RAS P21 PROTEIN-LEVELS IN HUMAN PLASMA FROM PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE (COPD) COMPARED WITH LUNG-CANCER PATIENTS AND HEALTHY CONTROLS

To explore the value of an increase in ras p21 proteins in plasma as a biomarker for the carcinogenic process or for the general disease sta te, we have directly analysed for ras p21 proteins, plasma samples fro m Polish human patients with chronic obstructive pulmonary disease (CO PD). They were compared with appropriate controls and also with the Po lish lung cancer patients previously examined before treatment [D. And erson, J.A. Hughes, A. Cebulska-Wasilewska, E. Nizankowska, B. Graca, Ras oncoproteins in human plasma from lung cancer patients and healthy controls, Mutat. Res. 349 (1996) 121-126]. An elevated level of ras p 21 proteins was considered to be greater than 2 standard deviations (S D) above the mean negative control values. Nine out of 20 COPD patient s (mean age = 65.9 years) had increased ras p21 protein levels when co mpared with 20 age-matched (mean age = 62.4 years) controls of the pre sent study with a mean + 2 SD of 0.70, Eighteen out of 40 lung cancer patients (mean age = 60.1 years) had increased ras p21 protein levels compared with their concurrent controls (mean age = 40.2 years) with a mean + 2 SD of 2.53. However when compared with the age-matched contr ols of this present study, there were 35 out of 40 (87.5%) with increa sed levels. When the COPD patients and lung cancer patients were compa red with 101 historical controls (age range 25-76 years, of those whos e age was recorded) from unexposed healthy populations from Poland, Es tonia and Spain with a mean + 2 SD of 1.83, then 4 out of 20 (20%) COP D patients and 30 out of 40 (75%) lung cancer patients had increased l evels. Whether using concurrent controls, age-matched controls or hist orical controls, the data would suggest that an increase in ras p21 pr otein levels in plasma from lung cancer patients could be a possible p rognostic marker or biomarker for lung cancer. COPD patients when comp ared with historical controls or age-matched controls had lower ras p2 1 protein values than cancer patients. Their ras p21 protein values mi ght also be a biomarker for cancer. It is possible that some of these COPD patients were in the process of developing cancer or perhaps woul d die from COPD before cancer develops. It cannot be ruled out that th e increases could be a biomarker of exposure since many of the lung ca ncer patients and most of the COPD patients were smokers. (C) 1998 Els evier Science B.V. All rights reserved.