Venous thromboembolism incidence in radiation oncology: Retrospective trial.

Abstract

e18289 Background: Venous thromboembolism (VTE) prevention in oncology patients during external beam radiation therapy (RT) in outpatient setting is the challenging question. We performed analysis of our own data. The aim of study is the clear assessment of VTE incidence in these patients Methods: In retrospective analysis 5134 patients' medical records were included (2612 with RT and 2522 with chemotherapy). Inclusion criteria were: RT in outpatient setting and chemotherapy in outpatient setting. Exclusion criteria: combined radiochemotherapy, hospitalzation, central venous catheter, palliative treatment. 487 patients were selected for the final analysis and stratified in 3 groups: group I (n = 165) 3D-conformal RT for brain tumors or brain metastasis; group II (n = 158) RT for body tumors (abdominal, retroabdominal, pelvic, chest, breast); group III (n = 164) was control –brain and body tumors on chemotherapy. Mean fraction numbers were 25 (11 - 32), mean total dose – 52 Gy (22 - 66). VTE assessment based on clinical data, ultrasound examination (US) and chest CT. Statistical analysis was performed by OpenEpi, Version 3 software pack. Results: Deep vein thrombosis (DVT) was detected in 10 cases (6.06%) in group I, 4 cases in group II and 4 case in control group. VTE patients has a different tumors (astrocytomas, brain trunk tumors, skull basis cancer, rectal cancer, breast cancer). 3 patients were available for long-term outcomes assessment (12 months after radiation therapy). During 1-year period we haven’t detected thrombosis recurrence. One patient on 11th follow-up month was exposed with repeated course of RT without any complications. The difference between VTE incidence for group I and group III characterized by statistical significance (p = 0.018). Risk difference for these groups was 5% (p < 0.05). Conclusions: Based on study results we suggest that external beam radiation therapy is potentially an independent risk factor for VTE development even in outpatient settings. High degree of clinical suspicion and aggressive diagnostic work-up in case of suspicion is necessary. In our opinion low molecular weight heparins prevention should be considered at least during active radiation therapy.

Venous thromboembolism and radiation therapy: The final radiation‐induced thrombosis study analysis

“…Actually, when comparing the number of VTE events that were reported, VTE incidences upon RT are quite similar between studies and the present cohort. In the retrospective analysis that assessed VTE incidence in RT‐treated patients versus chemotherapy‐treated patients, four cases were reported in the RT group for body tumors, out of 158 patients, thus suggesting a comparable VTE incidence to our study 26 . By contrast, in the post‐hoc analysis of the COMPASS‐CAT trial, the authors reported a higher VTE incidence of about 9.1%, with 33 events in 336 evaluable patients, considering that all patients were treated by chemotherapy and that 25% of patients were metastatic 27,30 .…”

“…18 Moreover, in a retrospective analysis that stratified patients in three groups (i.e., RT for brain tumors, RT for body tumors, chemotherapy-treated brain and body tumors), external beam RT was identified as an independent risk factor for VTE development in outpatient setting, with a risk difference of 5% (p 0.018) in comparison to chemotherapy. 26 Similarly, in a recent sub-analysis of the COMPASS-CAT study, a significant correlation between RT and VTE was described in patients with breast, lung, ovarian or colon cancer (HR 2.47, 95% CI 1.47-4.12, p 0.011). 27 Yet, other studies did not find any specific association between RT and cancer-associated thrombosis.…”

“…In the retrospective analysis that assessed VTE incidence in RT‐treated patients versus chemotherapy‐treated patients, four cases were reported in the RT group for body tumors, out of 158 patients, thus suggesting a comparable VTE incidence to our study. 26 By contrast, in the post‐hoc analysis of the COMPASS‐CAT trial, the authors reported a higher VTE incidence of about 9.1%, with 33 events in 336 evaluable patients, considering that all patients were treated by chemotherapy and that 25% of patients were metastatic. 27 , 30 In this context, it is therefore tempting to speculate that the inclusion of advanced stage of cancers may bias this incidence, given that the presence of distant metastases increases the risk of VTE.…”

“…In a small series, Guy and collaborators reported a plausible relationship between brachytherapy and the occurrence of VTE in patients with gynecological cancers 18 . Moreover, in a retrospective analysis that stratified patients in three groups (i.e., RT for brain tumors, RT for body tumors, chemotherapy‐treated brain and body tumors), external beam RT was identified as an independent risk factor for VTE development in outpatient setting, with a risk difference of 5% ( p 0.018 ) in comparison to chemotherapy 26 . Similarly, in a recent sub‐analysis of the COMPASS‐CAT study, a significant correlation between RT and VTE was described in patients with breast, lung, ovarian or colon cancer (HR 2.47, 95% CI 1.47–4.12, p 0.011 ) 27 .…”

Association between Radiotherapy and Risk of Cancer Associated Venous Thromboembolism: A Sub-Analysis of the COMPASS—CAT Study

“…A retrospective analysis of outpatient cancer patients, who were treated with RT or chemotherapy, was conducted to assess the impact of RT on the risk of CAT. In this study, patients were divided into three groups including 165 treated with 3-Dimensional conformal RT for brain tumors or brain metastasis (10 patients-around 6% had VTE), 158 treated with RT for body tumors (four patients had VTE), and a third control group including 164 patients treated with chemotherapy (four patients had VTE) [ 15 ]. External beam RT was associated with a significantly increased risk of VTE compared to chemotherapy, with a risk difference of 5% ( p = 0.018).…”