New Cancer Drug Boosts Blood Pressure
But doctors say sunitinib's benefits outweigh its risks
WEDNESDAY, Jan. 2, 2008 (HealthDay News) -- The new anti-cancer drug sunitinib (Sutent) can cause high blood pressure in patients with kidney cancer, French researchers report.
The finding echoes the results of a study published last month that found the drug increased blood pressure and the risk of heart failure among patients with stomach cancer.
"Patients taking sunitinib and other similar [drugs] may experience increases in blood pressure of 15 to 25 percent," said study author Dr. Michel Azizi, a professor of vascular medicine at Georges Pompidou European Hospital in Paris. The report is published in the Jan. 3 issue of the New England Journal of Medicine.
For the study, Azizi and his colleagues used home blood pressure monitoring, with the results sent automatically by telephone to the hospital. They found an immediate and marked increase in blood pressure in 14 patients with kidney cancer who were treated with 50 milligrams of sunitinib a day for four weeks.
The increase in blood pressure was not seen when blood pressure was measured in a physician's office, Azizi said. "It started within four to seven days of the first cycle of sunitinib, disappeared within two weeks of treatment discontinuation, and recurred during the following treatment cycle," he said.
Sunitinib works by blocking the activity of vascular endothelial growth factor (VEGF). Besides sunitinib, other so-called VEGF inhibitors have been developed, including bevacizumab (Avastin). Although these drugs are promising in fighting several types of cancer, they are associated with side effects, including high blood pressure, bleeding, gastrointestinal perforation, wound-healing complications and clotting, Azizi noted.
Azizi thinks that, despite the increase in blood pressure, the cancer-fighting benefits of sunitinib outweigh the risks. Sunitinib and similar drugs are prescribed for patients with advanced malignancies and short life expectancies, he explained.
Also, for patients with normal blood pressure, the increase caused by the drug is manageable with blood pressure-lowering drugs, he noted.
"However, our observations show that in initially hypertensive patients [people with high blood pressure] the additional sunitinib-related increase in blood pressure is not easy to control and that recommended blood pressure targets are not easily achievable despite administration of multiple anti-hypertensive drugs," Azizi said.
Rapid increases in blood pressure should be expected for every patient treated with sunitinib, Azizi said, so close monitoring is needed.
"We strongly advise the routine use of home blood pressure monitoring in standard care for early detection and accurate assessment of blood pressure changes in patients treated with any sunitinib-like drugs," Azizi said.
Dr. Ming Hui Chen is an assistant professor of medicine at Harvard Medical School, a cardiologist at Children's Hospital Boston and lead author of the December sunitinib study that was published in The Lancet. She agreed that patients taking sunitinib need to have their blood pressure monitored.
"In general, hypertension is one of the most treatable of all medical conditions," Chen said. "VEGF inhibitor-associated hypertension is not uncommon, but in my experience a very manageable one."
"We should not lose sight that this type of anti-cancer therapy is effective for patients with metastatic renal cell [kidney] and gastrointestinal stromal [stomach] tumors," Chen said.
For patients, Chen recommends making sure that "you with your doctor together are monitoring and treating your blood pressure while you are undergoing this type of anti-cancer treatment. Early identification and aggressive treatment of hypertension are key."
In a statement released in December for the The Lancet study, sunitinib's maker, Pfizer Inc., agreed that these heart risks do exist. However, the company added that the cardiovascular events "were medically manageable in most patients and underscore the importance of having a collaborative team of health-care professionals working together to appropriately manage patients who have limited available options" in treating their cancer.
In the statement, Pfizer added that, "Lower incidences of cardiovascular effects have been observed in subsequent randomized Phase 3 prospective Sutent [sunitinib] studies in both renal cell carcinoma and gastrointestinal stromal tumor[s]." That includes a lower incidence of events such as congestive heart failure, impaired heart function, and high blood pressure that were noted in Chen's retrospective analysis, the company said.
For more on sunitinib, visit the U.S. National Library of Medicine.