Use of warfarin and risk of urogenital cancer: a population-based, nested case-control study

New insights into vitamin K biology with relevance to cancer

Phylloquinone (vitamin K1) and menaquinones (vitamin K2 family) are essential for post-translational γ-carboxylation of a small number of proteins, including clotting factors. These modified proteins have now been implicated in diverse physiological and pathological processes including cancer. Vitamin K intake has been inversely associated with cancer incidence and mortality in observational studies. Newly discovered functions of vitamin K in cancer cells include activation of the steroid and xenobiotic receptor (SXR) and regulation of oxidative stress, apoptosis, and autophagy. We provide an update of vitamin K biology, non-canonical mechanisms of vitamin K actions, the potential functions of vitamin K-dependent proteins in cancer, and observational trials on vitamin K intake and cancer.

Is periodontal disease a risk indicator for urogenital cancer? A systematic review and meta-analysis of cohort studies

Objectives

The objective of the present work was to conduct a systematic review and meta-analysis to assess the association between periodontal disease (PD) and urogenital cancer (UC) risk.

Materials and methods

An electronic search in PubMed, EMBASE, the Cochrane Library, and Web of Science was conducted using MeSH terms to identify cohort studies published before May 17, 2022. Cohort studies examining the association between PD and UC risk were included. We used a random-effects model to summarize the effect sizes with 95% confidence intervals (CIs) of the included studies with PD as the indicator and UC as the outcome.

Results

Eleven cohort studies met the inclusion criteria. Our results suggest that PD patients increases the risk of UC by 1.24-fold (hazard ratio (HR), 1.24; 95% CI, 1.17-1.31; I², 22.4%). The strength of the sensitivity analysis and cumulative meta-analysis confirmed the reliability of the results.

Conclusion

We found that PD is a potential risk factor for UC. Our results indicate that along with the decrease in the incidence of PD,PD treatment may help prevent UC. We hope that our study will raise awareness of periodontal health, thereby reducing the incidence of UC.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021244405.

Commonly Prescribed Anticoagulants Exert Anticancer Effects in Oral Squamous Cell Carcinoma Cells In Vitro

Simple Summary

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide with 840,000 new cases and 420,000 deaths in 2020. Anticoagulants are widely prescribed medications routinely administered to help prevent blood clots. Despite the great relevance of these two topics, there is complete lack of knowledge regarding the potential effects that these drugs could exert on oral cancer patients. In this in vitro study, we comprehensively investigated the effect of anticoagulants on OSCC activity. This includes the effect of these drugs on cancer cell ability to survive, migrate to colonise distant sites, and resist treatment with conventional chemotherapy. We have demonstrated for the first time that various anticoagulants have anticancer effects on OSCC. Moreover, some of the anticoagulants tested were able to reduce the migratory ability of cancer cells. Finally, the great majority of anticoagulants studied reduced the effectiveness of the tested chemotherapeutic agent, allowing an increase in cancer cell proliferation. Our results highlight the need for urgent further research in the field, to improve the anticoagulant strategies in patients with oral cancer, and in turn their prognosis.

Abstract

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. With anticoagulant usage on the rise, it is important to elucidate their potential effects on tumour biology and interactions with chemotherapeutics. The aim of the present study was to investigate the effects of anticoagulants on OSCC cell lines and their interactions with the drug 5-fluorouracil (5-FU). Cell proliferation was assessed using an MTS in vitro assay in two human OSCC cell lines (H357/H400) and in normal oral keratinocytes (OKF6) treated with the 5-FU (0.2/1/5/10 μg/mL), conventional anticoagulants warfarin (1/5/10/20 μM) and heparin (5/20/80 U), as well as four new oral anticoagulants, dabigatran (5/10/20 μM), rivaroxaban (5/10/20 μM), apixaban (0.1/1/5 μg/mL), and edoxaban (5/10/20 μM). Cell migration was assessed at 3 h intervals up to18 h using a wound healing assay. Our results clearly demonstrate, for the first time, that commonly prescribed anticoagulants exert in vitro antiproliferative effects on OSCC cells. Furthermore, treatment with some anticoagulants reduced the migration of OSCC cell lines. Nevertheless, most of the anticoagulants tested reduced the effectiveness of the chemotherapeutic agent tested, 5-FU, highlighting potential flaws in the current pharmacological management of these patients. Our findings showed the need for the immediate translation of this research to preclinical animal models.

Association of Vitamin K and Non-Vitamin K Oral Anticoagulant Use and Cancer Incidence in Atrial Fibrillation Patients

The association between the use of vitamin K antagonists (VKAs) and cancer risk reduction remains unclear. We aimed to assess the association between the use of VKAs or direct oral anticoagulants (DOACs) and the incidence of cancer in a large cohort of patients with atrial fibrillation (AF) by means of a population‐based, propensity‐weighted cohort study using population‐wide databases including patients diagnosed with nonvalvular AF (NVAF) followed for up of 5 years (median 2.94 years). We created two cohorts based on the initiation therapy (VKA or DOAC). Initiation with VKA or DOAC was defined as filling a prescription with no previous exposure in the preceding 12 months. Cancer diagnoses of any type and for specific tumors (lung, colon, prostate, bladder, and breast). We included 39,989 patients, 31,200 (78.0%) in the VKA cohort. Incidence rate for any cancer was 12.45 per 1,000 person‐year in the DOAC cohort vs. 14.55 in the VKA cohort (adjusted hazard ratio (HR): 1.16, 95% confidence interval (CI): 1.02–1.32). In secondary outcomes, no differences were found for specific types of cancer, such as lung (HR: 1.28, CI: 0.89–1.83), colon (HR: 0.84, CI: 0.62–1.13), prostate (HR: 1.40, CI: 0.94–2.10), bladder (HR: 1.07, CI: 0.76–1.52), and breast (HR: 1.05, CI: 0.66–1.69). Sensitivity analyses yielded similar results. Subgroup analyses also produced consistent findings, except for men, for whom VKA was associated with a lower risk of colon cancer (HR: 0.68, 95% CI: 0.48–0.96). Our results do not confirm a chemoprotective effect of VKA when compared with DOAC in a large, real‐world cohort of patients with NVAF followed for up to 5 years.

Use of Warfarin or Direct Oral Anticoagulants and Risk of Prostate Cancer in PCBaSe: A Nationwide Case-Control Study

Existing literature examining warfarin's association with prostate cancer (PCa) risk provides conflicting results, while the association with direct oral anticoagulants (DOACs) has not yet been studied. We investigated the association of warfarin and DOAC use on PCa risk among men within the population-based Prostate Cancer database Sweden (PCBaSe), using a case-control design. The study population included PCa cases diagnosed 2014–2016 and five age-matched PCa-free controls. Conditional logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (CI) for PCa associated with warfarin and DOAC use, adjusted for marital status, education level, other drug use, and comorbidities. Among 31,591 cases and 156,802 controls, there were 18,522 (9.8%) warfarin and 4,455 (2.4%) DOAC users. Warfarin ever-use was associated with reduced risk of PCa overall (OR 0.92 95% CI 0.88–0.96) as were both past and current use. DOAC use was not associated with PCa risk. For some warfarin exposures, decreased risk was observed for unfavorable PCa (high risk/locally advanced/distant metastatic) but not with favorable PCa (low/intermediate risk). Increased risk of favorable PCa was observed for men whose initial warfarin exposure occurred in the 12 month period before diagnosis (OR 1.39; 95% CI 1.13–1.70). Our findings are consistent with previous publications reporting decreased PCa risk with warfarin exposure. Increased risk of favorable PCa suggests detection bias due to increased prostate specific antigen testing when starting on warfarin. Decreased overall PCa risk could reflect bias due to reduced biopsy rates among long-term warfarin users.

The Association between Oral Anticoagulants and Cancer Incidence among Individuals with Nonvalvular Atrial Fibrillation

Objective Existing evidence on the association between vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) and cancer is limited and contradictory. No observational studies have been conducted to simultaneously address the cancer safety of VKAs and DOACs. The objective of this study was to determine whether use of VKAs and DOACs, separately, when compared with nonuse, is associated with cancer overall and prespecified site-specific incidence.

Methods Using the United Kingdom Clinical Practice Research Datalink, we identified patients newly diagnosed with nonvalvular atrial fibrillation (NVAF) between 2011 and 2017. Using a time-varying exposure definition, each person-day of follow-up was classified as use of (1) VKAs, (2) DOACs, (3) VKAs and DOACs (drug switchers), and (4) nonuse of anticoagulants (reference). We also conducted a head-to-head comparison of new users of DOACs versus VKAs using propensity score fine stratification weighting. Hazard ratios (HRs) with 95% confidence intervals (CIs) for cancer overall and prespecified subtypes were estimated using Cox proportional hazards models.

Results Compared with nonuse, use of VKAs was not associated with cancer overall (HR: 1.05, 95% CI: 0.91–1.22) or cancer subtypes. Similarly, use of DOACs was not associated with cancer overall (HR: 1.13, 95% CI: 0.93–1.37), but an association was observed for colorectal cancer (HR: 1.73, 95% CI: 1.01–2.99), and pancreatic cancer generated an elevated, though nonsignificant HR (HR: 2.15, 95% CI: 0.72–6.44). Results were consistent in the head-to-head comparison.

Conclusion Use of oral anticoagulants is not associated with the incidence of cancer overall among patients with NVAF. Possible associations between DOACs and colorectal and pancreatic cancer warrant further study.

Chronic oral anticoagluation and risk of prostate cancer: Evidence of detection bias

Warfarin treatment has been associated with lower risks of prostate cancer, without a specified biological mechanism. Our study tested the hypothesis that reluctance to perform prostate biopsies in men who are anticoagulated results in lower rates of diagnosed prostate cancer, leading to an apparent protective effect. Rates of prostate biopsies have decreased from 2000 to 2015, allowing calendar time to be used as the intervention. In a national population-based sample of elderly men, our study compared trends in prostate cancer incidence between 17,815 men treated with chronic oral anticoagulation for prosthetic heart valve thromboprophylaxis and a general population comparison group of 356,300 men. Cancer events were based on administrative claims. Among men enrolled in 2000-2001 and followed through 2015, prostate cancer incidence was substantially lower in the anticoagulation group (adjusted incidence rate ratio [IRR] 0.70; 95% confidence interval [CI] 0.62-0.80). Incidence decreased over time in the general population group to approach that of the anticoagulation group among men enrolled in 2008-2010 (IRR 0.86; 95% CI 0.71-1.04). Rates of prostate biopsies also decreased over time in the general population group to match the rate in the anticoagulation group. These results indicate that the apparent protective effect of warfarin treatment on the risk of prostate cancer is likely the result of detection bias from lower rates of biopsies among men who are anticoagulated.

Peroxisome proliferator-activated receptor gamma controls prostate cancer cell growth through AR-dependent and independent mechanisms

BACKGROUND

Prostate cancer (PC) remains a leading cause of cancer mortality and the most successful chemopreventative and treatment strategies for PC come from targeting the androgen receptor (AR). Although AR plays a key role, it is likely that other molecular pathways also contribute to PC, making it essential to identify and develop drugs against novel targets. Recent studies have identified peroxisome proliferator-activated receptor gamma (PPARγ), a nuclear receptor that regulates fatty acid (FA) metabolism, as a novel target in PC, and suggest that inhibitors of PPARγ could be used to treat existing disease. We hypothesized that PPARγ acts through AR-dependent and independent mechanisms to control PC development and growth and that PPARγ inhibition is a viable PC treatment strategy.

METHODS

Immunohistochemistry was used to determine expression of PPARү in a cohort of patients with PC. Standard molecular techniques were used to investigate the PPARү signaling in PC cells as well a xenograft mouse model to test PPARү inhibition in vivo. Kaplan-Meier curves were created using cBioportal.

RESULTS

We confirmed the expression of PPARү in human PC. We then showed that small molecule inhibition of PPARγ decreases the growth of AR-positive and -negative PC cells in vitro and that T0070907, a potent PPARγ antagonist, significantly decreased the growth of human PC xenografts in nude mice. We found that PPARγ antagonists or small interfering RNA (siRNA) do not affect mitochondrial activity nor do they cause apoptosis; instead, they arrest the cell cycle. In AR-positive PC cells, antagonists and siRNAs reduce AR transcript and protein levels, which could contribute to growth inhibition. AR-independent effects on growth appear to be mediated by effects on FA metabolism as the specific FASN inhibitor, Fasnall, inhibited PC cell growth but did not have an additive effect when combined with PPARγ antagonists. Patients with increased PPARү target gene expression, but not alterations in PPARү itself, were found to have significantly worse overall survival.

CONCLUSIONS

Having elucidated the direct cancer cell effects of PPARγ inhibition, our studies have helped to determine the role of PPARγ in PC growth, and support the hypothesis that PPARγ inhibition is an effective strategy for PC treatment.

Breast Tissue Biology Expands the Possibilities for Prevention of Age-Related Breast Cancers

Preventing breast cancer before it is able to form is an ideal way to stop breast cancer. However, there are limited existing options for prevention of breast cancer. Changes in the breast tissue resulting from the aging process contribute to breast cancer susceptibility and progression and may therefore provide promising targets for prevention. Here, we describe new potential targets, immortalization and inflammaging, that may be useful for prevention of age-related breast cancers. We also summarize existing studies of warfarin and metformin, current drugs used for non-cancerous diseases, that also may be repurposed for breast cancer prevention.

Vitamin K intake and prostate cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial

Background

Vitamin K inhibits prostate cancer cells, and an altered expression of vitamin K-dependent proteins in prostate tumors has been linked to their aggressiveness and progression. However, little is known about the effect of vitamin K intake on prostate cancer in human populations.

Objectives

We evaluated the associations of dietary intake of phylloquinone (vitamin K-1), menaquinones (vitamin K-2), and total vitamin K with the development of prostate cancer among participants in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial.

Design

Dietary intake of vitamin K was assessed with the Dietary Questionnaire (DQX) at baseline and the Dietary History Questionnaire (DHQ) at the third anniversary of randomization by using high-performance liquid chromatography-based food-composition data obtained from the USDA and published studies. During a median follow-up of 11.8 y, 2978 cases of prostate cancer (including 490 advanced cases) were identified from the 28,356 men who completed DQX. Similarly, 2973 cases of prostate cancer (including 647 advanced cases) were documented from the 48,090 men who completed DHQ. Cox proportional hazards regression was used to estimate prostate cancer risk in relation to the dietary intake of vitamin K.

Results

After adjustment for confounders, dietary intakes of phylloquinone, menaquinones, and total vitamin K, assessed with either the DQX or DHQ, were not significantly associated with the risk of advanced, nonadvanced, and total prostate cancer. These results remained virtually the same when vitamin K intake was modeled as a categorical (divided into quintiles) or continuous (per IQR increase) variable or after outliers of total vitamin K intake (defined as a value that falls above the sum of third quartile and twice the IQR) were excluded.

Conclusions

The present study does not suggest that vitamin K intake influences the occurrence of total and advanced prostate cancer in the general US population.

Is use of vitamin K antagonists associated with the risk of prostate cancer?: A meta-analysis

BACKGROUND

Vitamin K antagonists (VKAs) may have potential antitumor effects in prostate cancer. However, the findings of observational studies are inconsistent. The purpose of the present study was to estimate the quantitative association between VKAs use and prostate cancer risk by combining the results of all eligible observational studies.

METHODS

PubMed and Web of Science database were searched from inception until May, 2018. A DerSimonian random-effects model was used to combine the studies. Study heterogeneity was measured using the chi-squared and I statistics.

RESULTS

Six eligible studies were eventually included in our meta-analysis. There was an inverse but not statistically significant association between ever use of VKAs and the risk of prostate cancer (relative risk [RR] 0.84, 95% confidence interval [CI] 0.70-1.01, P = .063) with large heterogeneity across studies (P < .001 for heterogeneity, I = 94.6%). When analysis restricted to long term of VKAs user (>3 years), the pooled risk estimate was 0.83 (0.77-0.90) without obvious heterogeneity (P = .597, I = 0.0%).

CONCLUSION

This meta-analysis indicates that VKAs use may be associated with a decreased risk of prostate cancer, especially in long-term users.

A randomized clinical trial on the antitumoral effects of low molecular weight heparin in the treatment of esophageal cancer

The current treatment approaches for esophageal cancer are associated with poor survival, and there are ongoing efforts to find new and more effective therapeutic strategies. There are several reports on the antitumoral effects of low-molecular-weight heparins (LMWHs). We have assessed the possible survival benefit of LMWHs in esophageal malignancies. This was a randomized, single-blind, multicenter, Phase II clinical trial on nonmetastatic esophageal cancer candidate for neoadjuvant chemoradiotherapy. Patients were randomly assigned to the chemoradiotherapy-only arm or chemoradiotherapy plus enoxaparin arm using 1:1 allocation. Radiotherapy was delivered in 1.8-Gy daily fractions to a dose of 50.4 Gy in both groups. Paclitaxel 50 mg/m² and carboplatin (AUC 2) were administered weekly, concurrent with radiotherapy. In the intervention group, patients received enoxaparin (40 mg) and chemoradiation daily. 4-6 weeks after treatment, all patients underwent esophagectomy. After a median follow up of 7 months, estimated 1 year disease-free survival (DFS) in the intervention group was 78.9% and was 70% in the control groups ( p = 0.5). Toxicity from the experimental treatment was minimal, and there were no treatment-related deaths. A pathologically complete response in intervention and control group was 64.8% and 62.5%, respectively ( p = 0.9). There was a nonsignificant trend toward improved survival by the addition of enoxaparin to the concurrent chemoradiotherapy regimen. However, 1 y DFS of both groups were high as expected. A longer follow-up and a larger sample size are required.

Anti-tumoral effects of low molecular weight heparins: A focus on the treatment of esophageal cancer

Esophageal cancer is one of the most prevalent types of cancer globally. With current treatment options, the survival is poor, and there are ongoing efforts to find new and more efficient therapeutic approaches. There are several reports on the anti-tumoral effects of low-molecular-weight heparins (LMWH). We have assessed the possible survival benefits and underlying mechanisms of LMWHs in malignancies with a focus on esophageal cancer. We conclude that the effects of LMWHs on survival of cancer patients is probably due to a combination of direct anti-tumoral, anti-angiogenic, and immunomodulatory effects and indirect effects on the coagulation system.

The role of peroxisome proliferator-activated receptor gamma in prostate cancer

Despite great progress in the detection and treatment of prostate cancer, this disease remains an incredible health and economic burden. Although androgen receptor (AR) signaling plays a key role in the development and progression of prostate cancer, aberrations in other molecular pathways also contribute to the disease, making it essential to identify and develop drugs against novel targets, both for the prevention and treatment of prostate cancer. One promising target is the peroxisome proliferator-activated receptor gamma (PPARγ) protein. PPARγ was originally thought to act as a tumor suppressor in prostate cells because agonist ligands inhibited the growth of prostate cancer cells; however, additional studies found that PPARγ agonists inhibit cell growth independent of PPARγ. Furthermore, PPARγ expression increases with cancer grade/stage, which would suggest that it is not a tumor suppressor but instead that PPARγ activity may play a role in prostate cancer development and/or progression. Indeed, two new studies, taking vastly different, unbiased approaches, have identified PPARγ as a target in prostate cancer and suggest that PPARγ inhibition might be useful in prostate cancer prevention and treatment. These findings could lead to a new therapeutic weapon in the fight against prostate cancer.

Association of Warfarin Use With Lower Overall Cancer Incidence Among Patients Older Than 50 Years

IMPORTANCE

In cancer models, warfarin inhibits AXL receptor tyrosine kinase-dependent tumorigenesis and enhances antitumor immune responses at doses not reaching anticoagulation levels. This study investigates the association between warfarin use and cancer incidence in a large, unselected population-based cohort.

OBJECTIVE

To examine the association between warfarin use and cancer incidence.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study with subgroup analysis used the Norwegian National Registry coupled with the Norwegian Prescription Database and the Cancer Registry of Norway. The cohort comprised all persons (N = 1 256 725) born between January 1, 1924, and December 31, 1954, who were residing in Norway from January 1, 2006, through December 31, 2012. The cohort was divided into 2 groups-warfarin users and nonusers; persons taking warfarin for atrial fibrillation or atrial flutter were the subgroup. Data were collected from January 1, 2004, to December 31, 2012. Data analysis was conducted from October 15, 2016, to January 31, 2017.

EXPOSURES

Warfarin use was defined as taking at least 6 months of a prescription and at least 2 years from first prescription to any cancer diagnosis. If warfarin treatment started after January 1, 2006, each person contributed person-time in the nonuser group until the warfarin user criteria were fulfilled.

MAIN OUTCOMES AND MEASURES

Cancer diagnosis of any type during the 7-year observation period (January 1, 2006, through December 31, 2012).

RESULTS

Of the 1 256 725 persons in the cohort, 607 350 (48.3%) were male, 649 375 (51.7%) were female, 132 687 (10.6%) had cancer, 92 942 (7.4%) were classified as warfarin users, and 1 163 783 (92.6%) were classified as nonusers. Warfarin users were older, with a mean (SD) age of 70.2 (8.2) years, and were predominantly men (57 370 [61.7%]) as compared with nonusers, who had a mean (SD) age of 63.9 (8.6) years and were mostly women (613 803 [52.7%]). Among warfarin users and compared with nonusers, there was a significantly lower age- and sex-adjusted incidence rate ratio (IRR) in all cancer sites (IRR, 0.84; 95% CI, 0.82-0.86) and in prevalent organ-specific sites (lung, 0.80 [95% CI, 0.75-0.86]; prostate, 0.69 [95% CI, 0.65-0.72]; and breast, 0.90 [95% CI, 0.82-1.00]). There was no observed significant effect in colon cancer (IRR, 0.99; 95% CI, 0.93-1.06). In a subgroup analysis of patients with atrial fibrillation or atrial flutter, the IRR was lower in all cancer sites (IRR, 0.62; 95% CI, 0.59-0.65) and in prevalent sites (lung, 0.39 [95% CI, 0.33-0.46]; prostate, 0.60 [95% CI, 0.55-0.66]; breast, 0.72 [95% CI, 0.59-0.87]; and colon, 0.71 [95% CI, 0.63-0.81]).

CONCLUSIONS AND RELEVANCE

Warfarin use may have broad anticancer potential in a large, population-based cohort of persons older than 50 years. This finding could have important implications for the selection of medications for patients needing anticoagulation.

Vitamin K and cancer

Subclinical vitamin K deficits refer to carboxylation defects of different types of vitamin K-dependent hepatic and extrahepatic so-called Gla proteins without prolongation of the prothrombin time. This condition has been reported in different clinical situations due to insufficient supply or malabsorption of vitamin K as well as drug interactions. This review discusses the effects of different vitamin K subspecies on tumour growth and the possible anti-tumour effects of increased vitamin K intake. Blocking carboxylation of vitamin K-dependent proteins with warfarin anticoagulation - what are the risks/benefits for carcinogenesis? Previous studies on both heparin and low molecular weight heparin blocking of the vitamin K-dependent factors X and II have shown tumour suppressive effects. Vitamin K has anti-inflammatory effects that could also impact carcinogenesis, but little data exists on this subject.

Vitamin K epoxide reductase regulation of androgen receptor activity

Long-term use of warfarin has been shown to be associated with a reduced risk of prostate cancer. Warfarin belongs to the vitamin K antagonist class of anticoagulants, which inhibit vitamin K epoxide reductase (VKOR). The vitamin K cycle is primarily known for its role in γ-carboxylation, a rare post-translational modification important in blood coagulation. Here we show that warfarin inhibits the transcriptional activity of the androgen receptor (AR), an important driver of prostate cancer development and progression. Warfarin treatment or knockdown of its target VKOR inhibits the activity of AR both in cell lines and in mouse prostate tissue. We demonstrate that AR can be γ-carboxylated, and mapped the γ-carboxylation to glutamate residue 2 (E2) using mass spectrometry. However, mutation of E2 and other glutamates on AR failed to suppress the effects of warfarin on AR suggesting that inhibition of AR is γ-carboxylation independent. To identify pathways upstream of AR signaling that are affected by warfarin, we performed RNA-seq on prostates of warfarin-treated mice. We found that warfarin inhibited peroxisome proliferator-activated receptor gamma (PPARγ) signaling, which in turn, inhibited AR signaling. Although warfarin is unfit for use as a chemopreventative due to its anticoagulatory effects, our data suggest that its ability to reduce prostate cancer risk is independent of its anticoagulation properties. Furthermore, our data show that warfarin inhibits PPARγ and AR signaling, which suggests that inhibition of these pathways could be used to reduce the risk of developing prostate cancer.

Role of the Coagulation System in Genitourinary Cancers: Review

Tumor progression is associated with aberrant hemostasis, and patients with malignant diseases have an elevated risk of developing thrombosis. A crosstalk among the vascular endothelium, components of the coagulation cascade, and cancer cells transforms the intravascular milieu to a prothrombotic, proinflammatory, and cell-adhesive state. We review the existing evidence on activation of the coagulation system and its implication in genitourinary malignancies and discuss the potential therapeutic benefit of antithrombotic agents. A literature review was performed searching the Medline database and the Cochrane Library for original articles and reviews. A second search identified studies reporting on oncological benefit of anticoagulants in genitourinary cancer. An elevated expression of procoagulatory tissue factor on tumor cells and tumor-derived microparticles seems to stimulate cancer development and progression. Several components of the hemostatic system, including D-dimers, von Willebrand Factor, thrombin, fibrin-/ogen, soluble P-selectin, and prothrombin fragments 1 + 2 were either overexpressed or overactive in genitourinary cancers. Hypercoagulation was in general associated with a poorer prognosis. Experimental models and small trials in humans showed reduced cancer progression after treatment with anticoagulants. Main limitations of these studies were heterogeneous experimental methodology, small patient numbers, and a lack of prospective validation. In conclusion, experimental and clinical evidence suggests procoagulatory activity of genitourinary neoplasms, particularly in prostate, bladder and kidney cancer. This may promote the risk of vascular thrombosis but also metastatic progression. Clinical studies linked elevated biomarkers of hemostasis with poor prognosis in patients with genitourinary cancers. Thus, anticoagulation may have a therapeutic role beyond prevention of thromboembolism.

Risk of cancer after anticoagulation in patients with unprovoked venous thromboembolism: an observational cohort study

Essentials Data on long-term cancer risk are controversial in patients with venous thromboembolism (VTE). We assessed long-term rates and risk factors of cancer in patients with VTE. Cancer risk after anticoagulation is not higher in VTE patients than in the general population. VTE recurrence is not predictive of a future cancer diagnosis.

SUMMARY

Background Patients with venous thromboembolism (VTE) are at risk of having a subsequent cancer diagnosis. The risk is highest during the first 6 months. Reports on cancer rates thereafter are controversial. We aimed to assess long-term rates and risk factors of cancer in patients with VTE. Methods and Results We followed patients with a first unprovoked VTE after discontinuation of anticoagulation, and excluded those receiving long-term antithrombotic therapy or with major thrombophilia. The study endpoint was the occurrence of cancer. Sixty-two (5.2%) of 1188 patients developed cancer during a median follow-up of 98 months. The cumulative incidence rates of cancer were 0.7% (95% confidence interval [CI] 0.2-1.2%), 3.1% (95% CI 2.0-4.1%) and 9% (95% CI 6.5-11.5) after 1, 5 and 15 years; these were not significantly different from those in the matched general population (0.6%, 3.4%, and 12.2%, respectively). The corresponding standardized incidence ratios (ratio of the observed cancer cases and the number of cases based on national cancer incidence rates) of 1.1 (95% CI 0.5-2.5), 1.0 (95% CI 0.6-1.4) and 0.9 (95% CI 0.7-1.2) did not indicate a difference in cancer incidence between our cohort and the general population. Advancing age (hazard ratio [HR] per decade 1.5, 95% CI 1.2-2.0) and shorter duration of anticoagulation (HR per 1-month decrease 1.3, 95% CI 1.1-1.6) were associated with an increased cancer risk, whereas VTE recurrence was not (HR 1.17, 95% CI 0.66-2.07). Conclusions Asymptomatic patients with unprovoked VTE who have completed anticoagulation therapy do not have a higher cancer risk. The inverse association between the duration of anticoagulation and the incidence of cancer warrants further investigation.

Clinical Significance of Hematuria in Atrial Fibrillation With Oral Anticoagulation Therapy

BACKGROUND

Hematuria is a common and important complication in atrial fibrillation (AF) patients on oral anticoagulation therapy (OAT). This study evaluated the clinical significance of hematuria and its relationship with genitourinary disease in AF patients receiving OAT.Methods and Results:Among 20,456 consecutive AF patients who visited a tertiary hospital from January 2005 to April 2015, 5,833 had hematuria. Of these 5,833 patients, 3,798 were on OAT (OAT(+) group) and 2,035 were not (OAT(-) group). A total of 1,785 patients from each group were then matched on propensity score analysis. The prevalence of cancer and other diseases in the genitourinary tract was evaluated. While there was no difference in the prevalence of genitourinary stones or urinary tract infection, genitourinary cancer was significantly more common in the OAT(+) group than in the OAT(-) group (1.6% vs. 0.7%, P=0.011). Bladder cancer was the most common genitourinary malignancy, and it was significantly more common in the OAT(+) group (1.2% vs. 0.5%, P=0.019). Subjects on warfarin were more likely to have bladder cancers of lower pathologic grade (63.6% vs. 33.3%, P=0.124).

CONCLUSIONS

OAT was associated with a higher prevalence and early detection of genitourinary cancer in AF patients with hematuria. Meticulous evaluation of the cause of hematuria is necessary in AF patients with hematuria receiving OAT.

The Role of TAM Family Receptors in Immune Cell Function: Implications for Cancer Therapy

The TAM receptor protein tyrosine kinases-Tyro3, Axl, and Mer-are essential regulators of immune homeostasis. Guided by their cognate ligands Growth arrest-specific gene 6 (Gas6) and Protein S (Pros1), these receptors ensure the resolution of inflammation by dampening the activation of innate cells as well as by restoring tissue function through promotion of tissue repair and clearance of apoptotic cells. Their central role as negative immune regulators is highlighted by the fact that deregulation of TAM signaling has been linked to the pathogenesis of autoimmune, inflammatory, and infectious diseases. Importantly, TAM receptors have also been associated with cancer development and progression. In a cancer setting, TAM receptors have a dual regulatory role, controlling the initiation and progression of tumor development and, at the same time, the associated anti-tumor responses of diverse immune cells. Thus, modulation of TAM receptors has emerged as a potential novel strategy for cancer treatment. In this review, we discuss our current understanding of how TAM receptors control immunity, with a particular focus on the regulation of anti-tumor responses and its implications for cancer immunotherapy.

Warfarin use and prostate cancer risk in the Finnish Randomized Study of Screening for Prostate Cancer

OBJECTIVE

Anticoagulants, especially vitamin K antagonists (VKAs) such as warfarin, have been hypothesized to have antitumor properties, and use of VKAs has been associated with a lower prostate cancer (PCa) risk. This study estimated PCa risk among users of warfarin and other anticoagulants.

MATERIALS AND METHODS

All anticoagulant use among 78,615 men during 1995-2009 was analyzed. Cox regression, adjusted for age, screening trial arm and use of other medications, with medication use as a time-dependent variable, was used to estimate PCa risk overall, and by tumor grade and stage.

RESULTS

In total, 6537 men were diagnosed with PCa during 1995-2009 (1210 among warfarin users). Compared to non-users, warfarin use was associated with an increased risk of PCa [multivariable-adjusted hazard ratio (HR) = 1.11, 95% confidence interval (CI) 1.01-1.22]. This was limited to short-term, low-dose use, and was not observed in long-term use. A similar overall risk increase was observed for Gleason grade 7-10 PCa. Low-dose, short-term use of warfarin was associated with an increased risk of metastatic PCa. However, the increase in risk vanished with continued use. Compared to other anticoagulants, low-dose use of warfarin was associated with a slightly elevated overall PCa risk (HR = 1.19, 95% CI 1.00-1.43). The increase in risk disappeared in long-term, high-dose use.

CONCLUSIONS

This study, which included a larger number of PCa cases with warfarin exposure than previous studies, does not support previous notions of decreased risk of PCa among warfarin users. A similar risk of PCa was found among warfarin users and the general population, and no difference in risk was found between warfarin and other anticoagulants.

Use of oral anticoagulants and risk of prostate cancer: a population-based case-control study in Montreal, Canada

PURPOSE

A few recent epidemiological observations suggest that anticoagulant medications may protect against prostate cancer development. Most studies have been small or subjected to methodological issues, including potential confounding. We provide here new evidence on this association in the context of a population-based case-control study of prostate cancer conducted in Montreal, Canada.

METHODS

Cases were 1,588 men with incident prostate cancer, aged ≤75 years, diagnosed across French hospitals in the Montreal area between 2005 and 2009. Concurrently, 1,618 population controls from the same residential area and age distribution (±5 years) were randomly selected from the electoral list of French-speaking men. In-person interviews elicited information on socio-demographic, lifestyle and environmental factors, along with a detailed medical history. Unconditional logistic regression was used to assess the association between lifetime use of anticoagulants and prostate cancer risk.

RESULTS

102 subjects (2.6 % of cases and 3.7 % of controls) reported a history of oral anticoagulant therapy. After controlling for age, ancestry, education, family history of prostate cancer, prostate cancer screening frequency, diabetes, body mass index and statin use, ever use of oral anticoagulants showed a weak inverse, non-statistically significant association with prostate cancer (odds ratio 0.76, 95% confidence interval 0.50-1.16). Similar results were observed in analyses considering duration of use or indication for use, restricted to subjects recently screened or stratified by cancer aggressiveness.

CONCLUSIONS

Our findings provide weak support for a protective effect of oral anticoagulant therapy against prostate cancer. Further confirmation is required, especially in light of potential bleeding complications associated with anticoagulants.

Does Statin or ASA Affect Survival When Prostate Cancer Is Treated with External Beam Radiation Therapy?

Background. Prior studies evaluating the effect of statins or acetylsalicylic acid (ASA) on the survival of men receiving prostate cancer were treatment have reported conflicting results, and have not adjusted for comorbidity. Our aim is to investigate the influence of statins and ASA on prostate cancer survival, when comorbidity is adjusted for, in men treated with external beam radiation therapy (EBRT) for prostate cancer. Methods. A cohort of 3851 patients with prostate cancer treated with curative EBRT ± androgen deprivation therapy (ADT) between 2000 and 2007. Stage, treatment, medication use, and Charlson comorbidity index (CCI) scores were analyzed. Results. Median followup was 8.4 years. Mean age was 70.3 years. Neoadjuvant ADT was used in 67%. Statins were used in 23%, ASA in 24%, and both in 11%. Comorbidity scores were 0 in 65%, 1 in 25%, and ≥2 in 10% of patients. Statin and ASA use were associated with increased age and comorbidity. Although statin and ASA use were significantly associated with improved prostate cancer specific survival (PCSS) on univariate analysis, neither were on multivariate analysis. Conclusion. Neither statin nor ASA use impacted PCSS on multivariate competing risks analysis. Survival was impacted by increased comorbidity as well as statin and ASA use.

Influence of concurrent medications on outcomes of men with prostate cancer included in the TAX 327 study

OBJECTIVES

The TAX 327 trial was pivotal in establishing docetaxel in castration refractory metastatic prostate cancer. Various commonly prescribed and over-the-counter co-administered medications are thought to exhibit anti-neoplastic properties and/or could potentially have pharmacokinectic interactions with docetaxel lessening the effectiveness of chemotherapy.

METHODS

To examine the effect of on prostate cancer outcomes within this trial, we examined overall survival, prostate-specific antigen (PSA) response, percent PSA reduction, pain response and QOL responses for 14 families of medications including metformin, digoxin, verapamil, proton pump inhibitors, nitrates, statins, cox-2 inhibitors, warfarin, heparins, ascorbic acid, selenium, tocopherol, antidepressants and erythropoietin.

RESULTS

Our findings did not reveal any medication that had a significant additive or synergistic effect with docetaxel. We did note, however, that patients on digoxin or verapamil had poorer overall survival, possibly due to a trend of fewer cycles of administered chemotherapy being administered to the verapamil group, consistent with a pharmacokinectic interaction.

CONCLUSIONS

These data are only hypothesis-generating given the statistical limitations, but may form a basis for similar future analysis in other malignancies. The data suggest the need to be aware of pharmacokinectic interactions with medications that may interact with docetaxel.

Risk of prostate cancer death in long-term users of warfarin: a population-based case-control study

PURPOSE

Recent evidence suggests that warfarin use may be associated with a reduced risk of prostate cancer. We aimed to determine whether exposure to warfarin is also associated with a reduced risk of prostate cancer death.

METHODS

A nested case-control study was conducted within a population-based cohort of 10,012 men aged ≥50 years with newly diagnosed prostate cancer between 1985 and 2002 and with no history of cancer since 1970 using the linked records of Saskatchewan Health and Saskatchewan Cancer Agency registry. We identified 2,309 cases who died of prostate cancer during follow-up. For each case, one control alive at the time of the case's death and matched for length of follow-up (±6 months) was randomly selected. Prescription counts were used to define warfarin exposure. Multivariate conditional logistic regression analysis was used to calculate the adjusted incidence rates of prostate cancer death in relation to warfarin use while adjusting for confounding by age, year of prostate cancer diagnosis, clinical stage and grade of cancer at diagnosis, Chronic Disease Score, and use of warfarin before diagnosis.

RESULTS

Ever use of warfarin following a diagnosis of prostate cancer was associated with an adjusted rate ratio of 1.44 (95 % confidence interval (CI) 1.33-1.84) for prostate cancer death. The adjusted rate ratio with one-year use of warfarin was 1.77 (95 % CI 1.25-2.50) compared to never use. The unadjusted rate ratio with five-year use of warfarin was 0.64 (95 % CI 0.40-1.00) and remained unchanged in the adjusted analysis (0.65, 95 % CI 0.37-1.13), although no longer statistically significant.

CONCLUSION

Our study does not provide conclusive evidence for a protective effect of long-term warfarin on prostate cancer-specific mortality. Moreover, short-term warfarin use may be associated with an increased risk of prostate cancer death.

Cancer risk in long-term users of vitamin K antagonists: a population-based case-control study

Some evidence suggests that long-term use of vitamin K antagonists (VKAs) has a cancer chemopreventive effect. Such an effect would have considerable implications in terms of understanding tumor biology. To evaluate if long-term VKA treatment influences the risk of developing cancer, we performed a matched case-control analysis. We used data from four Danish nationwide registers. Cases were all Danish individuals with a first-time cancer diagnosis (except nonmelanoma skin cancer) between 2000 and 2009. For each case, eight controls, matched by birth year and gender, were selected from the source population by risk-set sampling. Long-term VKA use was defined as exposure to VKA for a period of 3 or more years. Conditional logistic regression was used to compute odds ratios (ORs) for cancer associated with long-term VKA exposure, adjusting for potential confounders. Prespecified subanalyses were performed for selected cancer sites, subgroups and measures of exposure. A total of 238,196 cases and 1,713,176 controls were included. The adjusted OR for cancer associated with long-term VKA exposure was 0.99 (95% CI: 0.95-1.02). Long-term VKA use was associated with increased ORs for alcohol- or obesity-related cancer sites, whereas we observed a decreased risk of prostate cancer (OR: 0.86; 95% CI: 0.78-0.95). Our study does not support a general chemopreventive effect of VKA drugs. However, in accordance with findings from previous studies, we found an inverse association between use of VKA and prostate cancer.

Effect of statins and anticoagulants on prostate cancer aggressiveness

PURPOSE

Statins and anticoagulants (ACs) have both been associated with a less-aggressive prostate cancer (PCa) and a better outcome after treatment of localized PCa. The results of these studies might have been confounded because patients might often take both medications. We examined their respective influence on PCa aggressiveness at initial diagnosis.

MATERIALS AND METHODS

We analyzed 381 patients treated with either external beam radiotherapy or brachytherapy for low-risk (n = 152), intermediate-risk (n = 142), or high-risk (n = 87) localized PCa. Univariate and multivariate logistic regression analyses were used to investigate an association between these drug classes and prostate cancer aggressiveness. We tested whether the concomitant use of statins and ACs had a different effect than that of either AC or statin use alone.

RESULTS

Of the 381 patients, 172 (45.1%) were taking statins and 141 (37.0%) ACs; 105 patients (27.6%) used both. On univariate analysis, the statin and AC users were associated with the prostate-specific antigen (PSA) level (p = .017) and National Comprehensive Cancer Network risk group (p = .0022). On multivariate analysis, statin use was associated with a PSA level <10 ng/mL (odds ratio, 2.9; 95% confidence interval, 1.3-6.8; p = .012) and a PSA level >20 ng/mL (odds ratio, 0.29; 95% confidence interval, 0.08-0.83; p = .03). The use of ACs was associated with a PSA level >20 ng/mL (odds ratio, 0.13; 95% confidence interval, 0.02-0.59, p = .02).

CONCLUSION

Both AC and statins have an effect on PCa aggressiveness, with statins having a more stringent relationship with the PSA level, highlighting the importance of considering statin use in studies of PCa aggressiveness.

The association between vitamin K antagonist therapy and site-specific cancer incidence estimated by using heart valve replacement as an instrumental variable

Earlier studies suggest a protective association between vitamin K antagonist (VKA) anticoagulants and the incidence of cancer. The authors examined the associations between VKA therapy and incidence of 24 site-specific cancers with a Danish population-based cohort study, using heart valve replacement as an instrumental variable. The authors enrolled 9,727 Danish residents who received a replacement heart valve between 1989 and 2006. The heart valve recipients were matched with 95,481 unexposed individuals on age and sex. The authors used the heart valve replacement instrument to estimate rate ratios associating VKA therapy with incidence of the 24 site-specific cancers using Poisson regression models. Direct associations between VKA therapy and incidence of the 24 cancers were estimated in a prescription validation subset. The instrumental variable associations were plotted according to the inverse normal of rank percentile and subjected to semi-Bayes shrinkage adjustment for multiple comparisons. The pattern of associations was consistent with a null-centered Gaussian distribution. No individual cancer site showed a substantial positive or negative association with VKA therapy in the prescription validation subset, the instrumental variable analysis, or the analysis with semi-Bayes adjustment. These results do not support the existing hypothesis that VKA therapy is associated with reduced cancer risk.

Long-term use of vitamin K antagonists and incidence of cancer: a population-based study

Whether long-term use of vitamin K antagonists (VKAs) might affect the incidence of cancer is a longstanding hypothesis. We conducted a population-based study including all cancer- and thromboembolism-free patients of our health area; study groups were defined according to chronic anticoagulant use to VKA-exposed and control groups. Cancer incidence and cancer-related and overall mortality was assessed in both groups. 76 008 patients (3231 VKA-exposed and 72 777 control subjects) were followed-up for 8.2 (± 3.2) years. After adjusting for age, sex, and time-to-event, the hazard ratio of newly diagnosed cancer in the exposed group was 0.88 (95% confidence interval [95% CI] 0.80-0.98; P < .015). VKA-exposed patients were less likely to develop prostate cancer, 0.69 (95% CI 0.50-0.97; P = .008). The adjusted hazard ratio for cancer-related and overall mortality was 1.07 (95% CI 0.92-1.24) and 1.12 (95% CI 1.05-1.19), respectively. These results support the hypothesis that anticoagulation might have a protective effect on cancer development, especially prostate cancer.

Venous thromboembolism and cancer: a systematic review

Venous thromboembolism (VTE) is a serious and potentially fatal disorder, which is often associated with a significant impact on the quality of life and on the clinical outcome of cancer patients. The pathophysiology of the association between thrombosis and cancer is complex: malignancy is associated with a baseline hypercoagulable state due to many factors including release of inflammatory cytokines, activation of the clotting system, expression of hemostatic proteins on tumor cells, inhibition of natural anticoagulants, and impaired fibrinolysis. Several risk factors, related to the patient, the disease, and the therapeutic interventions, have been identified as contributing to the occurrence of VTE. There is convincing evidence to recommend the use of heparins or fondaparinux for prevention of VTE in selected cancer patients, and, especially in some particular types of malignancies and cancer treatments. Management of VTE in patients with cancer is more challenging and bleeding complications associated with the use of anticoagulants are significantly higher in cancer patients than in those without malignancy. Important issues that need to be considered in all cases are interference with anticancer therapy, inconvenience of treatment, and impact on quality of life.

Ginkgo biloba and risk of cancer: secondary analysis of the Ginkgo Evaluation of Memory (GEM) Study

PURPOSE

Evidence from in vitro and in vivo studies suggests that Ginkgo biloba has cancer chemopreventive properties, but epidemiological evidence is sparse. We analyzed cancer as a secondary endpoint in the Ginkgo Evaluation of Memory (GEM) Study, the largest randomized, double-blind, placebo-controlled clinical trial of Ginkgo supplementation to date.

METHODS

A total of 3069 GEM participants 75+ years of age were randomized to twice-daily doses of either 120 mg Ginkgo extract (EGb 761) or placebo and followed for a median 6.1 years. We identified hospitalizations for invasive cancer by reviewing hospital admission and discharge records for all reported hospitalizations over follow-up. Using an intention-to-treat approach, we compared the risk of cancer hospitalization between participants assigned to treatment and those assigned to placebo.

RESULTS

During the intervention, there were 148 cancer hospitalizations in the placebo group and 162 in the EGb 761 group (Hazard ratio (HR), 1.09; 95% confidence interval (CI), 0.87-1.36; p = 0.46). Among the site-specific cancers analyzed, we observed an increased risk of breast (HR, 2.15; 95%CI, 0.97-4.80; p = 0.06) and colorectal (HR, 1.62; 95%CI, 0.92-2.87; p = 0.10) cancer, and a reduced risk of prostate cancer (HR, 0.71; 95%CI, 0.43-1.17; p = 0.18).

CONCLUSIONS

Overall, these results do not support the hypothesis that regular use of Ginkgo biloba reduces the risk of cancer.

The use of anticoagulants improves biochemical control of localized prostate cancer treated with radiotherapy

BACKGROUND

: Substantial experimental evidence suggests that anticoagulants (ACs) may inhibit cancer growth and metastasis, although the limited data from clinical trials have been inconsistent. The potential antineoplastic effect of ACs was investigated in patients who received radiotherapy for localized prostate cancer.

METHODS

: The study cohort consisted of 662 patients with adenocarcinoma of the prostate who received radiotherapy (RT) with curative intent. Among those 622 men, 243 (37%) were receiving ACs (warfarin, clopidogrel, and/or aspirin). All patients received external-beam RT, permanent seed implantation, or a combination of both. Prostate-specific antigen (PSA) values were monitored for biochemical control of disease.

RESULTS

: At a median follow-up of 49 months, the biochemical control rate at 4-years was significantly better in patients who received ACs at 91% compared with 78% in patients who did not receive ACs (P = .0002). The distant metastasis rate at 4 years also was reduced in the AC group compared with the non-AC group (1% vs 5%; P = .0248). In subgroup analysis, the improvement in biochemical control was significant only for patients with high-risk disease. Along with Gleason score, T classification, and initial PSA, the use of AC therapy was associated independently with improved biochemical control in multivariate analysis.

CONCLUSIONS

: AC therapy was associated with an improvement in biochemical control in patients with prostate cancer who received RT with curative intent. The effect was most prominent in patients who had high-risk disease. Cancer 2010. (c) 2010 American Cancer Society.

Antithrombotic therapy and survival in patients with malignant disease

A broad range of studies suggest a two-way relationship between cancer and venous thromboembolism (VTE). Patients with cancer have consistently been shown to be at elevated risk for VTE; this risk is partly driven by an intrinsic hypercoagulable state elicited by the tumour itself. Conversely, thromboembolic events in patients without obvious risk factors are often the first clinical manifestation of an undiagnosed malignancy. The relationship between VTE and cancer is further supported by a number of trials and meta-analyses which, when taken together, strongly suggest that antithrombotic therapy can extend survival in patients with cancer by a mechanism that extends beyond its effect in preventing VTE. Moreover, accumulating evidence from in vitro and in vivo studies has shown that tumour growth, invasion, and metastasis are governed, in part, by elements of the coagulation system. On 22 May 2009, a group of health-care providers based in the United Kingdom met in London, England, to examine recent advances in cancer-associated thrombosis and its implications for UK clinical practice. As part of the discussion, attendees evaluated evidence for and against an effect of antithrombotic therapy on survival in cancer. This paper includes a summary of the data presented at the meeting and explores potential mechanisms by which antithrombotic agents might exert antitumour effects. The summary is followed by a consensus statement developed by the group.

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

BACKGROUND

Basic and clinical research support the hypothesis that activation of the coagulation and inflammation pathways may affect cancer onset, but there is limited epidemiological data to support this.

METHODS

We examined a large range of haemostatic and inflammation markers, including fibrinogen, in 19 303 male participants from three English cohorts followed for up to 30 years. After excluding the first 3 years of follow-up, 2908 incident cancers were accrued. Competing risk models were fitted to estimate rate ratios (RRs) for cancer incidence, adjusting for age and other confounders.

RESULTS

Baseline white blood cell (WBC) count and circulating levels of fibrinogen, C-reactive protein (CRP), factor VII antigen (VIIa) and prothrombin fragment F1.2 were positively associated with risk of smoking-related cancers, particularly lung cancer. The magnitude of these associations was highest for persistently raised fibrinogen levels. There was, however, substantial confounding by smoking with risk being fully (WBC, CRP and VIIa) or partially (fibrinogen) removed after adjustment. The pooled RRs (95% confidence interval) per one standard deviation increase in fibrinogen levels before and after adjustment for smoking habits were 1.23 (1.12, 1.36) and 1.12 (1.05, 1.20), respectively. The fibrinogen associations were present only among current smokers at entry. The effect of smoking on smoking-related cancers was partly mediated by fibrinogen levels.

CONCLUSIONS

Our results are consistent with elevated circulating levels of fibrinogen and F1.2 being predictors of risk of smoking-related cancers. Further research is necessary to clarify whether elevated levels of fibrinogen and F1.2 are causally relevant or simply correlates of the smoking-cancer association.

Hematological issues in critically ill patients with cancer

Patients with solid and hematologic malignancies presenting with major bleeding or thrombotic complications, potentially life-ending events in a cancer patient's clinical course, usually require admission to an intensive care unit (ICU), making their diagnosis and management even more important for the intensivist. Given the significant advances in the diagnosis and treatment of almost all types of cancers in recent years, the intensivist is likely to encounter an ever-increasing number of cancer patients in the ICU setting with these complications. Abnormal hemostasis can occur as a consequence of both the pathology and treatment of cancer. Because cancer can have multiple effects on hemostatic equilibrium, treatment of these complications can be more complex than in the general population. This article reviews the physiology of coagulation and fibrinolysis, with special attention to those aspects that are most frequently altered in the setting of malignancy. The pathophysiology of bleeding and thrombotic complications specific to critically ill cancer patients are then detailed, and the diagnostic and therapeutic strategies are discussed. Special emphasis is placed on new cancer medications that have an effect on hemostasis, and on novel clotting and anticoagulant agents that are available to the intensivist for the management of these patients.

The potential benefits of low-molecular-weight heparins in cancer patients

Cancer patients are at increased risk of venous thromboembolism due to a range of factors directly related to their disease and its treatment. Given the high incidence of post-surgical venous thromboembolism in cancer patients and the poor outcomes associated with its development, thromboprophylaxis is warranted. A number of evidence-based guidelines delineate anticoagulation regimens for venous thromboembolism treatment, primary and secondary prophylaxis, and long-term anticoagulation in cancer patients. However, many give equal weight to several different drugs and do not make specific recommendations regarding duration of therapy. In terms of their efficacy and safety profiles, practicality of use, and cost-effectiveness the low-molecular-weight heparins are at least comparable to, and offer several advantages over, other available antithrombotics in cancer patients. In addition, data are emerging that the antithrombotics, and particularly low-molecular-weight heparins, may exert an antitumor effect which could contribute to improved survival in cancer patients when given for long-term prophylaxis. Such findings reinforce the importance of thromboprophylaxis with low-molecular-weight heparin in cancer patients.

Vitamin K, an example of triage theory: is micronutrient inadequacy linked to diseases of aging?

The triage theory posits that some functions of micronutrients (the approximately 40 essential vitamins, minerals, fatty acids, and amino acids) are restricted during shortage and that functions required for short-term survival take precedence over those that are less essential. Insidious changes accumulate as a consequence of restriction, which increases the risk of diseases of aging. For 16 known vitamin K-dependent (VKD) proteins, we evaluated the relative lethality of 11 known mouse knockout mutants to categorize essentiality. Results indicate that 5 VKD proteins that are required for coagulation had critical functions (knockouts were embryonic lethal), whereas the knockouts of 5 less critical VKD proteins [osteocalcin, matrix Gla protein (Mgp), growth arrest specific protein 6, transforming growth factor beta-inducible protein (Tgfbi or betaig-h3), and periostin] survived at least through weaning. The VKD gamma-carboxylation of the 5 essential VKD proteins in the liver and the 5 nonessential proteins in nonhepatic tissues sets up a dichotomy that takes advantage of the preferential distribution of dietary vitamin K1 to the liver to preserve coagulation function when vitamin K1 is limiting. Genetic loss of less critical VKD proteins, dietary vitamin K inadequacy, human polymorphisms or mutations, and vitamin K deficiency induced by chronic anticoagulant (warfarin/coumadin) therapy are all linked to age-associated conditions: bone fragility after estrogen loss (osteocalcin) and arterial calcification linked to cardiovascular disease (Mgp). There is increased spontaneous cancer in Tgfbi mouse knockouts, and knockdown of Tgfbi causes mitotic spindle abnormalities. A triage perspective reinforces recommendations of some experts that much of the population and warfarin/coumadin patients may not receive sufficient vitamin K for optimal function of VKD proteins that are important to maintain long-term health.