OBJECTIVETo explore the expression of cancerous inhibitor of phosphatase 2A (CIP2A) protein in small cell lung cancer and their relationship with clinicpathological features and prognosis.

METHODSA total of 112 cases of surgical specimens or bronchoscopic biopsies of small cell lung cancer were collected. There were specimens of 94 cases of SCLC tissues and 40 cases of paracancerous lung tissues. Quantitative RT-PCR and immunohistochemistry analysis were performed to determine the CIP2A expression in SCLC tissues. Kaplan-Meier curves were used to estimate the association between CIP2A expression and clinicopathological characteristics and prognosis of the patients.

RESULTSThe expression of CIP2A in SCLC tissue was 7.605 ± 1.893, significantly higher than that in the paracancerous tissues (1.041 ± 0.786) (P < 0.01). The positive rate of CIP2A expression in cancer tissues was 82.8%, significantly higher than that in the paracancerous tissues (13.3%) (P < 0.01). The median disease-free survival was 9.88 months in the CIP2A-high expressing patients, significantly shorter than the 20.92 months in CIP2A-low expressing patients (P < 0.001). CIP2A expression was significantly correlated with the tumor stage, chemotherapeutic sensitivity, and survival (P < 0.05 for all).

CONCLUSIONSCIP2A expression is associated with the pathogenesis of SCLC, and may become a potential prognostic indicator of SCLC.