Introduction
Alpha-1 antitrypsin (AAT) is a glycoprotein whose main function is the inhibition of serine proteases. Its deficiency increases the risk of pulmonary emphysema. Lung cancer (LC) is one of the neoplasms with the highest incidence and the highest mortality in both sexes worldwide. The objective of this study was to analyze, from a cohort of patients with lung cancer, the differences in clinical, functional, radon levels and analytical characteristics between patients with a normal genotype (Pi*MM) and deficient genotypes.

Material and methods
Inclusion of patients with histological diagnosis of PC consecutively from November 2019 to November 2022. All participants underwent an interview with collection of clinical (sex, age, smoking, PC histology, tumor stage), radon levels, functional and analytical data.All patients were genotyped for AAT using the PROGENIKA Biopharma system (Grifols)

Results
284 patients were included, 71.8% male and mean age 66.3 years. 44.4% of the cases were active smokers. The mean values of radon were 189,45 Bq/m3. The predominant histology was adenocarcinoma with 59.2% The mean plasma AAT concentration was 181 mg/dl. Regarding the distribution of the AAT genotypes, we found the genotype MM (79.6%), MS (14.4%), MZ (2.8%), SS (1.8%), SZ (0.4 %) and rare genotypes (1.1%).Table 1 shows collect the characteristics classified between patients carrying the MM genotype versus those with deficient genotypes.

Conclusions
No significant differences were found in the clinical, functional or analytical characteristics between patients with PCa with the MM genotype compared to carriers of deficient genotypes.