Carboplatin is widely used to treat lung cancer in the United States as an alternative to cisplatin. Several studies have demonstrated that cisplatin-based regimen is associated with a high frequency of thromboembolic complications. However, there has been limited investigation directly comparing the risk of thromboembolic events (TEEs) between cisplatin- and carboplatin-treated patients with lung cancer.

All lung cancer patients treated with cisplatin or carboplatin at Wilmot Cancer Center, University of Rochester between 2011 and 2014 were included. Patient characteristics including exposure (cisplatin vs. carboplatin) and outcome (TEEs between the time of the first dose of cisplatin or carboplatin and 4 weeks after the last dose) were collected by reviewing electronic medical records. A Fisher's exact test was used to compare the proportion of incident TEEs between cisplatin and carboplatin groups. The risk of TEE associated with carboplatin compared to cisplatin was assessed using multiple logistic regression.

Among 415 subjects, 317 patients (76.4%) received carboplatin and 98 (23.6%) patients received cisplatin. In the carboplatin group, 10.9% (33/302) of evaluable patients developed treatment-related TEEs vs. 14.7% (14/95) in the cisplatin group. There was no significant difference in the risk of developing TEEs between the two groups (P = 0.32). However, 15.2% of carboplatin-related TEEs were arterial thromboses compared to none in the cisplatin group.

The incidence of carboplatin-related TEEs was high in lung cancer patients without significant difference in the risk of developing TEEs between cisplatin and carboplatin groups. Potential use of prophylactic anticoagulation in all platinum-treated patients should be further investigated.