The assessment of prognosis in patients with advanced cancer remains problematical. The value of C-reactive protein concentration in this context has not been clearly defined. Patients with a diagnosis of colorectal (n = 182), gastric (n = 87), breast (n = 99), or bronchogenic (n = 404) cancer and who had measurements of C-reactive protein and albumin were identified. Median survival, from the time of sampling, ranged from 478 days in the colorectal cancer patients to 60 days in patients with bronchogenic cancer. On univariate analysis, there was, in each tumor type, a significant relationship between the duration of survival and both log10 C-reactive protein and albumin concentrations (P < or = 0.0002). On multivariate analysis, in each tumor type, log10 C-reactive protein remained a significant independent predictor of survival (P < or = 0.0002). When all four groups of cancer patients were analyzed (n = 772), the hazard ratio for a 10-fold increase in C-reactive protein concentration in cancer-specific survival was 2.21 (95% confidence interval = 1.92-2.56, P < 0.0001) and the corresponding hazard ratio for non-cancer survival was 5.48 (95% confidence interval = 3.55-8.46, P < 0.0001). The results of the present study indicate that in advanced cancer patients the presence of a systemic inflammatory response and the magnitude of that response predict the duration of cancer-specific and non-cancer survival.