Cancer risk in people with epilepsy using valproate-sodium

Use of Antiepileptic Drugs and Risk of Prostate Cancer: A Nationwide Case-Control Study in Prostate Cancer Data Base Sweden

An inverse association between use of antiepileptic drugs (AEDs) and prostate cancer (PCa) has been suggested, putatively due to the histone deacetylases inhibitory (HDACi) properties of the AEDs. In a case-control study in Prostate Cancer data Base Sweden (PCBaSe), PCa cases diagnosed between 2014 and 2016 were matched to five controls by year of birth and county of residence. AED prescriptions were identified in the Prescribed Drug Registry. Odds ratios (ORs) and 95% confidence intervals for risk of PCa were estimated using multivariable conditional logistic regression, adjusted for civil status, education level, Charlson comorbidity index, number of outpatient visits, and cumulative duration of hospital stay. Dose responses in different PCa risk categories and HDACi properties of specific AED substances were further explored. 1738/31591 (5.5%) cases and 9674/156802 (6.2%) controls had been exposed to AED. Overall, users of any AED had a reduced risk of PCa as compared to nonusers (OR: 0.92; 95% CI: 0.87-0.97) which was attenuated by adjustment to healthcare utilisation. A reduced risk was also observed in all models for high-risk or metastatic PCa in AED users compared to nonusers (OR: 0.89; 95% CI: 0.81-0.97). No significant findings were observed for dose response or HDACi analyses. Our findings suggest a weak inverse association between AED use and PCa risk, which was attenuated by adjustment for healthcare utilisation. Moreover, our study showed no consistent dose-response pattern and no support for a stronger reduction related to HDAC inhibition. Further studies focusing on advanced PCa and PCa treatments are needed to better analyse the association between use of AED and risk of PCa.

Anti-epileptic drugs and prostate cancer-specific mortality compared to non-users of anti-epileptic drugs in the Finnish Randomized Study of Screening for Prostate Cancer

BACKGROUND

Drugs with histone deacetylase inhibitory (HDACi) properties have shown to decrease prostate cancer (PCa) cell growth in vitro.

METHODS

A cohort of 9261 PCa cases from the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) was used to evaluate prostate cancer-specific mortality in men using anti-epileptic drugs (AEDs). A national subscription database was used to obtain information on medication use. Cox regression with AED use as a time-dependent variable was used to analyse prostate cancer mortality in men using AEDs compared to non-users, and in men using HDACi AEDs compared to users of other AEDs. The analysis was adjusted for age, screening trial arm, PCa risk group, primary treatment of PCa, Charlson co-morbidity score and concomitant use of other drugs.

RESULTS

The use of AEDs, in general, was associated with an increased risk of PCa death. The use of HDACi AEDs was not significantly associated with decreased PCa mortality compared to use of other AEDs (HR 0.61, 95% CI 0.31-1.23).

CONCLUSIONS

AED usage is associated with elevated PCa mortality compared to non-users, likely reflecting the differences between men with epilepsy and those without. No benefit was observed from HDACi drugs compared to other AEDs.

Antiepileptic drugs and prostate cancer risk in the Finnish Randomized Study of Screening for Prostate Cancer

Antiepileptic drugs (AEDs) with histone deacetylase (HDAC) inhibitor properties decrease prostate cancer (PCa) cell proliferation in vitro. A population-based cohort of 78 615 men was used to evaluate the risk of PCa among users of AEDs. Study population was linked to the Finnish national prescription database to obtain information on individual medication reimbursements in 1996 to 2015. Cox regression with antiepileptic medication use as a time-dependent variable was used to analyze PCa risk overall, and low, medium and high-risk PCa separately. The analysis was adjusted for age, screening trial arm, and other drugs in use, including statins, antidiabetic drugs, antihypertensive drugs, aspirin, and nonsteroidal anti-inflammatory drugs. Compared to the nonusers of AEDs, overall PCa risk was decreased among AED users (hazard ratio [HR] = 0.86, 95% confidence interval [CI] = 0.76-0.96). A similar PCa risk decrease was observed among users of HDACi AEDs (HR = 0.87, 95% CI = 0.76-1.01), but no risk difference was found when comparing HDACi AED users to users of other AEDs (HR = 0.98, 95% CI = 0.76-1.27). Our study showed a decrease in overall PCa risk among men using AEDs compared to nonusers. The risk associations were similar for HDAC inhibitors as for AEDs in general.

Long-term use of valproic acid and the prevalence of cancers in bipolar disorder patients in a Taiwanese population: An association analysis using the National Health Insurance Research Database (NHIRD)

BACKGROUND

Epigenetic events play a major role in the carcinogenesis of many cancers. A retrospective cohort study had been performed to evaluate the effects of exposure to the anticonvulsant agent valproic acid (VPA), a histone deacetylase inhibitor, on the risk of developing cancers.

METHODS

The study was based on the 1998 through 2009 National Health Insurance Research Database (NHIRD), provided by the Taiwan National Health Research Institute. Patients with a diagnosis of bipolar disorder (ICD-9-CM codes 296.0, 296.1, 296.4-8) from 1998 to 2009 were identified. VPA and lithium were the primary index drugs. Patients treated with anticonvulsants who did not use VPA or lithium were selected as the control group. Competing risk regression analysis were used to estimate hazards ratios (HR) and 95% confidence intervals (95% CI) reflecting the association between use of VPA and cancer incidence.

RESULTS

The cancer incidence of bipolar disorder patients treated with VPA was no significant difference than treated with lithium and other anticonvulsants. In subgroup analysis, VPA associated to higher risk of genitourinary cancer in the duration < 1 year group (HR: 3.49; 95%CI: 1.04, 11.67). No significant differences in other cancers incidence in any duration of VPA treatment.

LIMITATIONS

The cancer prevalence in selected bipolar disorder patients was still low. The sample size was not enough for some types of cancer.

CONCLUSIONS

A role of VPA in cancer prevention was not found in this study. An increased subgroup risk of genitourinary cancer was observed.

Use of lithium and cancer risk in patients with bipolar disorder: population-based cohort study

BACKGROUND

Lithium inhibits glycogen synthase kinase-3, which is an enzyme involved in the pathogenesis of cancer.

AIMS

To investigate the association between lithium and cancer risk in patients with bipolar disorder.

METHOD

A retrospective cohort study was designed using the National Health Insurance Research Database (NHIRD) in Taiwan. Patients using lithium comprised the index drug group and patients using anticonvulsants only comprised the control group. Time-dependent Cox regression was used to evaluate the hazard ratios (HRs) for risk of cancer.

RESULTS

Compared with anticonvulsant-only exposure, lithium exposure was associated with significantly lower cancer risk (HR = 0.735, 95% CI 0.554-0.974). The hazard ratios for the first, second and third tertiles of the cumulative defined daily dose were 0.762 (95% CI 0.516-1.125), 0.919 (95% CI 0.640-1.318) and 0.552 (95% CI 0.367-0.831), respectively.

CONCLUSIONS

Lithium is associated with reduced overall cancer risk in patients with bipolar disorder. A dose-response relationship for cancer risk reduction was observed.

Antiepileptic drugs with histone deacetylase inhibition activity and prostate cancer risk: a population-based case-control study

Previous studies suggest that antiepileptic drugs with histone deacetylase (HDAC) inhibitor properties may have prostate cancer preventive effects. We evaluated the association between antiepileptic drug use and prostate cancer risk in a population-based case-control study. The study included all new prostate cancer cases diagnosed in Finland in 1995-2002 and matched controls (24,657 case-control pairs) identified from the Finnish Cancer Registry and the Population Register Center, respectively. Information on antiepileptic drug purchases was obtained from the national prescription reimbursement database. Odds ratios and their 95 % confidence intervals were estimated using age-adjusted and multivariable-adjusted conditional logistic regression analysis. Compared to never-users of antiepileptic drugs, the overall prostate cancer risk was decreased among users of phenobarbital, carbamazepine, and valproic acid (multivariable-adjusted odds ratio (OR) 0.47, 95 % CI 0.24-0.92; OR 0.82, 95 % CI 0.71-0.94, and OR 0.62, 95 % CI 0.42-0.92, respectively), but not among users of other antiepileptic drugs. Overall prostate cancer risk decreased in a dose-dependent manner by cumulative amount, duration and yearly dosage (intensity) of HDAC inhibitors valproic acid and carbamazepine. The risk of advanced prostate cancer was decreased only among carbamazepine users (OR 0.65, 95 % CI 0.44-0.96). Our results support possible prostate cancer preventive effects of HDAC inhibitors. However, also phenobarbital use was associated with decreased prostate cancer risk, despite not having HDAC inhibiting activity. The mechanism of action for antiepileptic drugs in prostate cancer deserves further study.

Sodium channel-inhibiting drugs and survival of breast, colon and prostate cancer: a population-based study

Metastasis is the leading cause of cancer-related deaths. Voltage-gated sodium channels (VGSCs) regulate invasion and metastasis. Several VGSC-inhibiting drugs reduce metastasis in murine cancer models. We aimed to test the hypothesis that patients taking VGSC-inhibiting drugs who developed cancer live longer than those not taking these drugs. A cohort study was performed on primary care data from the QResearch database, including patients with breast, bowel or prostate cancer. Cox proportional hazards regression was used to compare the survival from cancer diagnosis of patients taking VGSC-inhibiting drugs with those not exposed to these drugs. Median time to death was 9.7 years in the exposed group and 18.4 years in the unexposed group, and exposure to these medications significantly increased mortality. Thus, exposure to VGSC-inhibiting drugs associates with reduced survival in breast, bowel and prostate cancer patients. This finding is not consistent with the preclinical data. Despite the strengths of this study including the large sample size, the study is limited by missing information on potentially important confounders such as cancer stage, co-morbidities and cause of death. Further research, which is able to account for these confounding issues, is needed to investigate the relationship between VGSC-inhibiting drugs and cancer survival.

Histone deacetylase 2 controls p53 and is a critical factor in tumorigenesis

Histone deacetylase 2 (HDAC2) regulates biological processes by deacetylation of histones and non-histone proteins. HDAC2 is overexpressed in numerous cancer types, suggesting general cancer-relevant functions of HDAC2. In human tumors the TP53 gene encoding p53 is frequently mutated and wild-type p53 is often disarmed. Molecular pathways inactivating wild-type p53 often remain to be defined and understood. Remarkably, current data link HDAC2 to the regulation of the tumor suppressor p53 by deacetylation and to the maintenance of genomic stability. Here, we summarize recent findings on HDAC2 overexpression in solid and hematopoietic cancers with a focus on mechanisms connecting HDAC2 and p53 in vitro and in vivo. In addition, we present an evidence-based model that integrates molecular pathways and feedback loops by which p53 and further transcription factors govern the expression and the ubiquitin-dependent proteasomal degradation of HDAC2 and of p53 itself. Understanding the interactions between p53 and HDAC2 might aid in the development of new therapeutic approaches against cancer.

Could valproic acid be an effective anticancer agent? The evidence so far

Valproic acid is an inhibitor of class I histone deacetylases. Epigenetic therapies in cancer have been focus of a keen interest and histone deacetylase inhibitors, in particular, have been approved for certain types of hematologic malignancies. Valproic acid is an attractive candidate for cancer therapy due to its mechanism of action, its low cost and generally good clinical tolerability. In the following editorial, we will review its role as monotherapy for cancer, its place in combination epigenetic therapy, and its role as chemosensitizer, and cancer preventative agent.

Valproic acid suppresses Nrf2/Keap1 dependent antioxidant protection through induction of endoplasmic reticulum stress and Keap1 promoter DNA demethylation in human lens epithelial cells

Recent epidemiological studies confirm the prevalence of cataract in epileptic patients. Similarly, the drugs used to treat epilepsy also show the connection with increased cataract formation. In this present study, we investigated the suppression of Nrf2/Keap1 dependent antioxidant protection through induction of endoplasmic (ER) stress and Keap1 promoter DNA demethylation in human lens epithelial cells (HLECs) treated with valproic acid (VPA), an antiepileptic drug. 20 mM VPA induces ER stress and activates the unfolded protein response (UPR) within 4 h by activating the ER stress sensor proteins, such as PERK, IRE1α, and ATF6 in HLECs. Consequently, the integrated ER stress signals, such as eIF2α, ATF4, BiP, and CHOP are altered accordingly to induce ER-Ca2+ release, reactive oxygen species (ROS) overproduction, and cell death in HLECs treated with VPA. VPA also suppresses the Nrf2, catalase, and glutathione reductase expressions with significant increases in Keap1 protein. Bisulphite genomic DNA sequencing reveals the promoter DNA demethylation in the Keap1 promoter, which results in the overexpression of Keap1 mRNA and protein in HLECs treated with 20 mM VPA. VPA also alters the expression profiles of passive DNA demethylation pathway enzymes such Dnmt1, Dnmt3a, Dnmt3b, and active DNA demethylation pathway enzyme, TET1 leading to DNA demethylation in the Keap1 promoter of HLECs. Overexpressed Keap1 decreases the Nrf2 level, thereby abolishing the Nrf2 dependent antioxidant protection. This might be responsible for lenticular proteins oxidation and cataract formation.

Epilepsy, anti-epileptic medication use and risk of cancer

Whether the powerful medications used to treat epilepsy increase the risk of cancer has been debated for decades, but until now no study could disentangle the contributions of anti-epileptic medications and epilepsy itself to cancer risk. Using a cohort comprising all Danish residents ≥ 16 years old at some point during the period 1996-2010 (>56 million person-years of follow-up) and information from national health registers, we examined associations between anti-epileptic medication use and cancer rates in persons with and without epilepsy, and between epilepsy and cancer rates in treated and untreated individuals. Associations were expressed as incidence rate ratios (IRRs) estimated using Poisson regression. Among persons without epilepsy, use of anti-epileptic medication increased the rates of most cancers little or not at all, although we observed moderately increased rates of liver, mouth and throat, and respiratory tract cancers (IRRs 1.40-1.59). In contrast, we observed strong associations between epilepsy and the rates of central nervous system and mouth and throat cancers (IRRs 2.00-3.91), and a modest association between epilepsy and the rate of respiratory tract cancers (IRRs 1.30-1.35), independent of anti-epileptic medication use. Our finding of only modest increases in cancer risk directly attributable to anti-epileptic medication use suggests that these medications may not be as strongly carcinogenic as has been feared, and that it is not primarily anti-epileptic medications that are responsible for the increased cancer risk among epileptics but another aspect of epilepsy diagnosis or treatment or an etiologic factor common to the two conditions.

Epilepsy meets cancer: when, why, and what to do about it?

The lifetime risk of having epileptic seizures is profoundly increased in patients with cancer: about 20% of all patients with systemic cancer may develop brain metastases. These patients and those with primary brain tumours have a lifetime risk of epilepsy of 20-80%. Moreover, exposure to chemotherapy or radiotherapy to the brain, cancer-related metabolic disturbances, stroke, and infection can provoke seizures. The management of epilepsy in patients with cancer includes diagnosis and treatment of the underlying cerebral pathological changes, secondary prophylaxis with antiepileptic drugs, and limiting of the effect of epilepsy and its treatment on the efficacy and tolerability of anticancer treatments, cognitive function, and quality of life. Because of the concern of drug-drug interactions, the pharmacological approach to epilepsy requires a multidisciplinary approach, specifically in a setting of rapidly increasing choices of agents both to treat cancer and cancer-associated epilepsy.