Aflatoxin and HCC — DTM&H MCQ

Instant feedback + full explanation. One question, done properly.

ModerateEnvironmental HealthAflatoxin and HCCDTM&H

A 45-year-old farmer in sub-Saharan Africa presents with hepatocellular carcinoma. He has chronic hepatitis B and his staple diet of stored groundnuts has been found to be contaminated. What dietary contaminant most likely contributed?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Aflatoxin B1

The correct answer is D, Aflatoxin B1. Aflatoxin B1 is produced by Aspergillus flavus and Aspergillus parasiticus, which contaminate poorly dried and stored groundnuts and other cereals in hot, humid tropical climates typical of sub-Saharan Africa. It is classified by IARC as a Group 1 human carcinogen because it is metabolised by hepatic cytochrome P450 (CYP3A4) to an epoxide that forms DNA adducts, causing a characteristic mutation at codon 249 of the TP53 tumour suppressor gene. Chronic hepatitis B infection and aflatoxin exposure act synergistically, not merely additively, to markedly increase hepatocellular carcinoma risk, which is why the combination in this farmer (chronic HBV plus contaminated groundnuts) is the classic exam vignette for this mechanism. This dual exposure pattern explains the very high HCC incidence seen in aflatoxin-endemic, HBV-endemic regions of Africa and Asia. Why the other options are wrong: B. Ochratoxin A: produced by Aspergillus and Penicillium species, contaminates cereals and coffee, and is nephrotoxic, associated with Balkan endemic nephropathy and urothelial tumours rather than hepatocellular carcinoma. C. Fumonisin B1: found on contaminated maize (not groundnuts), disrupts sphingolipid metabolism, and is linked to oesophageal cancer and neural tube defects, not primary liver cancer. E. Deoxynivalenol: a trichothecene mycotoxin from Fusarium on cereals causing acute gastrointestinal toxicity (vomiting toxin), with no established hepatocarcinogenic role. A. Zearalenone: a Fusarium mycotoxin with oestrogenic effects causing reproductive disturbances in livestock and humans, not hepatocarcinogenesis. Key point: Aflatoxin B1 from mould-contaminated groundnuts acts synergistically with chronic hepatitis B infection via TP53 codon 249 mutation to drive hepatocellular carcinoma in tropical regions.

Reference: IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Aflatoxins (Group 1 carcinogen); Manson's Tropical Diseases, chapter on Hepatocellular Carcinoma and Aflatoxin/HBV synergy