MUC1 mucin mRNA expression in stage I lung adenocarcinoma and its association with early recurrence

Background. MUC1 is a membrane-bound mucin with an extensively O-glycosylated core protein and is developmentally regulated and aberrantly expressed by carcinomas. A high level of MUC1 mucin expression and secretion is associated with high metastatic potential and a poor prognosis. We studied the expression of MUC1 messenger ribonucleic acid (mRNA) in stage I lung adenocarcinoma by reverse transcriptase–polymerase chain reaction and examined its correlation with early recurrence. Methods. The expression of MUC1 mRNA, in surgical specimens from 33 patients with stage I lung adenocarcinoma was determined by reverse transcriptase–polymerase chain reaction. The MUC1 and β-actin sequences were subsequently coamplified to analyze the semiquantitative determination by polymerase chain reaction. The ratio of MUC1 to β-actin product was used for further analysis. Results. An analysis of the disease-free survival (median follow-up, 33.4 months) revealed that a high expression of MUC1 was associated with early recurrence (p = 0.0191). Six of the 33 patients had recurrence within 2 years after operation. The recurrence sites suggested hematogenic metastasis. Conclusions. Our results indicate that MUC1 mRNA level may be useful as a marker of early recurrence in stage I lung adenocarcinoma.