Venous thromboembolism (VTE) is a frequent complication in patients with lung cancer.  It can be fatal. This study aimed to develop and validate a risk score for early prediction of VTE in these patients.

Four hundred and one patients with lung cancer from three pulmonary departments hospitalized between January 2011 and December 2021 were retrospectively assessed. The population was divided into two groups: development group (182 patients) and validation group (199 patients). In the development group, the risk score system was developed, via univariate and multivariate analysis, based on demographic and clinicopathological variables and then validated in the validation group.

The incidence of VTE was 26.8%, 25.8%, and 27.6% in all patients, in the development and validation groups, respectively. Hemoglobin level <10g/l, metastasis, histological type non-small cell carcinoma difficult to type, and active smoking were the items of the risk score system. This latter allowed proper stratification of patients with either high or low risk of VTE in the development group (c statistic =0.703). The patients in the development group were classified into 3 risk groups: low risk (scores 0-1), moderate risk (scores 2-3), and high risk (scores 4-5).  When validated in the validation group, there was a moderate loss of predictive power of the score, but the categorization of the patients by the score remained clinically useful.
This risk score requires prospective validation studies on a nationwide scale in order to use it as a valid tool for the prevention of VTE in lung cancer.