Hypercoagulable State in Patients with Advanced Gastrointestinal Cancer: Evidence for an Acquired Resistance to Activated Protein C

Aims and background

Thromboembolic complications are common in patients with cancer and represent the second cause of death in patients with overt malignant disease. The aim of this study was to investigate the activated protein C pathway in cancer.

Methods

We studied the coagulation cascade, natural clotting inhibitors, fibrinolytic proteins and resistance to activated protein C in 20 patients with advanced gastrointestinal cancer and 84 volunteers by measuring PT, APTT, fibrinogen, AT III, PC, PS, APC resistance, fibrinolytic system (PLG, ANPL, PAI-1 and t-PA) and activation peptides (D-Dimers, prothrombin 0 fragment 1+2/F1+2).

Results

Laboratory tests confirmed coagulation abnormalities in cancer patients. Fibrinogen, D-Dimers and F1+2 were increased, while t-PA activity was significantly lower than that of controls. APC resistance was higher in cancer patients compared to the control group (55% vs 2%; P < 0.0001). Excess thrombin generation was manifested by increased F1+2 plasma levels in APC-resistant cancer patients. Genetic analyses showed that only one patient with a poor response to APC carried a factor V R506Q mutation in exon 10.

Conclusions

Our findings show a high prevalence of APC resistance in cancer, compatible with an acquired defect in the APC pathway.

Analysis of Interleukin-2/Interleukin-2 Receptor System in Advanced Non-Small-Cell Lung Cancer

Aims and background

The purpose of the study was to investigate the IL-2/IL-2 receptor system in patients with advanced non-small-cell lung cancer (NSCLC).

Patients and methods

Sera from 40 subjects and 80 patients with stage III and IV NSCLC were assayed for soluble interleukin-2 receptor (sIL-2R) and interleukin-2 (IL-2) by the enzyme-linked immunosorbent assay. Circulating CD25+ cells were analyzed by flow cytoflorimetry. The data were related to clinical status by comparing the levels of slL-2R and IL-2 at diagnosis and during the treatment.

Results

The mean slL-2R concentrations of the NSCLC patients were significantly higher than the control population (P=0.0001); the patients with metastatic disease had significantly higher levels than those with locally advanced disease (P=0.02). No correlation was seen between circulating CD25+ cells and slL-2R levels. Disease progression was associated with an increase in slL-2R levels and a decline in IL-2; the sIL-2R/IL-2 ratio showed a gradual increase with tumor progression.

Conclusions

Our study demonstrates in a large series of patients that in advanced NSCLC there is an imbalance of the IL-2/IL-2 receptor system. Furthermore, circulating slL-2R levels and the sIL-2R/IL-2 ratio may be useful as markers of disease activity and treatment response, suggesting a potential prognostic value.