Medicines Found to Protect Heart Health of People Taking HER2-Targeting Therapies

Medicines approved for other uses were shown to protect the heart from side effects of trastuzumab, or Herceptin, a widely used medicine in HER2-positive breast cancer
Breast Cancer News
December 8, 2018
Eric Fitzsimmons

The final day of presentations at the 2018 San Antonio Breast Cancer Symposium included studies about quality of lifeinfo-icon, the effect of exercise programs, and easing hot flashes for women on hormonal therapyinfo-icon. One notable study found two medicines used to treat congenital heart failure and other heart problems could be used to prevent heart effects in people taking trastuzumabinfo-icon (Herceptininfo-icon) and certain chemotherapyinfo-icon medicines.

Beta Blockers, ACE Inhibitors Can Protect Heart During HER2 Treatment

Trastuzumabinfo-icon (Herceptininfo-icon) is a widely used targeted therapyinfo-icon for HER2-positive breast cancers. It can cause side effects to the heart. Most heart-related side effects are not permanent, but they may cause doctors to lower the doseinfo-icon or stop giving trastuzumab.

Beta blockers and ACE inhibitors, also called angiotensin converting enzyme inhibitors, are two types of medicineinfo-icon that treat heart problems. Both are used often and readily available. Researchers in this study wanted to see if adding these types of medicines to trastuzumab would decrease the chances of heart side effects.

The study had 468 participants with early-stageinfo-icon HER2-positive breast cancer who planned to have chemotherapyinfo-icon and 12 months of trastuzumab. Participants were split based on whether their chemotherapy included an anthracyclineinfo-icon, such as doxorubicininfo-icon (Adriamycin), which can also harm the heart. Everyone was then randomly assigned to one of three study groups to get either a placeboinfo-icon, the beta blocker carvedilol (Coreg) or the ACE inhibitor Lisinopril (Zestril). To find out if the medicines had an effect, researchers measured the ejection fraction, or how much blood leaves the heart each time it contracts.

As a whole, there were no differences in effects on the heart between those who took the placebo and those who got active medicines. But when analyzed by anthracycline use, those who got the medicine had a statistically significantinfo-icon increase in how long they went without any signs of a heart effect.

Based on these results, doctors should consider recommending either lisinopril or carvedilol to people taking trastuzumab and anthracyclines, the researchers said. That statement was reinforced during the Alamo Breast Cancer Foundation’s Hot Topic Mentor Session Friday evening. Debu Tripathy, MD, head of breast medical oncologyinfo-icon at University of Texas MD Anderson Cancer Center in Houston, said because these medicines are already available and FDAinfo-icon approved for other conditions, he would start having these conversations with people in his practice on Monday morning. 

Approved Therapy Treats Hot Flashes From Hormonal Therapy

In the afternoon, researchers shared results from the ACCRU study SC-1603 of the medicineinfo-icon oxybutynin (Ditropan) to help manage hot flashes. It’s a medicine FDAinfo-icon approved to treat problems with an overactive bladder.

Hot flashes are common in those who have or had breast cancer, especially in people taking anti-estrogeninfo-icon therapyinfo-icon. They can disrupt day-to-day life and sleep, and in some cases cause so much discomfort that people stop taking hormonal therapyinfo-icon. Past research also shows many people hesitate to report these side effects to their doctors. Finding options to lessen hot flashes could improve lives and help people stay on their medicine.

The trial was open to women who had frequent hot flashes, including those taking tamoxifeninfo-icon or aromatase inhibitors. They were assigned to get either a placeboinfo-icon, a 2.5 milligram doseinfo-icon of oxybutynin or 5 milligrams of oxybutynin.

Using oxybutynin led to fewer and less severe hot flashes, the researchers reported. Despite the medicine’s side effects, including dry mouth, abdominal pain, and trouble urinating, most people found them tolerable. Though the researchers didn’t formally test the doses against each other, the 5 milligram dose had a stronger effect and better marks on some quality-of-life measures.

Virginia Kaklamani, MD, leader of the breast cancer program at University of Texas Health San Antonio, discussed this trial at the Alamo Breast Cancer Foundation’s evening Hot Topic session. She noted that those in the 5 milligram arm had an 80 percent decrease in the number of hot flashes, an improvement over the 60 percent reported for other medicines used today to manage this side effectinfo-icon.

“Come Monday morning, if I see a patient with hot flashes, I will talk to my patients about this drug,” Dr. Kaklamani said.

Guided Exercise Program Helps People With Breast Cancer Maintain Heart Fitness

People face a higher risk of heart disease after breast cancer, so researchers behind the EBBA-II trial set out to see if enrolling people with breast cancer to an exercise program would help maintain heart health through treatment.

Participants with DCISinfo-icon, LCIS, or stageinfo-icon I or II breast cancer were randomly assigned to

  • get standard of careinfo-icon, with no additional help with exercise OR
  • enroll in a 12-month exercise program

The exercise program featured twice-weekly group sessions with a physiotherapist plus home workouts. (Physiotherapists help people restore, maintain and use their physical strength.) The results were gauged using a measure of oxygen use in an exercise test.

Overall, participants who did the exercise program had better heart fitness than those in the standard of care group. Though both groups had a decline in fitness 6 months after surgeryinfo-icon, the decline was less in the exercise group. A year after surgery the exercise group had slightly better fitness, and the control groupinfo-icon was still worse than it had been before surgery.

Researchers say these results support offering supervised and tailored exercise programs to people in chemotherapyinfo-icon. During discussion, doctors said the fitness measure is a good sign, but there is still a demand for exercise programs to show an impact on survival.

SUCCESS C Trial Looks at Health Program Effects on Disease-Free Survival

The SUCCESS C trial, also presented Friday morning, looked at whether a fitness program can increase rates of people living without breast cancer returning. Participants were randomly assigned either to a lifestyle program for 2 years based on phone calls and mailings to guide diet, exercise, and health goals such as losing weight, or to a more standard approach of receiving educational mailings about healthy living.

People in the lifestyle program lost a kilogram (about 2.2 pounds) on average in this period, while those in the mailing group gained a kilogram on average, researchers reported. Only 48 percent of people in the fitness group completed the program. There was no difference between the two groups in the rates of cancer recurrenceinfo-icon.

The researchers followed participants longer and noted the fitness group had better outcomes: they lost more weight and were less likely to have cancer return. But since this data was found after the study closed, the researchers warned the findings could be biased.

There are many reasons to start or maintain an exercise program. To learn more, talk with your healthcare team about safe first steps to meet your goals.

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