Women with ovarian cancer who took a certain type of beta-blocker drug for heart problems unrelated to their cancer lived more than four years on average longer than those who did not take the drug, according to a retrospective study published online Monday in the journal Cancer.
Prescribed to treat heart disease, high-blood pressure, glaucoma and migraines, beta-blockers target a receptor protein in heart muscles that causes the heart to beat harder and faster when activated by “fight or flight” stress hormones, said Dr. Anil Sood of the University of Texas MD Anderson Cancer Research Center in Houston, the principal investigator of the study.
“Our research has shown that the same stress mechanisms [targeted by beta-blockers] impact ovarian cancer progression, so these drugs could play a new role in cancer treatment,” Sood said in a statement.
While hailing the correlation between use of the drugs and longer survivorship as “important” and “encouraging,” researchers – the study’s authors among them – cautioned that randomized clinical trials are needed to prove that one actually caused the other. Additional studies would also be needed to look at such questions as dosage, optimal length of treatment, and biological markers that might predict benefits and risks.
“I see this paper as another important piece of data that supports that stress pathways can influence progress in ovarian cancer,” said Dr. Bonnie McGregor, a clinical psychologist and public health researcher at Fred Hutchinson Cancer Research Center. She did not take part in the study. And the good news, McGregor adds, is that women with ovarian cancer – or any person with cancer – can take steps now to reduce stress.
The study, published Monday, looked back at the medical records of 1,425 women with ovarian cancer treated at multiple medical centers between 2000 and 2010 and compared overall survival between patients who used beta-blockers while they were receiving chemotherapy and those who used none. Unlike in previous studies of beta-blocker use and cancer, Sood and his colleagues also compared two different types of beta-blockers. Of the 268 women in the cohort who took beta-blockers, 193 used beta-1-adrenergic receptor selective agents and 75 used an older generation beta-blocker called nonselective beta antagonists.
For patients who used any type of beta-blocker, the median overall survival was 47.8 months, compared to 42 months for nonusers. But a more dramatic increase in survival was observed specifically in women who used the older, nonselective beta antagonist. Their overall survival was 94.9 months, compared with 38 months for women on the selective beta-blocker.
Even before this study, researchers had suspected that beta-blockers could have an effect on cancer progression but had found mixed results. That is because they didn’t differentiate between the two kinds of beta blockers, according to Sood.
Still, McGregor pointed out that although the size of the overall cohort was large, the results are based on just 75 women who took the nonselective beta-blockers, another reason that more studies are needed.
In an accompanying editorial in Cancer, Dr. Christina M. Annunziata of the National Cancer Institute and Dr. Kristen Bunch of Walter Reed National Military Medical Center, who were not associated with the study, wrote that “despite the small numbers, the authors uncovered a dramatic survival advantage in patients taking nonselective beta-blockers that warrants further study in the clinic.” Clinical verification in larger populations “is necessary, and currently underway,” they wrote, and added: “Complementary approaches to cancer treatment, such as developing programs to decrease stress or improve social networks, could be a cost-effective intervention to enhance the quality of life for patients with ovarian cancer while improving outcomes.”
Nearly 22,000 women in the United States are diagnosed with ovarian cancer each year, and more than 14,000 will die from it, according to the National Cancer Institute. Ovarian cancer causes more deaths than any other female reproductive system cancer, in part because the lack of both early symptoms and effective screening means most cases are diagnosed at an advanced stage.
“We can’t say that stress causes cancer,” said Fred Hutch’s McGregor. “Buddhist monks get cancer and die from it.”
But research has shown that stress can play one role in the progression of cancer, and research by Sood and others has shown that ovarian cancer seems to be especially vulnerable to its effects, McGregor said.
The good news? “The nice thing is, you have control over [stress]” McGregor said. “You don’t have control over your genes. But there are a lot of things women can do to reduce stress.”
Yoga, mindfulness meditation and relaxation exercise are techniques shown to reduce stress, McGregor said. Another is for patients to seek out close friends and family. In the editorial accompanying Sood’s paper, Annunziata and Bunch noted studies showing that socially isolated women with breast cancer had a two-fold increased risk of dying from their disease and that greater social support was associated with lower risk of death. The quality rather than the size of the network is what counted.
McGregor and researchers at the University of Iowa are developing a new, web-based program specifically for women with ovarian cancer to foster community and improve quality of life. A clinical trial to test the approach will open in September. Participation will involve about two hours a week for 10 weeks and can be done from home.
For more information, contact McGregor at email@example.com.
Mary Engel is a former staff writer at Fred Hutchinson Cancer Center. Previously, she covered medicine and health policy for the Los Angeles Times, where she was part of a team that won a Pulitzer Prize for Public Service. She was also a fellow at the Knight Science Journalism Program at MIT. Follow her on Twitter @Engel140.