Background: Evidence suggests that the fibrinolysis system and peritumoral connective tissue play important roles in tumor spread.
Methods: In this study, the authors evaluated the following parameters in 30 consecutive patients with lung cancer: thrombin-antithrombin complex (TAT), cross-linked fibrin split products D-dimer (DD), plasmin-alpha 2-antiplasmin inhibitor complex (PAP), and two antigens related to connective tissue, the aminoterminal propeptide of type III procollagen (PIIIP) and the 7S domain of type IV collagen (7S-collagen).
Results: Each parameter was increased significantly in the patients with cancer compared with the control subjects. Except for PIIIP, their concentration in blood was elevated to a significantly greater extent in the patients with distant metastases. The PAP concentration correlated well with the plasma concentration of TAT (r = 0.5; P < 0.01) and DD (r = 0.9; P < 0.0001). There was also a strong correlation between the serum concentrations of PIIIP and 7S-collagen (r = 0.7; P < 0.001). In patients with localized disease, DD levels were correlated significantly with those of PIIIP (Spearman rank-order correlation [rs] = 0.6; P < 0.025) and 7S-collagen (rs = 0.6; P < 0.01). In the group with disseminated metastases, there was a significant inverse relationship between serum PAP concentrations and serum concentrations of 7S-collagen (rs = -0.6; P < 0.025).
Conclusions: These results confirm the presence of a subclinical chronic activation of the parameters of intravascular clotting-fibrinolysis and alterations in the extracellular matrix of patients with lung cancer. These parameters may be useful as indicators of the clinical progression of malignant disease, particularly of lung cancer.