Using data from a case-control study conducted between 1986 and 1992 i
n Northern Italy on 367 cases of laryngeal cancers (350 men and 17 wom
en) and 1931 hospital controls (1373 men and 558 women), we estimated
the relative risks (RR) and the population attributable risks (AR) for
laryngeal cancer in relation to tobacco and alcohol consumption and a
diet containing little fresh fruit and vegetables (low beta-carotene
intake). In men, the RR and their 95% confidence interval (CI), derive
d from multiple logistic regression, including terms for center, age,
and education, plus, simultaneously, tobacco, alcohol, and beta-carote
ne) were 3.3 (95% CI, 1.9 to 5.5) for ex- or moderate smokers (<15 cig
arettes/day) and 8.8 (95% CI, 5.2 to 14.8) for heavy current smokers c
ompared to never smokers; the RR were 1.5 (95% CI, 1.0 to 2.2) for dri
nkers of 6 to <8 alcoholic drinks/day and 2.2 (95% CI, 1.6 to 3.0) for
drinkers of 8 or more drinks/day compared to teetotallers or moderate
drinkers; with respect to carotene intake the RR were 1.4 (95% CI, 1.
0 to 2.0) for the intermediate tertile and 1.8 (95% CI, 1.3 to 2.5) fo
r the lowest tertile, as compared to the highest tertile of intake. AR
were estimated assuming a multiplicative model: the single factor wit
h the largest AR was smoking, which accounted for about 77% of larynge
al cancers in men; alcohol intake explained about 25% of cases, low be
ta-carotene intake accounted for about 18% of cases, and together the
three factors were responsible for about 86% of laryngeal cancers in m
en. In women, the RR were significant for current smokers compared to
never smokers (RR = 23.9, 95% CI, 5.2 to 110.9) and heavy drinkers (gr
eater-than-or-equal-to 4 drinks/day) compared to abstainers and light
drinkers (<4 drinks/day) (RR = 4.6, 95% CI, 1.4 to 15.2). The AR were
similar to those for men (83% for tobacco, 28% for alcohol, 15% for lo
w beta-carotene intake, and 86% for the combination of the three facto
rs). However, all the estimates in women were unstable because of the
small number of cases. Thus, intervention on tobacco, alcohol, and a f
ew simple dietary items could, in principle, reduce laryngeal cancer d
eaths in Italy from 2500 to about 300 per year.