HER2-directed therapy is associated with an increased rate of cardiologic emergency department visits in real-world breast cancer patients.

BACKGROUND

Subtype is a key prognostic factor for breast cancer. In HER2-positive disease, HER2-directed therapies have improved outcomes, though they can cause cardiac side effects, potentially leading to emergency department (ED) visits.

OBJECTIVES

To assesses reasons for ED presentations in breast cancer patients, highlighting subtype-specific differences in reason for presentation, 3-month mortality (3 MM) and the possible association of cardiologic visits with HER2-directed therapy.

METHODS

In this retrospective study, visits by breast cancer patients at an Austrian tertiary care ED were analysed. Subtype frequency rates and subtype-specific 3 MM rates were calculated using Chi-Square tests (separately for early and advanced disease). A possible association between HER2-directed therapies and cardiologic ED visits was investigated using a Fisher's exact test and a multinomial logistic regression controlling for age.

RESULTS

There was a total of 463 ED visits among 322 patients between August 2016 and December 2019. Subtype distribution was as follows: 42% (n = 135) luminal B-like/HER2-negative, 23% (n = 74) triple negative, 16% (n = 50) luminal B-like/HER2-positive, 10% (n = 33) luminal A-like and 9% (n = 30) HER2-positive (non-luminal). In patients with advanced BC, subtype was significantly associated with 3 MM (p = 0.006), with the highest mortality rate observed in TNBC (54%). Active HER2-directed therapy (n = 70) was associated with increased cardiologic ED visits (OR = 4.536 [95%CI, 1.850- 11.125]).

CONCLUSIONS

BC subtype influenced the frequency of ED visits and patient survival. HER2-directed therapy was associated with an increased risk for cardiologic ED visits among real-world cancer patients, emphasizing the need for tailored cardio-oncologic care strategies to optimize tolerability and reduce healthcare burdens.