摘要AIM: To analyze the serum levels of retinoids and Leiden mutation in patients with esophageal, gastric, liver,pancreatic, and colorectal cancers.METHODS: The changes in serum levels of retinoids (vitamin A, α- and β-carotene, α- and β-cryptoxanthin,zeaxanthin, lutein) and Leiden mutation were measured by high liquid performance chromatography (HPLC)and polymerase chain reaction (PCR) in 107 patients (70 males/37 females) with esophageal (0/8), gastric (16/5), liver (8/7), pancreatic (6/4), and colorectal (30/21including 9 patients suffering from in situ colon cancer)cancer. Fifty-seven healthy subjects (in matched groups)for controls of serum retinoids and 600 healthy blood donors for Leiden mutation were used.RESULTS: The serum levels of vitamin A and zeaxanthin were decreased significantly in all groups of patients with gastrointestinal (GI) tumors except for vitamin A in patients with pancreatic cancer. No changes were obtained in the serum levels of α- and β-carotene,α- and β-cryptoxanthin, zeaxanthin, lutein in patients with GI cancer. The prevalence of Leiden mutation significantly increased in all groups of patients with GI cancer.CONCLUSION: Retinoids (as environmental factors)are decreased significantly with increased prevalence of Leiden mutation (as a genetic factor) in patients before the clinical manifestation of histologically different (planocellular and hepatocellular carcinoma, and adenocarcinoma) GI cancer.