To survive and grow, cancer tumors depend on blood vessels supplying oxygen and nutrition. The growth of blood vessels, which is called angiogenesis, also helps cancer tumors spread to other areas of the body.
That is why cancer treatment often includes therapies to block the growth of blood vessels. These agents are also known as anti-angiogenic therapies.
Targeted therapies to block growth of new blood vessels include:
- Monoclonal antibodies (mAbs): These drugs attach and block those proteins that help blood vessels grow.
- Tyrosine kinase inhibitors (TKIs): These drugs block the action of enzymes known as tyrosine kinases, which help cells grow, divide, and send and receive signals.
Monoclonal antibodies and certain tyrosine kinase inhibitors that block the growth of blood vessels are called vascular endothelial growth factor inhibitors (VEGF inhibitors).
VEGF inhibitors block the signals causing abnormal growth of blood vessels and to prevent oxygen and nutrients from reaching the cancer cells. At the same time, it is important to know that VEGF inhibitors also can affect healthy cells.
Use this condition center to learn how anti-angiogenic therapies can affect your heart and what you can do to prevent developing heart disease.
Cancer Types Treated
Anti-angiogenic therapies have been approved by the U.S. Food and Drug Administration to treat several types of cancers. These therapies work well for solid tumors because solid tumors require blood vessels to bring oxygen and nutrients to the tumor.
Below is a list of some common cancers that may be treated with anti-angiogenic therapy:
- Renal cell carcinoma (kidney cancer)
- Non-small cell lung cancers
- Colo-rectal cancer
- Liver (hepatocellular) carcinoma
- Gastro-intestinal carcinoma
- Neuroendocrine tumors
- Endocrine tumors
- Cervical Cancer
- Ovarian epithelial cancers.
Possible Heart Effects:
Treatment to block growth of blood vessels to cancer tumors can cause some side effects including high blood pressure, kidney injury, heart failure, heart attack or stroke, and bleeding or clotting problems.
In the following sections, learn how therapy can cause these complications and when to call the doctor.
High Blood Pressure:
High blood pressure is the most common side effect linked to VEGF inhibitor treatment. It can occur in 20%-60% of patients, depending on which therapy is used.
The normal range for blood pressure is less than 120/80 mm Hg. It is important to check your blood pressure regularly and to go over your results with your health care professional. That will help you detect whether the anti-angiogenic therapy is causing your blood pressure to go up. It doesn’t mean you need to stop the medication, just that your blood presume may need treatment.Before you start therapy
Your doctor will assess your risk of developing serious problems linked to high blood pressure. If your blood pressure is high, your doctor will treat it. High blood pressure should be well controlled before starting anti-angiogenic therapy.
Over time, high blood pressure increases your risk of developing heart disease and stroke. During anti-angiogenic therapy, your goal for blood pressure will depend on your overall health and other medical conditions.
For most people during treatment, this means their blood pressure should be under 140/90. But you should discuss your blood pressure target with your doctor.
Healthy eating and regular physical activity are also important. Your doctor may also prescribe medicine to keep your blood pressure within a normal range during treatment.
In general, if your blood pressure is ≥140/90 mm Hg, treatment includes lifestyle changes along with medications
Your doctor will check your blood pressure during your office visits. He or she likely will ask you to take your blood pressure at home, too. If you develop high blood pressure, medications—along with lifestyle changes such as following a heart-healthy diet and lowering your salt intake—can help you manage the condition.
When to Call the Doctor: If your blood pressure is above 140/90 mm Hg often or your diastolic blood pressure (lower number) has increased a lot, you should talk to your doctor. If your blood pressure is elevated and you are also having a headache, chest pain, shortness of breath, swelling, vision changes, or clouded thinking, you should seek emergency help.
Anti-angiogenic therapy can affect how your kidney functions and lead to a loss of protein in the urine. Protein in the urine occurs in about 20% of patients. In severe cases, losing protein in the urine can sometimes lead to swelling, cholesterol problems, nutritional deficiencies, or increase your risk for blood clots. Kidney injury may be more common in patients who have high blood pressure.
Your doctor will check your kidney function with blood and urine tests before starting treatment. He or she will regularly monitor your kidney function during your treatment as well.
When to Call the Doctor: Kidney injury can cause fluid buildup and the loss of protein in the urine. If you develop kidney problems, you may be urinating less and notice swelling particularly in your feet and legs or that your urine appears foamy. If you notice these symptoms, be sure to talk to your doctor.
Kidney injury is usually treated based on the underlying cause of stress on the kidneys, such as high blood pressure or poor management of blood sugar (glucose). If you develop kidney problems from anti-angiogenic treatment, blood pressure medications can help improve kidney function. In some cases, specific medicines can cause kidney injury. Your doctor may have you stop taking certain medications and prescribe others.
Heart Failure and Cardiomyopathy:
Anti-angiogenic therapies can cause weakening of the heart muscle (cardiomyopathy), which means your heart muscle can’t pump well enough to meet your body’s needs for oxygen and blood. About 10%-15% of patients who receive anti-angiogenic therapy may develop weakening of the heart muscle, and a proportion of these patients may develop symptoms of shortness of breath and related symptoms consistent with heart failure. A history of coronary artery disease, high blood pressure, or heart failure can increase your risk of developing heart failure during treatment.
Signs of heart failure include swelling especially in your feet and legs, increased fatigue, shortness of breath, or difficulty breathing when lying down. For patients at an increased risk of developing heart failure, your doctor may order cardiac testing before starting therapy. He or she likely also will monitor your heart function during therapy.
When to Call the Doctor: You should also talk to your doctor if you have shortness of breath, fatigue, poor exercise tolerance, swelling on the legs, trouble sleeping at night because of shortness of breath, or unexplained weight gain of 3 pounds or more in two to three days.
Treatment for heart failure may include changes in lifestyle, medications, exercise and, in some cases, surgical placement of cardiac devices.
Patients are also at an increased risk of a heart attack (myocardial infarction or acute coronary syndrome) with anti-angiogenic therapy. A heart attack occurs when the heart is deprived of enough blood, usually due to a blockage in a blood vessel that supplies the heart.
Aspirin or blood thinners may help to reduce the risk of heart attack in patients who are receiving anti-angiogenic therapy, but more research is ongoing.
When to Call the Doctor: Chest pain, shortness of breath and sweating can be warning signs of a heart attack. If you experience these symptoms, call 911 and seek emergency help.
An urgent heart attack is treated with both medications and surgical procedures to help restore blood flow to the heart. Both medications and cardiac rehabilitation are important for patients who are recovering from heart attacks.
Stroke and blood clots:
Anti-angiogenic treatment also increases your risk of stroke. A stroke occurs when a blood vessel that supplies nutrients and oxygen to the brain ruptures or is blocked by a clot. It is important for patients and family members to know the signs and symptoms of a stroke. They include
- Sudden loss of vision
- Paralysis of one side of the body
- Slurred speech
A “mini-stroke,” also called a transient ischemic attack (TIA), can be a warning of an impending stroke. A mini-stroke occurs when blood flow to part of the brain is temporarily reduced or blocked, usually by a blood clot. Mini-strokes last only a short time and don’t cause permanent damage. However, if you think you are having a mini-stroke, call 911 and seek emergency help.
Blood clots can develop in various parts of the body during anti-angiogenic therapy. Symptoms may include leg pain and swelling. Blood clots also may cause a stroke.
When to Call a Doctor: If you have symptoms of a stroke such as numbness or weakness in a limb, slurred speech, or clouded thinking, call 911.
Appropriate treatment for stroke depends on early identification of symptoms by patients or family members. If symptoms are identified within three hours of the start of a stroke, blood flow can be restored to the brain, usually through treatment with a medication to dissolve the blood clot. Other medicines may also be prescribed to help prevent a stroke in the future.