By Katherine Kozlowski, Medical Author and Contributor to Vein News and www.VeinsVeinsVeins. com
The prevalence of venous thromboembolism (VTE) in patients undergoing chemotherapy has not been fully elucidated. Kakkos et al did a prospective analysis to investigate the frequency of deep vein thromboses (DVTs) and symptomatic VTEs in cancer patients undergoing chemotherapy.
Who was included in the study?
231 patients (164M:67F) were studied.
36 patients had pancreatic cancer.
136 patients had lung cancer.
32 patients had ovarian cancer.
27 patients had prostate cancer.
83.1% (N=192) of patients were undergoing their first round of chemotherapy, and 39 patients were undergoing additional rounds of chemotherapy.
How were the patients analyzed?
All of the patients included in the study followed up for 3-6 months, and the frequency of VTE was assessed.
What are the results of the study?
17 patients (10.3%) had venous thromboembolism (10 symptomatic, 7 asymptomatic diagnosed via ultrasound)
Which types of cancer had the highest rates of VTE?
16% (4 of 25) of pancreatic cancer patients had VTE with follow-up.
11.5% (3 of 26) of ovarian cancer patients had VTE with follow-up.
10.6% (10 of 94) of lung cancer patients had VTE with follow-up.
However, there was no statistically significant difference in VTE rates among cancer types (p=.36). This means that the difference in results among types of cancer may be due to natural variability in the sample, not necessarily due to the type of cancer.
What about cancer that has metastasized (spread)?
In patients with metastases, VTE occurred more frequently.
15.3% (13 of 85) patients with metastases had VTE compared with 5% (4 of 80) patients without metastasis (p=.03).
In the subgroup of patients receiving their first round of chemotherapy, VTE occurred more frequently in patient with metastases. 13 of 84 (15.5%) in this group were diagnosed with VTE. In the same group of patients receiving their first round of chemotherapy, but without metastases, 2 of 53 (3.8%) were diagnosed with VTE (p=.033).
In patients with types of cancer that had the highest rate of VTE (pancreatic, lung, and ovarian), patients with metastatic disease were diagnosed with VTE at 19.5% compared with 4.0% in patients with the same types of cancer without metastases (p=.015).
What can we conclude from the results of this study?
Patients with disseminated forms of pancreatic, lung, and ovarian cancer receiving their first round of chemotherapy had the highest occurrence of venous thromboembolism.
Patients with malignant forms of cancer are likely to be in a prothrombotic state, thus leading to a higher incidence of venous thromboembolism in said patients undergoing chemotherapy. Being in a prothrombotic state means that the blood is more likely to coagulate and leads to an increased risk of developing blood clots.
Reference: Kakkos S., Arnaoutoglou E., Tsolakis I. et al. Frequency and predictors of chemotherapy-associated venous thromboembolism: the prospective PREVENT study. Int Angiol 2020; 39(2): 112-117.