The Association between Angiotensin Receptor Blocker Usage and Breast Cancer Characteristics

The renin-angiotensin-aldosterone system (RAAS) signaling pathways and cancer: foes versus allies

The renin-angiotensin-aldosterone system (RAAS), is an old system with new fundamental roles in cancer biology which influences cell growth, migration, death, and metastasis. RAAS signaling enhances cell proliferation in malignancy directly and indirectly by affecting tumor cells and modulating angiogenesis. Cancer development may be influenced by the balance between the ACE/Ang II/AT1R and the ACE2/Ang 1-7/Mas receptor pathways. The interactions between Ang II/AT1R and Ang I/AT2R as well as Ang1-7/Mas and alamandine/MrgD receptors in the RAAS pathway can significantly impact the development of cancer. Ang I/AT2R, Ang1-7/Mas, and alamandine/MrgD interactions can have anticancer effects while Ang II/AT1R interactions can be involved in the development of cancer. Evidence suggests that inhibitors of the RAAS, which are conventionally used to treat cardiovascular diseases, may be beneficial in cancer therapies.Herein, we aim to provide a thorough description of the elements of RAAS and their molecular play in cancer. Alongside this, the role of RAAS components in sex-dependent cancers as well as GI cancers will be discussed with the hope of enlightening new venues for adjuvant cancer treatment.

Angiotensin Receptor Blockers Associated with Improved Breast Cancer Survival-A Nationwide Cohort Study from Finland

BACKGROUND

Breast cancer incidence has been associated with hypertension, which might worsen disease prognosis, but few nationwide studies have investigated the association between antihypertensive drug use and breast cancer prognosis.

METHODS

A cohort of 73,170 women diagnosed with breast cancer during 1995-2013 identified from the Finnish Cancer Registry was combined with information on antihypertensive drug use during the same time period from a national prescription database. Antihypertensive drugs were analyzed in groups categorized by mechanism of action. Usage of antihypertensive drugs, statins, antidiabetic, and anticoagulative drugs was analyzed as time-dependent exposure to model for simultaneous use of multiple drug groups. Influence of protopathic bias was evaluated in lag-time analyses.

RESULTS

In prediagnostic use, only angiotensin receptor (ATR)-blockers were associated with decreased risk of breast cancer death as compared with nonusers (HR: 0.76, 95% confidence interval, CI: 0.69-0.82), and there was an inverse association with cumulative dose of use. Postdiagnostic use of ATR-blockers, angiotensin-converting enzyme (ACE)-inhibitors, beta-blockers, and calcium-channel blockers was dose dependently associated with better breast cancer survival compared with nonusers. The risk decrease was strongest for ATR-blockers (HR: 0.69, 95% CI: 0.63-0.75) and remained for exposures occurring up to 3 years earlier.

CONCLUSIONS

Only ATR-blockers were associated with improved breast cancer survival in both prediagnostic and postdiagnostic use. The association was dose dependent and supported by a biological rationale as a causal explanation. In postdiagnostic use, similar reduction was found also for other antihypertensives, supporting a prognostic role of hypertension control.

IMPACT

Inhibition of angiotensin receptor subtype 1 (AT₁) could be a promising novel way to affect breast cancer progression.

Targeting the renin-angiotensin system to improve cancer treatment: Implications for immunotherapy

Renin-angiotensin system (RAS) inhibitors (RASi)-widely prescribed for the treatment of cardiovascular diseases-have considerable potential in oncology. The RAS plays a crucial role in cancer biology and affects tumor growth and dissemination directly and indirectly by remodeling the tumor microenvironment. We review clinical data on the benefit of RASi in primary and metastatic tumors and propose that, by activating immunostimulatory pathways, these inhibitors can enhance immunotherapy of cancer.