Fibrinogen kinetics in patients with neoplastic disease.

Fibrinogen half-life was determined in 30 patients with active or inactive malignancies by monitoring survival of administered 125I-labeled autologous fibrinogen. Six patients had no evidence of active disease and served as controls having fibrinogen levels and half-lives within the normal range reported in the literature. Twenty-six studies were conducted on 24 patients with various active malignancies. Significantly shorter fibrinogen half-lives were found in patients with active malignancies. The fractional catabolic rates calculated from both the plasma data and the urinary isotope excretion were significantly increased in patients in this group. Although there is some evidence that exposure to intensive chemotherapy may further shorten fibrinogen survival, there is no significant difference between treated and untreated or responding and nonresponding groups. The major determinant of fibrinogen survival appears to be the presence of active malignant disease, in addition to the specific type of malignancy involved.