Methods Prospective multicentric and national study evaluating the prevalence of lung cancers through low-dose CT of 450 individuals with a known HIV-infection, with a nadir level of TCD4 cells < 350/µl, ≥ 40 years old and with a smoking history ≥ 20 packs a year (either active or with <3 years of weaning). CT interpretations and lung biopsies are guided by a suggested workup algorithm, which is not imposed in each HIV-caring centre.