PO-10 - Lung cancer with tumour thrombosis: a poor prognosticator

Literature has reported tumour thrombus along the inferior vena cava as a result of underlying renal cell carcinoma (RCC) or along the portal vein from hepatocellular carcinoma (HCC). However, tumor thrombus is a rather uncommon complication of a metastatic tumour deposit in the superior vena cava in lung adenocarcinoma. Detection of tumour thrombus at the time of cancer diagnosis is a significant predictor of morbidity and mortality. Unlike RCC with vena caval extension where surgical resection provides meaningful long term survival, lung adenocarcinoma with vena cava involvement has a very dismal outcome.

We discuss a rare case of a tumor thrombus secondary to a lung malignancy, the differentiation between a tumor and a bland thrombus and the rationale behind treatment of the tumor thrombus.

We report a case of a 77 year-old male who presented with right sided chest pain and was subsequently found to have a right upper lobe lung mass. The lung biopsy confirmed the diagnosis of a adenocarcinoma. Computed tomography scans for staging detected focal destruction of the right second rib and tumour thombus in the superior vena cava with partial extension to the left brachiocephalic vein. No other metastases were noted. The patient received chemotherapy with paclitaxel and carboplatin for the stage IV lung adenocarcinoma. He was also started on subcutaneous heparin for tumour thrombus. However, the patient died of pneumonia eight weeks later.

A review of literature did not show effective treatment for tumour thrombus. Pathogenesis of tumour thrombus is unclear, however several theories have been postulated for the formation of tumour thrombus; it could result from the direct invasion by tumour resulting in epithelial damage or because of formation of tumour thrombus on top of bland thrombosis, related to cancer hypercoagulability. Irrespective of etiology, tumour thrombus itself being a thrombophilic condition should be treated with anticoagulation, however the mainstay of treatment is treating the underlying cancer.

Adenocarcinoma of the lung with tumour thrombus significantly alter prognosis although the individual's Karnofsky performance scale and response to treatment play a major role in determining life expectancy. Further studies need to be done to address the preferred modality and duration of anticoagulation for tumor thrombus.