A common heart drug called a beta blocker was associated with a striking increase in survival for women with ovarian cancer in a study that suggests a possible new strategy for treating a variety of tumors.
Researchers analyzing a database of 1,425 women with the tough-to-treat cancer found those who had taken a certain type of beta blocker lived more than four years longer on average than those who hadn’t been prescribed the drug. The women were taking the medicine to treat high blood pressure or another heart problem, not as part of their cancer treatment.
The study was retrospective, and thus wasn’t randomized, and had other important limitations, researchers said. Further research, which is under way, is necessary to determine whether the findings could be translated into a new treatment for the disease.
“It’s very interesting and very thought-provoking,” said Christina M. Annunziata, clinical director of the women’s malignancies branch of the Center for Cancer Research at the National Institutes of Health. “I don’t think it’s practice-changing quite yet.” Dr. Annunziata, who wasn’t involved in the study, co-authored an editorial accompanying the report, published in Cancer, a journal of the American Cancer Society.
More than 21,000 women in the U.S. will be diagnosed with ovarian cancer this year, the cancer society estimates. More than 14,000 will die from it, making it the fifth most deadly cancer among women. Recurrence rates are high and there have been few advances made beyond standard chemotherapy in some 30 years.
- 47.8 months: Median survival for women taking any beta blocker, a common heart drug, during chemotherapy for ovarian cancer
- 42 months: Median survival for women not taking a beta blocker during chemotherapy
- 94.9 months: Median survival for women taking a nonselective (first generation) beta blocker during chemotherapy
- 38 months: Median survival for women taking a selective (second generation) beta blocker during chemotherapy
Source: the journal Cancer
Dr. Annunziata and the study authors cautioned that beta blockers have side effects and more research is needed to see if the drugs’ benefits outweigh risks for cancer patients.
In recent years, studies have shown that chronic stress promotes the growth and spread of ovarian and other cancers. One way is by stimulating so-called fight-or-flight hormones such as adrenaline and norepinephrine, said Anil Sood, professor of gynecologic oncology and cancer biology at the University of Texas MD Anderson Cancer Center in Houston and senior author of the new report. Beta blockers can mitigate stress but previous studies that looked at their effect on ovarian cancer have been mixed.
Beta blockers come in different versions. Mouse and test-tube studies have shown that so-called nonselective beta blockers inhibit molecular pathways that promote tumor growth. Selective versions, designed to minimize side effects for heart patients, are less effective in hitting such targets. Dr. Sood and his colleagues wondered if the same effect would be found in people.
The 1,425 patients in the study were treated at four different institutions between 2000 and 2010; 268 had been treated with beta blockers, including 75 given a nonselective version, while they were on chemotherapy. The researchers found that median survival for those treated with any blocker was 47.8 months, compared with 42 months for those not taking the medicines.
But difference between those taking a nonselective beta blocker—propranolol in essentially all cases—and those taking a selective version was much more dramatic: 94.9 months versus 38 months.
“We would have predicted that there would be some difference but we were surprised to see the magnitude of difference that was coming up here,” Dr. Sood said.
Still, it would “require prospective studies to feel really good that there is a significant benefit,” Dr. Sood said. The study didn’t show what dose might be effective or how long patients were on the drugs, for instance, or what biological markers might help predict which patients would benefit.
“This is not something that people should rush out and start taking,” Dr. Annunziata said. “There are so many side effects of these drugs especially if you don’t have high blood pressure.” For instance, people with a history of asthma would be at risk for serious side effects with a nonselective beta blocker.
Since essentially all beta blockers, including propranolol, are generic, drug companies aren’t likely to sponsor the large prospective study that would likely be necessary to determine any role beta blockers might have in cancer. Grants would be required, Dr. Sood said. But other research has suggested that stress may similarly affect colon, lung and prostate cancers.
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