Adherence to cardiac monitoring less than ideal in trastuzumab recipients
Drug-related cardiotoxicity leading to incident cases of heart failure after a breast cancer diagnosis occurred even with so-called targeted therapies, according to a retrospective study.
Among adults diagnosed with non-metastatic invasive breast cancer in 2009 to 2014, 4.2% developed cardiotoxicity. Certain groups were at particularly high risk of cardiotoxicity:
- Trastuzumab (Herceptin): 8.3% vs 2.7% for those not treated with it (HR 2.01, 95% CI 1.72-2.36)
- Anthracyclines: 4.6% vs 4.0% (HR 1.53, 95% CI 1.30-1.80)
- Deyo comorbidity scores 1: 5.6% vs 3.4% for those scoring 0 (HR 1.38, 95% CI 1.15-1.66) and 2-plus: 11.7% vs 3.4% (HR 2.47, 95% CI 1.94-3.15)
- Hypertension: 5.8% vs 3.3% (HR 1.28, 95% CI 1.09-1.51)
- Valve disease: 10.1% vs 4.0% (HR 1.93, 95% CI 1.48-2.51)
Less than half of those treated with trastuzumab (n=4,325) got LVEF monitoring at baseline and every 4 months during treatment, however. "Cardiac monitoring among trastuzumab-treated patients should be a priority among high-risk patients and in the presence of comorbidities or other chemotherapies such as those using anthracyclines," said Mariana Chavez-MacGregor, MD, of the MD Anderson Cancer Center in Houston, and colleagues in JACC: Cardiovascular Imaging.
Individuals younger than age <49 were less likely to develop cardiotoxicity than those ages ≥65. Heart failure was also more frequently identified in those getting cardiac monitoring (10.4% vs 6.5% for peers going without, P<0.001).
"In examining the rates of both cardiac monitoring and cardiotoxicity, we could begin to address the controversial issue of whether cardiac monitoring is warranted in young breast cancer patients," the authors said.
"The number of cancer survivors is expected to increase over time, and we will continue to see patients develop treatment-related cardiotoxicity. Thus, more research, evidence-based guidelines, and tools for prediction of cancer treatment-related cardiotoxicity are needed," according to Chavez-MacGregor's group.
Their study included 16,456 breast cancer patients who were treated within 6 months of diagnosis, as identified from the Truven Health MarketScan database.
Guideline-adherent monitoring was linked to anthracyclines (OR 1.58, 95% CI 1.35-1.87), taxanes (OR 1.63, 95% CI 1.27-2.08), and radiation therapy (OR 1.22, 95% CI 1.08-1.39).
"The U.S. FDA currently recommends LVEF monitoring every 3 months while the patient is taking adjuvant trastuzumab therapy, based on protocols in the clinical trials. These recommendations have been adopted by several co-operative groups and embedded in clinical practice guidelines," stated Chau Dang, MD, of Memorial Sloan Kettering Cancer Center in New York City, and colleagues.
"However, one must ask if there are sufficient data to demonstrate that adherence to cardiovascular monitoring guidelines is associated with better outcomes and if these guidelines are still relevant today," they said in an accompanying editorial, adding that it's unclear whether asymptomatic LVEF drops point to subsequent heart failure in patients with early-stage breast cancer treated with trastuzumab-based therapy.
Trials investigating a change in cardiac monitoring schedules based on patient risk of developing cardiotoxicity should be conducted, Dang's group suggested.
Their own study relied on claims from patients with private insurance, limiting the data's generalizability, they acknowledged. In addition, the researchers couldn't stratify by cancer stage or race and ethnicity.
Chavez-MacGregor disclosed support from the Susan G. Komen Breast Cancer Foundation and relevant relationships with Pfizer and Roche.
Dang disclosed support to her institution from Roche/Genentech and PUMA.
JACC: Cardiovascular Imaging
Source Reference: Henry ML, et al "Cardiotoxicity and cardiac monitoring among chemotherapy-treated breast cancer patients" JACC Cardiovasc Imag 2018; DOI: 10.1016/j.jcmg.2018.06.005.
JACC: Cardiovascular Imaging
Source Reference: Dang CT, et al "Left ventricular ejection fraction monitoring adherence rates: why so low?" JACC Cardiovasc Imag 2018; DOI:10.1016/j.jcmg.2018.02.027.
Read the original article on Medpage Today: Herceptin Tied to Heart Issues in Breast Ca Patients