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Biomedical subjects

G M Swanson

Publications and source records attributed to G M Swanson.

At least 19 recordsLinked to original sources
PubMed1997

Lung carcinoma in African Americans and whites. A population-based study in metropolitan Detroit, Michigan.

BACKGROUND: African Americans are at higher risk for lung carcinoma than whites in the United States. This racial disparity is greater among younger people. The authors evaluated whether racial differences in lung carcinoma risk can be explained by differences in cigarette smoking behaviors. METHODS: For this study, 5588 population-based cases of African Americans and whites with pathologically confirmed lung carcinoma, diagnosed between 1984 and 1987, were identified through the Metropolitan Detroit Cancer Surveillance System. Also identified were 3692 population-based controls. Logistic regression methods were used to evaluate the risk of lung carcinoma associated with race both within cigarette smoking category and after adjustment for cigarette-smoking behaviors. RESULTS: The difference in lung carcinoma incidence between African Americans and whites was explained almost entirely by differences in smoking habits among study participants age 55-84 years. However, among males age 40-54 years, African Americans were 2-4 times more likely to develop lung carcinoma of any histologic type than whites even after adjustments were made for smoking habits. Similar excesses in risk among African American females age 40-54 years were demonstrated only for squamous cell and small cell carcinomas (odds ratios [OR] and 95% confidence intervals [CI] = 3.7 [1.5-8.9] and 2.7 [1-7.3], respectively). Also, in this younger age group, African American male nonsmokers and smokers of 1-40 pack-years had a significantly higher risk of lung carcinoma than white males belonging to the same age group with a similar cigarette-smoking history (ORs and 95% CIs = 8 [2-32.8] and 3.1 [1.9-5.4] respectively). CONCLUSIONS: Elevated risk for lung carcinoma among younger (but not among older) African Americans, particularly among males, exists both within cigarette smoking exposure level and beyond that associated with smoking habits. This may indicate a high risk group particularly susceptible to lung carcinogens, or it may indicate unique exposures not yet identified.

Adenocarcinoma↗
PubMed1997

Genetic analysis of families with nonsmoking lung cancer probands.

As part of a genetic epidemiologic study of lung cancer among nonsmokers, we investigated the role of genetic predisposition in familial aggregation. Cases were identified from the Metropolitan Detroit Cancer Surveillance System. Information on lung cancer occurrence, smoking habits (active or passive), and chronic respiratory diseases in first-degree relatives was obtained for 257 nonsmoking lung cancer probands (71 males, 186 females) diagnosed at ages 40-84 years. Among the 2,021 first-degree relatives, 24 (2.6%) males and 10 (1.1%) females were reported as having lung cancer. The occurrence of lung cancer among smoking and nonsmoking relatives was 4.5% and 1.1% in males and 2.8% and 0.4% in females, respectively. To evaluate the role of a putative Mendelian gene (one locus, two alleles) in the presence of other risk factors, we performed complex segregation analyses on the data using two different regressive model approaches [Segregation Analysis of a Discrete Trait Under a Class A Regressive Logistic Model, V4.0 (REGD) and Segregation Analysis of a Truncated Trait, V2.0, Model 1(REGTL)] as implemented in the Statistical Analysis for Genetic Epidemiology (SAGE) program. Using either approach, an environmental model best explained the observed lung cancer aggregation in families ascertained through nonsmoking probands. Based on our final model, only 0.04% of this population had a very high risk and 4.2% had a moderate risk of lung cancer. The rest of the population had virtually no risk of lung cancer during their lifetime unless they have multiple risk factors. Among the high-risk individuals without any risk factor under study, the estimated risks at ages 40, 60, and 80 years in males were 16.7%, 83.6%, and 95.4%, and in females were 14.0%, 72.2%, and 88.0%, respectively. Among at-moderate-risk smokers the estimated risks at the same age and gender groups were essentially the same as in the high-risk nonsmokers. Our results suggest that the pattern of lung cancer occurrence in families of nonsmoking lung cancer patients differs from that in families of smoking lung cancer patients. Despite the profound effect of smoking on the risk of lung cancer, other environmental and/or genetic risk factors need to be identified.

Adult↗
PubMed1997

Cancers of the salivary gland: workplace risks among women and men.

PURPOSE: The purpose of this study was to assess the risk of salivary gland cancers associated with diverse occupations and industries. METHODS: A population-based case referent study utilized data obtained from a SEER program cancer registry for cases and by telephone interview for cases and referents to evaluate workplace risks of salivary gland cancer for black and white women and men. RESULTS: Significantly elevated odds ratios were observed among women employed as hairdressers and those working in beauty shops. CONCLUSIONS: The risk of salivary gland cancer is elevated among women employed as hairdressers. Further research should assess dyes, sprays, and other inhaled chemicals that may be acting as carcinogens.

Adult↗
PubMed1997

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.

Adult↗
PubMed1997

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.

Adult↗
PubMed1996

Human exposure to mercury: a critical assessment of the evidence of adverse health effects.

The ubiquitous nature of mercury in the environment, its global atmospheric cycling, and its toxicity to humans at levels that are uncomfortably close to exposures experienced by a proportion of the population are some of the current concerns associated with this pollutant. The purpose of this review is to critically evaluate the scientific quality of published reports involving human exposures to mercury and associated health outcomes as an aid in the risk evaluation of this chemical. A comprehensive review of the scientific literature involving human exposures to mercury was performed and each publication evaluated using a defined set of criteria that are considered standards in epidemiologic and toxicologic research. Severe, sometimes fatal, effects of mercury exposure at high levels were primarily reported as case studies. The disasters in Minamata, Japan, in the 1950s and in Iraq in 1971-1972 clearly demonstrated neurologic effects associated with ingestion of methylmercury both in adults and in infants exposed in utero. The effects were convincingly associated with methylmercury ingestion, despite limitations of the study design. Several well-conducted studies have investigated the effects of methylmercury at levels below those in the Iraq incident but have not provided clear evidence of an effect. The lower end of the dose-response curve constructed from the Iraq data therefore still needs to be confirmed. The studies of mercury exposure in the workplace were mainly of elemental or inorganic mercury, and effects that were observed at relatively low exposure levels were primarily neurologic and renal. Several studies have investigated effects associated with dental amalgam but have been rated as inconclusive because of methodologic deficiencies. In our overall evaluation, 29 of 110 occupational studies and 20 of 54 studies where exposure occurred in the natural environment provided at least suggestive evidence of an exposure-related effect.

Adult↗
PubMed1996

Familial risk of lung cancer among nonsmokers and their relatives.

The role of family history of lung cancer in predicting lung cancer risk among nonsmokers and their relatives was evaluated in a population-based family study conducted in metropolitan Detroit. Lung cancer risk factor data were collected through telephone interviews with 257 nonsmoking lung cancer cases 40-84 years of age diagnosed between 1984 and 1987, their 2,252 relatives, 277 nonsmoking controls, and their 2,408 relatives. Lung cancer in a first-degree relative was associated with a 7.2-fold (95% confidence interval 1.3-39.7) increased risk of lung cancer among nonsmokers in the 40- to 59-year-old age group. This significant increased risk remained after adjustment for the smoking, occupational, and medical history of each family member (relative risk = 6.1, 95% confidence interval 1.1-33.4). Offspring of nonsmoking cases comprised another lung cancer high risk group (relative risk = 7.2, 95% confidence interval 0.5-103). A positive family history did not increase lung cancer risk among nonsmokers 60-84 years of age or their relatives. These findings suggest that susceptibility to lung cancer in families of nonsmoking cases may be evident only in a subset of relatives of early-onset nonsmoking cases.

Adenocarcinoma↗
PubMed1996

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.

Adult↗
PubMed1996

Socioeconomic status and the incidence of multiple myeloma.

This population-based case-control study examined the risk of multiple myeloma in relation to socioeconomic status. Subjects included 689 cases with newly diagnosed multiple myeloma during 1977-1981 from four U.S. populations and 1,680 controls selected from residents of these same populations. We collected lifetime occupational histories and coded them according to the 1970 Duncan Socioeconomic Index and Nam-Powers Socioeconomic Status scores. We classified scores for the occupations held the longest, highest ever held, and held most recently into quartiles based on the distribution among controls. After adjusting for age group, race, and study site, risk of multiple myeloma was inversely associated with socioeconomic status scores in both men and women. Risk among persons in the lowest quartile of scores was 63% higher (95% confidence interval 21%-119%) than that among those in the highest quartile when the highest Nam-Powers score was used. Similar trends were evident for all three methods of classifying occupational history and for both Duncan and Nam-Power scores. These results changed little after removing from analyses occupations previously associated with increased risk. The occupation-based scores were stronger predictors of risk than years of education. As a proxy measure of occupational, environmental, or life-style factors, socioeconomic status may be a clue to etiologic factors for multiple myeloma.

Case-Control Studies↗
PubMed1996

Nasopharyngeal cancer in a low-risk population: defining risk factors by histological type.

Nasopharyngeal cancer (NPC) is a major public health problem in parts of Southeast Asia and North Africa, but is rare among whites and blacks. Although infection with the EBV and genetic susceptibility appear to play large roles in high-incidence populations, migrant studies suggest that environmental factors may also be important. Aside from the high risks associated with ingestion of salted fish, surprisingly few other risk factors have been established from studies in endemic areas. We studied a low-incidence population to determine whether tobacco use, alcohol consumption, and certain medical conditions and treatments are related to NPC and to examine variations in risk by histology. We reasoned that new relationships might be best identified in the absence of strong causal pathways, such as intake of preserved foods and genetic susceptibility. A population-based case-control study was conducted from 1987 to 1993 at five cancer registries in the United States: western Washington, metropolitan Detroit, Connecticut, Iowa, and Utah. Controls were identified by random digit dialing and frequency matched to the gender and age distribution of cases at each registry. Telephone interviews were completed by 231 cases and 246 controls. We observed a strong dose-response relationship between cigarette smoking and risk of differentiated squamous cell carcinoma (test for trend, P < .001). The highest risk [odds ratio (OR), 6.5; 95% confidence interval (CI), 2.0-21.3] occurred among current smokers with a history of more than 60 pack-years. In contrast, there was no evidence that undifferentiated or nonkeratinizing carcinomas were associated with cigarette smoking. Similarly, a significant increase in risk was observed for the heaviest alcohol consumers (21 or more drinks/week) only for differentiated squamous cell carcinomas (OR, 2.9; 95% CI, 1.2-6.9). The associations with cigarettes and alcohol appeared to be stronger among persons 50 years or older. There was a suggestion that diagnosis with infectious mononucleosis (a marker of late infection with EBV) is linked with decreased NPC risk (OR, 0.4; 95% CI, 0.1-1.1). This report indicates that over two-thirds of differentiated squamous cell NPC cases arising in older persons in the United States can be accounted for by cigarettes and alcohol, but leaves unexplained cases arising in the young and carcinomas of undifferentiated or nonkeratinizing histology. Future studies of NPC need to take into account histology and age in evaluating these and other environmental and genetic risk factors.

Adult↗
PubMed1996

Associations between human leukocyte antigen type and nasopharyngeal carcinoma in Caucasians in the United States.

A genetic component to nasopharyngeal carcinoma (NPC) has been suggested by associations of the malignancy with human leukocyte antigens (HLAs) in Southern Chinese populations, among which NPC is a major cancer. Data from other races are inconclusive. We have investigated associations between NPC and HLA antigens at the HLA-A, B, C, and DQ loci and alleles at the DRB1 locus in a population-based, multicenter investigation in the United States. Data from 82 cases and 140 controls are presented, making this the largest study population analyzing data from Caucasians to date. HLA frequencies from study cases were also compared with external control groups from the 11th International Histocompatibility Workshop and the National Marrow Donor Program. Logistic regression methods were used to investigate the effects of the joint occurrence of multiple HLA types and to assay for differences in HLA-associated risk in different age groups. A meta-analysis was undertaken to compare and summarize our results with previously published findings. The meta-analysis found a protective association with A2 antigen in non-Chinese [odds ratio (OR), 0.63; P < 0.001], a protective association with A11 across all races (OR, 0.54; P < 0.001), and an increased risk associated with B5 in Caucasians (OR, 2.81; P < 0.001). The present study also found independent associations, in a logistic regression model, between NPC and DRB1*1501 (OR, 0.33), DRB1*0405 (OR, 7.57), and Cw3 (OR, 0.42), although these data must be interpreted cautiously due to multiple-testing considerations. Associations were found to be more pronounced in younger patients for A2, A11, A28, B8, and B51.

Adult↗
PubMed1995

Recruiting minorities into clinical trials: toward a participant-friendly system.

The purpose of this review is to describe the state of the art in recruiting participants for clinical trials designed to test new methods of treatment or disease prevention. The ultimate objective of this review is to provide a summary of key issues in recruiting diverse populations into clinical trials, particularly ethnic and racial minorities. An overview of general issues related to clinical trial participation is followed by a detailed discussion of specific issues that must be addressed by investigators as they recruit minority populations for clinical trial. To date, the majority of clinical trials have included a limited segment of the U.S. population: middle-class, married white males. These trials have faced many problems in their efforts to recruit participants, including barriers to physician participation, barriers to subject participation, barriers to planning and implementing effective recruitment strategies, and costs of the recruitment phase of clinical trials. Following this general introduction is a discussion of the definition of diverse populations. The first step investigators must take as they prepare to recruit study participants is to develop a relevant definition of the subject populations. A detailed review of investigators' experiences in recruiting minorities into clinical trials is presented, including barriers to minority recruitment, barriers inherent in study design, researcher bias, barriers to minority physician participation, as well as strategies for minority recruitment, modifications of study design, and cost issues. Formal evaluation of recruitment strategies has been limited. Most investigators present descriptive reports of their experience in recruiting diverse populations into clinical trials. Research into the issues presented and rigorous testing of specific strategies is needed. A series of steps that are essential to effective clinical trials recruitment of diverse populations is presented.

Clinical Trials as Topic↗
PubMed1995

Alcohol and pancreatic cancer in blacks and whites in the United States.

A population-based, case-control study of pancreatic cancer based on direct interviews with 307 white and 179 black incident cases and 1164 white and 945 black population controls was conducted in three areas of the United States to determine the role alcohol drinking plays as a risk factor for pancreatic cancer and to estimate the extent to which it may explain the higher incidence of pancreatic cancer in blacks compared to whites. Our findings indicate that alcohol drinking at the levels typically consumed by the general population of the United States is probably not a risk factor for pancreatic cancer. Our data suggest, however, that heavy alcohol drinking may be related to pancreatic cancer risk. Among men, blacks and white who drank at least 57 drinks/week had odds ratios (ORs) of 2.2 [95% confidence interval (CI) = 0.9-5.6] and 1.4 (95% CI = 0.6-3.2), respectively. Among women, blacks who drank 8 to < 21 drinks/week had an OR of 1.8 (95% CI = 0.8-4.0), and those who drank at least 21 drinks/week had an OR of 2.5 (95% CI = 1.02-5.9), but whites with the same levels of alcohol intake experienced no increased risk. Compared to whites, blacks had significantly higher ORs associated with heavy alcohol drinking (> or = 57 drinks/week) in men (P = 0.04) and with moderate-to-heavy drinking (> or = 8 drinks/week) in women (P = 0.03). Additional research is needed to determine whether heavy alcohol drinking is causally related to pancreatic cancer and whether the risk of alcohol-related pancreatic cancer is greater in blacks than in whites.

Adult↗
PubMed1995

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.

Adult↗
PubMed1995

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.

Adenocarcinoma↗
PubMed1995

U.S. farm women's participation in breast cancer screening practices.

BACKGROUND: Surveys of women in the general population indicate that women are being screened for breast cancer at a much lower rate than recommended. There has been a concern that women living in rural areas may be screened for breast cancer even less often than women in urban or suburban areas because of reduced access to health practitioners. METHODS: A random sample of farm women age 40 years or older from 4 rural counties in Michigan was surveyed on knowledge, attitudes, and use of breast cancer screening. RESULTS: Six hundred eighty farm women completed a questionnaire. This was a response rate of 63.8%. The percentages of farm women who reported ever having had a mammogram, having had a mammogram in the past 3 years, and having had a mammogram in the last year were 80.6, 73.7, and 51.9%, respectively. The frequency of clinical breast examinations parallelled mammography usage at slightly higher percentages. Mammogram usage increased with higher education, income, and insurance coverage. Usage decreased in women age 75 years or older (ever 63.1%, in the last 3 years 58.2%, and in the last year 40.4%). Farm women were generally knowledgeable about symptoms and signs of breast cancer and understood the benefit of screening. There was, however, a range of answers on when to start or stop having a mammogram. Among farm women who reported not having a mammogram recently, the most important reasons were: haven't had any problems (29.4%), wasn't recommended by a doctor (14.3%), and procrastinated (11.3%). CONCLUSIONS: Farm women in this survey reported having had breast cancer screening at rates similar to or above those in the general population. Because of a limited response rate (63.5%) and the relative affluence of the farming community in the 4 counties surveyed, these results are probably not generalizable to all populations of farm or rural women.

Adult↗
PubMed1995

Human exposure to polychlorinated biphenyls (PCBs): a critical assessment of the evidence for adverse health effects.

Results from epidemiologic studies involving human exposures to polychlorinated biphenyls (PCBs) are often used to estimate the potential risk or hazard posed by the presence of these chemicals in the workplace or the environment. The use of results and conclusions from individual studies requires an assessment of the scientific quality of the information contained in published reports. The results of a critical review of the scientific literature reported here should be an aid to those who are interested in risk evaluations surrounding exposures to PCBs. There are diverse approaches that one could take to an evaluation of scientific reports of the health hazards of various chemicals. We present one approach to assessing the strengths and weaknesses of studies conducted to understand the potential association between PCB exposure and human health effects. A comprehensive review of the scientific literature involving human exposures to PCBs was performed and each study was evaluated on the basis of a defined set of criteria that were considered standards in epidemiologic research. Two of the 39 occupational studies reviewed provided positive evidence and 3 suggestive evidence for an exposure-related effect, whereas none of the 33 studies where exposure had occurred in the natural environment provided positive or suggestive evidence of an association with adverse effects.

Environmental Exposure↗