Kupert et al. BMC Cancer 2011, 11:513 http://www.biomedcentral.com/1471-2407/11/513 Table 3 High level of plasma sPLA2-IIa predicts lung cancer Table 3a: Determination of plasma sPLA2-IIa to predict lung cancer by ROC analysis. Plasma sPLA2-IIa < 2.4 ng/ml > 2.4 ng/ml BNLCC lung cancer vs. benign SPN Table 3b: Combined sPLA2-IIa, CEA, and Cyfra21.1 blood tests increase the sentisitivity to predict lung cancer. sPLA2-IIa < 2.4 ng/ml > 2.4 ng/ml CEA < 6.0 ng/ml > 6.0 ng/ml Cyfra21.1 < 3.3 ng/ml > 3.3 ng/ml BNLCC lung cancer vs. benign SPN Benign SPN Lung cancer Stage 1 lung cancer Stage 2 lung cancer GELCC lung cancer vs. benign SPN Lung cancer Benign SPN Lung cancer Stage 1 lung cancer Stage 2 lung cancer CEA BNLCC lung cancer vs. benign SPN Benign SPN Lung cancer Benign SPN Lung cancer Cyfra21.1 BNLCC lung cancer vs. benign SPN 24 50 24 6 16 22 36 18 5 28 77 27 83 5 46 20 12 28 7 60 26 13 1 19 2 13 86 76 97 93 < 6.0 ng/ml > 6.0 ng/ml Total case# %Senstivity %Specificity < 3.3 ng/ml > 3.3 ng/ml Total case# %Specificity increase in the size of a SPN is currently the parameter used to predict the presence of lung cancer. This repeated CT scan results in radiation exposure as well as anxiety. Patients may also undergo invasive proce- dures for diagnosis such as bronchoscopy, CT-guided fine needle aspiration, or thoracoscopic resection. It will become critical to have more effective ways to deter- mine which nodules are most likely malignant. We recently reported that there is an elevated level of plasma sPLA2-IIa in prostate cancer patients [17]. The current study showed that lung cancer tissues overex- press sPLA2-IIa and that patients with lung cancer have elevated levels of plasma sPLA2-IIa. The expression of the sPLA2-IIa gene is not tissue-specific or cancer-speci- fic [17]. It was reported that the levels of plasma sPLA2- IIa are elevated with bacterial and viral infection or IL-2 infusion [31,32] and in coronary heart disease [33-35]. However, a recent clinical study including more than 500 patients showed that there is no significant altera- tion in plasma level of sPLA2-IIa protein among patients with coronary artery disease relative to healthy controls [34]. In consideration of these complications, we included some patients with inflammatory nodules of the lung as controls. We found an increased basal level of plasma sPLA2-IIa in these controls relative to those in healthy donors, which may be a result of chronic inflammation due to fungal infection and pneu- monia. This active localized inflammation can occasion- ally lead to a moderate increased level of plasma sPLA2- IIa. Nevertheless, a significant high level of plasma sPLA2-IIa as a result of lung cancer can predict more than 48% of early stage lung cancers and up to 67% of T2 stage lung tumors with 86% specificity. sPLA2-IIa blood test has potential to help with the decision algo- rithm and determine the timing of subsequent CT scans and potential biopsy of concerning nodules. One concern for using sPLA2-IIa as a lung cancer bio- marker is that it lacks cancer specificity. This is one of the common features shared by all biomarkers currently in clinical use or under development and is simply due to the fact that genes contributing to cancer develop- ment overlap with those for other metabolic diseases, Page 6 of 10 Total case# %Senstivity %Specificity Total case# %Senstivity %Specificity 29 96 44 18 44 29 96 44 18 29 96 29 96 48 45 67 64 63 59 72 20 %Senstivity 14