Objective:
To study the
incidence and
risk factors of the corrected QT (QTc) prolongation in
breast cancer patients treated with
anthracyclines.
Methods:
From July 2017 to January 2019, 279
female breast cancer patients who underwent 4 cycles of
anthracycline treatment in Department of
Breast Surgery of the People′s
Hospital of Shanxi Medical
University were enrolled in the study. The
ECG of all
patients before
treatment showed sinus rhythm and QTc<440 ms. The most common electrocardiographic
abnormalities after treatment were the changes of QTc. There were 78 cases with prolonged QTc (≥440 ms, QTc prolongation group) and 201 cases with normal QTc (<440 ms, non-prolongation group). The
risk factors of QTc prolongation were analyzed by univariate and multivariate
logistic regression.
Cardiac toxicity was evaluated according to clinical symptoms and
ECG results during
treatment.
Results:
The common
ECG abnormalities after treatment were 78 cases of QTc prolongation (28.0%), 22 cases of ST-T changes (7.9%), and 18 cases of sinus
bradycardia (6.5%). Univariate
analysis showed that there were significant differences in
administration of
anthracyclines(contained
epirubicin in 48 and 73 cases, pirubicin in 10 and 33 cases,
doxorubicin in 4 and 12 cases, liposomal doxorubincin in 16 and 83 cases,χ 2=15.54, P<0.01),
dexrazoxane use (χ 2=5.43, P=0.02),
coronary heart disease (χ 2=4.56, P=0.03),
obesity or
overweight (χ 2=4.51, P=0.03) between two groups. Multivariate
logistic regression analysis showed that the use of different types of
anthracyclines ( OR=1.42, 95 %CI 1.37-1.48, P=0.02) and
overweight/
obesity ( OR=1.23, 95 %CI 1.16-1.30, P=0.04) were independent
risk facors of QTc prolongation. The liposomal
doxorubicin in
anthracyclines resulted in a minimum
incidence of the QTc prolongation (16.2%, 16/99), while that of
epirubicin was up to 39.7% (48/121). Preventive use of
dexrazoxane reduced the
incidence of the QTc prolongation to 11.4% (4/35). The
incidence of the QTc prolongation in
breast cancer with
coronary heart disease or
overweight/
obesity was relatively high, which was 4/6 and 34.4%(42/122), respectively. No cardiotoxic symptoms such as
chest pain, palpitation and
shortness of breath occurred during the
treatment, and no fatal
arrhythmia such as
ventricular tachycardia and
ventricular fibrillation was observed in
electrocardiogram.
Conclusion:
Although the
incidence of the QTc prolongation in
breast cancer patients treated with
anthracyclines is high, there is no serious
cardiotoxicity such as fatal
arrhythmia.
Breast cancer patients with
coronary heart disease or
overweight/
obesity are more likely to have the QTc prolongation. Preventive use of dextrazoxan or the selection of liposomal
doxorubicin can reduce the
incidence of the QTc prolongation.