The impact of prognostic markers on disease-free and overall survival reflects their relative role in tumour biology. Breast cancer and colon carcinoma can be taken as examples to demonstrate the clinical and biological relevance of 'new markers' of neoplastic disease. In breast cancer, receptor-bound urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 seem to play an important role in the dissolution of the surrounding tissue and the formation of tumour stroma. These processes are prerequisites for invasion and metastasis. The study of 'classical' and 'new' prognostic factors showed that uPA and PAI-1 content of breast cancer tissue are strong and independent prognostic factors. Also in colorectal cancer the prognostic relevance of plasminogen activators and inhibitors was analysed. In particular, low tissue plasminogen activator (tPA) levels, as antigen or as activity, high uPA: tPA antigen ratio in corresponding normal mucosa, high levels of uPA-related antigen and activity and of PAI-2 antigen in neoplastic tissue, and high uPA (neoplastic mucosa): tPA (normal mucosa) ratio, were all parameters associated with a poor overall survival. In conclusion, all these observations show the clinical importance of plasminogen activators and inhibitors at tissue levels with respect to cancer development and survival of patients affected by breast carcinoma or colorectal neoplasia. These new prognostic markers will also permit a better patient selection for a possible adjuvant treatment.