Loss of blood group antigen a in non-small cell lung cancer

Background: Many human tumor cells display alterations in blood group antigen expression, and the loss of antigen A expression by non-small cell lung cancer (NSCLC) in blood group A patients has recently been associated with decreased survival. Methods: To confirm this finding, we performed a retrospective study of 62 NSCLC patients undergoing potentially curative resection between August 1987 and December 1991 who were blood group A and had paraffin-embedded primary lung cancer tissue suitable for immunohistological analysis of antigen A expression. Twenty-seven patients expressed antigen A in their tumors, whereas 35 had loss of antigen expression. Disease-free survival (DFS) curves were calculated for stage I (n=26) and IIIA (n=25) patients. Results: The two groups of patients with or without antigen A expression did not have significantly different DFS. A proportional hazards regression analysis identified no significant difference in the DFS of stage I patients with or without antigen A, but stage IIIA patients who had preservation of antigen A had significantly shorter DFS than did those who lost antigen A (p=0.0002). Conclusions: The loss of expression of antigen A by primary tumor cells was not a significant adverse prognostic factor in DFS in our series, and we would recommend further studies to define clearly the clinical importance of antigen A expression in pulmonary carcinoma.