Excess incidence of squamous cell esophageal cancer among US Black men: role of social class and other risk factors

Data from a population-based case-control study were used to evaluate the relation between social class factors and squamous cell esophageal cancer and the extent to which alcohol, tobacco, diet, and low income contribute to the higher incidence among Black men than among White men in the United States. A total of 347 male cases (119 White, 228 Black) and 1,354 male controls (743 White, 611 Black) were selected from three US geographic areas (Atlanta, Georgia, Detroit, Michigan, and New Jersey). Cases were residents of the study areas aged 30-79 years who had been diagnosed with histologically confirmed esophageal cancer between 1986 and 1989. The adjusted odds ratios for subjects with annual incomes less than $10,000 versus incomes of $25,000 or more were 4.3 (95% confidence interval: 2.1, 8.7) for Whites and 8.0 (95% confidence interval: 4.3, 15.0) for Blacks. The combination of all four major risk factors-low income, moderate/heavy alcohol intake, tobacco use, and infrequent consumption of raw fruits and vegetables-accounted for almost all of the squamous cell esophageal cancers in Whites (98%) and Blacks (99%) and for 99% of the excess incidence among Black men. Thus, 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.

The excess incidence of squamous cell esophageal cancer among us black men. Role of social class and other risk factors

PURPOSE: To investigate the relationship between social class factors and squamous cell esophageal cancer and the extent to which alcohol, tobacco, diet, and social class contribute to the five-fold higher incidence among black than white men in the United States.METHODS: Interviews were conducted with 347 incident cases of squamous cell esophageal cancer (119 white males and 228 black males) and 1354 population-based controls (743 white males and 611 black males) from Atlanta, Detroit, and New Jersey. Risks were estimated using unconditional logistic regression controlling for potential confounders.RESULTS: Elevated risks of squamous cell esophageal cancer were associated with indicators of low social class, especially low annual income. The adjusted odds ratios (ORs) for subjects with incomes < $10,000 versus incomes of $25,000 or more were 4.3 (95% CI = 2.1-8.7) for whites and 8.0 (95% CI = 4.3-15.0) for blacks. The combination of all four major risk factors: annual income less than $25,000, moderate/heavy use of alcohol, use of tobacco for six months or longer, and consumption of less than 2.5 servings of raw fruits and vegetables per day accounted for almost all of the squamous cell esophageal cancers in whites (98%) and blacks (99%), and for 99% of the excess incidence among black men.CONCLUSIONS: Lifestyle modifications, especially a lower intake of alcoholic beverages, would markedly decrease the incidence of this cancer in both races and narrow the racial disparity in risk. Further studies into the determinants of social class may help identify a new set of exposures for this tumor that are amendable to intervention.

Commentary on the Women's Health Initiative

The Women's Health Initiative (WHI), established by the National Institutes of Health in 1991, is a long-term national health study that focuses on strategies for preventing heart disease, breast and colorectal cancer and osteoporosis in postmenopausal women. These chronic diseases are the major causes of death, disability and frailty in older women of all races and socioeconomic backgrounds. The WHI a 15-year multi-million dollar endeavor, and one of the largest U.S. prevention studies of its kind. The study involves over 161,000 women aged 50-79, and is one of the most definitive, far reaching clinical trials of women's health ever undertaken in the U.S. The WHI Clinical Trial and Observational Study will attempt to address many of the inequities in women's health research and provide practical information to women and their physicians about hormone replacement therapy, dietary patterns and calcium/vitamin D supplements, and their effects on the prevention of heart disease, cancer and osteoporosis. Emerging information from the NIH Women's Health Initiative and other studies of women's health begun in the 1990's should be changing the landscape of options for older women in the years to come.

Mortality of industrial workers exposed to acrylonitrile

OBJECTIVES

This study was designed to evaluate the relationship between occupational exposure to acrylonitrile and cancer mortality.

MATERIALS AND METHODS

Workers (18079 white men, 4293 white women, 2191 nonwhite men, and 897 nonwhite women) employed in acrylonitrile production or use in the 1950s through 1983 were followed through 1989 for vital status and cause of death. Exposure-response relationships were evaluated from quantitative estimates of historical exposures. Tobacco use was determined for a sample of workers to assess potential confounding. Mortality rates between the exposed and unexposed workers in the cohort were compared using the Poisson regression.

RESULTS

Analyses by cumulative, average, peak, intensity, duration, and lagged exposure revealed no elevated risk of cancers of the stomach, brain, breast, prostate or lymphatic and hematopoietic systems. Mortality from lung cancer was elevated for the highest quintile of cumulative exposure. When the decile categories were used, the relative risk did not continue to increase at higher levels. Adjustment for cigarette use reduced the risk for lung cancer only slightly. Separate analyses for wage and salaried workers, long-term and short-term workers, fiber and nonfiber plants, and individual plants revealed no clear exposure-response patterns.

CONCLUSIONS

The results indicate that exposure to acrylonitrile at the levels studied is not associated with an increased relative risk for most cancers of a priori interest. The excess of lung cancer in the highest quintile of cumulative exposure may indicate carcinogenic activity at the highest levels of exposure, but analyses of exposure-response do not provide strong or consistent evidence for a causal association.

Exposure assessment for a study of workers exposed to acrylonitrile

Procedures used to develop estimates of exposure to acrylonitrile for a cohort study (>25000 workers in 8 monomer, fiber, and resin companies from 1952 to 1983) are presented. Visits to the companies were made, interviews of workers were conducted, historical records were made, and measurements were taken. On the basis of similar tasks, locations, other exposures, and a similar distribution of exposures to acrylonitrile, 3600 exposure groups were formed. Special procedures were used to reduce the misclassification of workers performing tasks that varied in time but that were inadequately reflected in the job title. A software program organized and retained all exposure information on each exposure group. Quantitative estimates of acrylonitrile exposure were developed using a hierarchical approach in a software program that documented the derivation of each estimate and facilitated data review. Two of the estimation methods were evaluated in a comparison with measurement data.

A comparison of diets of blacks and whites in three areas of the United States

Dietary factors may contribute to the increased cancer risk of blacks. As a first step to explore this hypothesis, we examined food frequency data obtained by interview with 1,976 adults (881 blacks and 1,095 whites) randomly selected from three areas of the United States. The a priori hypothesis was that blacks were more likely to consume diets low in fruits and vegetables and/or high in fat, particularly saturated fat. Contrary to expectation, blacks were more frequent consumers of fruits and vegetables considered to be protective against cancer (e.g., citrus fruits, cruciferous vegetables, and vegetables rich in vitamins A and C). Intake of both total and saturated fat was slightly lower among blacks than whites. This analysis does not rule out a role for these dietary factors in the etiology of cancer but indicates that ascribing the excess cancer risk among blacks to their frequency of fruit and vegetable consumption or intake of fat per se is inadequate. This suggests that alternative dietary explanations for the racial disparity in cancer risk should be pursued in future studies.

Familial testicular cancer and urogenital developmental anomalies

In a case-control study of testicular cancer, 6 of 269 cases (2.2%) reported a first-degree relative with testicular cancer, compared to 1 of 259 controls (0.4%). Fathers and brothers of testicular cancer cases had a six-fold elevated risk of developing a testicular malignancy compared to men in the general population. Cryptorchidism was reported in a first-degree relative in 1 (17%) of the familial cases versus 7 of 259 (2.7%) controls and 14 of 263 (5.3%) cases with a negative family history for testicular cancer. One half of the 6 familial cases reported a first-degree relative with a groin hernia (all surgically repaired before age 12), compared to 12.7% of 259 controls and 10.3% of 263 nonfamilial cases. Three familial clusters identified through the case-control study were selected for clinical evaluation. One of the 6 surviving males with testicular cancer in these 3 families had undergone orchiopexy and inguinal herniorrhaphy at age 6 years, and one had a hydrocele associated with his testicular tumor. Of the 12 living fathers and brothers of these 6 men, 3 reported childhood inguinal hernias, two with coexisting hydroceles. One additional hernia and two additional hydroceles were detected during urologic evaluation of these healthy relatives. The high prevalence of cryptorchidism, inguinal hernias, and hydroceles among men in these families suggests that an underlying alteration in urogenital embryogenesis may be associated with the familial predisposition to testicular neoplasia.