Abstract

Background
Blood group anti#gens A, B, and H, identical with those present in erythrocytes, are also found in some normal tissues. The expression of blood group antigens allows the identification of residual pneumocytes inside the tumor and the proper classification of some neoplasms. Variability of blood group antigen expression among tumor cells is a potentially useful indicator of functional tumor cell heterogeneity or progression. We evaluated the prognostic value of expression of blood group antigen A as a prognostic factors. Method: This study analyzed the expressions and losses of blood group antigen A in lung cancer patients with blood type A or AB. The presence of blood-group antigens was assessed immunohistochemically in paraffin-embedded tumor samples from 30 patients who underwent curative surgery, bronchoscopic biopy, percutaneous needle biopsy, lymph node biopsy for diagnosis of lung cancer from 1991 through 1994. Results; 1) The expression of blood group isoantigen A was observed in 15 cases (50%) 2) The expression of blaod group isoantigen A was observed in 64% of stage II, 47% of stage III, 25% of stage IV. 3) The expression of blood group isoantigen A was observed in 0% of large cell carcinoma, 17 % of small cell carcinoma, 63% of squamous cell carcinoma, 50% of adenocarcinoma, 100% of bronchioloalveolar cell carcinoma. 4) The losses of blood group isoantigen A were observed in 67% of patient who survived below 1 year, 44% of patients who survived 1 to 2 years, but no loss of expression were observed in patients who survived more than 2 years. 5) The median survival times of expressed group and lossed group of isoantigen A were 16.0, 9.8 months, respetively. 6) The loss of blood group antigen A was higher in patients who had metastatic lymph nade than in patients who had not. Conclusion: the expression of blood group antigen A in cancer cells is important favorable prognostic factor in patients with lung cancer.

• Keywords: Blood group antigen A, Monoclonal antibody, Immunohistochemical stain, Lung cancer