Cancer-associated thrombosis (CAT) is the most frequent cause of death in patients with cancer after cancer itself . In addition, it is the most common cause of chemotherapy-related death and is associated with long-term physical and psychological sequelae .
In the last 20 years, thrombosis prophylaxis in cancer patients improved significantly. Clinicians learned the most relevant risk factors for cancer patients and accessed validated risk assessment models, randomized trials, and guidelines.
Recent clinical guidelines have recognized the importance of identifying patients receiving ambulant systemic anticancer therapy at risk of CAT who should be considered for primary thromboprophylaxis [3-5].
Despite these developments, adherence to CAT-specific clinical guidelines remains poor, and most systemic anticancer therapy-induced CAT cases presenting to clinical services have not received thromboprophylaxis .
Several reports have revealed treatment patterns for CAT that are not consistent with contemporary guideline recommendations, including both underuse and inappropriate choice of anticoagulant agents [7, 8]. In addition, oncologists seem to be less aware of guidelines and risk scores .
During her presentation at the 10th ICTHIC, Prof. Pabinger said: “It is like playing bubble soccer; the thrombosis community is in one bubble, and the oncologist is in another one. We don’t understand each other.”
Previous qualitative data suggest that patients embarking on systemic anticancer therapy receive little information regarding the risks of CAT or red flag symptoms that would warrant urgent medical attention. Consequently, many cases of CAT have a delayed presentation, with an increased risk of fatal pulmonary embolism (PE), extensive deep vein thrombosis (DVT), post-thrombotic syndrome, and long-term psychological distress .
The EMPOWER study
In 2017, the charity Anticoagulation UK (formerly Anticoagulation Europe) developed a patient information video called “Blood clots, cancer and you: what you need to know.” The EMPOWER study evaluated the impact of the video on patient care and healthcare resource usage .
Specifically, the study aimed to evaluate the impact of the video as evidenced by:
- Time taken for patients to seek medical attention from the development of symptoms suggestive of CAT.
- Use of radiology resources.
- Patient awareness of CAT-related symptoms.
- Views of oncology nurses regarding the need for, and utility of, the video in the clinical workplace .
The evaluation of the video occurred within a UK regional cancer service, serving 7000 new patients with cancer per annum from across a diverse mix of urban/rural, socioeconomic, ethnic, and cultural backgrounds .
All patients planned for systemic anticancer therapy attended a patient information session that chemotherapy specialist nurses delivered. In addition, patients received an individualized information/consent session comprising both written and verbal information. The video was incorporated as part of the information session and the standard written and verbal information .
Impact of the video on the time to seek medical attention
The primary aim of the EMPOWER study was to assess the impact of the video on the time taken for patients to seek medical attention from the development of symptoms of VTE .
Data were collected on 50 sequential patients with systemic anticancer therapy-associated VTE before the introduction of the video and then repeated 6 months after the video was embedded in clinical practice .
Before the introduction of the video, the time taken for patients to seek medical attention from the development of symptoms ranged from 1 to 21 days (median: 9 days; mode: 10; mean: 8.9) . After 6 months, the video was embedded into clinical practice, the time to presentation with symptomatic systemic anticancer therapy-associated VTE ranged from 12 hours to 14 days (median: 2 days; mode: 2; mean: 2.9) .
This suggests the video was associated with a 0.67 relative risk reduction (HR: 0.33, 95% CI: 4.50–7.47; p<0.0001) for the time to presentation of symptoms from 8.9 to 2.9 days .
Impact of the video on radiology usage
The study also evaluated whether the introduction of the video impacted radiology resource usage, with particular focus on increases in the number of negative scans. Increased symptom vigilance might generate a rise in radiology requests with subsequent health economic implications .
During the first 3-month cohort, 36% of investigations were positive for VTE . After 6 months, the video was embedded into practice, 32.4% of investigations were positive for VTE .
These results indicate that the introduction of the video was associated with a reduction in positive scan requests. Although these data also mean a slight increase in requests for negative scans, this increase can be seen as an acceptable trade-off in the face of a 67% reduction in time to investigation and treatment of VTE .
Impact of the video on CAT awareness
Questions were devised to explore how much patients who were due to embark on systemic anticancer therapy understood VTE and the associated risks with cancer treatments .
Only 6% of patients who didn’t see the video identified chemotherapy as a risk factor. Only 2% and 4% of them considered VTE to be neither a common consequence of systemic anticancer therapy nor a serious side effect, respectively .
On the other hand, systemic anticancer therapy was recognized as a risk factor for CAT in 60% of patients who saw the video, with 80% identifying it as one of the most serious complications .
In addition, the video increased the percentage of patients able to identify signs and symptoms of DVT and PE. A total of 33% and 43% of patients who did not see the video could not identify a single associated sign or symptom of DVT and PE, respectively. In comparison, only 3% and 4% of patients who saw the video could not describe any features of DVT and PE, respectively .
Impact of the video on nurses’ awareness
Lastly, the study highlighted a considerable knowledge gap around CAT and an education need for nurses. Interestingly, embedding the video into practice improved nurses’ self-reported knowledge of CAT and led to changes in their practice. It also created a desire for ongoing education on the topic .
This study showed that a simple, easy-to-implement tool like a video highlighting the risks of VTE from systemic anticancer therapy could help to reduce the time taken for patients to seek medical attention on the development of CAT symptoms. In addition, the video helped increase healthcare professionals’ CAT knowledge and highlighted the importance of sharing complications of systemic anticancer therapy when delivering prechemotherapy education.
This article has been sponsored by an unrestricted educational grant from LEO Pharma A/S.
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- Farge D, Frere C, Connors JM, et al. 2019 international clinical practice guidelines for the treatment and prophylaxis of venous thromboembolism in patients with cancer. Lancet Oncol. 2019;10:566-581.
- Mahé I, Puget H, Buzzi JC, et al. adherence to treatment guidelines for cancer-associated thrombosis: a French hospital-based cohort study. Support Care Cancer. 2016;24(8):3369-3377.
- Matzdorff A, Ledig B, Stuecker M, Riess H. Practice patterns for prophylaxis and treatment of venous thromboembolism in German cancer patients. Oncol Res Treat. 2016;39(4):194-201.
- Baddeley E, Torrens-Burton A, Newman A, et al. A mixed-methods study to evaluate a patient-designed tool to reduce harm from cancer-associated thrombosis: The EMPOWER study. Res Pract Thromb Haemost. 2021;5(5):e12545. Published 2021 Aug 11.
- Mahé I, Puget H, Buzzi JC, et al. Adherence to treatment guidelines for cancer-associated thrombosis: a French hospital-based cohort study. Support Care Cancer. 2016;24(8):3369-3377.
- Matzdorff A, Ledig B, Stuecker M, Riess H. Practice Patterns for Prophylaxis and Treatment of Venous Thromboembolism in German Cancer Patients. Oncol Res Treat. 2016;39(4):194-201.
- Martin KA, Molsberry R, Khan SS, Linder JA, Cameron KA, Benson A 3rd. Preventing venous thromboembolism in oncology practice: Use of risk assessment and anticoagulation prophylaxis. Res Pract Thromb Haemost. 2020;4(7):1211-1215