Combating cardiac complications caused by cancer treatment

Jun 26 2018

Amie Goins has completed eight 5K runs in 2018. An impressive feat for a 46-year-old mother with a full-time job and two teenage sons to care for – downright astounding for a woman who was diagnosed with stage 2 breast cancer two days before Christmas last year. She's conquered months of treatment and difficult side effects while continuing to lace up.

The treatment plan Mrs. Goins received from her UT Southwestern Medical Center physicians called for chemotherapy to shrink the tumor before her surgery. "It took me a little while to get my head around that treatment plan. I met Dr. (Vlad) Zaha, my cardiologist, and when I talked to him, that's really when I started to feel like this is something I could manage," she said. "I told him that I run around 10 miles a week, and he said, 'You'll be able to continue exercising. You'll just be slower during the chemotherapy. It'll make you tired, but exercise really does help to mitigate some of the symptoms.'"

Mrs. Goins is seeing a cardiologist as part of her cancer treatment because anthracyclines, a class of chemotherapy drugs used to treat breast cancer patients, can weaken the heart and lead to congestive heart failure years down the road in some patients. Pre-emptive treatment, including exercise, can help keep the heart strong.

"I think for so many decades in medicine, the focus has just been on getting rid of the cancer. How do we get rid of the cancer, keep the person from dying?" said Mrs. Goins. "For Dr. Zaha and all of my physicians, I know that they're looking out for my long-term health in addition to addressing this one crisis moment with my health. And that's important because I can't always focus on that thing down the road."

Mrs. Goins, who started distance running a little more than a decade ago, vowed to continue exercising straight through her chemotherapy period. Even if it was just a 30-minute walk in the days immediately following a treatment, when she was struggling with side effects such as exhaustion, bone pain, or nausea, she would maintain exercise as a part of her daily life.

And she has. "I won't say I was successful every day, but almost every day."

Searching for metabolic signs of heart problems

Oncologists have known for more than half a century that anthracyclines, a class of drugs used to treat solid tumors, can cause damage to the heart.

Dr. Vlad Zaha, Assistant Professor of Internal Medicine at UT Southwestern and a member of the Harold C. Simmons Comprehensive Cancer Center, is a cardiologist who specializes in heart problems caused by cancer treatment. He was recently awarded a $2.3 million grant from the Cancer Prevention and Research Institute of Texas (CPRIT) to study the metabolic changes that occur in the heart with anthracycline treatment.

The immediate goal is to identify metabolic changes that happen early on, before mechanical changes in the heart can be detected. "Currently, by the time we see signs of heart failure, damage has already been done to the heart muscle," Dr. Zaha said.

The ultimate goal of the study is to be able to tailor treatment to patients.

"Some patients might not be as sensitive and they could potentially get more treatment. For instance, a patient who has low cardiac sensitivity to anthracycline and has a recurrence of cancer might be able to get another round of anthracycline treatment," Dr. Zaha said.

"And in other patients the reverse could be true. In that case, identifying the damage early on could have the potential to inform the oncologist's treatment and lead to a decision to use alternative protocols," he continued. "Early detection of cardiac dysfunction allows prompt medical interventions to recover the heart function as close as possible to baseline."

The study will also be making use of new metabolic imaging technology that does not require radioactive tracers. Dr. Zaha's study will be the first large cardiology study in the nation to use this new, non-radioactive tracer-based imaging.

The clinical diagnostic trial will enroll 100 patients over the next four years, leading to an expanded understanding of the metabolic underpinnings of anthracycline-related cardiotoxicity.

Combating cardiac complications with exercise

As cancer treatments improve and patients survive for longer and longer periods of time, the need to understand long-term complications of treatment increases.

The National Cancer Institute estimates that there will be about 18 million cancer survivors in the United States by 2022. Many of those survivors will face long-term cardiovascular complications caused by chemotherapy or radiation therapy.

"The lifetime risk of heart failure increases with increasing cumulative doses of anthracyclines, but the risk is severely amplified by underlying cardiovascular risk factors in cancer survivors," Dr. Zaha said. "Sedentary lifestyle and hypertension would be at the top of the list of traditional risk factors, and exercise helps to counterbalance both."

For this reason, it is important for cancer patients to get out ahead of potential heart problems, and exercise is a key part of that pre-emptive effort.

Amie Goins, with her determination to keep running during her cancer treatment and beyond, is Dr. Zaha's star patient. She reports the miles she's logged each time she sees him, and once she sent him a photo of her crossing the finish line of a 5K that she won in her age category.

"It's something where she can use exercise instead of a pill to protect her heart in the course of the treatment, and that is very inspiring," Dr. Zaha said.

"I can't say enough about what the exercise does for your physical well-being, and just being able to shed the effects of the drugs temporarily is a huge help when you are going through chemotherapy," he continued.

Mrs. Goins said her commitment to exercise has given her a sense of control at a time when life could easily feel like it has spun out of control. Plus, it has paid off physically.

"I saw a huge benefit. Every time I made that step to get some type of exercise in, even if it was just a 30-minute walk, I always felt better afterward. No matter what the symptom was that I was struggling with, I always felt better afterward."

Mrs. Goins said she understands how easy it can be for someone undergoing cancer treatment to sink into self-comfort with a pile of pillows and cartons of ice cream, but she urges anyone facing chemotherapy to do their best to remain active.

Her personal cancer journey is continuing, with radiation treatments coming next. "Cancer treatment does feel like a journey, and a marathon of some sort. I'm going to cross the finish line," she said.​

Source: https://www.utsouthwestern.edu/newsroom/articles/year-2018/cancer-treatment-heart.html