Longitudinal association of hemostatic factors with risk for cancers of the breast, colorectum, and lung among postmenopausal women.

The aim of this study was to examine whether hemostatic factors associated with coagulation and inflammation pathways are associated with cancer risk in postmenopausal women. We used data from the Women's Health Initiative study to examine the association of plasma fibrinogen levels, factor VII antigen activity, and factor VII concentration measured at baseline and during follow-up with the risk for cancers of the breast, colorectum, and lung. Among 5287 women who were followed up for a median of 11.4 years, 275 cases of breast cancer, 102 cases of colorectal cancer, and 90 cases of lung cancer were identified. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for the association of hemostatic factors with each cancer. Hemostatic factors were not associated with breast cancer in either baseline or longitudinal analyses. Baseline hemostatic factors showed weak associations with colorectal cancer; however, no association was seen in longitudinal analyses. Fibrinogen was positively associated with lung cancer in both baseline and longitudinal analyses; the association was seen only in never and former smokers, not in current smokers. We found no evidence of an association between hemostatic factors and breast or colorectal cancer in postmenopausal women. The positive association of fibrinogen levels with lung cancer requires confirmation in larger studies.