Several studies showed that venous thrombosis can be the first clinical manifestation of an occult neoplasm. For this reason, numerous researchers studied how and when to screen for occult cancer in patients presenting with unprovoked venous thromboembolism. The association between cancer and arterial thrombosis is less well described. Some studies reported that patients with malignant neoplasms have an increased risk of developing arterial thrombosis (such as ischemic stroke) compared to non-oncological patients. However, it is still unknown whether the occurrence of arterial thrombosis can be associated with the presence of an occult neoplasm.
During the ICTHIC congress, a group of American researchers from the Weill Cornell university presented the results of a study performed using a large epidemiological registry (the Surveillance Epidemiology and End Results-Medicare linked database), which incorporated approximately 28% of all oncological patients of the United States. This study included 108,797 patients aged more than 66 years with a first diagnosis of lung cancer (74%), pancreatic cancer (17%) or stomach cancer (9%) between 2004 and 2013. Non-oncological patients, matched by age, sex, ethnicity, geographic region and co-morbidities, constituted the control group.
The authors evaluated the incidence of arterial thrombotic events in the year before cancer diagnosis. The incidence of arterial thrombotic events in cancer patients was similar to controls from 360 to 241 days before cancer diagnosis, but progressively increased near the date of cancer diagnosis, reaching the peak in the 30 days before. In fact, in the month before cancer diagnosis, 1177 (1.08%) arterial thrombosis have been reported, vs 0.11% in controls, corresponding to an odds ratio of 9.59 (95% CI, 7.96-11.54). Among the arterial thrombotic events, myocardial infarction (1.50%) was more common than ischemic stroke (1.14%) in the year before cancer diagnosis.
The results of this study need to be confirmed in further studies, but they interestingly suggest to pay attention to the possible concomitant presence of an occult neoplasm (at least lung, pancreas and stomach cancers) in patients presenting with a major arterial event. This association can likely be explained by the presence of common risk factors (e.g. cigarette smoking for lung cancer), but the temporal closeness between the two diagnoses suggests that cancer has a prothrombotic precipitating effect in patients already predisposed to atherothrombosis.
Navi BB, et al. Arterial thromboembolism risk before a diagnosis of lung, pancreas, or gastric cancer. Thromb Res 2018(164):S179,OC-02