Hypertension is a well-known risk factor for chemotherapy-induced cardiotoxicity, and if not controlled, can significantly influence cancer management and even lead to the discontinuation of certain therapies. In this video, , of Georgetown University and Director of MedStar Heart & Vascular Institute's Cardio-Oncology Program, discusses which types of therapies are causing hypertension, and what is known about management.
Following is a transcript of her remarks:
Hypertension has become and is evolving into an important issue and concern in cancer patients. It's not related to chemotherapy in a narrow sense, and it's very important to identify that upfront. The cancer drugs that are associated with hypertension are typically targeted therapies, so they don't belong in the world of what's called conventional or standard chemotherapy, which are cytostatics. That's usually in our history of knowing about these drugs, mostly related to that they cause hypotension.
Cancer therapeutics that are linked to hypertension typically target a pathway that's called vascular endothelial growth factor pathway, also known as VEGF pathway. These inhibitors have been discovered in the cancer world as very potent inhibitors of tumor growth. They are effective and there are a number of them. By mechanism, they are mostly grouped in two main groups. They can be either monoclonal antibodies or kinase inhibitors, which are taken orally.
Both of these drugs, mostly because they target the VEGF pathway, result in hypertension. This has taught us something about the role of the VEGF pathway in cardiovascular homeostasis where VEGF is an important component.
Now, what we know about managing hypertension is that it is really intriguing, and I would say fascinating. These drugs, as they were being developed, were mostly introduced in the metastatic setting, which means that a patient with a metastatic malignancy was first going to get this drug. One of the early cancers where these therapies were used was renal cell carcinoma. Researchers saw hypertension in 40%, 50%, and up to 70% of patients developing some degree of hypertension.
First, a very important concept: it's an on-target effect, so we know it's related to what the drug is supposed to do. It blocks VEGF, and therefore causes hypertension. The very mechanism is not yet well-defined; however, in the clinical world, we know that it results in the elevation of blood pressure.
The first question is: is it good for the patient to develop hypertension or not? That is perhaps, the most important message for a cardiology audience. Oncologists do know this already. Developing hypertension is an excellent thing in a patient because it has been associated with a good oncology prognosis. Patients who develop hypertension tend to respond better to oncology drugs with respect to the tumor regression. This is a very important concept.
The second concept, which already arose a couple of years ago, is that the treatment of hypertension does not reduce the efficacy of the oncology drug. That was the first fear, perhaps. The treatment of hypertension in these patients actually results in improved outcomes, whether that's because we can actually give more drugs or because there are potential synergies. This is a big research question to be answered, but right now it is recommended we screen for hypertension, monitor these patients for hypertension, and treat them.