ABSTRACT
BACKGROUND: Non-small cell lung cancer (NSCLC) lacks reliable serological biomarkers for predicting patients' survival and response to treatment. The present study examined the capability of serum LAMC2 and four known tumour markers for disease prognosis and patients' risk stratification. METHODS: LAMC2, CA 125, CEA, CYFRA 21-1 and SCC levels were retrospectively measured in sera obtained from 127 patients diagnosed with NSCLC by commercial immunoassays. Prognostic performance of the markers was compared with established clinical parameters and multivariate models were constructed to assess the prognostic complementarity of variables. RESULTS: LAMC2 showed significant prognostic ability for overall survival (hazards ratio: 1.607, 95% confidence interval: 1.268-2.037, P<0.0001) in the full cohort. LAMC2 and CYFRA 21-1 combination enhanced prognostic models based on common clinical parameters (c-index: 0.81 vs 0.72, P=0.00018), further enabling stratification of patients into clear risk groups. A bootstrap-based cross-validation analysis was supportive of our findings. Combination of LAMC2 and CA 125 showed similar performance. CONCLUSIONS: Our preliminary study proposes LAMC2 as a novel NSCLC prognostic factor. LAMC2 combined with CA 125 and CYFRA 21-1 could aid in clinical prediction of NSCLC patients' overall survival and inform clinical practice. Larger studies are necessary to unravel LAMC2's full potential as a new NSCLC biomarker.
Subject(s)
Carcinoma, Non-Small-Cell Lung/diagnosis , Laminin/blood , Lung Neoplasms/diagnosis , Adult , Aged , Aged, 80 and over , Antigens, Neoplasm/blood , Biomarkers, Tumor/blood , CA-125 Antigen/blood , Carcinoma, Non-Small-Cell Lung/blood , Carcinoma, Non-Small-Cell Lung/mortality , Female , Humans , Keratin-19/blood , Lung Neoplasms/blood , Lung Neoplasms/mortality , Male , Middle Aged , Predictive Value of Tests , Prognosis , Survival AnalysisABSTRACT
OBJECTIVE: This study was undertaken to investigate the presence of autoantibodies against the main cartilage proteoglycan, aggrecan, in systemic rheumatic disease sera, and to identify substructure(s) responsible for the autoimmune response. METHODS: Sera were obtained from 86 patients with various systemic rheumatic diseases, 14 with osteoarthritis (OA), 18 with cancer and 40 healthy individuals. The presence of autoantibodies against aggrecan was examined by a solid phase assay and by Western blotting, using proteoglycan aggregates treated with proteolytic enzymes. The positive bands were subjected to nanohigh performance liquid chromatography (nanoHPLC)-MS, in order to identify the aggrecan substructures involved in the autoimmune response. RESULTS: Autoantibodies against aggrecan were identified in all systemic rheumatic disease sera at a high titre, almost three times that observed in healthy controls. OA and cancer sera produced a reaction equal to that of the healthy. Western blotting analysis of aggrecan proteolytic fragments revealed the presence of a triple band, reacting with the patients' sera, of about 37 kDa, which also reacted with a polyclonal antibody against hyaluronan-binding region. NanoHPLC-MS analysis suggested that this band belonged to the G2 domain of aggrecan. CONCLUSION: At least a part of the autoimmune reaction to aggrecan, displayed by the systemic disease sera, involves the G2 domain. The significant difference observed between these sera and those from other diseases, especially cancer, may suggest a possible discriminatory role of anti-aggrecan antibodies. This may help in the differential diagnosis in complicated clinical cases. However, for this to be confirmed, studies in larger cohorts of patients should be performed.
