News

Cardiovascular risk factors common with breast cancer

View on the News

Cardiac risk increases over time

The study by Mr. Jones and his coinvestigators compared anthropometric baseline and vital sign measurements in 3,674 nononcology female patients with measurements in 740 cancer survivors. They evaluated the patients post treatment by eight different treatment regimens. Compared with a nononcology group, the patients undergoing breast cancer surgery alone had significantly higher blood pressure values, greater amounts of body fat, and larger waist circumferences. Adding two additional therapies such as hormone therapy, radiotherapy, or chemotherapy tended to show worsening parameters. The more therapy the patient had, the more likely she was to have one of these worse parameters.

The investigators concluded that several unfavorable body composition characteristics seemed to be associated with women who had completed treatment for breast cancer. And many of these changes in body composition led to an increased risk of developing cardiovascular diseases and different types of metabolic problems.


Dr. Julia White

These findings corroborate those from previous studies. For example, these patients have been found to have more high-risk features after they complete their breast cancer therapy. One small study that looked at physical activity in the year after breast cancer was treated found that total activity was reduced after breast cancer treatment – including household, sports, and occupational activities. Across the board, patients remained less active 1 year post treatment, with implications for their cardiovascular health (Breast Cancer Res. Treat. 2010;123:417-25).

This becomes very important when you think about the increased number of risk factors following therapy, and the fact that patients got less exercise the year after treatment. When you put that in perspective, the lifetime risk of death from cardiovascular disease among women aged 55 and older increases dramatically with additional risk factors (N. Engl. J. Med. 2012;366:321-9).

The study by Dr. Klemp and his associates looked at cardiovascular risk factors among 365 breast cancer survivors and the outcomes of cardio-oncology referrals at the university’s survivorship center between 2006 and 2012. The investigators evaluated the number of patients with three or more cardiovascular risk factors, both preexisting and treatment related. The cardiac risk factors were pretty similar to those in the general population. The cardiology referrals accounted for 21% of patients. The most common risk factors associated with cardio-oncology referrals were a high body mass index, an elevated LDL* level, less exercise exposure, and anthracycline exposure. The most common outcomes for those seen by cardio-oncology were additional diagnostic tests and medication changes. Interventions by cardiology referrals correlated with a higher number of risk factors. Patients with the highest number of risk factors were the most likely to continue with the cardiologist, receive medication, and undergo diagnostic tests.

These two studies together demonstrate the important message that cardiovascular disease is a significant risk for breast cancer survivors. With time, as the risk of breast cancer death decreases, the risk of cardiovascular death increases.

The best method for improved outcomes from breast cancer may be the addition of an exercise machine in our waiting rooms.

Dr. Julia White is the director of breast radiation oncology at Ohio State University, Columbus. These are excerpts of her remarks as the discussant of these papers at the meeting. She reported having no financial relevant financial disclosures.


 

AT THE ASCO BREAST CANCER SYMPOSIUM

SAN FRANCISCO – Breast cancer survivors shared several body composition characteristics associated with increased cardiac risk and were referred for cardiac consultation most commonly for a high body mass index, an elevated LDL* level, insufficient exercise, and exposure to anthracycline, two separate studies found.

In the first study, kinesiologists measured various characteristics in 3,674 nononcology female patients and compared them with measurements in 740 women in a breast cancer survivorship clinic who were stratified into 8 groups according to the type of treatment they received. All breast cancer patients underwent surgery: 41 women had surgery alone, 13 also underwent chemotherapy, 51 had surgery and radiotherapy, and 48 had surgery and hormone therapy. Most cancer survivors underwent multiple therapies: surgery, chemotherapy, radiation, and hormone therapy in 244; surgery, radiation, and hormone therapy in 207; surgery, chemotherapy, and radiation in 83; and surgery, chemotherapy, and hormone therapy in 30, David H. Jones and his associates found.

Dr. Jennifer Klemp

Statistically significant differences were seen between the control group and five of the eight treatment groups. Compared with the control group, patients who underwent surgery, chemotherapy, radiation, and hormone therapy had significantly higher mean diastolic blood pressure (77 vs. 74 mm Hg), mean systolic blood pressure (128 vs. 123 mm Hg), mean arterial pressure (94 vs. 90 mm Hg), A faster mean heart rate (77 vs. 73 beats per minute), a higher percentage of body fat (37% vs. 34%), and a greater waist circumference (88 vs. 85 cm), Mr. Jones reported in a poster at a breast cancer symposium sponsored by the American Society of Clinical Oncology.

Patients who underwent surgery, radiation, and hormone therapy also had a higher mean systolic blood pressure compared with controls (130 mm Hg), a higher mean arterial pressure (94 mm Hg), and greater body fat (37%). Patients who underwent surgery, chemotherapy, and radiotherapy had a higher mean systolic blood pressure (129 mm Hg), mean arterial pressure (94 mm Hg), heart rate (79 bpm), and body fat (38%) compared with controls, reported Mr. Jones of Ville-Marie Medical Center, Montreal.

Patients treated with surgery alone had a higher body mass index (29 vs. 26 kg/mm2), body fat percentage (39%), and waist circumference (90 cm) than did controls. Patients who underwent surgery and chemotherapy had significantly less mean muscle mass compared with controls (9.6 vs. 10.1 kg).

Previous studies have associated these body composition characteristics with increased risk for cardiovascular diseases and metabolic problems, Mr. Jones noted.

In the second study of 365 women with nonmetastatic breast cancer seen at a survivorship center in 2006-2012, 13% already were being followed by a cardiologist, 21% were referred to cardio-oncology after their initial visit to the survivorship center, and 66% were not referred, Jennifer R. Klemp, Ph.D., and her associates found.

Patients who were not referred had an average of four risk factors for cardiovascular disease, significantly fewer than the average of six cardiovascular risk factors in patients referred to cardio-oncology and those already seeing a cardiologist, reported Dr. Klemp, director of cancer survivorship at the University of Kansas, Westwood.

The risk factors considered in the study included exposure to cardiotoxic breast cancer treatment as well as traditional risk factors: a BMI greater than 25, diabetes; hypertension, an elevated HDL level, a history of smoking, a family history of an MI before age 60 years, and exercising fewer than 150 min/wk. Breast cancer treatment–related risk factors included an ejection fraction less than 50%; anti-hormone therapy; use of tamoxifen, anthracycline, or Herceptin (trastuzumab); and left chest wall radiation.

Among patients referred to cardio-oncology, 92% showed up. Most often they received additional diagnostic tests, changes in medications, or return visits for follow-up.

"These findings demonstrate the need to determine how to include treatment-related risk factors along with traditional cardiovascular risk factors in assessing and managing cardiovascular risk in breast cancer survivors," Dr. Klemp said.

Mr. Jones and Dr. Klemp reported having no relevant financial disclosures. Most of Dr. Jones’ associates were employees or leaders of Ville-Marie Medical Center.

sboschert@frontlinemedcom.com

On Twitter @sherryboschert

*Correction, 11/20/2013: A previous version of this article misstated one of the symptoms for both increased cardiac risk and increased risk for cardio-oncology referrals.

Next Article: