Abstract
Purpose: Previous studies showed that HLA-B40 and -B51 antigens were associated with the response to immunotherapy using protein-bound polysaccharide (PSK) and chemotherapy, respectively, in gastric cancer. We evaluated whether a putative HLA antigen correlated with the response to therapy, and associated with secondary malignancies. Patients and Methods: 413 patients with 302 gastric, 57 colon and 52 rectal cancers, and 2 synchronous gastric and colon cancers who underwent resection of the tumors from DEC-1990 to AUG-1993. They were examined 53 HLA antigens by using the micro-cytotoxicity assay and were randomized to immunotherapy or chemotherapy according to status of the positive or negative HLA -B40 and -B51 antigen and followed for secondary malignancy. Results: Three hundred two gastric cancers followed to be 12 secondary malignancies and 109 colorectal cancers 3. HLA-B40 and -B51 antigens were not significantly associated with the response to therapy. Patients in stage 1A gastric cancer without HLA-40 antigen who received chemotherapy and those with this antigen who received immunotherapy all lived. HLA-Cw3 positive patients with gastric cancer showed significantly higher incidence of secondary malignancies. Patients with heterozygous at HLA-A and -C, and those with homozygous at HLA-DQ also showed significantly higher incidence of secondary malignancies than those with homozygous at HLA-A and -C, and those with heterozygous at HLA-DQ. Conclusion: This study failed to confirm that HLA-B40 and -B51 antigens significantly associated with response to therapy, but we have discovered that HLA-Cw3 antigen was susceptible to subsequent malignancies in gastric cancer.
