Background: We previously selected a panel of 3 breast cancer biomarkers (BC1, BC2, and BC3) from serum samples collected at a single hospital based on their collective contribution to the optimal separation of breast cancer patients and noncancer controls by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The identities and general applicability of these markers, however, were unknown. In this study, we performed protein expression profiling on samples obtained from a second hospital, included a greater number of ductal carcinoma in situ (DCIS) cases, and performed purification and identification of the 2 confirmed markers.Methods: Using a case–control study design, we performed protein expression profiling on serum samples from the National Cancer Institute (Milan, Italy). The validation sample cohort consisted of 61 women with locally invasive breast cancer, 32 with DCIS, 37 with various benign breast diseases (including 13 atypical), and 46 age-matched apparently healthy women (age range, 44–68 years). Validated biomarkers were purified and identified with serial chromatography, 1-dimensional gel electrophoresis, in-gel ASP-N digestion, peptide mass fingerprinting, and tandem mass peptide sequencing.Results: The BC3 and BC2 expression patterns in this sample set were consistent with the first study sample set. BC3 and BC2 were identified to be complement component C3adesArg and a C-terminal–truncated form of C3adesArg, respectively.Conclusions: Evaluation of biomarkers in independent sample sets can help determine the broader utility of candidate markers, and protein identification permits understanding of their molecular basis. C3adesArg appears to lack specificity among patients with benign diseases, limiting its utility as a stand-alone tumor marker, but it may still be useful in a multimarker panel for early detection of breast cancer.

The prognostic role of baseline C-reactive protein (CRP) in chronic obstructive pulmonary disease (COPD) is controversial. In order to clarify this issue, we performed a systematic review and meta-analysis to assess the predictive effect of baseline CRP level in COPD patients. 15 eligible articles focusing on late mortality in COPD were included in our study. We performed a random-effects meta-analysis, and assessed heterogeneity and publication bias. We pooled hazard ratio (HR) estimates and their 95% confidence intervals on mortality for the comparison between the study-specific highest category of CRP levelversusthe lowest category. In overall analysis, elevated baseline CRP levels were significantly associated with higher mortality (HR 1.53, 95% CI 1.32–1.77,I²=68.7%, p<0.001). Similar results were observed across subgroups. However, higher mortality risk was reported in studies using a cut-off value of 3 mg·L⁻¹(HR 1.61, 95% CI 1.12–2.30) and in those enrolling an Asiatic population (HR 3.51, 95% CI 1.69–7.31). Our analysis indicates that baseline high CRP level is significantly associated with higher late mortality in patients with COPD. Further prospective controlled studies are needed to confirm these data.