Gefitinib Increases the Incidence of QT Prolongation in Patients with Non-Small Cell Lung Cancer.

Gefitinib (GEF) may increase the risk of corrected QT prolongation (QTc). We aimed to evaluate whether gefitinib increases the risk of corrected QT interval (QTc) prolongation and analyze the associated risk factors.A total of 122 cases of advanced EGFR-mutated non-small cell lung cancer (NSCLC) who received gefitinib therapy from January 2015 to December 2020 were evaluated. The results of at least two resting 12-lead electrocardiogram before and after gefitinib treatment were obtained. The Bazett and Fridericia formulas were used to calculate the QTc interval, and the changes of QTc interval values before and after treatment were evaluated. The correlation between gefitinib and QTc interval prolongation and related risk factors were analyzed.After gefitinib-targeted therapy, 23 patients (18.9%) had a prolonged QTc interval, which increased from a mean of 446 ± 25 ms at baseline to 478 ± 18 ms (P < 0.001). Three of the patients met criteria for Grade 3 QTc prolongation in the common term V5.0 for clinical adverse events. Univariate analysis showed that age (ORR, 1.054; 95% confidence interval [CI], 1.003-1.107; P = 0.038), history of hypertension (ORR, 3.409; 95% CI, 1.334-8.713; P = 0.01), CCB medication history (ORR, 0.259; 95% CI, 0.094-0.712; P = 0.009), history of lung cancer surgery (ORR, 0.231; 95% CI, 0.064-0.829; P = 0.025), and baseline QT interval (ORR, 0.978; 95% CI, 0.964-0.993; P = 0.004) were important predictors of QTc interval prolongation in patients treated with gefitinib. The results of multivariate analysis showed that the history of lung cancer surgery and the baseline QT interval were important factors affecting QTc interval prolongation in patients treated with gefitinib.Gefitinib increases the risk of QTc prolongation in NSCLC patients, which may be more pronounced in patients with advanced age, hypertension, CCB therapy, lung cancer surgery, and a long QT interval at baseline.