Venous Thromboembolism Risk in Patients With Locoregional Urothelial Tract Tumors

Thromboembolism in Muscle-Invasive Bladder Cancer. A Population-based Nationwide Study

BACKGROUND

Routine VTE prophylaxis within 30 days of radical cystectomy (RC) for urinary bladder cancer (UBC) is used to protect from venous thromboembolism (VTE). However, randomized studies and nationwide population-based studies are lacking.

OBJECTIVE

To study VTE and risk factors for VTE in muscle-invasive UBC in a nationwide population-based series, with a focus on the association with RC with and without chemotherapy.

MATERIALS AND METHODS

We studied all patients with clinical stage T2-T4 UBC diagnosed 1997 to 2014 in the Bladder Cancer Data Base Sweden (BladderBaSe). Previous VTE events and risk factors for VTE were registered from 1987. Cox regression analyses and Kaplan-Meier curves were performed to study risk factors for VTE and cumulative incidence of VTE.

RESULTS

In 9720 patients (71%males) with a median age of 74 years 546 (5.6%) had VTE after diagnosis. In Cox analyses controlling for patient's and tumour characteristics, and risk factors for VTE, VTE after diagnosis and first treatment date were associated with chemotherapy with or without RC. Cumulative incidence of VTE increased during 24 months after diagnosis and first treatment date. VTE were less common in patients with previous cardiovascular disease.

CONCLUSIONS

VTE was commonly observed after 30 days from diagnosis and from first treatment date in patients with T2-T4 UBC, particularly after chemotherapy. The findings suggest that long-term intervention studies of benefit and possible harms of VTE prophylaxis after UBC should be undertaken.

Chemotherapy regimen is associated with venous thromboembolism risk in patients with urothelial tract cancer

OBJECTIVE

To assess the association of venous thromboembolism (VTE) with different chemotherapy regimens in patients with urothelial tract cancer.

PATIENTS AND METHODS

We identified patients aged ≥66 years, diagnosed with urothelial tract cancer in the period 1998 to 2011 in the Surveillance, Epidemiology, and End Results (SEER) Medicare-linked database. The chemotherapy regimens analysed were gemcitabine/cisplatin (GC), methotrexate/vinblastine/doxorubicin/cisplatin (MVAC), or gemcitabine/carboplatin (CarboG). Propensity scores for treatment regimen based on comorbidities, tumour characteristics, age, and year of diagnosis were calculated. VTE rates within 120 days of chemotherapy initiation were calculated. VTE risk stratified by chemotherapy regimen was modelled using multivariable logistic regression, adjusting for treatment propensity scores and additional demographic characteristics. Overall survival stratified by VTE and chemotherapy regimen was estimated using Kaplan-Meier methods and the log-rank test.

RESULTS

Of 5594 identified patients, a VTE occurred in 13.0%. The VTE rates within 120 days of chemotherapy initiation were 15.3% for GC, 8.7% for MVAC, and 12.0% for CarboG. On multivariable analysis, MVAC (odds ratio [OR] 0.60, 95% confidence interval [CI] 0.39-0.94) and CarboG (OR 0.71, 95% CI: 0.59-0.85) were associated with lower VTE risk compared with GC. VTE was associated with worse overall survival (P < 0.001).

CONCLUSIONS

Compared with GC, MVAC and CarboG were associated with a lower rate of VTE. This finding suggests that gemcitabine may add to the increased thrombosis risk from cisplatin. Additionally, patients with a VTE had worse survival outcomes than those without a VTE. Analysis of the risk of blood clots with different chemotherapy regimens in patients with urothelial tract cancer showed that GC was associated with the highest rate. We also found that blood clots were associated with worse patient outcomes.