High risk of thrombosis in patients with advanced lung cancer harboring rearrangements in ROS1

Based on the high incidence of thromboembolic events (TEs) observed in lung adenocarcinomas with ALK translocations and taking into account the biological proximity of ROS1 and ALK, we conducted a retrospective analysis of patients with advanced lung carcinoma carrying rearrangements in ROS1 from 23 centres in Spain and one centre in Portugal. The main objective of the study was to analyse the incidence of TE in this population, looking for predictive risk factors, and its impact on overall survival. A total of 58 patients were included. The incidence of TEs throughout the disease was 46.6% (n = 27) with a median follow-up of 19 months (range: 1–78 months) and a median overall survival of 52 months in the total population and 50 months for the patients presenting TEs, with a hazards ratio of 1.12 (95% confidence interval: 0.47–2.65) p = 0.78. The majority of the events were venous (n = 24; 89%) and occurred in the ambulatory setting (n = 18; 67%). Almost half of the patients (n = 13; 48%) presented the TE in the peri-diagnostic period. The high incidence of thrombosis, especially during the cancer diagnosis process, requires special attention from a clinician. Despite the limitations of such a small descriptive study, its results are in accordance with previously reported data. It would be important to design prospective studies of antithrombotic prophylaxis in this population because of their possible impact in reducing the risk of TEs.