Cancer risk in users of calcium channel blockers

Impact of Antihypertensive and Lipid-Lowering Agents on Hepatocellular Carcinoma Risk in Patients with Fatty Liver Disease and Diabetes

BACKGROUND/AIM

This study aimed to evaluate the effects of antihypertensives, lipid-lowering agents, and antiplatelet medications on hepatocellular carcinoma (HCC) risk in patients with fatty liver disease (FLD) and type 2 diabetes (T2D).

METHOD

Using data from Korea Health Insurance Review and Assessment Service, 212,443 FLD-T2D patients were analyzed through Cox regression, propensity score matching (PSM), and Kaplan-Meier analysis. The analysis considered medication use and its relation to HCC development. Cohort admission day was set as the date of the first oral hypoglycemic prescription.

RESULTS

The multivariate Cox regression analysis revealed that old age, male sex, chronic viral hepatitis, alcoholic liver disease, liver cirrhosis, using a combination of insulin and oral hypoglycemic agents for antidiabetic treatment, and calcium channel blocker (CCB) use were significantly correlated with higher HCC development risk, whereas dyslipidemia and statin, ezetimibe, and fibrate use was correlated with lower HCC risk, in the study cohort of 212,443 patients. Patients who used statins (hazard ratio [HR] = 0.58, 95% confidence interval [CI] = 0.42-0.80, P = 0.001) and fibrates (HR = 0.46, 95% CI = 0.22-0.93, P = 0.031) showed a significantly lower risk of HCC development even after PSM. In contrast, CCB use was linked to an elevated HCC risk (HR = 1.35, 95% CI = 1.05-1.72, P = 0.019), highlighting the differential impact of various medications on HCC incidence.

CONCLUSION

The use of specific medications, such as statins and fibrates, may offer protective effects against HCC in patients with FLD-T2D, whereas that of CCB may increase the risk. This underscores the importance of tailored medication strategies for the management of chronic conditions.

Antihypertensive Medications and Risk of Melanoma and Keratinocyte Carcinomas: A Systematic Review and Meta-Analysis

Some antihypertensive medications are photosensitizing. The implications for skin cancer risk remain unclear because results from prior studies are inconsistent and as new evidence is published. We performed a systematic review and meta-analysis to evaluate the association between antihypertensives and common skin cancers (cutaneous squamous cell carcinoma, basal cell carcinoma, and melanoma) and to evaluate dose-response relationships. Forty-four articles met inclusion criteria, and 42 could be meta analyzed. Increased risks were seen for basal cell carcinoma with calcium channel blockers (relative risk [RR] = 1.17, 95% confidence interval [CI] = 1.11-1.22), diuretics (RR = 1.06, 95% CI = 1.03-1.10), and thiazides (RR = 1.10, 95% CI = 1.04-1.16); for squamous cell carcinoma with calcium channel blockers (RR = 1.08, 95% CI = 1.01-1.14), diuretics (RR = 1.29, 95% CI = 1.17-1.43), and thiazides (RR = 1.36, 95% CI = 1.15-1.61); and for melanoma in angiotensin-converting enzyme inhibitors (RR = 1.09, 95% CI = 1.03-1.14), calcium channel blockers (RR = 1.08, 95% CI = 1.03-1.12), and thiazides (RR = 1.09, 95% CI = 1.02-1.17). The quality of evidence was low or very low. We observed evidence for dose-response for thiazides with basal cell carcinoma; angiotensin-converting enzyme inhibitors, diuretics, and thiazides with squamous cell carcinoma; and angiotensin-converting enzyme inhibitors, diuretics, and thiazides with melanoma. Our meta-analysis supports a potential causal association between some antihypertensives, particularly diuretics, and skin cancer risk.

The use of specific antihypertensive medication and skin cancer risk: A systematic review of the literature and meta-analysis

BACKGROUND

The use of hydrochlorothiazide has recently been linked to skin cancer in observational studies. This may be explained by its photosensitizing properties, but photosensitivity has also been reported for other antihypertensive drugs. We conducted a systematic review and meta-analysis to compare skin cancer risk among antihypertensive drug classes and individual blood pressure lowering drugs.

METHODS

We searched Medline, Embase, Cochrane and the Web of Science and included studies that investigated the association between antihypertensive medication exposure and non-melanoma skin cancer (NMSC) or cutaneous malignant melanoma (CMM). We combined the extracted odds ratios (OR) using a random effects model.

RESULTS

We included 42 studies with a total of 16,670,045 subjects. Diuretics, in particular hydrochlorothiazide, were examined most frequently. Only 2 studies provided information about antihypertensive co-medication. Exposure to diuretics (OR 1.27 [1.09-1.47]) and CCB (OR 1.06 [1.04-1.09]) was associated with an increased risk for NMSC. The increased risk for NMSC was only observed in case control studies and studies that did not correct for sun exposure, skin phototype or smoking. Studies that did correct for covariates as well as cohort studies did not show a significantly increased risk for NMSC. Egger's test revealed a significant publication bias for the subgroup of diuretics and hydrochlorothiazide concerning NMSC (p < 0.001).

CONCLUSION

The available studies investigating the potential skin cancer risk that is associated with antihypertensive medication have significant shortcomings. Also, a significant publication bias is present. We found no increased skin cancer risk when analyzing cohort studies or studies that corrected for important covariates. (PROSPERO (CRD42020138908)).

The risk of second primary malignancies in colorectal cancer patients using calcium channel blockers

Calcium channel blockers are among the most commonly used agents in the treatment of cardiovascular diseases. There are several known side-effects associated with their long-term use, whereas other potential adverse effects are yet to be proven. This study aims to evaluate the association between calcium channel blockers exposure and the incidence of second primary malignancy. We established a cohort of 1401 patients with colorectal cancer diagnosed in our institution between January 2003 and December 2016. Patients were followed-up until December 2020. The tumor characteristics and basic clinical data including medication information were obtained from the hospital information system database. Second malignancy was detected in 301 patients (21.5%), and occurred in 27.8% of patients who used calcium channel blockers compared to only 19.9% among non-users. Their use was associated with an increased incidence of bladder cancer in particular. Subanalysis of patients with second malignancy displayed a higher proportion of right-sided colon cancer compared to rectal carcinoma in non-users. Survival analysis revealed significantly better outcomes in early-stage colorectal cancer patients without a history of calcium channel blockers treatment or second primary malignancy.

Dihydropyridine Calcium Channel Blockers and Risk of Pancreatic Cancer: A Population-Based Cohort Study

Background Recent studies have reported that dihydropyridine calcium channel blockers (dCCBs) may increase the risk of pancreatic cancer, but these studies had methodological limitations. We thus aimed to determine whether dCCBs are associated with an increased risk of pancreatic cancer compared with thiazide diuretics, a clinically relevant comparator. Methods and Results We conducted a new user, active comparator, population-based cohort study using the UK Clinical Practice Research Datalink. We identified new users of dCCBs and new users of thiazide diuretics between 1990 and 2018, with follow-up until 2019. Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% CIs for pancreatic cancer, comparing dCCBs with thiazide diuretics. Models were weighted using standardized morbidity ratio weights based on calendar time-specific propensity scores. We also conducted secondary analyses by cumulative duration of use, time since initiation, and individual drugs and assessed for the presence of effect modification by age, sex, smoking status, body mass index, history of chronic pancreatitis, and diabetes. The cohort included 344 480 initiators of dCCBs and 357 968 initiators of thiazide diuretics, generating 3 360 745 person-years of follow-up. After a median follow-up of 4.5 years, the weighted incidence rate per 100 000 person-years was 37.2 (95% CI, 34.1-40.4) for dCCBs and 39.4 (95% CI, 36.1-42.9) for thiazide diuretics. Overall, dCCBs were not associated with an increased risk of pancreatic cancer (weighted HR, 0.93; 95% CI, 0.80-1.09). Similar results were observed in secondary analyses. Conclusions In this large, population-based cohort study, dCCBs were not associated with an increased risk of pancreatic cancer compared with thiazide diuretics. These findings provide reassurance regarding the long-term pancreatic cancer safety of these drugs.

Anti-hypertensive medications and risk of colorectal cancer: a systematic review and meta-analysis

PURPOSE

Antihypertensive medications may impact colorectal cancer risk. We conducted a systematic review and meta-analysis of associations, with colorectal cancer risk, of five classes of antihypertensive medications: angiotensin-converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), beta-blockers (BBs), calcium channel blockers (CCBs), and diuretics.

METHODS

A systematic search was conducted in MEDLINE, Embase, Web of Science, and the Cochrane library to identify relevant studies evaluating associations of ACEIs, ARBs, BBs, CCBs, and diuretics with colorectal cancer risk. Meta-analytic risk ratios (RRs) and corresponding 95% confidence intervals (95% CIs) were calculated using the inverse variance method.

RESULTS

No overall significant associations with colorectal cancer risk were observed; ACEIs (5 studies) RR 1.05, 95% CI 0.91-1.23, ARBs (5 studies) RR 0.94, 95% CI 0.80-1.11, BBs (4 studies) RR 1.00, 95% CI 0.92-1.08, CCBs (4 studies) RR 1.02, 95% CI 0.88-1.18, and diuretics (6 studies) RR 1.02, 95% CI 0.90-1.17. There was considerable heterogeneity across studies, partly explained by differences in study design and location. When stratified by study location, there was significantly reduced colorectal cancer risk for ARB use in Asian populations (2 studies, RR 0.69, 95% CI 0.58-0.83).

CONCLUSION

No significant colorectal cancer risk with ACEIs, BBs, CCBs, or diuretics was observed. ARB use may be associated with decreased risk of colorectal cancer in Asian populations, although additional studies in diverse populations are needed to confirm associations and help understand possible reasons for geographical differences.

Breast Cancer-Epidemiology, Risk Factors, Classification, Prognostic Markers, and Current Treatment Strategies-An Updated Review

Simple Summary

Breast cancer is the most common cancer among women. It is estimated that 2.3 million new cases of BC are diagnosed globally each year. Based on mRNA gene expression levels, BC can be divided into molecular subtypes that provide insights into new treatment strategies and patient stratifications that impact the management of BC patients. This review addresses the overview on the BC epidemiology, risk factors, classification with an emphasis on molecular types, prognostic biomarkers, as well as possible treatment modalities.

Abstract

Breast cancer (BC) is the most frequently diagnosed cancer in women worldwide with more than 2 million new cases in 2020. Its incidence and death rates have increased over the last three decades due to the change in risk factor profiles, better cancer registration, and cancer detection. The number of risk factors of BC is significant and includes both the modifiable factors and non-modifiable factors. Currently, about 80% of patients with BC are individuals aged >50. Survival depends on both stage and molecular subtype. Invasive BCs comprise wide spectrum tumors that show a variation concerning their clinical presentation, behavior, and morphology. Based on mRNA gene expression levels, BC can be divided into molecular subtypes (Luminal A, Luminal B, HER2-enriched, and basal-like). The molecular subtypes provide insights into new treatment strategies and patient stratifications that impact the management of BC patients. The eighth edition of TNM classification outlines a new staging system for BC that, in addition to anatomical features, acknowledges biological factors. Treatment of breast cancer is complex and involves a combination of different modalities including surgery, radiotherapy, chemotherapy, hormonal therapy, or biological therapies delivered in diverse sequences.

Antihypertensive drugs and the risk of cancer: a critical review of available evidence and perspective

: The issue of a potential danger of antihypertensive drugs related to cancer susceptibility is currently generating a major debate in the scientific community, concerns in the public and emphasized interest from the media. The present article is a thorough review of what is known on the various classes of antihypertensive drugs concerning the risk of developing different neoplasms and about the suggested pathophysiological mechanisms, whenever available. The main limitations of evidence derived from studies currently available in this setting are also discussed, high-lightening the need for newly developed approaches to generate more accurate recommendations and informed advice for physicians.

Calcium channel blockers are associated with lower gastric cancer risk: A territory-wide study with propensity score analysis

Prior studies showed that calcium channel blockers (CCBs) could modify cancer risk, but data on gastric cancer (GC) are limited. We aimed to investigate whether CCBs could modify GC risk in Helicobacter pylori-eradicated patients. H pylori-infected patients with hypertension who are aged ≥50 and had received clarithromycin-based triple therapy between 2003 and 2016 were identified from a territory-wide healthcare database. Patients with eradication failure, GC diagnosed within 6 months after HP eradication, and gastric ulcer were excluded. Time-fixed Cox model with one-to-one propensity score matching was used to calculate hazard ratio (HR) of GC with CCBs. Sensitivity analysis using time-dependent multivariable Cox model in which CCB use was treated as time-varying covariate was also performed to address immortal time bias. 17 622 (29.6%) H pylori-eradicated patients with hypertension were included. During a median follow-up of 8.6 years, 105 (0.6%) developed GC. After PS matching, CCBs were associated with a lower GC risk (HR: 0.56; 95% CI: 0.32-0.97). Time-dependent analysis showed consistent result (aHR: 0.50; 95% CI: 0.33-0.75). A longer duration of CCB use was associated with even lower GC risk (adjusted HR [aHR]: 0.69; 95% CI: 0.61-0.79 for every 1-year increase in use). Long-acting CCBs (aHR: 0.47; 95% CI: 0.29-0.76) and dihydropyridines (aHR: 0.49; 95% CI: 0.32-0.73) conferred greater benefit than short-acting ones (aHR: 0.60; 95% CI: 0.36-1.03) and nondihydropyridines (aHR: 0.76; 95% CI: 0.24-2.48). The aHR was 0.57 (95% CI: 0.34-0.97) for noncardia and 0.59 (95% CI: 0.27-1.31) for cardia cancer. Use of CCBs was associated with lower risk of GC development in H pylori-eradicated patients, in a duration- and dose-response manner.

Association Between the Overall Risk of Prostate Cancer and Use of Calcium Channel Blockers: A Systematic Review and Meta-analysis

PURPOSE

Although calcium channel blockers (CCBs) are now commonly prescribed to treat hypertension as a first-line drug therapy, their impact on prostate cancer (PCa) is unclear. This systematic review and meta-analysis was conducted to determine the association between CCB use and the overall risk of PCa.

METHODS

PubMed, EMBASE, and Cochrane were searched up to December 26, 2019, stratified according to statistical method of outcome [odd ratios (ORs), relative ratios (RRs), hazard ratios (HRs)] and cumulative duration of CCB use. The quality assessment of included studies was evaluated by using the Newcastle-Ottawa Scale. Fixed effects models were used to study the association between CCB use and the risk of PCa. Between-study heterogeneity was quantified by using Cochran's Q-statistic and I² statistics. Sensitivity analysis was performed by excluding the studies one by one, and publication bias was analyzed by using funnel plots.

FINDINGS

Nineteen studies with 1,418,407 patients were identified for inclusion in the meta-analysis, which was based on the comparison of cohort studies, nested case-control studies, and case-control studies. Pooled estimates showed a RR of 1.08 (95% CI, 1.05-1.11; P < 0.00001) and a HR of 1.07 (95% CI, 1.02-1.13; P = 0.008) for association between CCB use and the risk of PCa. In addition, the results of subgroup analysis showed that CCB users of <5 years had an 8% increased overall risk of PCa (RR, 1.08; 95% CI, 1.04-1.12; P = 0.0001), and CCB users of 5-10 years had a 13% increased overall risk of PCa (RR, 1.13; 95% CI, 1.04-1.23; P = 0.003).

IMPLICATIONS

CCB use had a tendency to increase the overall risk of PCa, and cumulative duration of CCB use might also be positively correlated with the overall risk of PCa.

Comparative Evaluation of Conventional and Novel Extracts of Stem Bark of Terminalia arjuna for Antihypertensive Activity in BSO Induced Oxidative Stress based Rat Model

BACKGROUND

Terminalia arjuna (TA) has been reported and explored traditionally for its cardiotonic properties while the mechanism of antihypertensive effect of TA has not been clearly reported.

METHOD

The oxidative stress is a major cause for hypertension, hence different extracts of TA having variable marker yield were evaluated for their antihypertensive effect in buthionine sulfoxamine (BSO) induced oxidative stress based model. Soxhlet extraction (SE), room temperature extraction (RTE), microwave assisted extraction (MAE), and ultrasound assisted extraction (USAE) were quantitatively estimated for marker compounds arjunolic acid and arjunic acid through HPTLC.

RESULTS

The hypertension was induced using buthionine sulfoxamine (2 mmol/kg b.w. i.p.) and results suggested that the MAE and USAE showed better recovery of systolic blood pressure (110.33±0.10 and 118.33±0.10) and GSH level (3.62±0.07 nmoles/mL and 3.22±0.13 nmoles/mL), respectively as compared to the positive control group treated with ascorbic acid (Systolic BP: 119.67±0.10, GSH level: 3.11±0.10 nmoles/mL). The RTE and SE also showed a decrease in hypertension but were having moderate effect as compared with the standard positive control.

CONCLUSION

The total percentage yield, the yield of the marker compounds arjunolic and arjunic acid, the IC50 values for antioxidant activity as well as the antihypertensive effect were in order: MAE>USAE>SE>RTE that suggested the role of biomarkers arjunolic acid and arjunic acid in reversing the effect of buthionine sulfoxamine.

The Risk for Lung Cancer Incidence with Calcium Channel Blockers: A Systematic Review and Meta-Analysis of Observational Studies

INTRODUCTION

There are conflicting findings regarding the association between the use of calcium channel blockers (CCBs) and the risk of lung cancer. Considering the public health importance of lung cancer prevention, and emerging evidence of a significant biologic role of calcium channel regulation in the development of lung cancer, we conducted a meta-analysis to assess the risk of lung cancer in CCB users compared with non-CCB users.

MATERIALS AND METHODS

We conducted a comprehensive systematic search of leading medical databases for observational studies published up to December 2017 that examined CCB use and the risk of lung cancer. We used random-effects models to pool results. The impact of duration of CCB use on the estimated effect size was explored using random effects meta-regression.

RESULTS

Ten studies (six cohort and four case-control studies) that evaluated the overall cancer risk among 38,758 CCB users were included in the analysis. Overall risk ratio (RR) for CCB use and lung cancer was 1.15 (95% confidence interval [CI] 1.01-1.32). Subgroup analysis by duration of CCB use suggested that the observed increase in lung cancer risk was driven by the results of five studies with prolonged (≥ 4 years) exposure (RR 1.18; 95% CI 1.08-1.30).

CONCLUSIONS

Our analysis suggests exposure to CCBs is associated with an increased risk of lung cancer. Considering their widespread use, and the paucity of data on the long-term effects of chronic exposure to CCBs, these results are reason for concern and warrant further investigation.

SYSTEMATIC REVIEW REGISTRATION

The protocol for this study was registered at the PROSPERO registry of systematic reviews (registry number: CRD42017056362).

T-Type voltage gated calcium channels: a target in breast cancer?

PURPOSE

The purpose of this review article is to discuss the potential of T-type voltage gated calcium channels (VGCCs) as drug targets in breast cancer. Breast cancer, attributable to the different molecular subtypes, has a crucial need for therapeutic strategies to counter the mortality rate. VGCCs play an important role in regulating cytosolic free calcium levels which regulate cellular processes like tumorigenesis and cancer progression. In the last decade, T-type VGCCs have been investigated in breast cancer proliferation. Calcium channel blockers, in general, have shown an anti-proliferative and cytotoxic effects. T-type VGCC antagonists have shown growth inhibition owing to the inhibition of Ca_V3.2 isoform. Ca_V3.1 isoform has been indicated as a tumour-suppressor gene candidate and is reported to support anti-proliferative and apoptotic activity in breast cancer. The distribution of T-type VGCC isoforms in different breast cancer molecular subtypes is diverse and needs to be further investigated. The role of T-type VGCCs in breast cancer migration, metastasis and more importantly in epithelial to mesenchymal transition (EMT) is yet to be elucidated. In addition, interlaced therapy, using a combination of chemotherapy drugs and T-type VGCC blockers, presents a promising therapeutic approach for breast cancer but more validation and clinical trials are needed. Also, for investigating the potential of T-type VGCC blocker therapy, there is a need for isoform-specific agonists/antagonists to define and discover roles of T-type VGCC specific isoforms.

CONCLUSION

Our article provides a review of the role of T-type VGCCs in breast cancer and also discusses future of the research in this area so that it can be ascertained whether there is any potential of T-type VGCCs as drug targets in breast cancer.

Antihypertensive drugs use and the risk of prostate cancer: a meta-analysis of 21 observational studies

Background

Due to the lack of strong evidence to identify the relationship between antihypertensive drugs use and the risk of prostate cancer, it was needed to do a systematic review to go into the subject.

Methods

We systematically searched PubMed, Web of Science and Embase to identify studies published, through May 2015. Two evaluators independently reviewed and selected articles involving the subject. We used the Newcastle-Ottawa Scale (NOS) to assess the quality of the studies. All extracted results to evaluate the relationship between antihypertensive drugs usage and prostate cancer risk were pool-analysed using Stata 12.0 software.

Results

A total of 12 cohort and 9 case-control studies were ultimately included in our review. Most of the studies were evaluated to be of high quality. There was no significant relationship between angiotensin converting enzyme inhibitors (ACEI) usage and the risk of prostate cancer (RR 1.07, 95% CI 0.96–1.20), according to the total pool-analysed. Use of angiotensin receptor blocker (ARB) was not associated with the risk of prostate cancer (RR 1.09, 95% CI 0.97–1.21), while use of CCB may well increase prostate cancer risk based on the total pool-analysed (RR 1.08, 95% CI 1–1.16). Moreover, subgroup analysis suggested that use of CCB clearly increased prostate cancer risk (RR 1.10, 95% CI 1.04–1.16) in terms of case-control studies. There was also no significant relationship between use of diuretic (RR 1.09, 95% CI 0.95–1.25) or antiadrenergic agents (RR 1.22, 95% CI 0.76–1.96) and prostate cancer risk.

Conclusions

There is no significant relationship between the use of antihypertensive drugs (ACEI, ARB, beta-blockers and diuretics) and prostate cancer risk, but CCB may well increase prostate cancer risk, according to existing observational studies.

Electronic supplementary material

The online version of this article (10.1186/s12894-018-0318-7) contains supplementary material, which is available to authorized users.

Anti-hypertensive drugs and skin cancer risk: a review of the literature and meta-analysis

INTRODUCTION

Several anti-hypertensive drugs have photosensitizing properties, however it remains unclear whether long-term users of these drugs are also at increased risk of skin malignancies. We conducted a literature review and meta-analysis on the association between use of anti-hypertensive drugs and the risk of cutaneous melanoma and non-melanoma skin cancer (NMSC).

METHODS

We searched PubMed, EMBASE, Google Scholar and the Cochrane Library, and included observational and experimental epidemiological studies published until February 28th, 2017. We calculated summary relative risk (SRR) and 95% confidence intervals (95% CI) through random effect models to estimate the risk of skin malignancies among users of the following classes of anti-hypertensive drugs: thiazide diuretics, angiotensin converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), calcium channel blockers (CCB) and β-blockers. We conducted sub-group and sensitivity analysis to explore causes of between-studies heterogeneity, and assessed publication bias using a funnel-plot based approach.

RESULTS

Nineteen independent studies were included in the meta-analysis. CCB users were at increased skin cancer risk (SRR 1.14, 95% CI 1.07-1.21), and β-blockers users were at increased risk of developing cutaneous melanoma (SRR 1.21, 95% CI 1.05-1.40), with acceptable between-studies heterogeneity (I2 < 50%). There was no association between thiazide diuretics, ACEi or ARB use and skin cancer risk. We found no evidence of publication bias affecting the results.

CONCLUSION

Family doctors and clinicians should inform their patients about the increased risk of skin cancer associated with the use of CCB and β-blockers and instruct them to perform periodic skin self-examination. Further studies are warranted to elucidate the observed associations.

Calcium channel blockers and breast cancer incidence: An updated systematic review and meta-analysis of the evidence

Controversy exists regarding the potential association between taking calcium channel blockers (CCBs) and the development of breast cancer. As a positive association would have important public health implications due to the widespread use of CCBs, this study aimed to incorporate new evidence to determine whether an association is likely to exist. We searched MEDLINE, EMBASE and the Cochrane Library to 28 June 2016 for relevant literature. References and citing articles were checked and authors contacted as necessary. Two authors independently selected articles and extracted data. Twenty-nine studies were reviewed; 26 were non-randomised studies (NRS). Meta-analysis of study data where adjustment for 'confounding by indication' was judged to be present suggests that an association, if any, is likely to be modest in magnitude (pooled odds/risk ratio 1.09 (95% confidence interval (CI) 1.03-1.15, I²=0%, 8 sub-studies; pooled hazard ratio 0.99 (95% CI 0.94-1.03, I²=35%, 9 sub-studies)). There are credible study data showing an increased relative risk with long-term use of CCBs, but the results of our meta-analysis and of meta-regression of log relative risk against minimum follow-up time are mixed. The current summative evidence does not support a clear association between taking CCBs and developing breast cancer. However, uncertainty remains, especially for long-term use and any association might not be uniform between different populations and/or breast cancer sub-types. We thus recommend further NRS in settings where CCB use is highly prevalent and population-based cancer, prescription and health-registries exist, to resolve this continuing uncertainty. PROSPERO, CRD42015026712.

Antihypertensive drug use and breast cancer risk: a meta-analysis of observational studies

We conducted a meta-analysis of observational studies to examine the hypothesized association between breast cancer and antihypertensive drug (AHT) use. Fixed- or random- effect models were used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs) for all AHTs and individual classes (i.e., angiotensin-converting enzyme inhibitors, [ACEi]; angiotensin-receptor blockers, [ARBs]; calcium channel blockers, [CCBs]; beta-blockers, [BBs], and diuretics). Twenty-one studies with 3,116,266 participants were included. Overall, AHT use was not significantly associated with breast cancer risk (RR = 1.02, 95% CI: 0.98-1.06), and no consistent association was found for specific AHT classes with pooled RRs of 1.02 (95% CI: 0.96-1.09) for BBs, 1.07 (95% CI: 0.99-1.16) for CCBs, 0.99 (95% CI: 0.93-1.05) for ACEi/ARBs, and 1.05 (95% CI: 0.99-1.12) for diuretics. When stratified by duration of use, there was a significantly reduced breast cancer risk for ACEi/ARB use ≥10 years (RR = 0.80, 95% CI: 0.67-0.95). Although there was no significant association between AHT use and breast cancer risk, there was a possible beneficial effect was found for long-term ACEi/ARB. Large, randomized controlled trials with long-term follow-up are needed to further test the effect of these medications on breast cancer risk.

Antihypertensive medication use and risk of renal cell carcinoma

PURPOSE

Use of antihypertensive medications has been associated with renal cell carcinoma (RCC), but it is unclear whether specific types of medications increase RCC risk independent of the effect of hypertension, or whether the association varies by histologic subtype. To address this question, we analyzed data from a U.S. population-based case-control study of RCC.

METHODS

We collected information on participants' use of drugs to treat hypertension, heart problems, weight control, and swelling. We computed odds ratios (ORs) and 95% confidence intervals (CIs) for each of four major drug classes, separately for participants with (643 cases, 443 controls) and without (500 cases, 718 controls) a history of hypertension, using unconditional logistic and polytomous regression models.

RESULTS

None of the antihypertensive drug types was associated with RCC overall. Among participants with a history of hypertension, papillary RCC was associated with long-term use of diuretics (OR = 3.1, 95% CI = 1.4-6.7 for 16+ years, 16 cases, 31 controls; P-trend = 0.014) and calcium channel blockers (OR = 2.8, 95% CI = 1.1-7.4 for 16+ years, 8 cases, 14 controls; P-trend = 0.18), while corresponding ORs for clear cell RCC were weaker (ORs 0.9 and 1.5, respectively) and nonsignificant. The only significant finding among those with no hypertension history was an association between calcium channel blockers and papillary RCC (OR = 17.9, 95% CI = 5.9-54.5) that was based on small numbers (8 cases, 9 controls). There was little evidence of an association between RCC and use of ACE inhibitors or beta blockers.

CONCLUSIONS

Our study, while inconclusive for overall RCC, provides, to our knowledge, the first evidence supporting an association between antihypertensive medications and papillary RCC. These subtype-specific findings, although based on small numbers, warrant further investigation.

The Use of Antihypertensive Medication and the Risk of Breast Cancer in a Case-Control Study in a Spanish Population: The MCC-Spain Study

INTRODUCTION

The evidence on the relationship between breast cancer and different types of antihypertensive drugs taken for at least 5 years is limited and inconsistent. Furthermore, the debate has recently been fueled again with new data reporting an increased risk of breast cancer among women with a long history of use of antihypertensive drugs compared with nonusers.

METHODS

In this case-control study, we report the antihypertensive drugs-breast cancer relationship in 1,736 breast cancer cases and 1,895 healthy controls; results are reported stratifying by the women's characteristics (i.e., menopausal status or body mass index category) tumor characteristics and length of use of antihypertensive drugs.

RESULTS

The relationship among breast cancer and use of calcium channel blockers (CCB) for 5 or more years had odds ratio (OR) = 1.77 (95% CI, 0.99 to 3.17). Stratifying by BMI, the OR increased significantly in the group with BMI ≥ 25 (OR 2.54, 95% CI, 1.24 to 5.22). CCBs were even more strongly associated with more aggressive tumors, (OR for invasive tumors = 1.96, 95% CI = 1.09 to 3.53; OR for non ductal cancers = 3.97, 95% CI = 1.73 to 9.05; OR for Erbb2+ cancer = 2.97, 95% CI: 1.20 to 7.32). On the other hand, premenopausal women were the only group in which angiotensin II receptor blockers may be associated with breast cancer (OR = 4.27, 95% CI = 1.32 to 13.84) but this could not be identified with any type or stage. Use of angiotensin-converting-enzyme inhibitors, beta blockers and diuretics were not associated with risk.

CONCLUSIONS

In this large population-based study we found that long term use of calcium channel blockers is associated with some subtypes of breast cancer (and with breast cancer in overweight women).

Long-term use of calcium channel blocking drugs and breast cancer risk in a prospective cohort of US and Puerto Rican women

Background

In a recent case–control study, long-term use of calcium channel blocking drugs was associated with a greater-than-twofold increased breast cancer risk. If prospectively collected data confirm that calcium channel blocker use increases breast cancer risk, this would have major implications for hypertension treatment. The objective of this study was to determine whether women using calcium channel blockers for 10 years or more were at increased risk of developing breast cancer compared with women not using calcium channel blockers.

Methods

The Sister Study is a prospective volunteer cohort study of women from the USA and Puerto Rico designed to evaluate environmental and genetic risk factors for breast cancer. Beginning in 2003, women between the ages of 35 and 74 were recruited. They were eligible to participate if they had a sister with breast cancer but had not been diagnosed with breast cancer themselves. In total, 50,884 women enrolled in the cohort between 2003 and 2009; 50,757 women with relevant baseline data and available follow-up data are included in this study. The exposure of interest is current use of calcium channel blocking drugs and the reported duration of use at entry into the cohort. Secondary exposures of interest were the duration and frequency of use for all other subclasses of antihypertensive drugs. Our main outcome is a self-reported diagnosis of breast cancer during the study follow-up period. With patient permission, self-reported diagnoses were confirmed using medical records.

Results

Results showed 15,817 participants were currently using an antihypertensive drug, and 3316 women were currently using a calcium channel blocker at study baseline; 1965 women reported a breast cancer diagnosis during study follow-up. Using Cox proportional hazards modeling, we found no increased risk of breast cancer among women who had been using calcium channel blockers for 10 years or more compared with never users of calcium channel blockers (HR 0.88, 95 % CI 0.58–1.33).

Conclusions

We saw no evidence of increased risk of breast cancer from 10 years or more of current calcium channel blocker use. Our results do not support avoiding calcium channel blocking drugs in order to reduce breast cancer risk.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-016-0720-6) contains supplementary material, which is available to authorized users.

Calcium channel blockers and cancer: a risk analysis using the UK Clinical Practice Research Datalink (CPRD)

OBJECTIVE

The evidence of an association between calcium channel blockers (CCBs) and cancer is conflicting. The objective of the present study was to evaluate the risk of cancer (all, breast, prostate and colon cancers) in association with exposure to CCB.

METHODS

This is a population-based cohort study in patients exposed to CCBs from across the UK, using two comparison cohorts: (1) patients with no exposure to CCB (non-CCB) matched on age and gender and (2) unmatched patients unexposed to CCB and at least one other antihypertensive (AHT) prescription. Cancer incidence rates computed in the exposed and the two unexposed groups were compared using HRs and 95% CIs obtained from multivariate Cox regression analyses.

RESULTS

Overall, 150,750, 557,931 and 156,966 patients were included, respectively, in the CCB, non-CCB and AHT cohorts. Crude cancer incidence rates per 1000 person-years were 16.51, 15.75 and 10.62 for the three cohorts, respectively. Adjusted HRs (CI) for all cancers comparing CCB, non-CCB and AHT cohorts were 0.88 (0.86 to 0.89) and 1.01 (0.98 to 1.04), respectively. Compared to the AHT cohort, adjusted HRs (CI) for breast, prostate and colon cancer for the CCB cohort were 0.95 (0.87 to 1.04), 1.07 (0.98 to 1.16) and 0.89 (0.81 to 0.98), respectively. Analyses by duration of exposure to CCB did not show excess risk.

CONCLUSIONS

This large population-based study provides strong evidence that CCB use is not associated with an increased risk of cancer. The analyses yielded robust results across all types of cancer and different durations of exposure to CCBs.

Antihypertensive medication use and incident breast cancer in women

The purpose of this study was to evaluate whether antihypertensive medication use, including long-term use, is associated with increased breast cancer incidence in women. We studied 210,641 U.S. registered nurses participating in the Nurses' Health Study (NHS) and Nurses' Health Study II (NHS II). Information on antihypertensive medication use was collected on biennial questionnaires in both cohorts, and breast cancer cases were ascertained during this period. Multivariable-adjusted Cox proportional hazard models were used to estimate relative risks of invasive breast cancer over follow-up (1988-2012 in NHS, 1989-2011 in NHS II) across categories of overall antihypertensive medication use and use of specific classes (diuretics, beta blockers, calcium channel blockers, and angiotensin-converting enzyme inhibitors). During follow-up, 10,012 cases of invasive breast cancer developed (6718 cases in NHS and 3294 in the NHS II). Overall, current use of any antihypertensive medication was not associated with breast cancer risk compared with past/never use in NHS (multivariable-adjusted relative risk = 1.00, 95 % CI = 0.95-1.06) or NHS II (multivariable-adjusted relative risk = 0.94, 95 % CI = 0.86-1.03). Furthermore, no specific class of antihypertensive medication was consistently associated with breast cancer risk. Results were similar when we considered hypertensive women only, and when we evaluated consistency and duration of medication use over time. Overall, antihypertensive medication use was largely unrelated to the risk of invasive breast cancer among women in the NHS cohorts.

The incidence of cancer deaths among hypertensive patients in a large Chinese population: a cohort study

Current evidence is mixed regarding the association between antihypertensive prescriptions and cancer mortality. We evaluated this association in a large Chinese hypertensive population. We followed for five years all patients who were prescribed their first-ever antihypertensive agents between 2001 and 2005 in a public healthcare sector of Hong Kong. The association between antihypertensive drug class and cancer mortality was evaluated by Cox proportional hazard models with propensity score matching. Age, gender, socioeconomic status, service settings, district of residence, proportion of days covered reflecting medication adherence, and the number of comorbidities were adjusted. From 217,910 eligible patients, 9500 (4.4%) died from cancer within five years after their first-ever antihypertensive prescription. Most cancer deaths occurred in the digestive (38.9%) and respiratory system (30.4%); the breast (6.2%); and the lympho-hematopoietic tissues (5.3%). The proportion of patients who died from cancer was the highest in the calcium channel blocker (CCB) group (6.5%), followed by thiazide diuretics (4.4%), angiotensin converting enzyme inhibitors (4.2%) and β-blockers (2.6%). When compared with β-blockers, patients prescribed CCBs (Adjusted Hazard Ratio [AHR]=1.406, 95% C.I. 1.334-1.482, p<0.001) were more likely to die from cancer. Thiazide users were also more likely to suffer from cancer deaths (AHR=1.364, 95% C.I. 1.255-1.483, p<0.001), but became insignificant in stratified analysis. The association between cancer mortality and use of CCB, and perhaps thaizide, may alert physicians to the need for more meticulous and comprehensive care of these patients in clinical practice. We recommend prospective studies to evaluate cause-and-effect relationships of these associations.

Calcium channel blockers and risk of breast cancer: a meta-analysis of 17 observational studies

PURPOSE

Studies on the association between the use of calcium channel blockers (CCBs) and breast cancer risk have reported inconsistent results. We quantitatively assessed this association by conducting a meta-analysis based on the evidence from observational studies.

METHODS

We searched PubMed, MEDLINE, EMBASE and the Cochrane Library for relevant studies published up to and including December 31, 2013. We calculated pooled risk ratios (RRs) for cancer risk.

RESULTS

A total of 17 studies (9 cohort studies, 8 case-control studies) were selected for further study. These studies included 149,607 female subjects, of which 53,812 were CCBs users, who were followed for 2-16 years. The risks of breast cancer among patients receiving CCBs were significantly different for the pooled RRs (95% confidence interval) of cohort studies 1.08 (0.95, 1.20) and case-control studies 0.98 (0.86, 1.09). Differences were also noted for cancer risk, for CCBs use of <5 years 0.96 (0.78, 1.15), and for >5 years 1.01 (0.74, 1.28), as well as for ever used 1.08 (0.95, 1.20), and for current use 1.13 (0.83, 1.42). The RR for studies longer than 10 years was 1.71 (1.01, 2.42), and for studies evaluating nifedipine was 1.10 (0.87, 1.33) and diltiazem was 0.75 (0.40, 1.10).

CONCLUSIONS

The long-term use of CCBs appears to have a significant relationship with breast cancer. Well-designed clinical trials are needed to optimize the doses and types of these drugs needed to minimize their carcinogenic potential.

Angiotensin-converting enzyme inhibitor therapy and colorectal cancer risk

BACKGROUND

Laboratory data suggest a role of angiotensin II in the pathogenesis of colorectal cancer (CRC). Whether angiotensin converting enzyme inhibitor (ACE-I) and/or angiotensin receptor blocker (ARB) use reduces the risk of colorectal neoplasia remains unclear. Given their widespread use, we sought to determine whether exposure to these agents would have a secondary benefit on CRC incidence.

METHODS

A nested case-control study was conducted using EPIC's General Practice Research Database (1987-2002). The study cohort consisted of hypertensive patients. Case patients were those diagnosed with CRC after the diagnosis of hypertension. Each case patient was matched to up to 10 control subjects on age, sex, and both calendar year and duration of follow-up using incidence density sampling. The association between CRC and ACE-I/ARB exposure was assessed with conditional logistic regression. All statistical tests were two-sided.

RESULTS

Two thousand eight-hundred forty-seven case patients were matched with 28239 control subjects. The adjusted odds ratios (ORs) of CRC were 0.84 (95% confidence interval [CI] = 0.72 to 0.98; P = .03) for or more years of ACE-I/ARB therapy and 0.75 (95% CI = 0.58 to 0.97; P = .03) for 5 or more years of exposure. The strength of this association increased with high-dose exposure (OR = 0.53; 95% CI = 0.35 to 0.79; P = .003 for ≥3 years of high-dose exposure). Among patients receiving antihypertensive medications, the association with long-term therapy was no longer statistically significant for ≥5 years), but the benefit of high-dose therapy remained (OR = 0.59; 95% CI = 0.39 to 0.89; P = .01 for ≥3 years of high-dose exposure).

CONCLUSIONS

Long-term/high dose exposure to ACE-Is/ARBs may be associated with a decreased incidence of CRC.

Use of antihypertensive medications and breast cancer risk among women aged 55 to 74 years

IMPORTANCE

Antihypertensive agents are the most commonly prescribed class of medications in the United States. Evidence regarding the relationship between different types of antihypertensives and breast cancer risk is sparse and inconsistent, and prior studies have lacked the capacity to assess impacts of long-term use.

OBJECTIVE

To evaluate associations between use of various classes of antihypertensive medications and risks of invasive ductal and invasive lobular breast cancers among postmenopausal women.

DESIGN, SETTING, AND PARTICIPANTS

Population-based case-control study in the 3-county Seattle-Puget Sound metropolitan area. Participants were women aged 55 to 74 years, 880 of them with invasive ductal breast cancer, 1027 with invasive lobular breast cancer, and 856 with no cancer serving as controls.

EXPOSURES

Recency and duration of use of antihypertensive medications.

MAIN OUTCOMES AND MEASURES

Risks of invasive ductal and invasive lobular breast cancers.

RESULTS

Current use of calcium-channel blockers for 10 or more years was associated with higher risks of ductal breast cancer (odds ratio [OR], 2.4; 95% CI, 1.2-4.9) (P= .04 for trend) and lobular breast cancer (OR, 2.6; 95% CI, 1.3-5.3) (P= .01 for trend). This relationship did not vary appreciably by type of calcium-channel blocker used (short-acting vs long-acting, dihydropyridines vs non-dihydropyridines). In contrast, use of diuretics, β-blockers, and angiotensin II antagonists were not associated with risk.

CONCLUSIONS AND RELEVANCE

While some studies have suggested a positive association between calcium-channel blocker use and breast cancer risk, this is the first study to observe that long-term current use of calcium-channel blockers in particular are associated with breast cancer risk. Additional research is needed to confirm this finding and to evaluate potential underlying biological mechanisms.

Cav1.3 channel α1D protein is overexpressed and modulates androgen receptor transactivation in prostate cancers

Widespread use of L-type calcium channel blockers for treating hypertension has led to multiple epidemiologic studies to assess the risk of prostate cancer incidence. These studies revealed a reverse correlation between the likelihood of prostate cancer risk and the use of L-type calcium channel blockers among men without family history but the mechanism was not clear. In this study, we examined the expression profiles of multiple L-type calcium channel genes in prostate cancers and determined their functional roles in androgen receptor (AR) transactivation and cell growth. By reanalyzing the ONCOMINE database, we found that L-type calcium channel CACNA1D gene expression levels in cancer tissues were significantly higher than noncancer tissues in 14 of 15 published complementary deoxyribonucleic acid microarray data sets, of which 9 data sets showed an increase of 2- to 17-folds. Quantitative polymerase chain reaction and immunostaining experiments revealed that CACNA1D gene and its coding protein α1D were highly expressed in prostate cancers, especially in castration-resistant diseases, compared with benign prostate tissues. Consistent with the notion of CACNA1D as an ERG-regulated gene, CACNA1D gene expression levels were significantly higher in prostate cancers with TMPRSS2-ERG gene fusion compared with the cases without this gene fusion. Blocking L-type channel's function or knocking down CACNA1D gene expression significantly suppressed androgen-stimulated Ca(2+) influx, AR transactivation, and cell growth in prostate cancer cells. Taken together, these data suggest that CACNA1D gene overexpression is associated with prostate cancer progression and might play an important role in Ca(2+) influx, AR activation, and cell growth in prostate cancer cells.

The calcium-channel blocker controversy: historical perspective and important lessons for future pharmacotherapies. An international society of pharmacoepidemiology 'hot topic'

Reports of adverse events in association with calcium-channel blockers led to heated controversy over the safety and efficacy of these drugs, as well as to panic among the general public. At the 1998 International Conference of Pharmacoepidemiology, four experts were asked to summarize, and draw lessons from, the controversy's development. We conducted our own review in order to provide a broader historical perspective on the subject and to present the discussants' views within the framework of additional published opinions. Several years after the controversy's onset, many uncertainties still remain about the merits of CCBs. Yet the media scare generated by a few studies might have been prevented had investigators placed greater emphasis, particularly in their reports to the media, on the limitations of their observational and meta-analytic designs. These studies, however, did call attention to the persistent use of CCBs for off-label indications, and the imperative to improve clinician prescribing practices. Moreover, they showed the pitfalls of reliance on surrogate endpoints, stressing the need for data on major clinical outcomes-with funding a responsibility of the pharmaceutical industry-before approving drugs destined for widespread, long-term use. Attention to these lessons will do us well as we evaluate emerging pharmacotherapies. Copyright (c) 2000 John Wiley & Sons, Ltd.

Diltiazem enhances the apoptotic effects of proteasome inhibitors to induce prostate cancer cell death

Diltiazem is a calcium channel blocker used to treat cardiovascular ailments. In addition, reports suggest that diltiazem induces cell death, which could make it a drug of choice for the treatment of cancer associated with hypertension. The goal of this research was to determine whether diltiazem is capable of inducing apoptosis in prostate cancer cells, either alone or in combination with the proteasome inhibitors, lactacystin and bortezomib (Velcade). Bortezomib is approved for the treatment of multiple myeloma; unfortunately, it has side effects that limit its utility. Presumably these side effects could be decreased by reducing its dose in combination with another drug. We have previously shown that lactacystin induces apoptosis in LNCaP cells; here, we show that this effect was enhanced by diltiazem. Furthermore, in proteasome inhibitor-resistant DU145 cells, diltiazem alone did not induce apoptosis but decreased cytosolic calcium levels and induced mitochondrial fission; likewise, lactacystin did not induce apoptosis but up-regulated the proapoptotic protein Bik. However, increasing concentrations of diltiazem in combination with lactacystin or bortezomib induced apoptosis in a dose-dependent and synergistic manner. The combination of diltiazem and lactacystin also up-regulated the levels of Bik and released Bak from Bcl-xL, indicating the involvement of the Bcl2 family pathway in this apoptosis. In addition, the drug combination up-regulated GRP78, suggesting also the involvement of endoplasmic reticulum stress in the apoptotic response. Thus, our results demonstrate a potential therapeutic advantage of combining a frequently used calcium channel blocker with proteasome inhibitors in the treatment of prostate cancer.

Targeting the IL-6 dependent phenotype can identify novel therapies for cholangiocarcinoma

Background

The need for new therapies for cholangiocarcinoma is highlighted by their poor prognosis and refractoriness to chemotherapy. Increased production of Interleukin-6 promotes cholangiocarcinoma growth and contributes to chemoresistance by activating cell survival mechanisms. We sought to identify biologically active compounds capable of ameliorating the phenotypic effects of IL-6 expression and to explore their potential therapeutic use for cholangiocarcinoma.

Methodology

A genomic signature associated with Interleukin-6 expression in Mz-ChA-1 human malignant cholangiocytes was derived. Computational bioinformatics analysis was performed to identify compounds that induced inverse gene changes to the signature. The effect of these compounds on cholangiocarcinoma growth was then experimentally verified in vitro and in vivo. Interactions with other therapeutic agents were evaluated using median effects analysis.

Principal Findings

A group of structurally related compounds, nitrendipine, nifedipine and felodipine was identified. All three compounds were cytotoxic to Mz-ChA-1 cells with an IC50 for felodipine of 26 µM, nitrendipine, 44 µM and nifedipine, 15 µM. Similar results were observed in KMCH-1, CC-LP-1 and TFK-1 cholangiocarcinoma cell lines. At a fractional effect of 0.5, all three agents were synergistic with either camptothecin or gemcitabine in Mz-ChA-1 cells in vitro. Co-administration of felodipine and gemcitabine decreased the growth of Mz-ChA-1 cell xenografts in nude athymic mice.

Conclusions

Computational bioinformatics analysis of phenotype-based genomic expression can be used to identify therapeutic agents. Using this drug discovery approach based on targeting a defined tumor associated phenotype, we identified compounds with the potential for therapeutic use in cholangiocarcinoma.

Hypertension, diuretics and antihypertensives in relation to bladder cancer

The aim of this study is to investigate the relationships between hypertension, hypertension medication and bladder cancer risk in a population-based case-control study conducted in Los Angeles. Non-Asians between the ages of 25 and 64 years with histologically confirmed bladder cancers diagnosed between 1987 and 1996 were identified through the Los Angeles County Cancer Surveillance Program. A total of 1585 cases and their age-, gender- and race-matched neighborhood controls were included in the analyses. Conditional logistic regression models were used to examine the relationship between history of hypertension, medication use and bladder cancer risk. A history of hypertension was not related to bladder cancer; however, among hypertensive individuals, there was a significant difference in bladder cancer risk related to the use of diuretics or antihypertensive drugs (P for heterogeneity = 0.004). Compared with individuals without hypertension, hypertensive individuals who regularly used diuretics/antihypertensives had a similar risk [odds ratio (OR) 1.06; 95% confidence interval (CI) 0.86-1.30], whereas untreated hypertensive subjects had a 35% reduction in risk (OR: 0.65; 95% CI: 0.48-0.88). A greater reduction in bladder cancer risk was observed among current-smokers (OR: 0.43; 95% CI: 0.27-0.71) and carriers of GSTM1-null (homozygous absence) genotypes (OR: 0.43; 95% CI: 0.22-0.85). Similarly, among smokers with GSTM1-null genotype, levels of 4-aminobiphenyl-hemoglobin adducts were significantly lower among untreated hypertensive individuals (45.7 pg/g Hb) compared with individuals without hypertension (79.8 pg/g Hb) (P = 0.009). In conclusion, untreated hypertension was associated with a reduced risk of bladder cancer.

Augmentation of 3-methylcholanthrene-induced bioactivation in the human hepatoma cell line HepG2 by the calcium channel blocker nicardipine

The abilities of the dihydropyridine calcium channel blocker nicardipine (Nic) to induce cytochrome P450 1 family enzymes (CYP1s) and to enhance the 3-methylcholanthrene (MC)-mediated induction of CYP1s and formation of MC-DNA adduct were examined in the human hepatoma cell line HepG2. The results from real time RT-PCR analysis demonstrated that Nic could induce CYP1 mRNAs and enhance the MC-mediated induction of the CYP1 mRNAs. The luciferase-reporter gene assay using the HepG2-A10 cell line, which has been previously established for the screening of aryl hydrocarbon receptor (AhR) activators, also indicated the augmentation of MC-mediated activation of AhR (induction of luciferase) by Nic, although Nic showed limited capacity for the activation of AhR. Furthermore, the results from the Western blot analysis of CYP1s, the enzyme activity assay, and the assay for MC-DNA adduct formation indicated that Nic could enhance the MC-mediated induction of CYP1s, especially CYP1A1. Furthermore, the intracellular accumulation level of [(3)H]MC after treatment of HepG2 cells with [(3)H]MC significantly increased in the presence of Nic. The present findings demonstrate that Nic can enhance the MC-mediated induction of CYP1s, especially CYP1A1, and the formation of MC-DNA adduct in HepG2 cells. Furthermore, the augmentation of the MC-mediated bioactivation by Nic is demonstrated to occur mainly through an increase in intracellular accumulation of MC.

Computational models for drug inhibition of the human apical sodium-dependent bile acid transporter

The human apical sodium-dependent bile acid transporter (ASBT; SLC10A2) is the primary mechanism for intestinal bile acid reabsorption. In the colon, secondary bile acids increase the risk of cancer. Therefore, drugs that inhibit ASBT have the potential to increase the risk of colon cancer. The objectives of this study were to identify FDA-approved drugs that inhibit ASBT and to derive computational models for ASBT inhibition. Inhibition was evaluated using ASBT-MDCK monolayers and taurocholate as the model substrate. Computational modeling employed a HipHop qualitative approach, a Hypogen quantitative approach, and a modified Laplacian Bayesian modeling method using 2D descriptors. Initially, 30 compounds were screened for ASBT inhibition. A qualitative pharmacophore was developed using the most potent 11 compounds and applied to search a drug database, yielding 58 hits. Additional compounds were tested, and their K(i) values were measured. A 3D-QSAR and a Bayesian model were developed using 38 molecules. The quantitative pharmacophore consisted of one hydrogen bond acceptor, three hydrophobic features, and five excluded volumes. Each model was further validated with two external test sets of 30 and 19 molecules. Validation analysis showed both models exhibited good predictability in determining whether a drug is a potent or nonpotent ASBT inhibitor. The Bayesian model correctly ranked the most active compounds. In summary, using a combined in vitro and computational approach, we found that many FDA-approved drugs from diverse classes, such as the dihydropyridine calcium channel blockers and HMG CoA-reductase inhibitors, are ASBT inhibitors.

Use of common medications and breast cancer risk

Prescription and over-the-counter medications are widely used in the United States and many western countries. More than two-thirds of women ages >45 years, who are at greatest risk for breast cancer, take prescription medication. In light of the ubiquitous nature of medication use and the fact that breast cancer remains the most common cancer in women, research on the role of medication use in breast cancer etiology is warranted. We summarize the epidemiologic evidence on the association between breast cancer risk and use of common medications, including antibiotics, antidepressants, statins, antihypertensives, and nonsteroidal anti-inflammatory drugs. Overall, there is little evidence that would implicate the use of antibiotics, antidepressants, statins, and antihypertensives in the etiology of breast cancer. Although several prospective studies and a randomized low-dose aspirin chemoprevention trial have not shown lower risk of breast cancer among aspirin users, most studies that have examined the potential chemoprotective effect of nonsteroidal anti-inflammatory drugs have shown significant risk reductions for regular and prolonged use of these drugs. The existing literature on the role of medication use in breast carcinogenesis is complicated. Interpretation of the evidence is hampered due to major methodologic differences across studies, including exposure assessment, exposure classification, and adjustment for potential confounding variables. These differences largely stem from the fact that the majority of articles on this topic represent secondary data analyses from studies with inadequate information on exposure or confounders. Thus, future epidemiologic studies specifically designed to study these ubiquitous and biologically plausible exposures are warranted.

Medication use and the risk of breast cancer

PURPOSE

To investigate whether the use of commonly-prescribed medications, primarily antihypertensives and antidepressants, is associated with an increased risk of breast cancer.

METHODS

Participants from a population-based case-control study were re-contacted 5-8 years after the original study regarding prescription and non-prescription medication use during the 10 years prior to diagnosis. Controls (n = 647) were frequency-matched to the cases (n = 600) by 5-year age groups. Medication use information was obtained during a telephone interview, and participants were sent the questionnaire in advance to facilitate recall. Odds ratios and 95% confidence intervals were estimated using conditional logistic regression.

RESULTS

A slightly increased risk of breast cancer was associated with use of calcium channel blockers (CCBs), but there was no trend with increasing duration or recency of use. Breast cancer risk was not associated with use of antidepressants, beta blockers, corticosteroids, or non-steroidal anti-inflammatory drugs. Results were similar when analyses were restricted to cases with localized disease.

CONCLUSIONS

These results support previous findings that CCBs may be associated with modest increases in breast cancer risk, but not findings that non-steroidal anti-inflammatory use reduces risk.

A cohort study of antihypertensive medication use and breast cancer among Danish women

BACKGROUND

It has been suggested that specific antihypertensive medications (AHT) may either increase or decrease breast cancer risk.

METHODS

We studied breast cancer incidence among 49,950 women in North Jutland, Denmark in order to determine if breast cancer risk is associated with specific classes of AHT use. Poisson regression analyses were used to calculate rate ratios for ever or exclusive use of each class of AHT, number of prescriptions for AHT, and years of follow-up.

RESULTS

There was no statistically significant association between ever use of any AHT overall (RR = 0.95; 95% CI = 0.81-1.10) or any specific class of AHT (diuretics, beta blockers, calcium channel blockers (CCBs), angiotensin converting enzyme (ACE) inhibitors, and angiotensin II antagonists) and breast cancer.

CONCLUSIONS

This study should offer further reassurance to women currently using AHT that their medication use is unlikely related to breast cancer risk.

Maternal use of Loratadine during pregnancy and risk of hypospadias in offspring

To examine the risk of hypospadias after exposure to loratadine and other antihistamines during pregnancy, we conducted a population-based case-control study in four Danish counties, which account for 30% of the Danish population (approximately 1.6 M). We obtained data on maternal use of antihistamines from prescription databases, and data on birth outcomes from the Danish Medical Birth Registry (MBR) and the Hospital Discharge Registry (HDR). A total of 65,383 male births with a full prescription history of the mother in the study period from 1989-2002 were available for analysis. Within this cohort, we identified cases with a diagnosis of hypospadias, and 10 selected controls per case without such a diagnosis (matched on birth month, gender and year of birth). We identified 227 cases of hypospadias recorded in the HDR within six months postpartum and 2270 controls. One case (0.4%) and eight (0.4%) controls were exposed to loratadine in the first trimester and up to 30 days before the time of conception. The adjusted odds ratio (OR) for hypospadias among users of loratadine relative to non-users was 1.4 (95% CI: 0.2-11.2) and the corresponding OR for other antihistamines was 1.9 (95% CI: 0.7-5.7). In this study, maternal exposure to loratadine did not appear to be associated with an increased risk of hypospadias when compared with other antihistamines, although it should be noted that the statistical precision of the risk estimates might be limited.

Validity of parental-reported questionnaire data on Danish children's use of asthma-drugs: a comparison with a population-based prescription database

The aim of this study was to examine the validity--estimated as the sensitivity, specificity, and predictive values--of questionnaire-based parental reporting on Danish children's use of asthma drugs. Within a population-based cross-sectional study on the association between asthma and dental anxiety, we compared parental answers on their children's use of asthma drugs during the past 12 months with National Health Service (NHS) data from a prescription database on prescriptions of inhaled beta 2-agonists, inhaled corticosteroids, or both for a period of 14 months preceding the date of posting the parental questionnaires. In four municipalities in North Jutland County, Denmark, in 2001, parents of 1273 children between the ages of 6 and 8 years completed the questionnaire. For frequency of use, the sensitivity increased from 57.9% (95% confidence interval [CI]: 47.8-67.3%) for the answer 'Every day' to 91.6% (95% CI: 84.3-95.7%) when the answers 'Every day', 'Often', and 'Sometimes' were combined. The specificity exceeded 95.9% (95% CI: 94.6-96.9%) for all answers. The positive predictive value (PPV) increased from 64.4% (95% CI: 56.1-72.0%) when the answers 'Every day', 'Often', and 'Sometimes' were combined to 94.8% (95% CI: 85.9-98.2%) for the answer 'Every day'. The negative predictive value (NPV) both exceeded 96.7% (95% CI: 95.5-97.6%) for all answers. Questionnaire-based parental reporting on children's one-year asthma-drug use appears to be valid in epidemiological research depending on the study question and design.

A cohort study of antihypertensive treatments and risk of renal cell cancer

We studied 335 682 county residents, of whom 113 298 had been prescribed antihypertensive treatment (AHT), in the period 1989–2002 in North Jutland County, Denmark to examine the relation between different AHTs and the risk of renal cell carcinoma (RCC). An internal comparison was performed among the different classes of AHT users with users of beta blockers as the reference, in order to address potential confounding and bias. The average follow-up was 10 years (range 0–13). Use of any AHT was associated with RCC (relative rate (RR)=1.6, 95% confidence interval (CI) 1.3–1.9) compared with nonusers in the general population. Specific classes of AHTs were nonsignificantly associated with RCC, but compared with users of beta blockers, the numbers observed were close to expectation. Analyses by duration of follow-up and number of prescriptions revealed no clear trends for any antihypertensive agent and after 5-years of follow-up, the RRs for all classes of AHT decreased. The elevated RRs for RCC among users of AHTs compared with the general population are unlikely to be causal, but rather reflect confounding due to failure to control for pre-existing hypertension, and protopathic bias, due to the presence of hypertension as an early sign of kidney disease.

Inverse association between prostate cancer and the use of calcium channel blockers

Calcium channel blockers block calcium signal-mediated apoptosis. It is hypothesized that the use of these drugs may be associated with the development of cancer. This study investigated the association between daily use of calcium channel blockers and prostate cancer in a community-based cohort of men who participated in a longitudinal study of lower urinary tract symptoms. Study subjects were men ages 40 to 79 years by January 1, 1990, and were randomly selected from Olmsted County in Minnesota. At baseline, participants underwent an interview to determine all medications taken on a daily basis, including calcium channel blockers and to elicit a family history of prostate cancer. During follow-up, all men with a histological diagnosis of prostate cancer were identified through patient self-report and by a review of the complete medical record. Over 12,668 person years of follow-up, 15 (6.8%) of 220 calcium channel blocker users and 120 (10.5%) of 1142 nonusers developed prostate cancer (P = 0.09; odds ratio, 0.62; 95% confidence interval, 0.36-1.10). With adjustment for age and family history of prostate cancer, the risk (odds ratio, 95% confidence interval) of prostate cancer was 0.55 (0.31-0.97) in calcium channel blocker users compared with nonusers. In analyses stratified by family history of prostate cancer, the risk of prostate cancer was 0.45 (0.23-0.88) in men without a family history and 2.64 (0.82-8.47) in men with a family history of prostate cancer (P = 0.006). These findings suggest an association between prostate cancer and daily use of calcium channel blockers that varies by family history of prostate cancer.

The validity of self-reported use of hormone replacement therapy among Danish nurses

BACKGROUND

Recent findings from randomized clinical trials on the effects of hormone replacement therapy (HRT) among postmenopausal women contradict findings from observational studies indicating a protective effect on the development of cardiovascular disease. Most observational studies on HRT are based on self-reported data, although data on the validity of HRT in postmenopausal women are sparse.

METHODS

We examined self-reported HRT use from questionnaires administered in 1993 (n = 2694) and again in 1999 (n = 2666) to a cohort of Danish nurses living in two Danish counties compared with prescription-reimbursement data from two administrative databases through the Danish National Health Service.

RESULTS

The sensitivity and specificity of the self-reported, current HRT use in 1993 were 78.4%[95% confidence interval (95% CI) 75.4-81.4] and 98.4% (95% CI 97.8-98.9), respectively. In 1999, the estimates were 74.8% (95% CI 72.0-77.7) and 98.0% (95% CI 97.3-98.8), respectively. None of the factors examined--including age, alcohol intake, physical activity, smoking, presence of hypertension, and body mass index--was strongly associated with validity. We found a relatively high validity of self-reported data on HRT use. Furthermore, agreement between self-reported and registry-based data was not strongly associated with a range of demographic and lifestyle factors.

CONCLUSION

These findings suggest that use of self-reported data is not an important contributor to the apparent discrepancy between observational studies and randomized trials on the cardiovascular effects of HRT use.

Risk of acute pancreatitis in users of finasteride: a population-based case-control study

GOALS

To examine the risk of acute pancreatitis in > or = 60-year-old male users of finasteride in a case-control study from a population of 490,000 persons in North Jutland County, Denmark, from 1993 to 2000.

STUDY

We identified all men age 60 and over with incident acute pancreatitis from the County Hospital Discharge Registry in North Jutland, 1993 to 2000, and selected 10 age-matched controls per case from the Danish Civil Registration System based on incidence density sampling. All prescriptions for finasteride within 90 days prior to admission with acute pancreatitis were identified from the population-based North Jutland Prescription Database. Data on potential confounding factors were also extracted from registries. We used conditional logistic regression to estimate the relative risk of acute pancreatitis, adjusted for these potential confounders.

RESULTS

There were 302 men age 60 and older with incident acute pancreatitis, of whom 3 were exposed to finasteride, and 2994 controls, of whom 37 were exposed to finasteride. The crude odds ratio for having reimbursed prescriptions for finasteride was 0.8 (95% confidence interval, 0.2-2.6). After adjustment for alcohol-related diseases, gallstone disease, hyperlipidemia, hypercalcemia, and hyperparathyroidism, the odds ratio was slightly decreased to 0.5 (95% confidence interval, 0.1-2.5).

CONCLUSION

We did not find any increased risk of acute pancreatitis in users of finasteride.

Relation between use of antihypertensive medications and risk of breast carcinoma among women ages 65-79 years

BACKGROUND

Limited data are available regarding the incidence of breast carcinoma among users of relatively recently introduced forms of antihypertensive therapy. Although it has been suggested that women who have taken calcium channel blockers (CCBs) have an increased risk and that women who have taken angiotensin-I-converting enzyme (ACE) inhibitors have a decreased risk, currently, no conclusions can be drawn.

METHODS

A population-based case-control study of women ages 65-79 years was conducted in western Washington State. The responses of 975 women who were diagnosed with invasive breast carcinoma during 1997-1999 were compared with the responses of 1007 women in a control group. Associations between use of different types of antihypertensive medications and breast carcinoma incidence were evaluated using logistic regression.

RESULTS

Overall, women who had ever used CCBs, beta-blockers, or ACE inhibitors did not have an altered risk of breast carcinoma relative to women who had never used antihypertensive medications. Although the use of immediate-release CCBs, thiazide diuretics, and potassium-sparing diuretics was associated with modestly increased risks of breast carcinoma (odds ratio [OR], 1.5; 95% confidence interval [95% CI], 1.0-2.1; OR, 1.4; 95% CI, 1.1-1.8; and OR, 1.6; 95% CI, 1.2-2.1, respectively), the absence of any trend in the size of excess risk with increasing duration or with current versus former use of these agents argues for a cautious interpretation.

CONCLUSIONS

The use of particular types of antihypertensive medications, including immediate-release CCBs and certain diuretics, may increase the risk of breast carcinoma among older women. Additional studies are warranted to clarify these potential associations. Cancer 2003;98:1504-13.