NEW YORK (Reuters Health) - Patients who suffer a first-time, unprovoked venous thromboembolism (VTE) have a cancer risk of less than 4% in the following year, a new epidemiological study suggests.
VTE can be the first manifestation of cancer, researchers note in an abstract presented on December 4 at the American Society of Hematology's annual meeting in San Diego, California.
Two trials have shown that limited cancer screening after a first VTE could become the new standard, the team adds, but the incidence of occult malignancy in those trials was lower than expected (4.5%).
"The low rate of occult cancer made us think that patients included in the trials were too much selected," lead author Dr. Aurelien Delluc of Brest University Hospital in Brest, France, told Reuters Health by email. "However, our results support the low rate of occult malignancy in patients with unprovoked VTE."
She added, "In most patients with unprovoked VTE, limited cancer screening is safe, especially in non-smokers."
Dr. Delluc and her colleagues examined all of the patients diagnosed with VTE in the district of Brest over the course of a year. They found 257 patients with a first-time unprovoked event. After a year of follow-up, nine had developed cancer, giving an incidence rate of 3.68%.
The rate was slightly higher (3.78%) among patients with a first unprovoked VTE and no prior history of provoked VTE.
Smokers had a significantly higher incidence of occult cancers than did non-smokers (8.05% vs. 0.81%, p=0.004). On multivariate analysis, smoking was independently associated with cancer risk (hazard ratio, 11.8).