Abstract Introduction Several publications have demonstrated that cardiovascular diseases (CVD) promote tumor growth in mouse models of breast, lung, and colon cancer, suggesting a causal relationship between both diseases. Cancer and CVD share several risk factors and pathophysiological mechanisms, including inflammation, oxidative stress, neurohormonal activation, and immune system dysfunction that combined could explain why patients with CVD are prone to develop cancer. Recent reports also suggest a link between hypertension and lung cancer, and between cardiac hypertrophy and breast cancer. Angiotensin II (ANGII) is a hormone involved in blood pressure regulation, vascular hemostasis and hypertrophy development. Moreover, ANGII is cancerogenic by increasing proliferation of several cancer cell types. Hence, ANGII could be a link in CVD-induced enhancement of cancer growth. Here, we investigated whether ANGII treatment, and subsequent hypertension and cardiac hypertrophy, could promote cancer growth and metastasis. Methods ANGII (2000ng.kg-1.min-1, 4w) was administered to 10w old C57B6/J mice using subcutaneous osmotic minipumps. After 3w, 5*10^5 Lewis lung carcinoma (LLC) cells or 2*10^5 MC38 colon cancer cells were injected onto the right flank of the mice. Tumor growth was monitored over 21d using a digital caliper. Tumor volume was calculated using the following formula: Length × width² × 0.5 On day 22, mice were sacrificed for further post-mortem analysis. Cardiac echography was performed after 3w of ANGII treatment and before sacrifice to assess cardiac function (data not shown). To assess the formation of cardiac fibrosis trichrome staining’s were performed. In addition, the effect of ANGII on LLC metastasis was investigated. Mice were treated with ANGII as described above. LLC cells, 2*10^6, were injected intravenously (i.v.). Mice were sacrificed 21d after cell injection. Metastatic growth was visualized and quantified by organ weighing and H&E staining. Results LLC tumor growth was significantly increased by ANGII treatment. In addition, post-mortem tumor weight was increased (0.62 ± 0.05 g control vs. 1.17 ± 0.24 g ANGII). Furthermore, we found lung weight increased in the ANGII-treated group injected i.v. with LLC cells, indicating an increase in metastatic growth (0.41 ± 0.08 g control vs. 0.57 ± 0.04 g ANGII). Interestingly, MC38 tumor growth decreased in the ANGII treated group as portrayed by the tumor weight (0.42 ± 0.06 g control vs. 0.19 ± 0.05 g ANGII). Figure 1 shows the tumor growth over time and tumor volume, weight post-mortem. Conclusion Our data suggest a role for ANGII in CVD-enhanced cancer growth, but also that this effect is not universal, illustrated by a differential effect of ANGII on distinct cancer types. Although further investigation is required to unravel the role of ANGII, screening cancer patients with CVD comorbidities for ANGII involvement might be warranted.