Abstract 11840: Angiotensin Receptor Blockers Inhibit De Novo Onset of Malignant Tumors, and Candesartan Has a Superior Inhibitory Effect Compared With the others

Abstract

Objective: Angiotensin II receptor blockers (ARBs) is a class of common anti-hypertensives. We previously reported that high dose of ARB inhibited growth of malignant tumors in mice. While recent meta-analysis of randomized clinical trials indicated no relation between cancer risk and ARBs, some data suggested potential anti-tumor efficacies of ARBs. We performed a retrospective-cohort for de novo onset of malignant tumors in Japanese hypertensive patients.

Methods: Study population consisted of patients without cancer treated for hypertension for >1year, enrolled from January 2003 to December 2008, grouped based on with or without ARB treatment. Kaplan-Meier time event curve was used to predict time to onset, and log-rank test was performed. In each anti-hypertensive agent (ARBs, ACEIs, calcium channel blockers, beta-blockers and diuretics), incidence rate was calculated using Cox hazard model with 95% confidence interval (CI).

Results: Among 3688 patients (2313 in the ARB and 1375 in the non-ARB group, mean age 60.9), 58 in the ARBs (2.51%) and 52 in the non-ARB group (3.78%) developed de novo tumor (log-rank test p=0.014). Cox hazard model revealed statistical significance in the inhibition of de novo occurrence of tumors in the ARB group (incidence rate ratio: 0.62, 95% CI 0.43-0.91). Univariate analysis did not show any significant inhibiting effects on the de novo tumors by other anti-hypertensive agents. In additional analysis of the incidence of de novo tumors in the ARBs group, a significant difference was found between candesartan and the others; 22 out of 1062 treated with candesartan, and 36 out of 1251 treated with other ARBs (p=0.048).

Conclusion: Development of de novo malignant tumors was significantly lower in hypertensive patients receiving ARBs. This phenomenon was more obvious in the candesartan group than in the other ARBs group. Further prospective study should be needed to examine the effects of ARBs on cancer incidence in hypertensive patients.