system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 67-year-old man comes to the physician because of a 4-month history of fatigue and weight loss. Physical examination shows jaundice. The liver is palpated 3 cm below the right costal margin. Serum studies show an elevated alpha-fetoprotein and a prolonged prothrombin time. Genetic analysis of a liver biopsy specimen shows a G:C to T:A transversion in codon 249 of the gene coding for the TP53 protein in affected cells. Which of the following risk factors is most specific to the patient's condition?
assistant
Dietary aflatoxin exposure