LOSS OF BLOOD-GROUP ANTIGEN-A IN NONSMALL 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 a ssociated with decreased survival. Methods: To confirm this finding, w e performed a retrospective study of 62 NSCLC patients undergoing pote ntially curative resection between August 1987 and December 1991 who w ere blood group A and had paraffin-embedded primary lung cancer tissue suitable for immunohistological analysis of antigen A expression. Twe nty-seven patients expressed antigen A in their tumors, whereas 35 had loss of antigen expression. Disease-free survival (DFS) curves were c alculated for stage I (n = 26) and IIIA (n = 25) patients. Results: Th e two groups of patients with or without antigen A expression did not have significantly different DFS. A proportional hazards regression an alysis identified no significant difference in the DFS of stage I pati ents with or without antigen A, but stage IIIA patients who had preser vation of antigen A had significantly shorter DFS than did those who l ost antigen A (p = 0.0002). Conclusions: The loss of expression of ant igen A by primary tumor cells was not a significant adverse prognostic factor in DFS in our series, and we would recommend further studies t o define clearly the clinical importance of antigen A expression in pu lmonary carcinoma.