A 58-year-old man with newly diagnosed pancreatic cancer presents with acute onset of bleeding from multiple sites: hemoptysis, hematuria, and severe epistaxis. Laboratory investigations reveal: platelet count 45,000/µL, PT 18 sec (normal 12–14), aPTT 48 sec (normal 25–35), fibrinogen 95 mg/dL (normal 200–400), D-dimer 8.5 µg/mL (normal <0.5). Peripheral blood smear shows schistocytes. What is the primary mechanism of thrombocytopenia in this patient?