Breast cancer is a common diagnosis among women in the United States, representing about 30% of all new female cancer cases each year. Radiation therapy is a frequently used and effective treatment for many individuals diagnosed with breast cancer. This treatment employs high-energy rays to target and destroy cancer cells, often after surgery to reduce the likelihood of the cancer returning.
Radiation Therapy and Blood Pressure Link
Radiation therapy for breast cancer, while effective, can have effects on the body beyond the targeted area. A potential association exists between breast cancer radiation and changes in cardiovascular health, including blood pressure. This link is particularly noted for individuals receiving radiation to the left side of the chest, which is closer to the heart.
High blood pressure, or hypertension, is a condition where the force of blood against artery walls is consistently too high. While radiation therapy is a localized treatment designed to minimize exposure to surrounding healthy tissues, some incidental radiation to the heart can occur, especially with left-sided breast cancer. Studies indicate that women who received left-sided radiation therapy had a higher risk of heart disease compared to those treated on the right side.
How Radiation May Affect Blood Pressure
Radiation therapy can influence blood pressure through several biological pathways, primarily by affecting the delicate structures of the cardiovascular system. One mechanism involves damage to the endothelium, the inner lining of blood vessels. Radiation can induce endothelial dysfunction, which impairs the ability of blood vessels to relax and contract properly. This dysfunction can contribute to increased vascular resistance, a factor in elevated blood pressure.
Beyond the endothelium, radiation exposure can lead to increased arterial stiffness. This stiffening reduces the elasticity of major arteries, making it harder for them to expand and contract with each heartbeat, thereby raising blood pressure. The process can involve the development of fibrosis, a thickening and scarring of tissues in and around the heart, which can impair cardiac function and structure over time.
Radiation can also trigger an inflammatory response within the body. This inflammation and increased oxidative stress, which involves an imbalance between free radicals and antioxidants, can promote the development of atherosclerosis, a hardening and narrowing of the arteries. These changes can stiffen blood vessels and increase systemic vascular resistance, contributing to hypertension. Additionally, radiation to areas near the kidneys or direct kidney irradiation can impact kidney function, which plays a role in blood pressure regulation. Damage to kidney tissue or the renal arteries can disrupt the body’s fluid and electrolyte balance, potentially leading to increased blood pressure.
Recognizing and Addressing High Blood Pressure
High blood pressure often has no noticeable symptoms, meaning individuals may not feel unwell even when their blood pressure is elevated. For this reason, regular blood pressure monitoring is a significant part of follow-up care for breast cancer survivors.
Healthcare providers typically monitor blood pressure before, during, and after cancer treatment to detect any changes. Initial management often includes lifestyle adjustments such as adopting a balanced diet, engaging in regular physical activity, and maintaining a healthy weight. If lifestyle modifications are insufficient, medication may be prescribed. Common antihypertensive medications, including ACE inhibitors, ARBs, beta-blockers, and dihydropyridine calcium channel blockers, are often considered for managing radiation-associated hypertension.
Ongoing Care for Cardiovascular Health
Long-term cardiovascular health management is crucial for breast cancer survivors, particularly for those who have received radiation therapy. The potential for cardiovascular effects, including changes in blood pressure, can extend for many years after treatment concludes. Continued monitoring of blood pressure and other cardiovascular risk factors is recommended as part of routine medical check-ups.
Maintaining a healthy lifestyle is a proactive measure that can reduce long-term cardiovascular risks. This includes regular exercise, a heart-healthy diet, and avoiding smoking. Collaboration between oncologists and cardiologists ensures comprehensive care, addressing both cancer surveillance and cardiovascular health throughout a survivor’s life.