[Correlation between Serum Cytokeratin 19 Fragment and the Clinicopathological Features and Prognosis of Thymic Epithelial Tumors].

BACKGROUND: So far there's no tumor maker applied in diagnosis and treatment of thymic epithelial tumors. This study is to assess the correlation between serum cytokine 19 fragment (Cyfra 21-1) and clinicopathological features and prognosis of thymic epithelial tumors (TETs).

METHODS: The clinical data of 159 patients with TETs in Shanghai Chest Hospital was retrospectively analysed. Patients were divided into groups according to different tumor stages and histotypes. Serum Cyfra 21-1 was thus compared. In addition, the possible relationship between perioperative serum Cyfra 21-1 level and the recurrent status was carrid out.

RESULTS: Preoperative Cyfra 21-1 serum concentrations in patiants with advanced stage (T4) and thymic carcinomas were significantly higher than that in others (P<0.001, P<0.001, respectively). When the preoperative serum level exceeds the out-off of 1.66 ng/mL, it possibly indicates the recurrence during follow up. Furthermore, the sensitivity, specificity, and positive as well as negative predictive value (PPV and NPV) of postoperative Cyfra 21-1 to predict tumor recurrence were evaluated. At a cut-off of Cyfra 21-1 of 2.66 ng/mL, the sensitivity was 0.7, the specificity was 0.925, the PPV was 0.5 and the NPV was 0.966.

CONCLUSIONS: The elevated level of preoperative serum Cyfra 21-1 indicates an advanced stage of tumor or a more malignant histotype (thymic carcinoma). It also probably suggests a higher risk of tumor recurrence. During the oncological follow up, in addition to regular imaging examinations, the blood test of serum Cyfra 21-1 is also suggested to improve the diagnosis of tumor recurrence in order to improve the prognosis.