P-Selectin - predictor of venous thromboembolism in cancer patients?

P-Selectin (SELP) is an adhesion molecule that belongs to the Selectin family of proteins and is expressed by various cell types, including platelets, endothelial cells, immune cells, and several types of cancer cells. Cancer patients are at high risk for venous thromboembolism (VTE). The high expression of SELP by activated platelets makes it a key component in the pathogenesis of thrombosis in general and cancer-associated thrombosis (CAT) in particular. Laboratory parameters with predictive value for VTE could help stratify patients into high- or low-risk groups. To investigate soluble P-selectin as a risk predictor for VTE in cancer patients, we conducted a retrospective cohort study involving 87 cancer patients who had experienced a VTE episode, comparing them to 80 cancer patients who had not suffered any VTE episodes at the time of enrollment. The main tumor types included malignancies of the breast (n = 12), lung (n = 8), gastrointestinal tract (n = 13), pancreas (n = 4), kidney (n = 9), prostate (n = 7), and brain (n = 5); 14 patients had hematologic malignancies, and 15 had other tumor types, with the group being nearly identical to the control group. In the baseline group, 53% of patients had P-selectin levels above the reference limit (63.1 ng/mL), compared to 21% of patients without a history of VTE (p = 0.044). After six months of follow-up, VTE occurred in 5.4% of patients in the control group with elevated P-selectin levels. In a multivariable analysis, elevated P-selectin (cutoff level: 63.1 ng/mL, 75th percentile of the study population) was identified as a statistically significant risk factor for VTE, even after adjusting for age, sex, surgery, chemotherapy, and radiotherapy (hazard ratio = 1.96, 95% confidence interval: 1.7-2.9, P = 0.04). The cumulative probability of VTE after three months in the control group with elevated P-selectin levels was 9.9% in patients above the 75th percentile and 4.7% in those below it (P = 0.049). Thus, high plasma P-selectin levels independently predict VTE in cancer patients. Measuring P-selectin at cancer diagnosis could help identify patients at an increased risk for VTE.