New research suggests that popular
blood pressure medications may add years to the lives of patients with
pancreatic cancer, a notoriously tough-to-treat cancer with low survival rates.
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II
receptor blockers (ARBs) reduce blood pressure by relaxing veins and arteries
and making it easier for the heart to pump blood.
Studies in animals have shown that these medications might slow
the growth of pancreatic cancer. Several small studies in people suggest the
same thing, but the numbers of patients included were too small to draw firm
conclusions.
Researchers looked at data from 3.7 million adults in Italy and
identified 8,158 people who had been diagnosed with pancreatic cancer between
2003 and 2011.
The vast majority of these patients (86 percent) died within six
months of their diagnosis, according to a study published last month in the
journal BMC Cancer.
Compared to similar patients who did not take ARBs after their
pancreatic cancer diagnosis, patients who took ARBs had a 20% lower risk of
dying.
ARB users had a 28 percent lower risk of dying in a smaller group
of cancer patients who had surgery.
Also, patients with pancreatic cancer who took ACE inhibitors had
a 13% lower risk of dying in the first three years after diagnosis, but this
benefit shrank later.
However, study investigator Scott Keith, Ph.D., of Thomas
Jefferson University in Philadelphia, cautions, "ARBs and ACE inhibitors
should be considered experimental treatments for pancreatic cancer."
Timothy Pawlik, MD, Ph.D., also cautions not to jump to firm
conclusions based on this study.
"While provocative," says Pawlik of an Ohio State
University Comprehensive Cancer Center, "the data cannot be considered
conclusive."
"The study is retrospective, making it susceptible to
selection and treatment bias. In addition, the data were derived from an
administrative health care database, which can be notorious for lacking
granular clinical data," he points out.
Pawlik also notes that studies evaluating the benefits of blood pressure medications on cancer risk and outcomes are mixed. Several previous studies, for instance, suggest ACE inhibitors and ARBs may protect against malignancies such as colorectal cancer. In contrast, other data suggest a possible link between ACE inhibitors and a higher risk for certain cancers, such as lung cancer.
Sources
- BMC Cancer: "Angiotensin blockade therapy and survival in pancreatic cancer: a population study."
- Timothy Pawlik, MD, PhD, Ohio State University Comprehensive Cancer Center.
- Scott Keith, PhD, Thomas Jefferson University, Philadelphia.