Does blood group affect survival following pancreatoduodenectomy for periampullary malignancy?

Background: Blood group is reported to have an effect upon survival following pancreatoduodenectomy for pancreatic ductal adenocarcinoma. The effect of blood group is not known, however, among patients with other periampullary cancers. This study sought to review this. Methods: Data were collected for a range of factors and survival outcomes from patients treated at two centres. Those with blood groups B and AB were excluded, due to small numbers. Patient survival was compared between patients with blood groups O and A using multivariable analysis which accounted for confounding factors. Results: Among 431 patients, 235 (54.5%) and 196 (45.5%) were of blood groups A and O respectively. Baseline comparisons found a significant difference in the distribution of tumour types (p = 0.011), with blood group O patients having more ampullary carcinomas (33.2% vs 23.4%) and less pancreatic ductal adenocarcinomas (45.4 vs 61.3%) than group A. On multivariable analysis, after accounting for confounding factors including pathologic variables, survival was found to be significantly shorter in those with blood group A than group O (p = 0.047, HR 1.30 [95%CI: 1.00–1.69]). Conclusions: There is a difference in the distribution of blood groups across the different types of periampullary cancers. Survival is shorter among blood group A patients.