Epithelial bone marrow cells in patients with advanced esophageal squamous cell carcinoma

The aim of the current study was to examine epithelial cells in the bone marrow and peripheral blood of patients with various stages of esophageal squamous cell cancer prior to surgical treatment and to analyze the prognostic significance of these carcinoma cells deposits to the stage of the disease and applied surgical therapy. Thirty-two patients (25 men and 7 women), and 5 healthy bone marrow donors serving as controls were studied. Bone marrow samples were evaluated by light microscopy and examined by flow cytofluorometry. Cells were phenotypically analyzed for the antigens CD45- and CD18+ and/or EMA+. Results are presented as the number of cells revealing the investigated phenotype per 10 (5)analyzed cells. CD18 was expressed in the bone marrow cells of 15 of the 32 (47%) patients and EMA in 20/32 (62%), but not in peripheral blood. In 13 of the 32 pts (41%), co-expression of CD18 and EMA was observed. Patients with the proportion of marrow erythroblasts below 15% had higher numbers of CD18+ and EMA+ cells and there was a negative correlation between the number of erythroblasts and EMA+ cells (r=0.54, p=0.01). In patients with esophageal cancer and anemia, the number of EMA+ cells was higher (p=0.05) and the percentage of erythropoietic cells in the bone marrow was lower (p=0.01). In conclusion, flow cytofluorometry using anti-cytokeratin and anti-EMA antibodies may be useful in evaluating microdeposits of esophageal squamous cells in bone marrow. A dysfunctioning erythropoietic system causing anemia can be a first signal for the presence of malignant cell microdeposits in the marrow of patients with esophageal carcinoma.