Renin-Angiotensin Inhibition in Combating Malignancy: A Review.

Our previous review of the literature assessed the existing knowledge (until 2000) about the possible link between angiotensin-converting enzyme inhibitors (ACEIs) and factors influencing the development of malignancies. We reviewed the literature for reports of statistical associations (or lack thereof) between ACEi treatment and incidence of specific cancers (e.g. breast, gastrointestinal, and skin). We concluded then that results from the epidemiological studies are conflicting, even taking the different methodology and endpoints into consideration, and thus inconclusive. Further investigation is needed beyond the observation period of most of these studies, and additional experimental studies are needed also to study the mechanisms by which agents blocking the renin-angiotensin system may obtain their inhibitory effect on tumor growth and metastasis. The present review elaborates further with more recent evidence from numerous human clinical studies from the past two decades (including large epidemiological studies, and long-term prospective and retrospective studies) on a protective association between ACEi treatment and the prognosis of patients with specific cancer types, malignancy characteristics or stage. Moreover, treatment with ACEI/angiotensin receptor blockers represents an adjuvant therapy with synergistic effects to chemotherapy and may improve patient outcomes (i.e. progression-free survival, and prolonged overall survival) in different types of cancers.