APOBEC3A/B deletion polymorphism and cancer risk.

Area of Science:

• Genetics
• Cancer Epidemiology
• Molecular Biology

Background:

• Apolipoprotein B mRNA editing enzyme, catalytic-polypeptide-like (APOBEC) enzymes are implicated in cancer mutagenesis.
• A germline APOBEC3A/B deletion polymorphism is linked to APOBEC-dependent mutational signatures and has shown varying cancer risk associations across populations.

Purpose of the Study:

• To investigate the association between the APOBEC3A/B deletion polymorphism and the risk of four major cancer types in a large Caucasian population.
• To explore potential age- and cancer-specific effects of this genetic variation.

Main Methods:

• Genotyping of the APOBEC3A/B deletion polymorphism in 11,106 Norwegian individuals (7,279 cancer cases and 3,827 controls).
• Analysis of breast, lung, colon, and prostate cancer incidence in relation to the polymorphism.
• Stratified analyses by age and cancer type, including age at diagnosis.

Main Results:

• The APOBEC3A/B deletion polymorphism showed no overall association with the risk of breast, lung, colon, or prostate cancer.
• A significant association was found between the deletion allele and increased lung cancer risk in individuals under 50 years old (OR 2.17).
• This association weakened with increasing age, and a similar, though less pronounced, pattern was observed for prostate cancer. The deletion was associated with younger age at diagnosis for lung and prostate cancers.

Conclusions:

• The APOBEC3A/B deletion polymorphism does not appear to be a general risk factor for these four cancers in the Caucasian population.
• Age-dependent effects are suggested, with a potential increased risk for lung and prostate cancer in younger individuals carrying the deletion.
• Further research is warranted to elucidate the mechanisms behind these age-specific associations.