Atrial fibrillation was changed into sinus bradycardia in a ROS1-positive advanced lung adenocarcinoma patient who achieved durable response to Crizotinib: A case report and literature review.

RATIONAL: The c-ros oncogene 1 receptor tyrosine kinase (ROS1)-rearrangements represent a new and rare genetic subtype of non-small-cell lung cancer. In recent years, the use of crizotinib in ROS1-rearranged lung cancer exhibits significant clinical efficacy. Crizotinib is generally well tolerated and the most frequent adverse events include visual disorders, gastrointestinal disturbances, cardiac, and endocrine abnormalities. From a cardiac perspective, crizotinib is associated with 2 main cardiac effects, QT interval prolongation and bradycardia.

PATIENT CONCERNS AND DIAGNOSES: We reported a case of a 67-year-old man with ROS1-rearranged advanced lung adenocarcinoma.

INTERVENTIONS: Crizotinib was initiated as first-line treatment, combined with whole brain radiation therapy.

OUTCOMES: Interestingly, after treatment of crizotinib, the patient suffered a transient QTc interval prolongation and his persistent atrial fibrillation was changed into sinus bradycardia. Only 22 days after crizotinib treatment, the patient's tumor achieved a partial response. So far the patient has taken crizotinib for >19 months with no evidence of disease progression.

LESSONS: The present study demonstrates dramatic benefit of crizotinib for patients with ROS1 rearrangement. Besides, we should caution the cardiac effects caused by crizotinb and our case provides evidence that crizotinib may be safe for patients with atrial fibrillation under close monitoring.