Variation of microsomal mixed function oxidase(s) and human lung cancer

Area of Science:

• Pharmacogenetics
• Oncology
• Environmental Health

Background:

• Individual variations in aryl hydrocarbon hydroxylase (AHH) activity are well-documented in humans and animals.
• Previous attempts to link AHH variations to cancer susceptibility in humans yielded inconclusive results.

Purpose of the Study:

• To investigate individual differences in benzo[a]pyrene metabolism using saliva antipyrine pharmacokinetics.
• To assess the relationship between metabolic clearance rates and lung cancer risk.

Main Methods:

• Saliva antipyrine half-lives and metabolic clearance rates were measured in 57 lung cancer patients, 57 cancer-free controls, and 59 healthy smokers.
• Lung cancer patients had largely ceased smoking prior to testing.

Main Results:

• Lung cancer patients demonstrated significantly shorter mean antipyrine half-lives compared to cancer-free controls (P < 0.001).
• Antipyrine half-lives in lung cancer patients were only slightly different from those in healthy smokers (P < 0.05).

Conclusions:

• Lung cancer patients exhibit accelerated metabolic oxidation rates.
• These increased oxidation rates, potentially independent of recent smoking status, may predispose individuals to lung cancer.