Cancer risk in severe alpha-1-antitrypsin deficiency.

Area of Science:

• Genetics and Epidemiology
• Oncology
• Pulmonology

Background:

• Severe alpha-1-antitrypsin deficiency (AATD), specifically phenotype PiZZ, is a known risk factor for lung emphysema and liver disease.
• The association between severe AATD and cancer risk remains largely uncharacterized.

Purpose of the Study:

• To investigate the risk of incident cancer in individuals with severe AATD (PiZZ phenotype).
• To identify risk factors associated with cancer development in this population.
• To compare cancer incidence in PiZZ individuals with the general population, considering smoking habits.

Main Methods:

• A longitudinal study involving 1595 PiZZ individuals from the Swedish National AATD Register and 5999 controls.
• Data linkage with national registers for cancer and mortality information.
• Proportional hazards and Fine-Gray regression models were used for risk factor analysis, adjusting for age, sex, smoking, and liver disease.

Main Results:

• Over a median follow-up of 17 years, PiZZ individuals showed significantly higher incidence rates for hepatic cancer (1.6 vs 0.1 per 1000 person-years) and non-hepatic cancer (8.5 vs 6.6 per 1000 person-years) compared to controls.
• Adjusted hazard ratios indicated a 23.4-fold increased risk for hepatic cancer and a 1.3-fold increased risk for non-hepatic cancer in PiZZ individuals.

Conclusions:

• Severe alpha-1-antitrypsin deficiency (AATD) is associated with an elevated risk of developing both hepatic and non-hepatic cancers.
• These findings suggest AATD as a potential risk factor for cancer beyond its known pulmonary and hepatic manifestations.