Asbestosis and lobar site of lung cancer.

OBJECTIVE To assess the evidence for the hypothesis that lung cancer has a predilection for the lower lobes in workers with asbestosis. METHOD A review of the available literature with relevant information. RESULTS Six published reports were analysed. In four studies limited to series of cases with diagnoses of asbestosis, three showed lower lobe predominance of lung cancer whereas the fourth study included cases in which the radiographic readings did not meet the usual criterion of profusion for asbestosis. One cohort study showed lower lobe predominance; the other reported only 33% lower lobe cancers compared with 20% in unexposed controls. CONCLUSION There is some support for the hypothesis but more studies are needed.