[kyro]

They definitely are. Cancerous masses tend to ramp up blood vessel production because that's how they survive. In fact, there are tests, like angiography, that are done to identify areas of increased blood flow, which may indicate cancerous areas.

However, there hasn't really been a link shown between cancer and heart disease, like hypertension, atherosclerosis, heart failure, etc, -- i.e. the two diseases haven't been shown to correlate pathophysiologically. But there is data showing a correlation between chemotherapy and heart disease, which could certainly contribute to the similarity in distributions in mortality between heart disease and cancer. For instance, doxorubicin is a chemotherapeutic agent infamously known for causing dilated cardiomyopathy.