Objectives: To clarify subsite-specific risk factors for hypopharyngeal and
esophageal cancers (HC and EC), we concluded a hospital-based case-referen
t study in Nagoya, Japan.
Methods: Subjects comprised 346 male cases with cancer of the hypopharynx (
n = 62) or esophagus (upper [U-EC] 53, middle [M-EC] 159, lower [L-EC] 72),
and 11,936 male referents free from cancer among first-visit outpatients a
ged 40-79 years in 1988-1997. Of histological confirmed cases, 93% comprise
d squamous cell carcinoma. Odds ratios (ORs) were estimated by a logistic r
egression model with adjustment for potential confounding factors.
Results: Cigarette smoking increased the OR for M-EC, and alcohol drinking
elevated the ORs for all subsites. The trend of ORs for combined cases of M
- and L-EC tended to increase with number of cigarettes (p = 0.056), and a
decreasing trend of the ORs was found with years after quitting smoking (p
= 0.006). The ORs for smoking with drinking were multiplicatively greater t
han those for smoking or drinking in combined cases of HC and EC. In contra
st, daily raw vegetable consumption lowered the ORs for all subsites.
Conclusions: This study suggests that the magnitude of risk with smoking is
stronger for M-EC within the esophagus, and drinking increases the risk at