Comparison of risk prediction scores for cancer-associated thrombosis in ambulatory cancer patients not receiving thromboprophylaxis: A prospective cohort study in a South-East Asian population.

INTRODUCTION

To date, there is limited data regarding the incidence and risk prediction of cancer-associated thrombosis among South-East Asian patients who do not receive thromboprophylaxis.

MATERIALS AND METHODS

This was a prospective cohort study conducted at a tertiary medical center from June 2020 to December 2021 in Thailand. We enrolled cancer patients aged ≥ 18 years, with ECOG score ≤ 1, scheduled to receive the first cycle of chemotherapy. We measured incidence of venous thromboembolism (VTE), all-cause mortality and performance of risk prediction scores.

RESULTS

A total of 457 patients were included with a mean age of 58.18 ± 12.60 years. By the end of 6 months period, VTE had occurred in 30 patients (6.56 %, 95%CI 4.36-9.21). The median time to the first thrombosis was 1.94 months (IQR 0.26-3.19). Cancer associated thrombosis incidence was 14.58 % for Khorana score ≥ 3, 6.67 % for scores 1-2 and 2.13 % for score 0. C-statistics were 0.50 (95%CI 0.41-0.60) for Khorana score cut-off ≥ 2, 0.57 (95%CI 0.49-0.65) for Khorana score ≥ 3, 0.55 (95%CI 0.46-0.65) for PROTECHT score ≥ 3, and 0.57 (95%CI 0.49-0.65) for CONKO score ≥ 3. Classifying cholangiocarcinoma as very-high-risk increased the Khorana score cut-off ≥ 3's C-statistic to 0.62 (95%CI 0.53-0.71).

CONCLUSIONS

A significant proportion of ambulatory South-East Asian cancer patients without thromboprophylaxis developed VTE. Further prospective studies investigating the benefit of thromboprophylaxis in high-risk patients with active cancer are warranted.