RESUMO
Objectives To study the clinical diagnostic value of soluble major histocompatibility complex class Ⅰ-related chain A(sMICA) and analyse the relationship of tumor biologic characteristics and sMICA in lung cancer. Methods The experimental level of sMICA was determined by ELISA in 116 lung cancer patients. The level of serum CEA, NSE, CA-199, CYFRA-211, SCC, ProGRP were determined by ELISA only in 91 lung cancer patients without any therapy. The level of sMICA in 50 normal persons was regarded as control group. Results The level of sMICA in lung cancer patients was significantly higher than that in control group (P<0.001); When sMICA cut-off was set as 240.5 ng/L, the sensitivity for the detection of lung cancer was 90.1%, the speciality was 46.9%. The positive rate of sMICA was significantly higher than that of CEA, NSE, CA-199, CYFRA-211, SCC, ProGRP(P<0.001 respectively); The level of sMICA in lung cancer patients with CR and PR after treatment were lower than that before treatment(P<0.05). The level of sMICA in lung cancer patients with relapse was higher than patients without any treatment (P<0.001). Conclusion SMICA may be a potential marker for diagnosing lung cancer with high sensitivity and speciality. It is associated with tumor progression and distant metastasis and may be helpful in the evaluation of diagnosis for lung cancer.