Advanced-stage bladder cancer, other comorbidities confer risk for VTE

All patients with bladder cancer had an increased incidence of venous thromboembolism compared with the general population, but those with regional or metastatic disease were at a significantly higher risk for venous thromboembolism and death, according to results of a large, population-based study.

Researchers merged data from the California Cancer Registry and the California Patient Discharge Data Set to assess the incidence of VTE in 24,861 patients with newly diagnosed bladder cancer between January 1993 and December 1995 and January 1997 and December 1999.

The researchers chose this time period because outpatient use of heparin was rare and patients who had symptomatic VTE required hospitalization. Cox proportional hazards models determined the risk for VTE and the effects of VTE on patient survival.

One- and two-year incidence of VTE among patients with bladder cancer was 1.6% and 1.9%, respectively. The highest incidence of VTE occurred during the first six months, regardless of age, sex, race, tumor stage or histologic subtype.

VTE incidence increased with advancing age and cancer stage. The highest incidence (15.3%) occurred among those diagnosed with remote-stage bladder cancer during the first six months after diagnosis; those with small cell cancer histology during the first six months had a 10.3% incidence rate.

When compared with those patients with local-stage disease, remote-stage disease was the strongest risk factor for VTE (HR=6.4; 95% CI, 4.8-8.7). In addition, patients who underwent surgery for bladder cancer had a 2.1-fold higher risk for VTE vs. those who did not undergo surgery (95% CI, 1.6-fold to 2.7-fold).

Major surgery, advanced disease stage and an increased number of comorbidities were significant risk factors for the development of VTE. Significant risk factors for mortality were black race, advanced-stage disease, increased comorbidities, nontransitional cell carcinoma histology and the development of VTE.

Sandhu R. Cancer. 2010;doi:10.1002/cncr.25004.