Diet and pharyngeal cancer.
Rossing MA; Vaughan TL; McKnight B
Int J Cancer 1989 Oct 15;44(4):593-7
A population-based case-control study was conducted to examine the effect
of ingestion of vitamin C, carotenoids and retinol on risk of pharyngeal
cancer. Data were available from 166 cases of pharyngeal cancer or their
next-of-kin, and from 547 controls similar in age and sex to the cases.
Odds ratios (ORs) relating consumption of vitamin C, carotenoids and retinol
from foods and vitamins C and A from supplements to risk of pharyngeal
cancer were calculated using multiple logistic regression analysis. After
adjustment for smoking and alcohol consumption, a significant increase
in risk associated with low intake of vitamin C from foods was observed.
Compared to the highest quartile, the OR for the lowest quartile of intake
was 2.5 (95% confidence interval, 1.5-4.2). No overall effect of dietary
carotenoid or retinol consumption was noted after adjustment for smoking
and alcohol. Decreasing use of either vitamin C or vitamin A supplements
was associated with increasing cancer risk among the case group as a whole.
However, the effect of vitamin C supplement use was substantially lower
when next-of-kin respondents were excluded from analysis. Also, the OR
for use of vitamin A supplements is based on a very small number of cases
reporting use, and must be viewed with caution. The results of our study
suggest that intake of vitamin C may be protective against pharyngeal
cancer, and are consistent with the results of previous studies which
reported a decreased risk of pharyngeal cancer associated with intake
of fruits and vegetables.