Lewis Antigen Phenotype and Survival of Patients With Pancreatic Cancer

The association of Lewis antigen phenotype with survival of patients with pancreatic ductal adenocarcinoma was investigated.A total of 1187 patients diagnosed with pancreatic ductal adenocarcinoma were evaluated in a prospective cohort. Patients were classified into 3 different groups according to Lewis antigen phenotype: Lewis antigen (1) A positive [Le(a+b-)], (2) B positive [Le(a-b+)], and (3) negative [Le(a-b-)]. Risk of mortality was analyzed with Cox regression after adjusting for other predictors.The risk of mortality increased in the order of Le(a+b-), Le(a-b+), and Le(a-b-) [reference; hazard ratio (HR), 1.27; 95% confidence interval (CI)], 1.03-1.57; P = 0.02; and HR, 1.65; 95% CI, 1.31-2.09; P < 0.001] after adjusting for other predictors. Among patients with serum carbohydrate antigen (CA) 19-9 lower than 37 U/mL, the association seemed more apparent (reference; HR, 1.50; 95% CI, 0.77-2.29; P = 0.22; and HR, 2.10; 95% CI, 1.10-4.02; P < 0.02).The risk of mortality increased in the order of Le(a+b-), Le(a-b+), and Le(a-b-). The difference in prognosis according to the Lewis antigen phenotype was more pronounced in the low CA 19-9 group, which suggests that the Lewis antigen phenotype works as a biomarker predicting the prognosis of patients with pancreatic cancer with undetectable CA 19-9 level.