Analysis of tumor markers in pleural effusion and serum to verify the correlations between serum tumor markers and tumor size, TNM stage of lung adenocarcinoma

BACKGROUND: The study of tumor markers (TM) in pleural effusion (PE) was not extensive. METHODS: TM in PE and serum were analyzed to determine whether TM was expressed in intrathoracic and extrathoracic tissues. To further verify the correlations between serum TM and tumor size, TNM stage of lung adenocarcinoma. RESULTS: Serum AFP was not correlated with tumor size, T stage, N stage, and M stage (P > .05). Serum CEA, serum CA125, serum CA15‐3 were positively correlated with tumor size, T stage, N stage, M stage (P < .05). Serum CA19‐9 was not significantly correlated with tumor size and T stage (P > .05), but was positively correlated with N stage and M stage (P < .05). The levels of PE CEA, PE CA125, PE CA15‐3 were higher than those of serum CEA, serum CA125, serum CA15‐3 (all P < .05). The level of PE AFP was lower than that of serum AFP (P < .05). The level of PE CA19‐9 was not significantly different from that of serum CA19‐9 (P > .05). The positive rates of PE CEA and PE CA125 were higher than those of serum CEA and serum CA125 (P < .05). The positive rates of PE AFP, PE CA15‐3, PE CA19‐9 were not significantly different from those of serum AFP, serum CA15‐3, serum CA19‐9 (P > .05).PE CEA, PE CA125, PE CA15‐3 were moderately positively correlated with serum CEA, serum CA125, serum CA15‐3, respectively (r = 0.597; r = 0.46; r = 0.583, all P < .05). However, PE AFP and PE CA19‐9 were very strongly positively correlated with serum AFP and serum CA19‐9, respectively (r = 0.888; r = 0.874, all P < .05). CONCLUSION: The expression characteristics of TM in PE and serum supported the correlations between serum TM and tumor size, TNM stage of lung adenocarcinoma.