Research has shown that women aged 65 and older who have breast cancer experience higher rates of heart failure compared to their age-matched counterparts, ranging from 29% of women with breast cancer who received no chemotherapy to 38% of women who received treatment with anthracyclines. However, little is known about the association between heart failure and long-term survival in older women with breast cancer, and it is unclear how the relative contribution of heart failure to mortality risk varies by breast cancer stage.

In their advanced print article from the January 2018 issue of the Oncology Nursing Forum, Harrison et al. reported on the results of their retrospective cohort study that examined the association between heart failure and long-term survival in older women with breast cancer and how oncology nurses can use the findings to improve survivorship care.

Cardiac Implications of Breast Cancer Treatment

Harrison et al. explained that cardiac disease and breast cancer have similar risk factors, such as advanced age, obesity, and smoking. Additionally, breast cancer therapies such as anthracyclines (e.g., doxorubicin), mediastinal radiation, and biologic agents (e.g., trastuzumab) can cause cardiotoxic effects.

Finally, older women with breast cancer may have pre-existing comorbidities that predispose them to developing heart failure, such as coronary artery disease, hypertension, or diabetes. On average, breast cancer survivors report 5.8 chronic comorbid conditions, including 2.9 conditions that occurred after their cancer diagnosis. 

Because women with comorbidities have been excluded from breast cancer clinical trials and many trials lack long-term follow-up to assess the survival impact of heart failure in patients with breast cancer, little is known about the association between the diseases.  

Heart Failure and Long-Term Survival

Using a population-based approach with data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results cancer registries, Harrison et al. identified complete data for 3,689 women with invasive breast cancer: 239 with self-reported heart failure and 3,450 without heart failure.

They noted several differences between the groups, where women with heart failure were more likely to:

  • Be older (78 versus 76 years).
  • Be non-Hispanic black (15% versus 8%).
  • Report comorbidities (e.g., hypertension, diabetes, other cardiovascular conditions, chronic lung disease, arthritis).
  • Have advanced stage cancer (16% versus 10%).

As expected, survival rates were lower among the women with heart failure. At five years, survival rates exceeded 70% for women with stage I or II breast cancer and were 48% for women with stage III or IV disease. At 10 years, rates fell to 43% for stage I, 40% for stage II, and 22% for stage III or IV cancers. Harrison et al. reported that “the contrast in survivorship between participants with and without heart failure was most pronounced at 10 years postdiagnosis."

After adjusting for comorbidities and other clinical and sociodemographic differences, the presence of heart failure was independently and significantly associated with increased risk of death up to 10 years after a breast cancer diagnosis. However, in adjusted subanalyses stratified by cancer stage, Harrison et al. found that heart failure was associated with increased likelihood of death in women with stage I or II cancer up to 10 years after cancer diagnosis but not in women with stage III or IV breast cancer.

What This Means for Oncology Nurses

The authors found that heart failure is associated with significantly lower short-term and long-term survival rates among older women with early-stage cancer, but the relationship was not significant among women with advanced cancer. Harrison et al. explained that in women with early-stage breast cancer, the mortality risk of heart failure may be greater than cancer. 

Because of this, oncology nurses should understand recommendations to minimize the cardiovascular risk of breast cancer treatment. Recommendations from the European Society of Cardiology and American Society of Clinical Oncology are summarized in Figure 1.

ACE inhibitors and beta blockers should be used as prophylaxis in high-risk patients with pre-existing cardiovascular disease, but the benefit for patients with low baseline risk is unclear. Patients should continue to see their primary providers throughout treatment for management of existing comorbidities.

Harrison et al. posited that “aggressive, multimodal treatment of early-stage breast cancer may cause more harm than benefit, particularly for older women with increased cardiovascular risk.” They encouraged the use of molecular profiling and clinical decision support tools to prevent overtreatment and called for clinician education about treatment guidelines for patients with early-stage breast cancer and multimorbidity.

Additionally, they noted the need for improved communication in two areas. First, patient-provider communication will help older adults make informed decisions about their cancer treatment. Second, communication between oncology and primary care providers during the survivorship transition will ensure understanding of the potential for long-term cardiovascular complications and the need for early recognition and treatment.

Because oncology nurses play a key role in the delivery of survivorship care plans, they can ensure that their institution’s care plans contain the appropriate information about cardiotoxic treatments and recommended surveillance. They can provide patient education to ensure women understand the potential for cardiac complications; provide recommendations to address modifiable risk factors, such as tobacco use, hypertension, and hypercholesterolemia; and teach women signs and symptoms that may indicate the need for additional assessment (e.g., dyspnea, fatigue). 

For more information on heart failure and long-term survival among older women with breast cancer, refer to the full article by Harrison et al.

This monthly feature offers readers a concise recap of full-length articles published in the Clinical Journal of Oncology Nursing or Oncology Nursing Forum (ONF). This edition summarizes “Heart Failure and Long-Term Survival Among Older Women With Breast Cancer,” by Jordan M. Harrison, PhD, RN, Christopher R. Friese, PhD, RN, AOCN®, FAAN, Debra L. Barton, PhD, RN, AOCN®, FAAN, Nancy K. Janz, PhD, Susan J. Pressler, PhD, RN, FAAN, FAHA, and Matthew A. Davis, PhD, MPH, an advanced print exclusive from the January 2018 issue of ONF. Questions regarding the information presented in this article should be directed to the ONF editor at Photocopying of this article for educational purposes and group discussion is permitted.