Diagnostic radiation and the risk of multiple myeloma (United States).

OBJECTIVE: To evaluate the relationship between cumulative lifetime exposure to diagnostic radiation and the risk of multiple myeloma using data from a large, multi-center, population-based case-control study. METHODS: Study subjects included a total of 540 cases with newly diagnosed multiple myeloma and 1998 frequency-matched population controls living in three areas of the United States (Georgia, Michigan, New Jersey). Information on exposure to diagnostic X-rays was obtained by personal interview. RESULTS: No association was found between case-control status and the total number of reported diagnostic X-rays of any type (odds ratio (OR) for 20 or more compared to less than 5 X-rays = 0.9, 95% confidence interval (95% CI) = 0.7-1.2). There was no evidence of an excess risk of multiple myeloma among individuals who reported exposure to 10 or more diagnostic X-rays that impart a relatively high radiation dose to the bone marrow, as compared to individuals reporting no such exposures (OR 0.7, 95% CI 0.4-1.3). CONCLUSIONS: These data suggest that exposure to diagnostic X-rays has a negligible impact, if any, on risk of developing multiple myeloma.

Diet and nutrition as risk factors for multiple myeloma among blacks and whites in the United States.

OBJECTIVES: To explore whether dietary factors contribute to the risk of multiple myeloma and the two-fold higher incidence among blacks compared to whites in the United States. METHODS: Data from a food-frequency questionnaire were analyzed for 346 white and 193 black subjects with multiple myeloma, and 1086 white and 903 black controls who participated in a population-based case-control study of multiple myeloma in three areas of the United States. RESULTS: Elevated risks were associated with obese vs. normal weight (OR = 1.9, 95% confidence interval (CI) = 1.2-3.1 for whites and OR = 1.5, 95% CI = 0.9-2.4 for blacks), while the frequency of obesity was greater for black than white controls. Reduced risks were related to frequent intake of cruciferous vegetables (OR = 0.7, 95% CI = 0.6-0.99) and fish (OR = 0.7, 95% CI = 0.5-0.9) in both races combined, and to vitamin C supplements in whites (OR = 0.6, 95% CI = 0.5-0.9) and blacks (OR = 0.8, 95% CI = 0.5-1.4), with the frequency of vitamin supplement use being greater for white than black controls. However, frequent intake of vitamin C from food and supplements combined was associated with a protective effect in whites (OR = 0.6, 95% CI = 0.4-0.9), but not blacks (OR = 1.2, 95% CI = 0.8-2.1). CONCLUSIONS: The greater use of vitamin C supplements by whites and the higher frequency of obesity among blacks may explain part of the higher incidence of multiple myeloma among blacks compared to whites in the United States. In addition, the increasing prevalence of obesity may have contributed to the upward trend in the incidence of multiple myeloma during recent decades.

Occupational exposure to pesticides and pancreatic cancer.

BACKGROUND: An increased risk of exposure to pesticides for pancreatic cancer has been suggested in a number of epidemiologic studies. METHODS: Cases (N = 484), aged 30-79 years, were diagnosed in 1986-1989. Controls (N = 2,095) were a random sample of the general population. Information on usual occupation and potential confounding factors was obtained. A job-exposure matrix (JEM) approach was used to estimate the level of occupational exposure to pesticides. RESULTS: A significant trend in risk with increasing exposure level of pesticides was observed, with ORs of 1.3 and 1.4 for low and moderate/high exposure levels, respectively. Excess risks were found for occupational exposure to fungicides (OR = 1.5) and herbicides (OR = 1.6) in the moderate/high level after adjustment for potential confounding factors. An increased risk for insecticide exposure was disappeared after adjustment for fungicide and herbicide exposures. Results of our occupation-based analysis were consistent with those from the JEM-based analysis. CONCLUSIONS: Our results suggest that pesticides may increase risk of pancreatic cancer, and indicate the need for investigations that can evaluate risk by specific chemical exposures. Published 2001 Wiley-Liss, Inc.

Socioeconomic status and multiple myeloma among US blacks and whites.

OBJECTIVES: This study examined the relation between socioeconomic status (SES) and risk of multiple myeloma among Blacks and Whites in the United States. METHODS: This population-based case-control study included 573 cases (206 Blacks and 367 Whites) with new diagnoses of multiple myeloma identified between August 1, 1986, and April 30, 1989, and 2131 controls (967 Blacks and 1164 Whites) from 3 US geographic areas. Information on occupation, income, and education was obtained by personal interview. RESULTS: Inverse gradients in risk were associated with occupation-based SES, income, and education. Risks were significantly elevated for subjects in the lowest categories of occupation-based SES (odds ratio [OR] = 1.71, 95% confidence interval [CI] = 1.16, 2.53), education (OR = 1.36, 95% CI = 1.06, 1.75), and income (OR = 1.43, 95% CI = 1.05, 1.93). Occupation-based low SES accounted for 37% of multiple myeloma in Blacks and 17% in Whites, as well as 49% of the excess incidence in Blacks. Low education and low income accounted for 17% and 28% of the excess incidence in Blacks, respectively. CONCLUSIONS: Our results indicate that the measured SES-related factors account for a substantial amount of the Black-White differential in multiple myeloma incidence.

Respiratory cancer in a cohort of copper smelter workers: results from more than 50 years of follow-up.

Several studies have linked inhalation of airborne arsenic with increased risk of respiratory cancer, but few have analyzed the shape of the exposure-response curve. In addition, since inhaled airborne arsenic affects systemic levels of inhaled arsenic, there is concern that inhaled arsenic may be associated with cancers of the skin, bladder, kidney, and liver, which have been linked to ingested arsenic. The authors followed 8,014 white male workers who were employed for 12 months or more prior to 1957 at a Montana copper smelter from January 1, 1938 through December 31, 1989. A total of 4,930 (62%) were deceased, including 446 from respiratory cancer. Significantly increased standardized mortality ratios (SMRs) were found for all causes (SMR = 1.14), all cancers (SMR = 1.13), respiratory cancer (SMR = 1.55), diseases of the nervous system and sense organs (SMR = 1.31), nonmalignant respiratory diseases (SMR = 1.56), emphysema (SMR = 1.73), ill-defined conditions (SMR = 2.26), and external causes (SMR = 1.35). Internal analyses revealed a significant, linear increase in the excess relative risk of respiratory cancer with increasing exposure to inhaled airborne arsenic. The estimate of the excess relative risk per mg/m3-year was 0.21/(mg/m3-year) (95% confidence interval: 0.10, 0.46). No other cause of death was related to inhaled arsenic exposure.

Sexual behaviour, STDs and risks for prostate cancer.

A population-based case-control study was carried out among 981 men (479 black, 502 white) with pathologically confirmed prostate cancer and 1315 controls (594 black, 721 white). In-person interviews elicited information on sexual behaviour and other potential risk factors for prostate cancer. Blood was drawn for serologic studies in a subset of the cases (n = 276) and controls (n = 295). Prostate cancer risk was increased among men who reported a history of gonorrhoea or syphilis (odds ratio (OR) = 1.6; 95% confidence internal (CI) 1.2-2.1) or showed serological evidence of syphilis (MHA-TP) (OR = 1.8; 95% CI 1.0-3.5). Patterns of risk for gonorrhoea and syphilis were similar for blacks (OR = 1.7; 95% CI 1.2-2.2) and whites (OR = 1.6; 95% CI 0.8-3.2). Risks increased with increasing occurrences of gonorrhoea, rising to OR = 3.3 (95% CI 1.4-7.8) among subjects with three or more events (Ptrend = 0.0005). Frequent sexual encounters with prostitutes and failure to use condoms were also associated with increased risk. Syphilis, gonorrhoea, sex with prostitutes and unprotected sexual intercourse may be indicators of contact with a sexually transmissible factor that increases the risk of prostate cancer.

Diabetes mellitus, other medical conditions and familial history of cancer as risk factors for pancreatic cancer.

In a population-based case-control study of pancreatic cancer conducted in three areas of the USA, 484 cases and 2099 controls were interviewed to evaluate the aetiologic role of several medical conditions/interventions, including diabetes mellitus, cholecystectomy, ulcer/gastrectomy and allergic states. We also evaluated risk associated with family history of cancer. Our findings support previous studies indicating that diabetes is a risk factor for pancreatic cancer, as well as a possible complication of the tumour. A significant positive trend in risk with increasing years prior to diagnosis of pancreatic cancer was apparent (P-value for test of trend = 0.016), with diabetics diagnosed at least 10 years prior to diagnosis having a significant 50% increased risk. Those treated with insulin had risks similar to those not treated with insulin (odds ratio (OR) = 1.6 and 1.5 respectively), and no trend in risk was associated with increasing duration of insulin treatment. Cholecystectomy also appeared to be a risk factor, as well as a consequence of the malignancy. Subjects with a cholecystectomy at least 20 years prior to the diagnosis of pancreatic cancer experienced a 70% increased risk, which was marginally significant. In contrast, subjects with a history of duodenal or gastric ulcer had little or no elevated risk (OR = 1.2; confidence interval = 0.9-1.6). Those treated by gastrectomy had the same risk as those not receiving surgery, providing little support for the hypothesis that gastrectomy is a risk factor for pancreatic cancer. A significant 40% reduced risk was associated with hay fever, a non-significant 50% decreased risk with allergies to animals, and a non-significant 40% reduced risk with allergies to dust/moulds. These associations, however, may be due to chance since no risk reductions were apparent for asthma or several other types of allergies. In addition, we observed significantly increased risks for subjects reporting a first-degree relative with cancers of the pancreas (OR = 3.2), colon (OR = 1.7) or ovary (OR = 5.3) and non-significantly increased risks for cancers of the endometrium (OR = 1.5) or breast (OR = 1.3). The pattern is consistent with the familial predisposition reported for pancreatic cancer and with the array of tumours associated with hereditary non-polyposis colon cancer.

Multiple myeloma and family history of cancer among blacks and whites in the U.S.

BACKGROUND: In the U.S., the incidence rate of multiple myeloma is more than twice as high for blacks as for whites, but the etiology of this malignancy is not well understood. METHODS: A population-based case-control interview study of 565 subjects (361 white, 204 black) with multiple myeloma and 2104 controls (1150 white, 954 black) living in 3 areas of the U.S. offered the opportunity to explore whether family history, of cancer contributes to the risk of multiple myeloma and explains the racial disparity in risk. RESULTS: For both races combined, the risk of multiple myeloma was significantly elevated for subjects who reported that a first-degree relative had multiple myeloma (odds ratio [OR] = 3.7, 95% confidence interval [CI] = 1.2-12.0). Increased risk was also associated with a family history of any hematolymphoproliferative (HLP) cancer (OR = 1.7, 95% CI = 1.0-2.8), especially in a sibling (OR = 2.3, 95% CI = 1.1-4.5). The risk associated with familial occurrence of HLP cancer was higher for blacks than for whites, but the difference between the ORs was not statistically significant. CONCLUSIONS: These data are consistent with previous studies that indicate a familial risk of multiple myeloma, but they explain little of the race-related difference in incidence rates.

Dietary factors and risks for prostate cancer among blacks and whites in the United States.

Prostate cancer is the most common malignancy in men in the United States, with substantially higher rates among American blacks than whites. We carried out a population-based case-control study in three geographic areas of the United States to evaluate the reasons for the racial disparity in incidence rates. A total of 932 men (449 black men and 483 white men) who had been newly diagnosed with pathologically confirmed prostate cancer and 1201 controls (543 black men and 658 white men) were interviewed in person to elicit information on potential risk factors. This report evaluates the impact of dietary factors, particularly the consumption of animal products and animal fat, on the risk of prostate cancer among blacks and whites in the United States. Increased consumption (grams/day) of foods high in animal fat was linked to prostate cancer (independent of intake of other calories) among American blacks [by quartile of intake, odds ratio (OR) = 1.0 (referent), 1.5, 2.1, and 2.0; Ptrend = 0.007], but not among American whites [by quartile of intake, OR = 1.0 (referent), 1.6, 1.5, and 1.1; Ptrend = 0.90]. However, risks for advanced prostate cancer were higher with greater intake of foods high in animal fat among blacks [by quartile of intake, OR = 1.0 (referent), 2.2, 4.2, and 3.1; Ptrend = 0.006] and whites [by quartile of intake, OR = 1.0 (referent), 2.2, 2.6, and 2.4; Ptrend = 0.02]. Increased intake of animal fat as a proportion of total caloric intake also showed positive but weaker associations with advanced prostate cancer among blacks (Ptrend = 0.13) and whites (Ptrend = 0.08). No clear associations were found with vitamin A, calcium, or specific lycopene-rich foods. The study linked greater consumption of fat from animal sources to increased risk for prostate cancer among American blacks and to advanced prostate cancer among American blacks and whites. A reduction of fat from animal sources in the diet could lead to decreased incidence and mortality rates for prostate cancer, particularly among American blacks.

Dietary and nutritional factors and pancreatic cancer: a case-control study based on direct interviews.

BACKGROUND: The relationship between diet and pancreatic cancer remains unclear. In this study, we assessed the role of diet and nutrition as risk factors for pancreatic cancer, using data obtained from direct interviews only, rather than data from less reliable interviews with next of kin. We evaluated whether dietary factors could explain the higher incidence of pancreatic cancer experienced by black Americans compared with white Americans. METHODS: We conducted a population-based case-control study of pancreatic cancer diagnosed in Atlanta (GA), Detroit (MI), and 10 New Jersey counties from August 1986 through April 1989. Reliable dietary histories were obtained for 436 patients and 2003 general-population control subjects aged 30-79 years. RESULTS: Obesity was associated with a statistically significant 50%-60% increased risk of pancreatic cancer that was consistent by sex and race. Although the magnitude of risk associated with obesity was identical in blacks and whites, a higher percentage of blacks were obese than were whites (women: 38% versus 16%; men: 27% versus 22%). A statistically significant positive trend in risk was observed with increasing caloric intake, with subjects in the highest quartile of caloric intake experiencing a 70% higher risk than those in the lowest quartile. A statistically significant interaction between body mass index (weight in kg/height in m2 for men and weight in kg/height in m1.5 for women) and total caloric intake was observed that was consistent by sex and race. Subjects in the highest quartile of both body mass index and caloric intake had a statistically significant 180% higher risk than those in the lowest quartile. CONCLUSIONS: Obesity is a risk factor for pancreatic cancer and appears to contribute to the higher risk of this disease among blacks than among whites in the United States, particularly among women. Furthermore, the interaction between body mass index and caloric intake suggests the importance of energy balance in pancreatic carcinogenesis.

Dietary factors and the risk of squamous cell esophageal cancer among black and white men in the United States.

OBJECTIVES: To investigate dietary factors for squamous cell esophageal cancer and whether these factors may contribute to the five-fold higher incidence of this cancer in the black versus white population of the United States. METHODS: Data from a food frequency questionnaire were analyzed for 114 white men and 219 black men with squamous cell esophageal cancer, and 681 white and 557 black male controls from three areas of the United States who participated in a population-based case-control study of esophageal cancer. RESULTS: Protective effects were associated with intake of raw fruits and vegetables (odds ratio for high versus low consumers = 0.3 in both white and black men) and use of vitamin supplements (especially vitamin C; odds ratio for high versus low consumers = 0.4 in both races), with the frequency of consumption of raw fruits and vegetables and vitamin supplements being greater for white than black controls. In addition, elevated risks were associated with high versus low intake of red meat (OR = 2.7 for blacks and 1.5 for whites) and processed meat (OR = 1.6 for blacks and 1.7 for whites), with the levels of consumption being greater for black than white controls. CONCLUSIONS: In the United States, these dietary factors may contribute in part to the much higher incidence of squamous cell esophageal cancer among black compared to white men.

Drinking practices and risk of squamous-cell esophageal cancer among Black and White men in the United States.

To evaluate whether the fivefold greater incidence rate of squamous-cell esophageal cancer in Black compared with White men is due to type of alcoholic beverage consumed or to other qualitative differences in alcohol consumption, we conducted a population-based case-control study with 373 males diagnosed with squamous-cell esophageal cancer (124 Whites and 249 Blacks) and 1,364 male controls (750 Whites and 614 Blacks) from three geographic areas in the United States. Included were all histologically confirmed cases newly diagnosed from 1 August 1986 through 30 April 1989, among White and Black men aged 30 to 79 years. Risks varied to some extent according to type of alcohol used, with beer a stronger contributor in Whites, and wine and liquor stronger contributors in Blacks. However, most of the differences in the odds ratios by type of alcohol and race were eliminated after controlling for average weekly amount of total alcohol consumed. Thus, while alcohol use in all forms is an important risk factor for squamous-cell esophageal cancer in Whites and Blacks, type of alcoholic beverage used does not appear to account for the racial differences in incidence.

Multiple myeloma among Blacks and Whites in the United States: role of cigarettes and alcoholic beverages.

In the United States, the incidence rates of multiple myeloma in Blacks are more than twice those in Whites, but the etiology of this cancer is poorly understood. A population-based case-control interview study of 571 subjects (365 White, 206 Black) with multiple myeloma and 2,122 controls (1,155 White, 967 Black) living in three areas of the United States (Georgia, Michigan, New Jersey) offered the opportunity to investigate the relationship with smoking and alcohol drinking and to evaluate whether these factors might contribute to the excess risk of multiple myeloma in Blacks. For Blacks and Whites of either gender, there were no significantly elevated risks associated with ever use of cigarettes or alcoholic beverages and no consistent patterns with either intensity or duration of use. These data support previous studies indicating that smoking and drinking are not related causally to the risk of multiple myeloma, and thus cannot account for the racial disparity in incidence rates.

Alcohol use and prostate cancer risk in US blacks and whites.

Prostate cancer is the most common malignancy in US men (more than 165,000 cases per annum) and occurs substantially more frequently in blacks than in whites. The causes of this disease are, however, poorly understood. Alcohol consumption, which has been clearly related to malignancies of the upper aerodigestive tract, may also increase risk of cancer at other sites, including the prostate. The authors investigated alcohol use as a risk factor for prostate cancer among US blacks and whites. A population-based, case-control study was carried out among 981 men (479 blacks and 502 whites) with pathologically confirmed prostate cancer diagnosed between August 1, 1986, and April 30, 1989, and 1,315 controls (594 blacks and 721 whites) who resided in Atlanta, Georgia; Detroit, Michigan; and 10 counties in New Jersey, geographic areas covered by three population-based cancer registries. In-person interviews elicited information on alcohol use and other factors possibly related to prostate cancer. Compared with never-users, risk for prostate cancer increased with amount of alcohol drunk (chi2 (trend), p < 0.001), with significantly elevated risks seen for those who had 22-56 drinks per week (odds ratio = 1.4; 95% confidence interval 1.0-1.8) and 57 or more drinks per week (odds ratio = 1.9; 95% confidence interval 1.3-2.7). The finding was consistent among blacks (chi2 (trend), p < 0.01) and whites (chi2 (trend), p < 0.05), and among young and old subjects; it was not restricted to a specific type of alcoholic beverage. In this first large study among US blacks and whites, increased risk for prostate cancer was associated with increased alcohol use. The risk was similar for whites and blacks and could not be attributed to tobacco use or to a number of other potential confounders.

Risks of non-Hodgkin's lymphoma, multiple myeloma, and leukemia associated with common medications.

We utilized data from two Kaiser Permanente medical care programs to evaluate risks of hematopoietic and lymphoproliferative (HLP) malignancies after use of 14 common medications. The subjects were adult cases of non-Hodgkin's lymphoma (NHL) (N = 94), multiple myeloma (N = 159), and leukemia (N = 257) and individually matched controls (N = 695). Abstractors reviewed medical records and recorded medication notations. Using a minimum 5-year exposure lag between first notation and malignancy diagnosis, the risk of NHL was greater among plan members who were prescribed amphetamines [odds ratio (OR) = 2.2; 95% confidence interval (CI) = 1.1-4.8], lidocaine (OR = 2.6; 95% CI = 1.2-5.5), and meprobamate (OR = 2.1; 95% CI = 1.03-4.3). The risk of NHL rose with increasing number of medical record notations for amphetamines; however, there was no association with number of notations for lidocaine or meprobamate. The odds ratio for total leukemia was decreased among patients who took chloramphenicol (OR = 0.4; 95% CI = 0.2-0.97).

Thyroid cancer after exposure to external radiation: a pooled analysis of seven studies.

The thyroid gland of children is especially vulnerable to the carcinogenic action of ionizing radiation. To provide insights into various modifying influences on risk, seven major studies with organ doses to individual subjects were evaluated. Five cohort studies (atomic bomb survivors, children treated for tinea capitis, two studies of children irradiated for enlarged tonsils, and infants irradiated for an enlarged thymus gland) and two case-control studies (patients with cervical cancer and childhood cancer) were studied. The combined studies include almost 120,000 people (approximately 58,000 exposed to a wide range of doses and 61,000 nonexposed subjects), nearly 700 thyroid cancers and 3,000,000 person years of follow-up. For persons exposed to radiation before age 15 years, linearity best described the dose response, even down to 0.10 Gy. At the highest doses (> 10 Gy), associated with cancer therapy, there appeared to be a decrease or leveling of risk. For childhood exposures, the pooled excess relative risk per Gy (ERR/Gy) was 7.7 (95% CI = 2.1, 28.7) and the excess absolute risk per 10(4) PY Gy (EAR/10(4) PY Gy) was 4.4 (95% CI = 1.9, 10.1). The attributable risk percent (AR%) at 1 Gy was 88%. However, these summary estimates were affected strongly by age at exposure even within this limited age range. The ERR was greater (P = 0.07) for females than males, but the findings from the individual studies were not consistent. The EAR was higher among women, reflecting their higher rate of naturally occurring thyroid cancer. The distribution of ERR over time followed neither a simple multiplicative nor an additive pattern in relation to background occurrence. Only two cases were seen within 5 years of exposure. The ERR began to decline about 30 years after exposure but was still elevated at 40 years. Risk also decreased significantly with increasing age at exposure, with little risk apparent after age 20 years. Based on limited data, there was a suggestion that spreading dose over time (from a few days to > 1 year) may lower risk, possibly due to the opportunity for cellular repair mechanisms to operate. The thyroid gland in children has one of the highest risk coefficients of any organ and is the only tissue with convincing evidence for risk about 1.10 Gy.

Prostate cancer risk in U.S. blacks and whites with a family history of cancer.

Prostate cancer occurs more frequently in U.S. blacks than whites. A population-based case-control study which investigated the association with family history of cancer was carried out among 981 men (479 black, 502 white) with pathologically confirmed prostate cancer, diagnosed between August 1, 1986, and April 30, 1989, and 1,315 controls (594 black, 721 white). Study subjects, aged 40-79, resided in Atlanta, Detroit, and 10 counties in New Jersey, geographic areas covered by population-based cancer registries. Prostate cancer risk was significantly elevated among those who reported a history of prostate cancer in first-degree relatives (O.R. = 3.2; 95% C.I.: 2.0-5.0), with blacks and whites having similarly elevated risks. These risks were unchanged by statistical adjustment for job-related socio-economic status, education, income, and marital status. Overall, the ORs associated with history of prostate cancer in fathers and brothers were 2.5 (95% C.I.: 1.5-4.2) and 5.3 (95% C.I.: 2.3-12.5), respectively. Risks associated with a family history of prostate cancer were consistently elevated among younger and older subjects. Only small non-significant excesses of prostate cancer risk were associated with a family history of breast, colorectal, or other cancers. While familial occurrence is a key risk factor for prostate cancer and likely to be genetically based, the similar familial risks among blacks and whites suggest that the ethnic disparity in incidence is influenced by environmental factors.

Adenocarcinoma of the esophagus: role of obesity and diet.

BACKGROUND: In the United States, the incidence of adenocarcinoma of the esophagus, including the esophagogastric junction, has been increasing rapidly over the past two decades. Except for an association with Barrett's esophagus, little is known about the etiology of these cancers. PURPOSE: Our purpose was to investigate dietary and nutritional risk factors for adenocarcinoma of the esophagus. METHODS: A population-based, case-control interview study of 174 white men with adenocarcinoma of the esophagus and 750 control subjects living in three areas of the United States was conducted during 1986 through 1989. RESULTS: Risk was significantly elevated for subjects in the heaviest quartile compared with the lightest quartile of body mass index (odds ratio [OR] = 3.1; 95% confidence interval [CI] = 1.8-5.3). No significant associations were seen with total calories from food, number of meals eaten per day, level of fat intake, or consumption of coffee and tea. Risks were highest for those consuming the least amount of vegetables, with some evidence of a dose response for the subcategories of cruciferous vegetables (P for trend < .001) and vegetables consumed raw (P for trend = .10). A significantly elevated risk was also seen for those consuming the least amount of raw fruit (P for trend = .05). No clear associations were reported for intake of particular micronutrients overall or in supplements, but a significant protective effect was associated with increasing intake of dietary fiber (P for trend = .004). CONCLUSIONS: The findings of an increased risk with obesity and decreased risks with intake of raw fruits and vegetables and dietary fiber provide useful directions to pursue in further investigations of this malignancy. IMPLICATIONS: The finding with respect to obesity is particularly noteworthy, since it may explain at least a portion of the recent epidemic increases reported in the incidence of this tumor.

Multiple myeloma among blacks and whites in the United States: the role of chronic antigenic stimulation.

Multiple myeloma (MM) is twice as common among Blacks than Whites in the United States. The reasons for this racial disparity are unknown, and the etiology of this cancer, in general, is poorly understood. Repeated or chronic antigenic stimulation (CAS) of the immune system has been suggested as a risk factor. Previous case-control studies have reported inconsistent CAS associations based on evaluations of individual and biologic categories of medical conditions. Interview data from 573 cases and 2,131 population-based controls were used to investigate further the CAS hypothesis using an immunologically based approach, and to determine whether CAS accounts for the excess of myeloma among Blacks. Over 50 medical conditions were grouped into biologically and immunologically related categories, and B-cell- and T-cell-mediated response groups. Except for urinary tract infections among Black men (odds ratio [OR] = 2.0), no significantly increased risks of MM were observed. However, there was a suggestion of increased risk among Blacks with an increased exposure to anaphylactic conditions. Analysis by immunoglobulin type revealed significantly elevated risks of IgG myeloma with eczema (OR = 2.1), the biologic category 'allergic conditions' (OR = 1.6), and the immunologic category 'anaphylaxis response' (OR = 1.6) among Whites, with Blacks having slightly lower risks. Our findings do not support a causal relationship between CAS and MM, nor do they explain the higher incidence among Blacks.

Are racial differences in squamous cell esophageal cancer explained by alcohol and tobacco use?

BACKGROUND: In the United States, incidence rates of squamous cell esophageal cancer are more than five times higher among black men than among white men. Reasons that might explain this large racial disparity are being sought. PURPOSE: We evaluated whether differential use of alcohol and tobacco can fully account for the excess of squamous cell esophageal cancer among U.S. blacks. METHODS: We conducted a population-based, case-control study with in-person interviews with 373 squamous cell esophageal cancer case patients (124 white males and 249 black males) and 1364 control subjects (750 white males and 614 black males) from three U.S. geographic areas. Histologically confirmed cases of squamous cell esophageal cancer newly diagnosed from August 1, 1986, through April 30, 1989, among white and black men aged 30-79 years were included. RESULTS: Alcohol use of more than one drink per day and/or current cigarette use of at least one pack per day accounted for 92.7% (95% confidence interval [CI] = 86.8%-98.5%) of the squamous cell esophageal cancers in blacks, versus 86.3% (95% CI = 75.5%-97.1%) in whites, and for 94% of the difference between the black and white annual incidence rates. The interaction between race and the continuous drinking/smoking variable in a logistic regression analysis was statistically significant (two-sided, P = .02). Exposure rates among controls at all levels of combined alcohol and tobacco use examined were slightly higher among blacks and accounted for a small portion of the racial differences in incidence rates. CONCLUSION: Although the vast majority of esophageal cancers in both blacks and whites in our data can be explained by use of alcohol and tobacco, it is not clear why heavy consumption of alcohol and/or tobacco is responsible for 14.9 per 100,000 per year more cases of squamous cell esophageal cancer among blacks than among whites. The differences in the odds ratios appear to account for more of the racial differences in incidence rates than do the prevalences of exposure to alcohol and tobacco alone. The reasons for this apparent racial difference in carcinogenic risk from the same level of alcohol and tobacco use are unknown, but they may include qualitative differences in alcohol consumption, differences in other environmental exposures that interact with alcohol and/or tobacco to modify risks, or differences in susceptibility to these factors.