Blood Pressure Drugs Counter Cancer?

May 23, 2006 -- Certain cancers may be less common among people taking a type of blood pressure drug called ACE inhibitors, new studies show.

"ACE" stands for angiotensin converting enzyme. ACE inhibitors widen or dilate the blood vessels, lowering blood pressure and increasing blood flow. The drugs are prescribed for high blood pressurehigh blood pressure, heart failureheart failure, heart attackheart attack, diabetesdiabetes, and heart diseaseheart disease prevention in high-risk individuals.

The new studies -- presented in Los Angeles, at Digestive Disease Week 2006 -- showed fewer cancers of the colon, pancreas, and esophagus in people taking ACE inhibitors.

However, researcher Vikas Khurana, MD, stresses that it's too early to start using ACE inhibitors to ward off those cancers, or even to favor ACE inhibitors in picking a high blood pressure drug.

Khurana works at the Overton Brooks VA Medical Center in Shreveport, La. Advances Against Colon Cancer Advances Against Colon Cancer

Researcher's Comments

"Although our studies are very interesting they are still case-controlled studies and should not be used for clinical decisions at this time," Khurana told reporters, in a teleconference.

He notes that the data doesn't show the dose, duration, or specific drugs that were used and doesn't make any recommendations for people who need drugs to treat high blood pressure.

Treating high blood pressure is "a very specialized field," Khurana says, adding that drug decisions "need to be made based on individual patients and their cardiologist or general internist."

"What we're studying is whether we have additional benefits out of these agents, and I think still we need more time and more research on this to change any clinical decisions at this time," Khurana says.

Tracking Cancer, ACE Inhibitors.

Data covered 483,733 veterans cared for from October 1998 to June 2004 in the South Central VA Health Care Network, which covers eight states in the south-central U.S. More than 184,700 of those veterans were taking ACE inhibitors.

A total of 6,697 veterans had colon and rectal cancer, 475 had pancreatic cancerpancreatic cancer, and 659 had esophageal cancer.

Khurana and colleagues checked which veterans had been prescribed ACE inhibitors before diagnosis with colon, esophageal, or pancreatic cancer. The researchers also adjusted for factors that might influence cancer risk, including age, race, gender, BMI (body mass index), smoking, alcohol use, diabetesdiabetes, and statin use.

Statins are cholesterol-cutting drugs that may lower the risk of some cancers. Khurana and colleagues had previously reported that statin users were less likely to have certain cancers. In their new study they separated the effects of ACE inhibitors and statins and found that ACE inhibitors were associated with a reduced risk of colon, pancreatic, and esophageal cancers.

After crunching the numbers, the risk reduction in veterans taking ACE inhibitors was 53% for colon cancer, 52% for pancreatic cancer, and 46% for esophageal cancer, Khurana told reporters.

The data doesn't prove that ACE inhibitors were responsible for those results. The figures simply tracked those three cancers and use of ACE inhibitors prior to diagnosis with any of those three cancers.

"We can't take the database studies as the definitive answer. We need to have randomized, placebo-controlled trials before we use these agents as chemoprotective agents against cancer," Khurana says.

In randomized, placebo-controlled trials, researchers randomly assign people to take either an active drug (ACE inhibitors, in this case) or a pill containing no medicine (placebo). That wasn't done in this study; none of the veterans was asked to take any drugs for the sake of research.

Khurana notes that he is on the speakers' bureau for AstraZeneca, which makes drugs including ACE inhibitors.

SOURCES: Digestive Disease Week 2006, Los Angeles, May 20-25, 2006. WebMD Medical Reference provided in collaboration with The Cleveland Clinic: "ACE Inhibitors as Heart Disease Medicine." WebMD Medical News: "Statin Drugs Linked to Reduced Cancer Risk." News release, Digestive Disease Week 2006.