Cancer risk and mortality in users of calcium channel blockers. A cohort study

QuEChERS-Based Approach to the Extraction of Five Calcium Channel Blockers from Plasma Determined by UPLC-MS/MS

Here, a QuEChERS (quick, easy, cheap, effective, rugged, and safe) pretreatment method was combined with UPLC-MS/MS to facilitate the rapid and reliable simultaneous detection of five calcium channel blockers (CCBs) in human plasma. For this approach, samples were treated with 1 mL of acetonitrile, 350 mg of magnesium sulfate, and 70 mg of PSA adsorbent prior to centrifugation. Supernatants then underwent gradient elution for 8 min with an Agilent C18 column using an acetonitrile-water solution supplemented with 5 mmol⋅L^-1 of ammonium acetate. This technique exhibited a good linear response in the 1-800 ng⋅mL^-1 range for the analyzed drugs, with an R²≥ 0.9921, an accuracy of 87.54-113.05%, a matrix effect (ME) of 91.21-116.39%, a precision of 0.19-11.64%, and stability of no more than 10.05%. This time-saving QuEChERS reagent-based pretreatment technique thus allowed for the simultaneous and accurate detection of five CCBs in human plasma samples, providing a promising new basis for therapeutic drug monitoring in patients with hypertension.

The Risk for Prostate Cancer With Calcium Channel Blockers: A Systematic Review, Meta-Analysis, and Meta-Regression

BACKGROUND

For decades, conflicting results were published regarding the increased risk of Prostate cancer (PCa) among calcium channel blocker (CCB) users.

OBJECTIVE

We aimed to evaluate the association between PCa and CCB exposure and assess moderating factors.

METHODS

We performed a systematic literature search in PubMed, Embase, and Cochrane databases for observational and randomized studies published until November 2020 with no language limitations, including data on the risk for PCa in CCB users compared with non-CCB users. We applied a random-effects model meta-analysis to pool results. In addition, we investigated potential moderating factors, such as CCB type, study type, participants' age, and duration of exposure, using meta-regression methods.

RESULTS

In our primary analysis, we included 18 studies. A statistically significant 5% increase in the risk for PCa was observed among CCB users (risk ratio [RR] = 1.05; 95% confidence interval [CI]: 1.01-1.10), with no significant association between the duration of exposure to CCBs and the risk for PCa (RR = 1.08; 95% CI: 0.98-1.19 for exposure for < 5years and RR = 1.01; 95% CI: 0.9-1.14 for exposure ≥ 5 years). The association remained statistically significant for the subgroup of dihydropyridines (RR = 1.13; 95% CI: 1.05-1.22). In addition, the association was not influenced by participants' age.

CONCLUSION AND RELEVANCE

CCBs are an important modality in treating hypertension. The 5% increased risk observed in the current meta-analysis could be influenced by residual confounding factors and should not affect hypertension treatment guidelines until more studies provide additional clinical information.

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.

Calcium Channel Blocker Use and the Risk for Breast Cancer: A Population-Based Nested Case-Control Study

Simple Summary

Calcium channel blockers (CCBs) are widely used among hypertension and heart disease patients. These drugs are effective and well-tolerated. Some studies have found that patients who used CCBs have a higher incidence of breast cancer (BCa). However, other studies did not find such an association. We investigate whether exposure to CCBs in patients with hypertension is associated with an increased risk of BCa. From a cohort of patients prescribed their first antihypertensive medication between 2000 and 2016, we detected 4875 BCa cases. For each case, we matched ten patients without BCa (controls). We found no association between CCB users and an increased risk of BCa compared to the use of other antihypertensive medications. There was no increase in risk even with longer exposure to CCBs (above eight years) and high doses. Considering that CCBs are a widely used antihypertensive drug class, our results provide important safety information on a population level, especially for patients with increased BCa risk.

Abstract

We investigated whether long-term exposure to calcium channel blockers (CCBs) is associated with an increased risk of breast cancer (BCa). We designed a nested case–control study based on data from the Clalit electronic database, the largest Israeli Health Services organization. All newly diagnosed breast cancer (BCa) cases were selected from a cohort of patients with hypertension. Ten controls were matched for each BCa case. The odds ratios (ORs) of BCa among CCBs users were calculated using multivariate conditional logistic regression analyses. A total of 4875 patients with newly diagnosed BCa were identified from the cohort with a median follow-up of 5.15 years. The exposure to CCBs was not associated with an increased risk of BCa (OR = 0.98; 95% CI, 0.92–1.04). Additionally, there was no association between long-term exposure to CCBs (above eight years) and increased BCa risk (OR = 0.91; 95% CI, 0.67–1.21). Higher cumulative doses of CCBs were not associated with an elevated risk of BCa (OR = 0.997; 95% CI, 0.962–1.034, calculated per 1000 DDD). Based on this large population-based study, long-term exposure to CCBs was not associated with an increased risk of BCa. Considering that CCBs are widely used medications, our results provide important safety information on a population level, especially for patients with an increased risk of BCa.

Effects of Antihypertensive Drugs Use on Risk and Prognosis of Colorectal Cancer: A Meta-Analysis of 37 Observational Studies

Background: Antihypertensive drugs might play a key role in the risk and poor prognosis of colorectal cancer. However, current epidemiologic evidence remains inconsistent. The aim of this study is to quantify the association between antihypertensive drugs and colorectal cancer. Methods: To identify available studies, we systematically searched electronic databases: PubMed, Web of Science, Embase, Cochrane Library. The risk estimates and their corresponding 95% confidence intervals (CIs) were collected and analyzed by using random-effects models. Heterogeneity test and sensitivity analysis were also performed. Results: Overall, 37 observational studies were included in this analysis (26 studies with cohort design, three studies with nested case-control design, and 8 studies with case-control design). Antihypertensive drugs did not present a significant effect on the risk or overall survival of patients with colorectal cancer [Risk ratio (RR) = 1.00, 95% CI: 0.95-1.04; Hazard ratio (HR) = 0.93, 95% CI: 0.84-1.02]. In the subgroup analysis, diuretics use was significantly associated with a worse overall survival of patients with colorectal cancer (HR = 1.27; 95% CI: 1.14-1.40). However, use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers was associated with improved progression-free survival of patients who suffered from colorectal cancer (HR = 0.83; 95% CI: 0.72-0.95). Conclusion: Antihypertensive drug usage did not influence the risk and overall survival of patients with colorectal cancer in general. Further investigation reminded us that diuretics use might reduce the overall survival time in colorectal cancer patients, whereas those who took Angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers had a longer progression-free survival.

Antihypertensive medications and risks of recurrence and mortality in luminal, triple-negative, and HER2-overexpressing breast cancer

PURPOSE

Antihypertensives are commonly prescribed medications and their effect on breast cancer recurrence and mortality is not clear, particularly among specific molecular subtypes of breast cancer: luminal, triple-negative (TN), and HER2-overexpressing (H2E).

METHODS

A population-based prospective cohort study of women aged 20-69 diagnosed with a first primary invasive breast cancer between 2004 and 2015 was conducted in the Seattle, Washington and Albuquerque, New Mexico greater metropolitan areas. Multivariable-adjusted Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for risks of breast cancer recurrence, breast cancer-specific mortality, and all-cause mortality associated with hypertension and antihypertensives.

RESULTS

In this sample of 2,383 luminal, 1,559 TN, and 615 H2E breast cancer patients, overall median age was 52 (interquartile range, 44-60). Hypertension and current use of antihypertensives were associated with increased risks of all-cause mortality in each subtype. Current use of angiotensin-converting enzyme inhibitors was associated with increased risks of both recurrence and breast cancer-specific mortality among luminal patients (HR: 2.5; 95% CI: 1.5, 4.3 and HR: 1.9; 95% CI: 1.2, 3.0, respectively). Among H2E patients, current use of calcium channel blockers was associated with an increased risk of breast cancer-specific mortality (HR: 1.8; 95% CI: 0.6, 5.4).

CONCLUSION

Our findings suggest that some antihypertensive medications may be associated with adverse breast cancer outcomes among women with certain molecular subtypes. Additional studies are needed to confirm these findings.

Association Between Antihypertensive Medication Use and Breast Cancer: A Systematic Review and Meta-Analysis

Background: The prevalence rate of hypertension and breast cancer increases with advancing age. Renin-angiotensin system inhibitors (RASIs), β-blockers (BBs), calcium channel blockers (CCBs), and diuretics are widely used to treat patients with hypertension. Although, the association between the use of antihypertensive medication and breast cancer has been highly debated, recent evidence supporting this association remains controversial. Objective: To evaluate the association between the use of antihypertensive medication and the risk of breast cancer and its prognosis. Methods: This study was conducted using data from the PubMed, Embase, and Cochrane Library databases retrieved for the period from January 2000 to April 2021. Articles and their references were checked and summary effects were calculated using random- and fixed-effects models. Heterogeneity test and sensitivity analysis were also performed. Results: This meta-analysis included 57 articles, which were all related to breast cancer risk or prognosis. Assessment of breast cancer risk using the pooled data showed that the use of BBs or CCBs or diuretics was associated with increased cancer risk [BB: relative risk (RR) = 1.20, 95% confidence interval (CI) = 1.09-1.32; CCBs: RR = 1.06, 95% CI 1.03-1.08; diuretics: RR = 1.06, 95% CI 1.01-1.11]. Long-term use of diuretic increased the risk of breast cancer (RR = 1.10, 95% CI 1.01-1.20), whereas long-term RASIs treatment reduced the risk (RR = 0.78, 95% CI 0.68-0.91). In addition, we found that diuretic users may be related to elevated breast cancer-specific mortality [hazard ratio (HR) = 1.18, 95% CI 1.04-1.33], whereas using other antihypertensive medications was not associated with this prognosis in patients with breast cancer. Conclusion: Using CCBs, BBs, and diuretics increased the risk of breast cancer. In addition, diuretics may elevate the risk of breast cancer-specific mortality. The long-term use of RASIs was associated with a significantly lower breast cancer risk, compared with non-users. Thus, this analysis provides evidence to support the benefits of the routine use of RASIs in patients with hypertension, which has important public health implications.

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.

Impact of Polypharmacy for Chronic Ailments in Colon Cancer Patients: A Review Focused on Drug Repurposing

Colorectal cancer is characterized by high incidence worldwide. Despite increased awareness and early diagnosis thanks to screening programmes, mortality remains high, particularly for patients with metastatic involvement. Immune checkpoint inhibitors or poly (ADP-ribose) polymerase (PARP)-inhibitors have met with disappointing results when used in this setting, opposed to other malignancies. New drugs with different mechanisms of action are needed in this disease. Drug repurposing might offer new therapeutic options, as patients with metastatic colorectal cancer often share risk factors for other chronic diseases and thus frequently are on incidental therapy with these drugs. The aim of this review is to summarise the published results of the activity of drugs used to treat chronic medications in patients affected by colorectal cancer. We focused on antihypertensive drugs, Non-Steroid Anti-inflammatory Drugs (NSAIDs), metformin, antidepressants, statins and antibacterial antibiotics. Our review shows that there are promising results with beta blockers, statins and metformin, whereas data concerning antidepressants and antibacterial antibiotics seem to show a potentially harmful effect. It is hoped that further prospective trials that take into account the role of these drugs as anticancer medications are conducted.

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.

Statin use and lung cancer risk in chronic obstructive pulmonary disease patients: a population-based cohort study

Background

Patients living with chronic obstructive pulmonary disease (COPD) are at an increased risk of lung cancer. A common comorbidity of COPD is cardiovascular disease; as such, COPD patients often receive statins. This study sought to understand the association between statin exposure and lung cancer risk in a population-based cohort of COPD patients.

Methods

We identified a population-based cohort of COPD patients based on having filled at least three prescriptions for an anticholinergic or short-acting beta-agonist (SABA). We used an array of methods of defining medication exposure including three conventional methods (ever statin exposure, cumulative duration of use, and cumulative dose) and two novel methods (recency-weighted cumulative duration of use and recency-weighted cumulative dose). To assess residual confounding, a negative control exposure was used to test the validity of our results. All exposure variables were time-dependent.

Results

The population-based cohort of COPD had 39,879 patients with mean age of 70.6 (SD: 11.2) years and, of which, 53.5% were female. There were 12,469 patients who received at least one statin prescription. Results from the reference case multivariable analysis indicated a reduced risk from statin exposure (HR: 0.85 (95% CI: 0.73–1.00) in COPD patients, but this result not statistically significant. Using the two recency-weighted modelling approaches, statin exposure was associated with a statistically significant reduction in lung cancer risk (recency-weighted cumulative dose, HR: 0.85 (95% CI: 0.77–0.93) and recency-weighted cumulative duration of use, HR: 0.97 (95% CI: 0.96–0.99). Multivariable analysis incorporating the negative control exposure was not statistically significant (HR: 0.89 (95% CI: 0.75–1.10).

Conclusions

The results of this population-based analysis indicate that statin use in COPD patients may reduce the risk of lung cancer. While the effect was not statistically significantly across all exposure definitions, the overall results support the hypothesis that COPD patients might benefit from statin therapy.

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).

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.

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.

Use of Antihypertensive Medications and Risk of Adverse Breast Cancer Outcomes in a SEER-Medicare Population

Background: It is unclear if use of common antihypertensive medications influences the risk of adverse breast cancer outcomes.Methods: Using the linked Surveillance, Epidemiology and End-Results (SEER)-Medicare database, we identified 14,766 women between ages 66 and 80 years diagnosed with incident stage I/II breast cancer between 2007 and 2011. Medicare Part D data were obtained to characterize women's post-cancer use of various antihypertensive medications. Outcomes included a second breast cancer event (SBCE; a composite outcome defined as the first of a recurrence or a second contralateral primary breast cancer), breast cancer recurrence, and breast cancer-specific mortality. Time-varying Cox proportional hazard models were used to estimate hazard ratios (HR) and their associated 95% confidence intervals (CI).Results: There were 791 SBCEs, 627 breast cancer recurrences, and 237 breast cancer deaths identified over a median follow-up of 3 years. Use of diuretics (n = 8,517) after breast cancer diagnosis was associated with 29% (95% CI, 1.10-1.51), 36% (95% CI, 1.14-1.63) and 51% (95% CI, 1.11-2.04) higher risks of a SBCE, recurrence, and breast cancer death, respectively. Compared with nonusers, β-blockers users (n = 7,145) had a 41% (95% CI, 1.07-1.84) higher risk of breast cancer death. Use of angiotensin II receptor blockers, calcium channel blockers and angiotensin-converting enzyme inhibitors were not associated with risks of breast cancer outcomes.Conclusions: Use of diuretics and β-blockers may be associated with increased risk of breast cancer outcomes among older women.Impact: Most antihypertensive medications are safe with respect to breast cancer outcomes, but more research is needed for diuretics and β-blockers. Cancer Epidemiol Biomarkers Prev; 26(11); 1603-10. ©2017 AACR.

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.

Nifedipine promotes the proliferation and migration of breast cancer cells

Nifedipine is widely used as a calcium channel blocker (CCB) to treat angina and hypertension,but it is controversial with respect the risk of stimulation of cancers. In this study, we demonstrated that nifedipine promoted the proliferation and migration of breast cancer cells both invivo and invitro. However, verapamil, another calcium channel blocker, didn't exert the similar effects. Nifedipine and high concentration KCl failed to alter the [Ca2+]i in MDA-MB-231 cells, suggesting that such nifedipine effect was not related with calcium channel. Moreover, nifedipine decreased miRNA-524-5p, resulting in the up-regulation of brain protein I3 (BRI3). Erk pathway was consequently activated and led to the proliferation and migration of breast cancer cells. Silencing BRI3 reversed the promoting effect of nifedipine on the breast cancer. In a summary, nifedipine stimulated the proliferation and migration of breast cancer cells via the axis of miRNA-524-5p-BRI3-Erk pathway independently of its calcium channel-blocking activity. Our findings highlight that nifedipine but not verapamil is conducive for breast cancer growth and metastasis, urging that the caution should be taken in clinic to prescribe nifedipine to women who suffering both hypertension and breast cancer, and hypertension with a tendency in breast cancers.

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.

Meta-analysis: risk of esophageal adenocarcinoma with medications which relax the lower esophageal sphincter

Reasons for the rising annual incidence of esophageal adenocarcinoma (EAC) remain uncertain. Previous studies have given conflicting results, but some have suggested that drugs which relax the lower esophageal sphincter (LES) may increase the risk of EAC. This study is to determine systematically the risk of EAC associated with individual medications which relax the LES and compare risks with esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA). Relevant published studies were identified by systematic searching PubMed for case-control studies reporting on risk of EAC, ESCC or GCA with use of medications known to reduce LES pressure. Pooled odds ratios (ORs) were calculated for each malignancy. Data were analyzed from four case-control studies involving 9,412 participants. EAC was significantly associated with theophylline use (OR 1.55, 95% confidence interval [CI] 1.05-2.28; P= 0.03, I(2) = 0%) and anticholinergic medications (OR 1.66, 95% CI 1.13-2.44; P= 0.01, I(2) = 84%). This effect was not observed in cases of ESCC or GCA. Other drug groups including calcium channel modulators and nitrates did not increase the risk of EAC. An inverse relationship was observed between ESCC and nitrates and between GCA and benzodiazepines. The lack of increased EAC risk with many commonly used medications is reassuring. However, a significant correlation was found between EAC and the use of anticholinergics and theophyllines. This may reflect common causality between obstructive lung disease and EAC, and further studies to explore these relationships are warranted.

Record linkage for pharmacoepidemiological studies in cancer patients

BACKGROUND

An increasing need has developed for the post-approval surveillance of (new) anti-cancer drugs by means of pharmacoepidemiology and outcomes research in the area of oncology.

OBJECTIVES

To create an overview that makes researchers aware of the available database linkages in Northern America and Europe which facilitate pharmacoepidemiology and outcomes research in cancer patients.

METHODS

In addition to our own database, i.e. the Eindhoven Cancer Registry (ECR) linked to the PHARMO Record Linkage System, we considered database linkages between a population-based cancer registry and an administrative healthcare database that at least contains information on drug use and offers a longitudinal perspective on healthcare utilization. Eligible database linkages were limited to those that had been used in multiple published articles in English language included in Pubmed. The HMO Cancer Research Network (CRN) in the US was excluded from this review, as an overview of the linked databases participating in the CRN is already provided elsewhere. Researchers who had worked with the data resources included in our review were contacted for additional information and verification of the data presented in the overview.

RESULTS

The following database linkages were included: the Surveillance, Epidemiology, and End-Results-Medicare; cancer registry data linked to Medicaid; Canadian cancer registries linked to population-based drug databases; the Scottish cancer registry linked to the Tayside drug dispensing data; linked databases in the Nordic Countries of Europe: Norway, Sweden, Finland and Denmark; and the ECR-PHARMO linkage in the Netherlands. Descriptives of the included database linkages comprise population size, generalizability of the population, year of first data availability, contents of the cancer registry, contents of the administrative healthcare database, the possibility to select a cancer-free control cohort, and linkage to other healthcare databases.

CONCLUSIONS

The linked databases offer a longitudinal perspective, allowing for observations of health care utilization before, during, and after cancer diagnosis. They create new powerful data resources for the monitoring of post-approval drug utilization, as well as a framework to explore the (cost-)effectiveness of new, often expensive, anti-cancer drugs as used in everyday practice.

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.

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.

Migraine in postmenopausal women and the risk of invasive breast cancer

BACKGROUND

The frequency of migraine headache changes at various times of a woman's reproductive cycle. Menarche, menses, pregnancy, and perimenopause may carry a different migraine risk conceivably because of fluctuating estrogen levels, and in general, migraine frequency is associated with falling estrogen levels. Given the strong relationship between endogenous estrogen levels and breast cancer risk, migraine sufferers may experience a reduced risk of breast cancer.

METHODS

We combined data from two population-based case-control studies to examine the relationship between migraine and risk of postmenopausal invasive breast cancer among 1,199 ductal carcinoma cases, 739 lobular carcinoma cases, and 1,474 controls 55 to 79 years of age. Polytomous logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI).

RESULTS

Women who reported a clinical diagnosis of migraine had reduced risks of ductal carcinoma (OR, 0.67; 95% CI, 0.54-0.82) and lobular carcinoma (OR, 0.68; 95% CI, 0.52-0.90). These associations were primarily limited to hormone receptor-positive tumors as migraine was associated with a 0.65-fold (95% CI, 0.51-0.83) reduced risk of estrogen receptor-positive (ER+)/progesterone receptor-positive (PR+) ductal carcinoma. The reductions in risk observed were seen among migraine sufferers who did and did not use prescription medications for their migraines.

CONCLUSIONS

These data suggest that a history of migraine is associated with a decreased risk of breast cancer, particularly among ER+/PR+ ductal and lobular carcinomas. Because this is the first study to address an association between migraine history and breast cancer risk, additional studies are needed to confirm this finding.

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.

Antidepressants and risk of prostate cancer: a nested case – control study

Although the association between antidepressant drug use and risk of cancer has received considerable attention in the past years, no work has been done specifically on prostate cancer. We carried out a population-based case-control study to assess the risk of prostate cancer in association with exposure to tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). 7767 prostate cancer cases diagnosed between 1981 and 2000 were accrued through the Saskatchewan Cancer Agency. Saskatchewan Health identified a total of 31,068 male controls who were matched on age and calendar time. Data on exposure to TCAs and SSRIs were compiled from the Saskatchewan outpatient prescription drug database, and covered a period upto 24 years. A positive significant association was found between TCA use and risk of prostate cancer, when exposure took place 2-5 years before diagnosis, with rate ratios of 1.31, 1.58, and 2.42 at the low, medium and high average daily dose levels, respectively. Exposure to SSRIs was not found to be significantly associated with the risk of prostate cancer. TCA use 2-5 years in the past was associated with a small dose-dependent increase in the risk of prostate cancer. Nevertheless, detection bias could have contributed to the observed association.

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.

Obesity, hormone therapy, estrogen metabolism and risk of postmenopausal breast cancer

Hormone therapy (HT) and body mass index (BMI) have been associated with postmenopausal breast cancer. Because estrogen metabolism may affect breast cancer risk and can be altered by weight and HT, it might play a role in the HT-BMI-breast cancer associations. We undertook a nested case-control study within the Observational Study of the Women's Health Initiative. Baseline levels of 2- and 16alpha-hydroxy estrone (2-OHE1 and 16alpha-OHE1) were measured in 200 women who developed breast cancer during follow-up and 200 healthy controls matched to cases by ethnicity, enrollment date, clinic site, type of HT and years since menopause. Wilcoxon nonparametric tests were used to compare estrogen metabolite levels between cases and controls. Conditional logistic regression was used to assess the relationship between BMI, estrogen metabolites and breast cancer risk. 16alpha-OHE1 levels were modestly but significantly higher in HT users among cases (median 356 pg/ml vs. 315 pg/ml) and controls (354 pg/ml vs. 298 pg/ml). 2-OHE1 levels were substantially and significantly higher in HT users among cases (369 pg/ml vs. 125 pg/ml) and controls (347 pg/ml vs. 134 pg/ml). For non-HT users only, greater BMI and higher 16alpha-OHE1 levels were individually and jointly associated with increased breast cancer risk (OR for women with high BMI and high 16alpha-OHE1 compared to those with low BMI and low 16alpha-OHE1 = 3.51, 95% CI = 1.34-9.16). No associations between BMI, estrogen metabolism and breast cancer risk were found for HT users. Estrogen metabolism differs according to both BMI and HT use, potentially explaining the interaction between BMI and HT in relation to breast cancer risk.

Pharmacological, Pharmacokinetic, and Clinical Properties of Benidipine Hydrochloride, a Novel, Long-Acting Calcium Channel Blocker

Benidipine is a dihydropyridine-derived calcium channel blocker developed in Japan, with several unique mechanisms of action, that is, triple calcium channels (L, N, and T) blocking action with a membrane approach. Benidipine has relatively high vascular selectivity and is expected to show protective effects on vascular endothelial cells. Renal protective effects of benidipine also have been shown in several basic and clinical studies. Moreover, anti-oxidative action and enhancing nitric oxide production have been noted with this drug, following its cardio-protective effects in patients with ischemic heart diseases. In fact, benidipine exerted a better prognostic effect than other calcium channel blockers in the therapy for patients with vasospastic angina. In addition, benidipine showed reliable antihypertensive, renoprotective effects if used in combination with angiotensin II type 1 receptor blockers (ARBs) when adequate anti-hypertensive effects are not achieved by ARBs alone, indicating that benidipine is an useful calcium channel blocker in combination therapy for hypertension. Benidipine was launched on the Japanese market 14 years ago, but few severe side effects have been reported, suggesting that this is a drug with established safety and long-acting pharmacological effects.

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.

Cancer risk among statin users: a population-based cohort study

Hydroxymethylglutaryl-CoA reductase inhibitors (statins) have been linked with potential chemopreventive effects; however, the data are conflicting. We conducted a population-based cohort study using data from the Prescription Database of North Jutland County and the Danish Cancer Registry for the period 1989-2002. In a study population of 334,754 county residents, we compared overall and site-specific cancer incidence among 12,251 statin users (> or =2 prescriptions) with cancer incidence among nonusers and users of other lipid-lowering drugs (n = 1,257). Statistical analyses were based on age-standardization and Poisson regression analysis, adjusting for age, gender, calendar period and use of NSAIDs, hormone replacement therapy and cardiovascular drugs. We identified 398 cancer cases among statin users during a mean follow-up period of 3.3 years (range 0-14 years). The age- and gender-standardized incidence rates of cancer overall were 596 per 100,000 person-years among statin users, 645 per 100,000 person-years among nonusers and 795 per 100,000 person-years among users of other lipid-lowering drugs. Adjusted rate ratios for cancer overall among statin users were 0.86 (95% CI, 0.78-0.95) compared to nonusers and 0.73 (95% CI, 0.55-0.98) compared to users of other lipid-lowering drugs. No significantly increased or decreased rate ratios were observed for any of the studied site-specific cancers (liver, colorectum, lung, breast, prostate, female genital organs and lymphatic and haematopoietic tissue), but most estimates tended to be less than 1.0. Stratification by duration of follow-up or number of prescriptions revealed no clear trends. In summary, individuals prescribed statins experienced a slightly reduced cancer incidence compared to population controls of nonusers and users of other lipid-lowering drugs. Larger and longer-term studies are needed to determine the potentially protective effect of statin use on cancer development.

Use of antibiotics and risk of breast cancer: a population-based case-control study

We examined the use of antibiotics among 2728 women with a first diagnosis of breast cancer during 1994–2003, and 27 280 population controls in North Jutland County, Denmark, based on hospital discharge diagnoses, prescription use from 1989 to 2002, and population registry data. We found no increased relative risk of breast cancer associated with use compared with nonuse. The odds ratio for breast cancer associated with more than 10 prescriptions for antibiotics was 1.00 (95% CI 0.86 –1.15). Relative risks were similar for different classes of antibiotics. A subanalysis based on cases and controls younger than 70 years of age, with data on first birth and number of children, showed similar risk estimates even after adjustment for age at first birth and parity. In our study, use of antibiotics was not associated with an increased risk of breast cancer.

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.

Risk of cancer in a large cohort of nonaspirin NSAID users: a population-based study

There is increasing evidence of an inverse association between use of nonsteroidal anti-inflammatory drugs (NSAIDs) and risk of colorectal cancer. However, data regarding other cancer sites are limited. Using data from the population-based North Jutland Prescription Database and the Danish Cancer Registry, we compared cancer incidence among 172 057 individuals prescribed nonaspirin NSAIDs with expected incidence (based on county-specific cancer rates) during a 9-year study period. A total of 6081 incident cancer cases were diagnosed among NSAID users vs 5722 expected (standardised incidence ratio (SIR) 1.1, 95% confidence interval (CI)1.0-1.1). The SIRs for colon and rectal cancer among persons who obtained 10 or more prescriptions were 0.7 (95% CI 0.6-0.9) and 0.6 (95% CI 0.4-0.9), respectively. Similarly, reduced risk estimates were found for stomach (SIR 0.7, 95% CI 0.4-1.1) and ovarian cancer (SIR 0.7, 95% CI 0.4-1.0). Standardised incidence ratios for other cancers among those with 10 or more prescriptions tended to be close to 1.0, except for lung, kidney, and prostate cancers with SIRs of 1.3 (95% CI 1.1-1.6), 1.4 (95% CI 0.9-2.1), and 1.6 (95% CI 1.3-2.0), respectively. We found protective associations of NSAIDs against colon, rectal, stomach, and ovarian cancer. Reasons for the increased risk for some cancer sites are not clear.

Carcinogenicity of antihypertensive therapy

Several studies have suggested that antihypertensive treatment may promote cancer through unknown mechanisms. Early retrospective studies implicated reserpine in breast cancer, but data from prospective studies and meta-analysis of several case-controlled studies showed only a weak association between reserpine and breast cancer which, although statistically significant, is of little clinical concern. Data from case-controlled studies and several cohort studies suggested an association between the use of a diuretic and the occurrence of renal cell cancer, particularly in women. A recent study showed an association between the use of a diuretic and the occurrence of colon cancer. Several prospective studies showed that treatment with atenolol may increase mortality from malignancy. However, other studies that analyzed data from several thousand patients could not confirm this association. In three prospective and a few case-controlled studies, angiotensin converting enzyme inhibitors were not associated with increased mortality from malignancy. In addition, a recent retrospective study showed that long-term use of angiotensin converting enzyme inhibitors had a protective effect against malignancy. Data from three large case-controlled studies and the combined data from eight randomized controlled studies and seven longitudinal studies showed a similar risk for malignancy among users and nonusers of calcium antagonists. Until further data from prospective clinical trials are available, we advise caution about long-term diuretic therapy in women. With regard to other antihypertensive drug classes, we suggest continuing the management of hypertension according to current treatment guidelines with little fear of any substantial cancer risk.

Antihypertensive therapy and cancer risk

The aim of this article is to provide an overview of the available data linking antihypertensive drug therapy to cancer risk. In recent years, a number of mainly retrospective studies have reached different conclusions on the risk of cancer in patients with hypertension being treated with different antihypertensive drugs. At some point or another nearly all antihypertensive drugs have been suggested to increase the risk of cancer. Some studies have even found an association between hypertension itself and increased carcinogenesis. For calcium channel antagonists, beta-blockers and alpha-blockers, the available evidence seems to favour a neutral effect on cancer development and death rate. For ACE inhibitors, the overall data suggest a similar neutral effect on cancer or, possibly, a small protective effect. Perhaps the strongest evidence in favour of a link, although probably weak, between cancer and antihypertensive drugs is with the diuretics. Until further solid data are available from prospective clinical trials, we suggest that the management of hypertension should continue according to current treatment guidelines with little fear of any substantial cancer risk.

Angiotensin-converting enzyme inhibitors and the risk of cancer: a population-based cohort study in Denmark

BACKGROUND

A recent observational study suggested that the use of angiotensin-converting enzyme (ACE) inhibitors protects against cancer in general and against breast and female reproductive tract cancers in particular. To explore these hypotheses, the authors examined cancer risk among users of ACE inhibitors in North Jutland County, Denmark.

METHODS

Using data from the population-based Prescription Database of North Jutland County and the Danish Cancer Registry, cancer incidence among 17,897 individuals prescribed ACE inhibitors was compared with expected incidence based on county specific cancer rates during an 8-year study period with a mean follow-up of 3.7 years. Standardized incidence ratios (SIRs) with corresponding 95% confidence intervals (95% CIs) were calculated for cancers overall and at selected sites. In addition, the authors performed a direct comparison of users of ACE inhibitors with users of beta-blockers or calcium channel blockers (n = 47,579 individuals) by means of a Cox proportional hazards model.

RESULTS

Overall, 909 cancer cases were observed among users of ACE inhibitors, with 846 expected based on general population rates, yielding an SIR of 1.07 (95% CI, 1.01-1.15). No risk reductions were observed for cancers of the breast and female reproductive tract, whereas nonsignificantly decreased SIRs were observed for cancers of the esophagus, stomach, and liver. Cancer of the kidney was found in significant excess (SIR, 1.6; 95% CI, 1.1-2.2). Stratification by duration of follow-up or number of prescriptions revealed no apparent trends, except for a tendency toward decreasing risk with increasing length of follow-up for smoking-related cancers. The direct comparison of users of ACE inhibitors with users of beta-blockers or calcium channel blockers yielded results comparable to those derived from the comparison with the general population, with a hazard ratio for cancer overall of 1.01 (95% CI, 0.93-1.09).

CONCLUSIONS

This large, population-based cohort study did not confirm a protective effect of ACE inhibitors on the development of cancer. The excess of kidney cancer observed likely reflects a correlation between hypertension and kidney cancer. Further investigation is needed to evaluate the long-term effects of ACE inhibitors beyond the observation period of this and previous studies. Also, the suggestive evidence of decreased risks for upper digestive system cancers and for smoking-related cancers over time may warrant additional investigation.