Carcinogenicity of antihypertensive therapy

Cardio-oncology Related to Heart Failure: Common Risk Factors Between Cancer and Cardiovascular Disease

There is a growing body of evidence that suggests cancer and cardiovascular disease have a shared biological mechanism. Although there are several shared risk factors for both diseases, including advancing age, gender, obesity, diabetes, physical activity, tobacco use, and diet, inflammation and biomarkers, such as insulinlike growth factor 1, leptin, estrogen, and adiponectin, may also play a role in the biology of these diseases. This article provides an overview of the shared biological mechanism between cancer and cardiovascular disease.

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.

Efflux as a mechanism of antimicrobial drug resistance in clinical relevant microorganisms: the role of efflux inhibitors

INTRODUCTION

Microbial resistance against antibiotics is a serious threat to the effective treatment of infectious diseases. Several mechanisms exist through which microorganisms can develop resistance against antimicrobial drugs, of which the overexpression of genes to produce efflux pumps is a major concern. Several efflux transporters have been identified in microorganisms, which infer resistance against specific antibiotics and even multidrug resistance. Areas covered: This paper focuses on microbial resistance against antibiotics by means of the mechanism of efflux and gives a critical overview of studies conducted to overcome this problem by combining efflux pump inhibitors with antibiotics. Information was obtained from a literature search done with MEDLINE, Pubmed, Scopus, ScienceDirect, OneSearch and EBSCO host. Expert opinion: Efflux as a mechanism of multidrug resistance has presented a platform for improved efficacy against resistant microorganisms by co-administration of efflux pump inhibitors with antimicrobial agents. Although proof of concept has been shown for this approach with in vitro experiments, further research is needed to develop more potent inhibitors with low toxicity which is clinically effective.

Comparative safety of cardiovascular medication use and breast cancer outcomes among women with early stage breast cancer

Breast cancer tends to occur in an older age group of women also burdened with comorbidities such as cardiovascular disease (CVD). Numerous medications used to manage CVD (e.g., statins and antihypertensives) are hypothesized to alter breast cancer risk, but there are few studies on breast cancer outcomes. The COmmonly used Medications and Breast Cancer Outcomes (COMBO) cohort was developed to study how medications and co-morbidities influence breast cancer prognosis. Cohort study among adult women, diagnosed with incident early stage breast cancer, and enrolled in an integrated health plan. Data sources included health plan administrative databases, Surveillance, Epidemiology, and End Results tumor registry, and medical records. Statins, angiotensin-converting enzyme inhibitors (ACEI), beta blockers (BB), calcium blockers, and diuretics were the exposures of interest. The outcome was second breast cancer events (SBCE) defined as recurrence or second primary breast cancer. We used multivariable Cox proportional hazards models to estimate hazard ratios (HR) and 95 % confidence intervals (CI) for SBCE, and components of SBCE. 4,216 women were followed for a median of 6.3 years, and 13.2 % experienced a SBCE (first of: n = 415 recurrences and n = 143 s primary breast cancers). Compared to non-users, we observed an increased risk of second primary breast cancer with ACEI use (HR = 1.66; 95 % CI, 1.06-2.58) and an increased risk of recurrence with BB use (HR = 1.29; 95 % CI, 1.01-1.64). There was suggestion of a reduced risk of SBCE with statin use (HR = 0.82; 95 % CI, 0.62-1.08) and second primary breast cancer with BB use (HR = 0.77; 95 % CI, 0.50-1.19). No differences in outcomes were observed by duration of medication use. A majority of CVD medications evaluated in this study appear safe with respect to SBCE, but ACEI and BB use warrant further evaluation. The study presented is one example of the questions that can be addressed using the COMBO cohort.

Multiple roles of angiotensin in colorectal cancer

Colorectal cancer (CRC) cells express renin and chymase through which they can activate angiotensin. Renin expression is induced by hyperglycemic conditions. As angiotensinogen is produced in the liver, CRC cells that can activate angiotensin have an enhanced ability to metastasize to this organ. In human CRC cases, patients with diabetes have higher activities of rennin and angiotensin-II in primary tumors, and on average, have a more progressed disease stage, especially with respect to liver metastasis. These patients exhibit a stronger association with Hemoglobin A1c levels and metastasis compared to patients without diabetes. In a combined diabetes/CRC liver metastasis mouse model, concurrent treatment with anti-angiotensin and hypoglycemic agents shows a synergic effect in terms of reduced liver metastasis and improved survival. The effect of anti-angiotensin treatment and blood sugar control as a baseline management for colon cancer patients with diabetes needs to be examined in clinical trials to establish whether it can prevent liver metastasis.

Update of carcinogenicity studies in animals and humans of 535 marketed pharmaceuticals

This survey is a compendium of information retrieved on carcinogenicity in animals and humans of 535 marketed pharmaceuticals whose expected clinical use is continuous for at least 6 months or intermittent over an extended period of time. Of the 535 drugs, 530 have the result of at least one carcinogenicity assay in animals, and 279 (52.1%) of them gave a positive response in at least one assay. Only 186 drugs (34.8%) have retrievable information on carcinogenicity in humans, and 104 of them gave to a variable extent evidence of a potential carcinogenic activity. Concerning the correlation between results obtained in animals and epidemiological findings, 58 drugs gave at least one positive result in carcinogenicity assays performed in animals and to a variable extent displayed evidence of carcinogenicity in humans, but 97 drugs tested positive in animals and were noncarcinogenic in humans or vice versa. Our findings, which are in agreement with previous studies, indicate that the evaluation of the benefit/carcinogenic risk ratio should be always made in prescribing a drug.

Diabetes-associated angiotensin activation enhances liver metastasis of colon cancer

We examined the effects of hyperglycemic conditions on liver metastasis of colorectal cancer (CRC). Angiotensin (A)-II increased growth, invasion, and anti-apoptotic survival in HT29 and CT26 cells. In contrast, angiotensinogen (ATG) increased these features in HT29 cells but not in CT26 cells. HT29 cells expressed A-II type 1 receptor, chymase, and rennin, whereas CT26 cells did not express renin. Renin expression and ATG-induced cell growth, invasion, and survival induced and increased as glucose concentration increased in HT29 cells and also CT26 cells. An inhibitor of renin or chymase abrogated A-II production in HT29 cells. Reduction of hepatic ATG production by cholesterol-conjugated antisense S-oligodeoxynucleotide suppressed liver metastasis of HT29 cells. An examination of 121 CRC patients showed that diabetes in CRC cases was associated with higher blood HbA1c, higher renin and A-II concentrations in the primary tumors, and higher incidence of liver metastasis than in nondiabetic cases. These results suggest that diabetes-associated angiotensin activation enhances liver metastasis of CRC and may therefore provide a possible target for antimetastatic therapy in CRC.

Adverse effects of prolactin in rodents and humans: breast and prostate cancer

Drugs and chemicals shown to induce mammary carcinogenesis in the rat/rodent via prolactin excess have traditionally been argued to pose little or no risk to humans in a regulatory toxicology context. The basis for this assumption is reviewed and placed into context with new evidence in humans that prolactin may be a tumour promoter in the breast and prostate. This evidence includes epidemiology, patient studies involving endocrine evaluation and molecular biology in human cells. It is concluded that hyperprolactinaemia is associated with an increase in breast cancer risk in both post and premenopausal women, that rat carcinogenicity studies are predictive of the human response, and that in a regulatory toxicology context prolactin-induced mammary tumours from nongenotoxic drugs and chemicals are an adverse effect that should not be ignored. More evidence is required concerning prostate cancer risk but molecular biology indicates that prolactin also induces prostate cell proliferation and inhibits apoptosis, which are similar to the responses observed in breast cancer cells.

Safety of Nifedipine GITS in Stable Angina: The ACTION Trial

AIM

We describe the safety profile of nifedipine GITS as assessed from adverse events reported in the ACTION trial in which 7,665 patients with stable, symptomatic coronary artery disease were randomly assigned nifedipine GITS or placebo and followed for a mean of 4.9 years.

METHODS

All adverse events were coded using the COSTART coding dictionary. The incidence rate for each event was calculated as the number of patients with the event concerned divided by the total time 'at risk'. Hazard ratios comparing nifedipine with placebo and their 95% confidence intervals were obtained by Cox proportional-hazards analysis.

RESULTS

As reported previously, nifedipine significantly reduced the incidence of cardiovascular events and procedures [hazard ratio (HR) 0.89, 95% confidence interval (CI) 0.83-0.95]. Apart from the known side effects of nifedipine, which include peripheral oedema, vasodilatation, hypotension, asthenia, constipation, leg cramps, non-specific respiratory complaints, impotence and polyuria, and which were reported more frequently in patients assigned nifedipine, the incidence rates of most other adverse events were similar. There were no differences in the occurrence of gastrointestinal haemorrhage, myocardial infarction and suicide. The rate of occurrence of death or new cancer excluding non-melanoma skin cancer for patients with no history of cancer at baseline was 2.53/100 patient years for patients assigned nifedipine and 2.37/100 patient years for patients assigned placebo (HR 1.06, 95% CI 0.93-1.22).

CONCLUSION

Overall nifedipine GITS was well tolerated by patients with stable symptomatic angina.

Can we justify goal blood pressure of <140/90 mm hg in most hypertensives?

Hypertension is a common disorder with well-recognized consequences on the heart, brain, and kidney as target organs. Guidelines espouse a treatment goal of blood pressure reduction to <140 mm Hg for the systolic pressure and <90 mm Hg for the diastolic pressure in most hypertensive patients. In this review, the basis for these recommendations, the practical achievement of these goals in various practice settings, and the risk versus the benefit of achieving such goals in most hypertensive patients are examined.