validated from these samples, and micro-RNA, ALK, Ros1, Pdl-1, and TKT, TKTL1 y G6PD expression will be analyzed. Tissue inflammatory markers and stromal cell markers will also be analyzed. Methylation of p16, DAPK, RASSF1a, APC and CDH13 genes in the tissue samples will be determined, and inflammatory markers in peripheral blood will also be analyzed. Variables that improve the prognostic and predictive accuracy of TNM in NSCLC by molecular staging may be identified from this extensive analytical panel.

C-reactive protein, interleukin-6 and the risk of colorectal cancer: a meta-analysis

PURPOSE

Many studies have evaluated the associations between pre-diagnostic circulating C-reactive protein (CRP), interleukin-6 (IL-6) and colorectal cancer risk, but their results are inconsistent. We therefore conducted a meta-analysis to investigate these associations.

METHODS

A comprehensive literature search up to October 2013 was undertaken in PubMed. Pooled relative risk (RR) estimates and 95% confidence intervals (CIs) were used to calculate estimated effect.

RESULTS

Eighteen studies on CRP comprising a total of 4,706 colorectal cancer cases were included in this meta-analysis. The summary RR of colorectal cancer for one unit change in natural logarithm (ln) CRP was 1.12 [95% CI (1.05-1.21)]. There was statistically significant heterogeneity among studies (p = 0.006; I (2) = 51.7%). After excluding the studies contributing most to the heterogeneity, summary estimate was essentially unchanged. In addition, the association was significant for colon cancer [RR = 1.13, 95 % CI (1.05-1.21)], not for rectal cancer [RR = 1.03, 95% CI (0.90-1.17)]. We also found that CRP was significantly associated with increased risk of colorectal cancer among men, but not among women. There were six studies on IL-6 that involved a total of 1,068 colorectal cancer cases. The pooled RR of colorectal cancer for one unit change in ln IL-6 was 1.10 (95% CI 0.88-1.36), and no statistically significant heterogeneity was found (p = 0.175; I(2) = 34.8%).

CONCLUSION

Our results suggest that pre-diagnostic circulating CRP is associated with increased risk of colorectal cancer. However, there is no significant association between IL-6 and colorectal cancer risk.

Association between systemic inflammatory markers and serum prostate-specific antigen in men without prostatic disease - the 2001-2008 National Health and Nutrition Examination Survey

BACKGROUND

Serum prostate specific antigen (PSA) may be elevated in otherwise healthy men; systemic inflammation has been associated with cancer. The study of systemic inflammatory markers in men without clinical prostate disease, but with elevated PSA may characterize the subgroup of men at higher risk for subsequent prostate cancer.

METHODS

We investigated the associations between systemic inflammatory markers and serum PSA in 3,164 healthy men without prostatic disease, aged >40 years, from the 2001 to 2008 U.S. National Health and Nutrition Examination Survey (NHANES). Serum total PSA levels and concentrations of serum C-reactive protein (CRP) and plasma fibrinogen, neutrophil count, lymphocyte count, and platelet count were recorded. Neutrophil-lymphocyte ratio (NLR) ratio and platelet-lymphocyte (PLR) ratio were calculated. PSA elevation was defined as levels equal or greater than 4 ng/ml.

RESULTS

Elevated serum PSA (194 men, 6.1% of the total), was significantly associated with plasma fibrinogen (ORmultiv  = 1.88; 95% CI, 1.09-3.25), and NLR (ORmultiv  = 1.14; 95% CI, 1.03-1.26), after adjustment for age, smoking, body mass index, education, race, co-morbidities, and use of medications.

CONCLUSIONS

Markers of systemic inflammation were associated with elevated PSA in men without known prostatic disease. Future studies are needed to examine these markers' relationship with prostate cancer occurrence and progression.

Effects of exercise training on chronic inflammation in obesity : current evidence and potential mechanisms

Chronic, systemic inflammation is an independent risk factor for several major clinical diseases. In obesity, circulating levels of inflammatory markers are elevated, possibly due to increased production of pro-inflammatory cytokines from several tissues/cells, including macrophages within adipose tissue, vascular endothelial cells and peripheral blood mononuclear cells. Recent evidence supports that adipose tissue hypoxia may be an important mechanism through which enlarged adipose tissue elicits local tissue inflammation and further contributes to systemic inflammation. Current evidence supports that exercise training, such as aerobic and resistance exercise, reduces chronic inflammation, especially in obese individuals with high levels of inflammatory biomarkers undergoing a longer-term intervention. Several studies have reported that this effect is independent of the exercise-induced weight loss. There are several mechanisms through which exercise training reduces chronic inflammation, including its effect on muscle tissue to generate muscle-derived, anti-inflammatory 'myokine', its effect on adipose tissue to improve hypoxia and reduce local adipose tissue inflammation, its effect on endothelial cells to reduce leukocyte adhesion and cytokine production systemically, and its effect on the immune system to lower the number of pro-inflammatory cells and reduce pro-inflammatory cytokine production per cell. Of these potential mechanisms, the effect of exercise training on adipose tissue oxygenation is worth further investigation, as it is very likely that exercise training stimulates adipose tissue angiogenesis and increases blood flow, thereby reducing hypoxia and the associated chronic inflammation in adipose tissue of obese individuals.

C-reactive protein, interleukin 6 and lung cancer risk: a meta-analysis

PURPOSE

Epidemiologic findings are inconsistent concerning the associations between C-reactive protein (CRP), interleukin 6 (IL-6) and lung cancer risk. We conducted a meta-analysis of epidemiologic studies to examine these associations.

METHODS

A systematic literature search up to October 2011 was performed in MEDLINE and EMBASE. Study-specific risk estimates were pooled using a random-effects model.

RESULTS

The 10 studies on CRP involved a total of 1918 lung cancer cases. The pooled RR of lung cancer for one unit change in natural logarithm (ln) CRP was 1.28 (95% CI 1.17-1.41). There was no statistically significant heterogeneity among studies (P = 0.116; I(2) = 36.6%). We also found that CRP was significantly associated with increased risk of lung cancer among men (RR 1.18, 95% CI 1.09-1.28) but not among women. The 5 studies on IL-6 involved a total of 924 lung cancer cases. The pooled RR of lung cancer for one unit change in ln IL-6 was 1.28 (95% CI 0.92-1.79), however, statistically significant heterogeneity was found. After excluding the study contributing most to the heterogeneity, the summary estimate was essentially unchanged.

CONCLUSION

CRP was associated with increased risk of lung cancer, especially among men. There was no significant association between IL-6 and lung cancer risk.

Pre-diagnostic levels of adiponectin and soluble vascular cell adhesion molecule-1 are associated with colorectal cancer risk

AIM: To examine the relationships between pre-diagnostic biomarkers and colorectal cancer risk and assess their relevance in predictive models.

METHODS: A nested case-control study was designed to include all first primary incident colorectal cancer cases diagnosed between inclusion in the SUpplémentation en VItamines et Minéraux AntioXydants cohort in 1994 and the end of follow-up in 2007. Cases (n = 50) were matched with two randomly selected controls (n = 100). Conditional logistic regression models were used to investigate the associations between pre-diagnostic levels of hs-CRP, adiponectin, leptin, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1, E-selectin, monocyte chemoattractant protein-1 and colorectal cancer risk. Area under the receiver operating curves (AUC) and relative integrated discrimination improvement (RIDI) statistics were used to assess the discriminatory potential of the models.

RESULTS: Plasma adiponectin level was associated with decreased colorectal cancer risk (P for linear trend = 0.03). Quartiles of sVCAM-1 were associated with increased colorectal cancer risk (P for linear trend = 0.02). No association was observed with any of the other biomarkers. Compared to standard models with known risk factors, those including both adiponectin and sVCAM-1 had substantially improved performance for colorectal cancer risk prediction (P for AUC improvement = 0.01, RIDI = 26.5%).

CONCLUSION: These results suggest that pre-diagnostic plasma adiponectin and sVCAM-1 levels are associated with decreased and increased colorectal cancer risk, respectively. These relationships must be confirmed in large validation studies.

High-sensitivity C-reactive protein and cancer

BACKGROUND

High-sensitivity C-reactive protein (hs-CRP) is a commonly used inflammatory marker. The association between hs-CRP and cancer is less consistent than that between hs-CRP and cardiovascular diseases. This study explored the association between hs-CRP and cancer, using a large database of Korean health examination records.

METHODS

A total of 80,781 Koreans who visited the health promotion center of a general hospital were included. There were 729 cases of cancer of any primary site during a 3-year period. Subjects with a known cancer or a condition capable of affecting hs-CRP were excluded.

RESULTS

Serum hs-CRP was significantly higher in cancer cases (2.9 mg/L) than in non-cases (1.4 mg/L; P < 0.0001). With the lowest hs-CRP category (<1 mg/L) as reference, the crude odds ratios (ORs) for cancer were 1.36 (95% confidence interval [CI] = 1.16-1.62) for the second highest category (1-3 mg/L) and 2.49 (95% CI = 2.02-3.07) for the highest category (>3 mg/L), and the adjusted ORs for cancer were 1.16 (95% CI = 0.95-1.42) for the second highest category and 1.94 (95% CI = 1.51-2.51) for the highest category. After excluding cancer cases detected within 1 year after the check-up, the associations remained, although the reduced number of cancer cases (n = 88) attenuated the significance of the associations.

CONCLUSIONS

Serum hs-CRP was positively associated with the risk of cancer, although causality cannot be inferred in this cross-sectional study. The results support the hypothesis that chronic inflammation plays a role in cancer.

Association between levels of C-reactive protein and leukocytes and cancer: three repeated measurements in the Swedish AMORIS study

OBJECTIVE

To study levels of C-reactive protein (CRP) and leukocytes, as inflammatory markers, in the context of cancer risk.

METHODS

From the Apolipoprotein MOrtality RISk (AMORIS) study, we selected 102,749 persons with one measurement and 9,273 persons with three repeated measurements of CRP and leukocytes. Multivariate Cox proportional hazards regression was applied to categories of CRP (<10, 10-15, 15-25, 25-50, >50 g/L) and quartiles of leukocytes. An inflammation-based predictive score (IPS) indicated whether someone had CRP levels of more than 10 mg/L combined with leukocytes of more than 10×10(9)/L. Reverse causality was assessed by excluding those with less than 3, 5, or 7 years of follow-up. To analyze repeated measurements of CRP and leukocytes, the repeated IPS (IPSr) was calculated by adding the IPS of each measurement.

RESULTS

In the cohort with one measurement, there was a positive trend between CRP and risk of developing cancer, with the lowest category being the 0.99 (0.92-1.06), 1.28 (1.11-1.47), 1.27 (1.09-1.49), and 1.22 (1.01-1.48) for the second to fifth categories, respectively. This association disappeared when excluding those with follow-up of less than 3, 5, or 7 years. The association between leukocytes and cancer was slightly stronger. In the cohort with repeated measurements, the IPSr was strongly associated with cancer risk: 1.87 (1.33-2.63), 1.51 (0.56-4.06), and 4.46 (1.43-13.87) for IPSr=1, 2, and 3 compared with IPSr=0. The association remained after excluding those with follow-up of less than 1 year.

CONCLUSIONS AND IMPACT

Our large, prospective cohort study adds evidence for a link between inflammatory markers and cancer risk by using repeated measurements and ascertaining reverse causality.

Chronic immune stimulation as a contributing cause of chronic disease in opiate addiction including multi-system ageing

Evidence of immune stimulation has been noted in opiate dependent patients for many decades. Documented changes have included lymphadenopathy, round cell infiltration of the hepatic portal triads, diffuse peri-bronchitis, hyperglobulinaemia, lymphocytosis, monocytosis, systemic cytokine stimulation, and cytokine and chemokine activation within the neuraxis. A parallel literature describes an elevated list of chronic degenerative disease as common in such patients including neurodegenerative conditions, atherosclerosis, nephrosclerosis, hepatic fibrosis and cirrhosis, chronic obstructive and fibrotic lung disease, osteoporosis, chronic periodontitis, various cancers, hair greying, and stem cell suppression. All of these disorders are now known to have an important immunological role in their pathogenic pathways. The multisystem nature of these myriad changes strongly suggest that the ageing process itself is stimulated in these patients. The link between the immunostimulation on the one hand and the elevated and temporally advanced nature of the chronic degenerative diseases on the other appears not to have been made in the literature. Moreover as immunostimulation is also believed to be an important, potent and principal contributor to the ageing process it appears that experimental and studies of this putative link are warranted. Verification of such an hypothesis would also carry management implications for dose and duration of chronic pain and addiction treatment, pharmacotherapeutic selection, and novel treatments such as long term naltrexone implant therapy and heroin trials.