Long-term allopurinol use decreases the risk of prostate cancer in patients with gout: a population-based study

Association between gout and cancers: A systematic review and meta-analysis

BACKGROUND

This study aimed to investigate the association between gout and cancer risk.

METHODS

This study was registered with the Prospective Registry for International Systematic Reviews (ID: CRD42023465587). We searched PubMed, Embase, Scopus, Cochrane, and Web of Science databases for studies related to gout and cancer risk, with a timeframe from the date the database was created to September 2023. We assessed the methodological quality of the included studies using the Newcastle-Ottawa scale and assessed heterogeneity between studies using the I2 statistic. Depending on the heterogeneity, we calculated pooled hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) using fixed-effects or random-effects models. In addition, we performed sensitivity analyses and publication bias tests.

RESULTS

In this study, we conducted a meta-analysis of 6 studies encompassing a total of 1279,804 participants. Our analysis revealed that individuals with gout are at a heightened risk of developing cancer in general (HR = 1.18, 95% CI = 1.04-1.34, P < .001). Moreover, specific types of cancer displayed a significant correlation with gout, including gastric cancer (HR = 1.31, 95% CI = 1.07-1.62, P = .012), liver cancer (HR = 1.24, 95% CI = 1.01-1.52, P < .001), lung cancer (HR = 1.26, 95% CI = 1.03-1.53, P = .001), and bladder cancer (HR = 1.57, 95% CI = 1.02-2.41, P < .001). Furthermore, gout exhibited a marginally increased risk for other cancer types, such as head and neck cancer and esophageal cancer, although these associations did not attain statistical significance.

CONCLUSION

Our study suggests that gout is a risk factor for cancer, especially for stomach, liver, lung, and bladder cancers. Patients with gout have an increased risk of developing overall cancers, lung cancer, liver cancer, stomach cancer, and bladder cancer. However, more high-quality epidemiologic studies are needed to explore the association between gout and individual cancers more accurately.

Allopurinol and prostate cancer survival in a Finnish population-based cohort

BACKGROUND

Allopurinol is gout medication that inhibits uric acid formation. Its possible anti-carcinogenic properties have been under research in past years. Studies based on Taiwanese registries showed that long term allopurinol use might reduce prostate cancer (PCa) incidence. However, our studies based on Finnish registries did not support those findings. In this study, we evaluate whether allopurinol use is associated with prostate cancer-specific survival (CSS) or overall survival (OS) in a Finnish population-based cohort.

METHODS

The study cohort was originally enrolled for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). We included all newly diagnosed PCa cases during 1996-2015, 9252 men in total. Information on allopurinol purchases was from the national prescription registry of the Social Insurance Institution of Finland. Information about deaths, treatments, and use of other medications was obtained from registries, and tumor stage and PSA at diagnosis from medical records. Follow-up started at diagnosis, and we analysed separately two endpoints: PCa-specific death and overall death. We used an extended Cox regression with adjustment for age at diagnosis, Charlson comorbidity index, FinRSPC trial arm, use of other drugs and EAU PCa risk group.

RESULTS

During a median follow-up of 9.86 years, 2942 deaths occurred, including 883 from PCa. There was no difference in CSS between allopurinol user and non-users, but allopurinol users had lower OS (multivariable-adjusted hazard ratio 1.77; 95% CI: 1.57-2.00). However, this decrease in OS was mitigated along with increasing intensity of allopurinol use.

CONCLUSIONS

We found no marked difference in CSS by allopurinol use. Allopurinol users had lower OS but there were no significant differences by duration or intensity of allopurinol use. Allopurinol use may not have anticancer effects against prostate cancer; instead, it may be a surrogate for metabolic problems causing shorter OS among men with PCa.

Lipidomics Analysis Deepen Understanding the Molecular Mechanisms in a Gouty Model Induced by Combination of MSU Crystals Injection and High-Fat Diet Feeding and the Intervention Mechanisms of Allopurinol

Background

Gouty arthritis (GA) is a common inflammatory disease caused by deposition of monosodium urate (MSU) crystals in diarthrodial joints. GA attacks commonly involved in joint with red, swollen, heat and pain, and often happened in unilateral foot-first metatarsophalangeal. Accumulated studies have proved that lipids play critical roles in biological processes and lipids biomarkers can substitute for the diagnosis of various diseases.

Methods

Herein, shotgun lipidomics was used to quantitatively analyze serum lipidomes of a gouty model which was induced by injecting MSU crystals and feeding high-fat diet with/without treatment with allopurinol. Meanwhile, ELISA kit was used to detect mouse serum levels of inflammatory cytokines (eg, tumor necrosis factor-α, interleukin 1 beta) and HE staining was used to observe the infiltration of inflammatory cells in the foot pad.

Results

A total of 9 types of serum lipids were detected in lipidomics by shotguns, and the result of NMDS' analysis demonstrated significant differences in lipids profiles between the control and model group. It is worth noting that lipid abnormality in GA (such as Ceramide (Cer), sphingomyelin (SM), 4-hydroxyalkenals (HNE), phosphatidylinositol (PI), ethanolamine glycerophospholipid (PE), etc.) is related with phospholipid and energy metabolism, and allopurinol treatment could correct the aberrant metabolism of lipid to some extent.

Conclusion

Our results indicated that various aberrant lipid metabolisms were present in the established gouty model, and allopurinol treatment could relief this aberrant metabolism of lipids to some degree.

Gout and Colorectal Cancer Likelihood: Insights from a Nested Case-Control Study of the Korean Population Utilizing the Korean National Health Insurance Service-National Sample Cohort

Considering the global importance of both gout and colorectal cancer (CRC) as significant health issues with mutual relevance, we aimed to examine the risk of colorectal cancer in Korean patients with gout. In this nested case-control study, we used data from 9920 CRC patients and 39,680 controls the Korean National Health Insurance Service-National Sample Cohort database. Propensity score overlap-weighted multivariate logistic regression analyses, adjusted for confounders, were used to assess the odds ratio (OR) and 95% confidence interval (CI) of the association between gout and CRC. Adjusted OR for CRC were similar between patients with gout and the control group (0.95; 95% CI, 0.86-1.04; p = 0.282). However, after adjustment, subgroup analysis revealed an 18% reduction in the probability of CRC among patients younger than 65 years with gout (95% CI, 0.70-0.95; p = 0.009). Conversely, absence of an association between gout and subsequent CRC persisted regardless of sex, income, residence, and Charlson Comorbidity Index score, even among individuals aged 65 years or older. These results imply that gout may not be a significant independent risk factor for CRC among the general population. However, in patients younger than 65 years with gout, a slightly reduced likelihood of CRC was observed. Further research is necessary to establish a causal relationship between gout and CRC and to generalize these findings to other populations.

Investigating the Anti-inflammatory Effect of Allopurinol on the Prevention of Prostate Cancer

Introduction Gout is a form of arthritis that arises from the accumulation of uric acid in the bloodstream. Allopurinol, a medication that reduces uric acid levels, has also been shown to have anti-inflammatory effects. Research in this area seems to have mixed results. Furthermore, limited research has examined the relationship between gout treated with Allopurinol and its possible protective factors against prostate cancer. The purpose of this study was to examine the relationship between Allopurinol use and prostate cancer, controlling for demographic and metabolic factors. Methods Information was collected from the National Health and Nutrition Examination Survey (NHANES) dataset of the Centers for Disease Control and Prevention (CDC). Logistic regression analysis was employed to establish the correlation between the usage of Allopurinol and the occurrence of prostate cancer while considering variables such as weight, hypertension, hyperlipidemia, race, educational level, and marital status. The research received approval from the review board of the Physician's Journal of Medicine. Results We found no significant association between Allopurinol use and prostate cancer, controlling for covariates. Age was found to have a positive association with prostate cancer. Marriage was found to have a negative association with prostate cancer. Conclusion The results of this study did not find a significant association between Allopurinol use and the risk of prostate cancer. However, this study adds to the limited body of research examining the relationship between gout, Allopurinol, and prostate cancer and suggests that further research is needed in this area. Overall, while Allopurinol has been shown to have anti-inflammatory effects and is used to treat gout, its use does not appear to have a significant impact on the risk of developing prostate cancer.

The double faced role of xanthine oxidoreductase in cancer

Xanthine oxidoreductase (XOR) is a critical, rate-limiting enzyme that controls the last two steps of purine catabolism by converting hypoxanthine to xanthine and xanthine to uric acid. It also produces reactive oxygen species (ROS) during the catalytic process. The enzyme is generally recognized as a drug target for the therapy of gout and hyperuricemia. The catalytic products uric acid and ROS act as antioxidants or oxidants, respectively, and are involved in pro/anti-inflammatory actions, which are associated with various disease manifestations, including metabolic syndrome, ischemia reperfusion injury, cardiovascular disorders, and cancer. Recently, extensive efforts have been devoted to understanding the paradoxical roles of XOR in tumor promotion. Here, we summarize the expression of XOR in different types of cancer and decipher the dual roles of XOR in cancer by its enzymatic or nonenzymatic activity to provide an updated understanding of the mechanistic function of XOR in cancer. We also discuss the potential to modulate XOR in cancer therapy.

A meta-analysis of allopurinol therapy and the risk of prostate cancer

Objective:

The aim of the study was to investigate the risk of prostate cancer among people with gout and/or hyperuricemia who used allopurinol and who did not use allopurinol.

Methods:

We conducted a meta-analysis to identify the cohort and case-control studies by searching PubMed and Web of Science. We used the random-effects model to calculate the pooled risk ratio with 95% confidence interval for the risk of prostate cancer associated with allopurinol treatment.

Results:

There were 5 cohort studies and 2 case-control studies included in the meta-analysis. All 7 eligible studies were published between 2012 and 2021. The study period ranged from 8 to 13years. The number of study subjects ranged from 25,770 to 1,623,550. The age of study subjects ranged from 20 to 99years. Overall, allopurinol treatment was not associated with the risk of prostate cancer (risk ratio = 1.13, 95% confidence interval = 0.96-1.34 and P = .13). The heterogeneity was high between studies (I2 = 93%).

Conclusions:

Our meta-analysis reveals that no association can be found between allopurinol treatment and the risk of prostate cancer among people with gout and/or hyperuricemia. We propose that the inhibition of xanthine oxidase and the reduction of serum uric acid via allopurinol treatment do not affect the probability of developing prostate cancer. Further studies are needed to confirm our findings.

Key Points

Cancer risk in Korean patients with gout

BACKGROUND/AIMS

Using a nationwide cohort, we investigated the cancer risk in Korean patients with gout.

METHODS

Data were obtained from the Korean National Health Insurance Service Database. Patients with gout were defined as those aged ≥ 20 years who were diagnosed with gout and received anti-gout medication (allopurinol, colchicine, and benzbromarone) between 2008 and 2010. Patients with nail disorders were randomly assigned to a control group (1:1 ratio) after frequency matching for age and sex. Cancer incidence was then investigated between 2012 and 2018. Cox proportional hazard regression analysis was used to investigate the association between gout and cancer after adjusting for concomitant diseases.

RESULTS

This study included 179,930 patients with gout and an equal number of matched controls. The incidence of overall cancer was higher in patients with gout than in controls (incidence rate ratio, 1.08). Cox proportional hazards regression analysis showed that gout was associated with a hazard ratio of 1.053 (95% confidence interval ,1.031 to 1.077) after adjusting for concomitant diseases.

CONCLUSION

Gout was associated with a significantly high risk of cancer, especially esophageal, stomach, colon, liver, pancreatic, lung, ovarian, renal, and bladder cancers.

Retrospective evaluation of the impact of non-oncologic chronic drug therapy on the survival in patients with bladder cancer

Background Chronic drug therapy may impact recurrence and survival of patients with bladder cancer and thus be of concern regarding drug choice and treatment decisions. Currently, data are conflicting for some drug classes and missing for others. Objective To analyze the impact of common non-oncologic chronic drug intake on survival in patients with bladder cancer and radical cystectomy. Setting. Patients with bladder cancer and radical cystectomy (2004–2018) at the University Hospital Munich. Method Data from an established internal database with patients with bladder cancer and radical cystectomy were included in a retrospective study. Drug therapy at the time of radical cystectomy and survival data were assessed and follow-up performed 3 months after radical cystectomy and yearly until death or present. Impact on survival was analyzed for antihypertensive, antidiabetic, anti-gout, antithrombotic drugs and statins, using the Kaplan–Meier method, log-rank test and Cox-regression models. Main outcome measure Recurrence free survival, cancer specific survival and overall survival for users versus non-users of predefined drug classes. Results Medication and survival data were available in 972 patients. Median follow-up time was 22 months (IQR 7–61). In the univariate analysis, a significant negative impact among users on recurrence free survival (n = 93; p = 0.038), cancer specific survival (n = 116; p < 0.001) and overall survival (n = 116; p < 0.001) was found for calcium-channel blockers, whereas angiotensin-receptor-blockers negatively influenced overall survival (n = 96; p = 0.020), but not recurrence free survival (n = 73; p = 0.696) and cancer specific survival (n = 96; p = 0.406). No effect of angiotensin-receptor-blockers and calcium-channel blockers was seen in the multivariate analysis. None of the other studied drugs had an impact on survival. Conclusion There was no impact on bladder cancer recurrence and survival for any of the analyzed drugs. Considering our results and the controverse findings in the literature, there is currently no evidence to withhold indicated drugs or choose specific drug classes among the evaluated non-oncologic chronic drug therapies. Thus, prospective studies are required for further insight. Trail registration This is part of the trial DRKS00017080, registered 11.10.2019.

Genetic Variants in Transcription Factor Binding Sites in Humans: Triggered by Natural Selection and Triggers of Diseases

Variants of transcription factor binding sites (TFBSs) constitute an important part of the human genome. Current evidence demonstrates close links between nucleotides within TFBSs and gene expression. There are multiple pathways through which genomic sequences located in TFBSs regulate gene expression, and recent genome-wide association studies have shown the biological significance of TFBS variation in human phenotypes. However, numerous challenges remain in the study of TFBS polymorphisms. This article aims to cover the current state of understanding as regards the genomic features of TFBSs and TFBS variants; the mechanisms through which TFBS variants regulate gene expression; the approaches to studying the effects of nucleotide changes that create or disrupt TFBSs; the challenges faced in studies of TFBS sequence variations; the effects of natural selection on collections of TFBSs; in addition to the insights gained from the study of TFBS alleles related to gout, its associated comorbidities (increased body mass index, chronic kidney disease, diabetes, dyslipidemia, coronary artery disease, ischemic heart disease, hypertension, hyperuricemia, osteoporosis, and prostate cancer), and the treatment responses of patients.

Exploring the Relationship Between Colorectal Cancer and Allopurinol: A Taiwanese Population-Based Propensity-Matched Case-Control Study

The role of allopurinol usage in colorectal cancer (CRC) has no definite conclusion. The aim of this study was to explore the correlation between allopurinol usage and CRC risk in Taiwan. Using the National Health Insurance Database, we conducted a case-control study of cases who were ≥20 years old and had newly diagnosed CRC for the period from 2000 to 2013. The controls were matched to cases by age, sex, index year, comorbidities, and socioeconomic status using propensity scores. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were measured by the conditional logistic regression model. We examined 4372 cases and 4372 matched controls. A statistically significant correlation was noted between allopurinol usage and CRC risk (OR, 0.79; 95%CI, 0.69-0.90). We used the cumulative-defined daily doses (cDDDs) in a further subgroup analysis, the ORs decreased from tertile 1 (T1; low dose, <12 cDDDs), T2 (medium dose, 12 to 88.5 cDDDs), to T3 (high dose, >88.5 cDDDs). These values were 0.85 (95%CI, 0.69-1.06), 0.77 (95%CI, 0.62-0.95), to 0.76 (95%CI, 0.61-0.94). The results indicated a dose-response relationship between allopurinol usage and CRC risk (P for trend < .001). We thus inferred that patients with medium and high doses of allopurinol (≥12 cDDDs) had a statistically significantly decreased CRC risk.

The Role of Oxidative Stress in Hyperuricemia and Xanthine Oxidoreductase (XOR) Inhibitors

Uric acid is the end product of purine metabolism in humans. Hyperuricemia is a metabolic disease caused by the increased formation or reduced excretion of serum uric acid (SUA). Alterations in SUA homeostasis have been linked to a number of diseases, and hyperuricemia is the major etiologic factor of gout and has been correlated with metabolic syndrome, cardiovascular disease, diabetes, hypertension, and renal disease. Oxidative stress is usually defined as an imbalance between free radicals and antioxidants in our body and is considered to be one of the main causes of cell damage and the development of disease. Studies have demonstrated that hyperuricemia is closely related to the generation of reactive oxygen species (ROS). In the human body, xanthine oxidoreductase (XOR) catalyzes the oxidative hydroxylation of hypoxanthine to xanthine to uric acid, with the accompanying production of ROS. Therefore, XOR is considered a drug target for the treatment of hyperuricemia and gout. In this review, we discuss the mechanisms of uric acid transport and the development of hyperuricemia, emphasizing the role of oxidative stress in the occurrence and development of hyperuricemia. We also summarize recent advances and new discoveries in XOR inhibitors.

Pharmacoepidemiological Evaluation in Prostate Cancer-Common Pitfalls and How to Avoid Them

Simple Summary

Pharmacoepidemiologic research provides opportunities to evaluate how commonly used drug groups, such as cholesterol-lowering drugs, may affect the prostate cancer risk or mortality. However, such studies need to be carefully designed in order to avoid biases caused by systematic differences between medication users and non-users. Similarly, data must be carefully analyzed and interpreted while acknowledging possible biases that can lead to erroneous conclusions. Here, we review common pitfalls in such studies and describe ways to avoid them in an effort to aid future research.

Abstract

Pharmacoepidemiologic research provides opportunities to evaluate how commonly used drug groups, such as cholesterol-lowering or antidiabetic drugs, may affect the prostate cancer risk or mortality. This type of research is valuable in estimating real-life drug effects. Nonetheless, pharmacoepidemiological studies are prone to multiple sources of bias that mainly arise from systematic differences between medication users and non-users. If these are not appreciated and properly controlled for, there is a risk of obtaining biased results and reaching erroneous conclusions. Therefore, in order to improve the quality of future research, we describe common biases in pharmacoepidemiological studies, particularly in the context of prostate cancer research. We also list common ways to mitigate these biases and to estimate causality between medication use and cancer outcomes.

Allopurinol Suppresses Azoxymethane-Induced Colorectal Tumorigenesis in C57BL/KsJ-db/db Mice

Obesity and related metabolic disorders, including chronic inflammation and enhanced oxidative stress, are closely associated with the development and progression of colorectal cancer. Previous epidemiological studies have demonstrated that increased serum uric acid is associated with the risk for various types of cancer, including colon cancer. This study examined the effects of a xanthine oxidase inhibitor allopurinol, widely used as a uric acid lowering medicine, on colorectal tumorigenesis in obese mice. Male C57BL/KsJ-db/db mice were injected with azoxymethane (15 mg/kg body weight) and then received drinking water containing allopurinol (30 mg/kg body weight) for fourteen weeks. At the time of sacrifice, allopurinol treatment significantly inhibited the development of colonic premalignant lesions. In the allopurinol-treated group, cellular proliferation in colonic mucosa was significantly suppressed, which was evaluated by the expression of proliferating cell nuclear antigen. Allopurinol also inhibited macrophage infiltration in the adipose tissue and decreased the serum level of TNF-α. The values of oxidative stress markers were markedly decreased in the allopurinol-treated group compared to those in the control group. These findings suggest that allopurinol attenuated chronic inflammation and decreased oxidative stress, preventing the development of colonic pre-neoplastic lesions in obesity-associated colon tumorigenesis model.

Friend or Foe? An Unrecognized Role of Uric Acid in Cancer Development and the Potential Anticancer Effects of Uric Acid-lowering Drugs

In recent years, metabolic syndrome (Mets) has been a hot topic among medical scientists. Mets has an intimate relationship with the incidence and development of various cancers. As a contributory factor of Mets, hyperuricemia actually plays an inseparable role in the formation of various metabolic disorders. Although uric acid is classically considered an antioxidant with beneficial effects, mounting evidence indicates that a high serum uric acid (SUA) level may serve as a pro-oxidant to generate inflammatory reactions and oxidative stress. In this review, we describe the unrecognized role of hyperuricemia in cancer development and summarize major mechanisms linking uric acid to carcinogenesis. Furthermore, we also discuss the potential mechanism of liver metastasis of cancer and list some types of uric acid-lowering agents, which may exert anticancer effects.

High Serum Uric Acid Levels Could Be a Risk Factor of Hepatocellular Carcinoma Recurrences

BACKGROUND

The Apolipoprotein-related MORtality RISk (AMORIS) study in Sweden revealed that serum uric acid (SUA) was significantly associated with hepatobiliary cancer occurrence. However, the association with postoperative hepatocellular carcinoma (HCC) recurrence has not been reported.

METHODS

A total of 256 surgically resected HCC patients were included (from January 2003 to December 2017) in this study. Comparisons in terms of clinicopathologic factors and long-term outcomes were made between patients with high SUA (>6.1 mg/dl) at the time of hepatectomy and low SUA. Besides, SUA data at one postoperative year (1POY) of the same cohort were collected and analyzed in the same manner.

RESULTS

About 88.8% of tumor relapse sites were the remnant liver. High SUA levels were associated with male and well-differentiated HCCs. Recurrence-free survival (RFS) of high SUA patients was significantly inferior to low SUA patients [median survival time (MST): 22.7 vs. 28.5 mo, P = 0.033], whereas no difference was observed in overall survival (MST: both not reached, P = 0.771). RFS of high SUA patients at 1POY also showed significantly poorer outcomes than low SUA patients (MST: 29.3 vs. 57.0 mo, P = 0.049).

CONCLUSIONS

High SUA implies a significant risk factor of activating hepatocarcinogenesis. Keeping the SUA level low may be recommended after HCC resections.

Overview of the Associations Between Cancer and Rheumatic Disease

People living with rheumatic diseases frequently encounter cancer, either as a potential harm of antirheumatic therapies or as a comorbidity that alters the conversation about management. This article provides a general overview of the issues related to cancer and rheumatic disease and serves as a springboard for the remaining chapters in this issue. Several topics are reviewed, including epidemiology, bidirectional causal pathways, and issues related to medications. Although uncertainties remain, the issue of cancer is of great importance to patients with rheumatic diseases, and an individualized, person-centered approach to assessment and management is necessary.

Seminal fluid metabolome and epididymal changes after antibiotic treatment in mice

Paternal environment can induce detrimental developmental origins of health and disease (DOHaD) effects in resulting offspring and even future descendants. Such paternal-induced DOHaD effects might originate from alterations in a possible seminal fluid microbiome (SFM) and composite metabolome. Seminal vesicles secrete a slightly basic product enriched with fructose and other carbohydrates, providing an ideal habitat for microorganisms. Past studies confirm the existence of a SFM that is influenced by genetic and nutritional status. Herein, we sought to determine whether treatment of male mice with a combination of antibiotics designed to target SFM induces metabolic alterations in seminal vesicle gland secretions (seminal fluid) and histopathological changes in testes and epididymides. Adult (10- to 12-week-old) National Institutes of Health (NIH) Swiss males (n = 10 per group) were treated with Clindamycin 0.06 mg/kg day, Unasyn (ampicillin/sulbactam) 40 mg/kg day and Baytril (enrofloxacin) 50 mg/kg day designed to target the primary bacteria within the SFM or saline vehicle alone. Fourteen-day antibiotic treatment of males induced metabolomic changes in seminal vesicles with inosine, xanthine and l-glutamic acid decreased but d-fructose increased in glandular secretions. While spermatogenesis was not affected in treated males, increased number of epididymal tubules showed cribriform growth in this group (7 antibiotic-treated males: 3 saline control males; P = 0.01). Antibiotic-treated males showed more severe cribriform cysts. Current findings suggest antibiotic treatment of male mice results in seminal fluid metabolome and epididymal histopathological alterations. It remains to be determined whether such changes compromise male reproductive function or lead to DOHaD effects in resulting offspring.

Association between allopurinol use and hepatocellular carcinoma in a case-control study in Taiwan

Background/objectives

Little is known about the role of allopurinol use on the risk of hepatocellular carcinoma (HCC). The study aimed to examine the association between allopurinol use and HCC in Taiwan.

Methods

Using the database from the Taiwan National Health Insurance Program, we designed a case-control study that consisted of 4901 subjects aged 20-84 years with newly diagnosed HCC as the case group, and 4901 subjects aged 20-84 years without HCC as the control group, from 2000 to 2013. Ever use of allopurinol was defined as a subject who had at least a prescription for allopurinol before the index date. Never use was defined as a subject who never had a prescription for allopurinol before the index date. The OR and 95% CI for HCC associated with allopurinol use was measured by the multivariable logistic regression model.

Results

After adjustment for confounding factors, the adjusted OR of HCC was 0.93 (95% CI 0.81 to 1.07) for subjects with ever use of allopurinol, compared with never use. The adjusted OR of HCC was 1.01 for subjects with increasing cumulative duration of allopurinol use for every 1 year (95% CI 0.92 to 1.12), compared with never use. The adjusted OR of HCC was 0.99 for subjects with increasing cumulative dosage of allopurinol use for every 50 mg (95% CI 0.94 to 1.05), compared with never use.

Conclusions

No statistical association can be detected between allopurinol use and HCC risk in Taiwan. There are no duration-dependent and dosage-dependent effects of allopurinol use on the risk of HCC.