The researchers evaluated the relation between social class factors and squamous cell esophageal cancer. They also examined the extent to which such factors may contribute to a higher incidence of this cancer among black men, than among white men in the USA.
347 male cases (119 white, 228 black) and 1,354 male controls (743 white, 611 black) were selected from three US geographic areas. All cases had been diagnosed with histologically confirmed esophageal cancer between 1986 and 1989, and were residents of the study areas.
The researchers, led by Linda Morris Brown, assessed four major risk-factors: (1) low income, (2) moderate/heavy alcohol intake, (3) tobacco use, and (4) infrequent consumption of raw fruit and vegetables.
The team found that risk of esophagal cancer was higher in subjects with an annual income less than $10,000 compared with those with incomes of $25,000 or more. The risk was 4.3 times higher for white men and 8.0 times higher for black men.
|Risk-factors for squamous cell esophagal cancer:|
1. Low income
2. Moderate/heavy alcohol intake
3. Tobacco use
4. Low raw fruit/vegetable consumption
|Am J Epidemiol|
The combination of all four major risk-factors accounted for almost all of the squamous cell esophageal cancers in whites and blacks, and for 99% of the excess incidence among black men.
Dr Brown said on behalf of the group, "Lifestyle modifications, especially a lowered intake of alcoholic beverages, would markedly decrease the incidence of squamous cell esophageal cancer in both racial groups and would narrow the racial disparity in risk."
"Further studies on the determinants of social class may help to identify a new set of exposures for this tumor that are amenable to intervention," she concluded.