Lobe of origin and histologic type of lung cancer associated with asbestos exposure in the Carotene and Retinol Efficacy Trial (CARET).
Lower lobe origin and histologic diagnosis of adenocarcinoma have been described as useful parameters for attributing lung cancer to prior asbestos exposure. To assess whether these characteristics differed between asbestos-exposed individuals and smokers, we evaluated lobe of origin and histologic type of tumors in 78 asbestos-exposed and 214 nonexposed heavy smokers developing lung cancer during the Carotene and Retinol Efficacy Trial (CARET), a prospective cancer chemoprevention trial. Most tumors in both cohorts, regardless of radiographic fibrosis at baseline, originated in upper lobes, representing 67% in asbestos-exposed and 80% in smokers, respectively (adjusted OR for lower lobe = 1.41; 95% CI = 0.69-2.91). Adenocarcinoma represented 32% of lung tumors in the asbestos cohort, and 30% in the smoking cohort (adjusted OR = 0.78; 95% CI = 0.40-1.55), and was inversely associated with radiographic fibrosis (adjusted OR = 0.19; 95% CI = 0.06-0.62). We conclude that neither anatomic site nor histologic cell type of tumors distinguishes effectively between smoking and asbestos as causal factors in development of lung cancer.
Brodkin
C A
CA
University of Washington, Department of Environmental Health, Seattle, USA. werd@u.washington.edu
McCullough
J
J
Stover
B
B
Balmes
J
J
Hammar
S
S
Omenn
G S
GS
Checkoway
H
H
Barnhart
S
S
D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology*; D016588:Anticarcinogenic Agents / Q000627:therapeutic use; D015984:Causality; D015986:Confounding Factors, Epidemiologic; D004224:Diterpenes; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000517:prevention & control; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D009784:Occupational Diseases / Q000453:epidemiology / Q000473:pathology*; D016273:Occupational Exposure; D011446:Prospective Studies; D011658:Pulmonary Fibrosis / Q000473:pathology; D016032:Randomized Controlled Trials as Topic; D000084562:Retinyl Esters; D012907:Smoking / Q000009:adverse effects*; D014801:Vitamin A / Q000031:analogs & derivatives / Q000627:therapeutic use; D019207:beta Carotene / Q000627:therapeutic use
D016588:Anticarcinogenic Agents; D004224:Diterpenes; D000084562:Retinyl Esters; D019207:beta Carotene; D014801:Vitamin A; C014794:retinol palmitate