CK19 mRNA expression in the bone marrow of patients with esophageal squamous cell carcinoma and its clinical significance.

The 5-year survival rate in resectable patients with esophageal cancer is only 20% to 36%. Regional relapse and distant metastasis are responsible for the failure of treatment and the majority of cancer-related deaths. Earlier detection of metastases, especially micrometastases, has the potential for more accurate risk stratification in subsequent therapy decisions. No effective techniques have yet been found to detect metastases in erroneously thought to have early stage disease. This study was designed to investigate the clinical significance of bone marrow micrometastases detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in patients with esophageal cancer. Expression of CK19 mRNA in the bone marrow of 61 patients with esophageal squamous cell carcinoma (ESCC) and 15 benign pulmonary and esophageal disease patients was assessed via RT-PCR. Correlation of CK19 mRNA expression to the clinicopathologic features and prognosis of the 61 patients was analyzed: 21.3% (13/61) were positive for expression of CK19 mRNA in patients with ESCC. No CK19 mRNA was detected of the 15 benign pulmonary and esophageal disease patients. CK19 mRNA expression did not correlate with the clinicopathologic features of the patients with ESCC, but patients with CK19 mRNA-positive bone marrow had earlier recurrence and shorter survival after surgery. In multivariate analysis, CK19 mRNA was found to be an independent predictor of a poor outcome. CK19 mRNA may be used as a molecular maker to detect bone marrow micrometastases in patients with ESCC and may help to select the proper therapy and predict the prognosis.