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Biomedical subjects

W J Blot

Publications and source records attributed to W J Blot.

At least 19 recordsLinked to original sources
PubMed1992

A population-based case-control study of cancers of the nasal cavity and paranasal sinuses in Shanghai.

A population-based case-control study of cancer of the nasal cavity and sinuses, involving interviews of 60 incident cases and 414 controls, was conducted in Shanghai. Cigarette smoking was associated with a mild elevation in risk of squamous-cell carcinoma but not cancers of other cell types. Occupational exposures to wood and silica dusts and to petroleum products, and the use of wood and straw as cooking fuel, were linked to moderate increases in risk, while 4-fold or greater increases were associated with a history of chronic nasal diseases, including those occurring 10 or more years prior to cancer diagnosis. Dietary analyses revealed a significant protective effect of consumption of allium vegetables, oranges and tangerines, with a 50% reduced risk of nasal cancer among individuals in the highest intake group of these foods. Consumption of salt-preserved vegetables, meat and fish was associated with a significantly increased risk of nasal cancer in a dose-response fashion, with a 5-fold excess observed for the heaviest intake of these salted foods. These findings suggest that dietary factors may contribute to the development of nasal cancer.

Adult↗
PubMed1992

Risk factors for renal-cell cancer in Shanghai, China.

A population-based case-control study of 154 histologically verified renal-cell cancer patients and 157 controls was performed in Shanghai, China, an area with low rates for this tumor. Elevated risks were observed for cigarette smoking (odds ratio (OR) = 2.3; 95% confidence interval (CI): 1.1 to 4.9), and for increasing categories of body weight and meat consumption, while reduced risks were seen for increasing categories of fruit and vegetable intake. An increased risk was also observed for regular use of phenacetin-containing analgesics (OR = 2.3; 95% CI:0.7 to 7.0). These findings are consistent with earlier studies in Western countries, and indicate that many of the same etiologic factors for renal-cell cancer operate in low- and high-risk societies.

Adult↗
PubMed1992

Cigarette smoking and other risk factors for progression of precancerous stomach lesions.

BACKGROUND: Stomach cancer is generally thought to evolve through a series of gastric mucosal changes, but the determinants of the precancerous lesions are not well understood. PURPOSE: Our purpose was to assess risk factors for intestinal metaplasia and gastric dysplasia arising from chronic atrophic gastritis in a general population at high risk for stomach cancer. METHODS: A population-based gastroscopic screening of more than 3000 residents was conducted in a county in China with one of the world's highest rates of stomach cancer. Information on the lifestyle and other characteristics of the participants was obtained by interview, and responses were compared between those in whom the most advanced gastric lesion was dysplasia or intestinal metaplasia versus those with chronic atrophic gastritis. RESULTS: Cigarette smoking was found to nearly double the risk of transition to dysplasia and to be a mild risk factor for intestinal metaplasia. Smoking accounted almost entirely for the 55% higher prevalence of dysplasia among men than among women. Risk of transition to dysplasia had a weak association with several dietary factors and was increased among those participants with a family history of stomach cancer and with blood type A. CONCLUSIONS: The findings provide strong evidence for a role of tobacco consumption and offer clues to other environmental and genetic factors involved in the process of gastric carcinogenesis.

Adult↗
PubMed1992

Diet and other risk factors for laryngeal cancer in Shanghai, China.

A population-based, case-control study of laryngeal cancer was conducted in Shanghai, China, during 1988-1990, in which 201 incident cases (177 males, 24 females) and 414 controls (269 males, 145 females) were interviewed. Cigarette smoking was the major risk factor, accounting for 86% of the male and 54% of the female cases. After adjusting for smoking, there was little increase in risk associated with drinking alcoholic beverages. Among men, cases more often reported occupational exposures to asbestos and coal dust. A protective effect was associated with the intake of fruits (particularly oranges and tangerines), certain dark green/yellow vegetables, and garlic, but there was an increased risk with the intake of salt-preserved meat and fish. The findings suggest that risk factors for laryngeal cancer in Shanghai resemble those in Western countries, and they provide further evidence that dietary factors play an important etiologic role.

Adult↗
PubMed1992

Second primary tumors in patients with oral cancer.

BACKGROUND: Patients with cancer of the oral cavity and pharynx have been described to be particularly susceptible to the development of new cancers. METHODS: Using data collected during 1973-1987 by nine population-based cancer registries in the United States, the authors evaluated risks of second primary cancers among 21,371 patients in whom oral and pharyngeal cancers were diagnosed. RESULTS: The rate of development of second tumors was 3.7% per year. The risk of a second primary cancer was 2.8 times greater than expected, with 20-fold excesses of second oral or esophageal cancers and 4-fold to 7-fold increases of respiratory cancers. Increased risks persisted unabated for cancers diagnosed 5 or more years after oral cancer, suggesting that the second cancers were new primary tumors and not misdiagnosed metastases. The increased risks of second primary tumors were found among both men and women and black and white patients; they were most prominent among patients who were 60 years or younger. CONCLUSIONS: The exceptionally high rate of cancer recurrence among patients with oral cancer (exceeding that for all other cancers) points to the need for close medical surveillance. Special emphasis should be placed on advising patients to avoid or limit consumption of tobacco and alcohol, the main risk factors for oral and most second cancers.

Age Factors↗
PubMed1992

Risk of lung cancer among cigarette and pipe smokers in southern China.

Studies in Shanghai and in north-east China indicate that cigarette smoking is a major contributor to the high rates of lung cancer in those areas, but doubts persist regarding the influence of cigarette use on lung cancer rates in other areas of China. In addition, the risk of lung cancer associated with other methods of tobacco consumption--in particular, the use of bamboo water-pipes and long-stem pipes--is uncertain. A population-based case-control study of 427 male lung cancer patients residing in a mining area of Southern China and 1,011 controls was carried out to address this and other issues. Of these patients, 63% smoked cigarettes and (water and long-stem) pipes; 17% and 14% smoked only cigarettes or pipes, respectively; and 6% did not smoke. Compared to non-smokers, smokers of cigarettes only, smokers of pipes only and mixed smokers were at increased risk; OR = 2.6 (95% CI 1.1-6.2), 1.8 (95% CI 0.8-4.2) and 4.1 (95% CI 2.3-9.2), respectively. Risk increased with duration of tobacco use; however, the rate of increase with years of cigarette use was significantly greater than for years of pipe use (p = 0.03). In addition, risks increased 8-fold in the highest quartile of number of cigarettes per day compared to non-cigarette smokers vs. 2.3-fold for the highest quartile of number of liang (50 g) smoked per month compared to non-pipe-smokers; the trends in the ORs differed significantly (p less than 0.001). Results suggest that, in this area of China, tobacco use is an important cause of lung cancer, and that smoking cigarettes may be more deleterious than smoking pipes (primarily water pipes).

Adult↗
PubMed1992

Vitamin supplement use and reduced risk of oral and pharyngeal cancer.

Use of vitamin and mineral supplements was assessed in a population-based case-control study of oral and pharyngeal cancer, conducted during 1984-1985 in four areas of the United States. There was no association with intake of multivitamin products, but users of supplements of individual vitamins, including vitamins A, B, C, and E, were at lower risk after controlling for the effects of tobacco, alcohol, and other risk factors for these cancers. After further adjustment for use of other supplements, vitamin E was the only supplement that remained associated with a significantly reduced cancer risk. The adjusted odds ratio of oral and pharyngeal cancer for "ever regularly used" vitamin E was 0.5 (95% confidence interval 0.4-0.6). To the authors' knowledge, this is the first epidemiologic study to show a reduced oral cancer risk with vitamin E use. Although it is not clear that the lower risk among consumers of vitamin E supplements is due to the vitamin per se, the findings are consistent with experimental evidence and should prompt further research on the role of vitamin E and other micronutrients as inhibitors of oral and pharyngeal cancer.

Age Factors↗
PubMed1992

Cigarette smoking, alcohol, and nasopharyngeal carcinoma: a case-control study among U.S. whites.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a relatively uncommon cancer in the United States. Its etiology among White Americans is not well known, but cigarette smoking has been implicated in some epidemiologic studies. PURPOSE: The purpose of this study was to investigate the roles of cigarette use and alcohol consumption as risk factors for NPC in the United States. METHODS: We conducted a case-control study using data from the National Mortality Followback Survey based on information from death certificates. In this study, we compared use of cigarettes and alcohol by 204 White American men and women who died of NPC with that by 408 who died of causes unrelated to cigarette smoking and alcohol use. RESULTS: Risk of NPC increased in proportion to the amount and duration of smoking (with a more than threefold increase among persons smoking heavily) and declined following cessation of smoking. After controlling for smoking, we found an 80% excess risk of NPC among persons whose intake of alcohol was heavy. CONCLUSION: Use of cigarettes and consumption of alcohol were found to be statistically significant risk factors for NPC. The findings are among the strongest to date indicating that use of cigarettes and perhaps alcohol may contribute to the etiology of these relatively rare cancers among Whites in the United States.

Adult↗
PubMed1992

Dietary determinants of lung-cancer risk: results from a case-control study in Yunnan Province, China.

The relation between diet and lung cancer was studied among male residents of a mining community in Yunnan Province. After obtaining food frequency data from subjects or proxies, we compared diets of 428 cases, aged 35-74 years, and 1,011 age-matched controls. Cases tended to consume slightly more rice, but less protein-rich foods (i.e., bean curd, meat, eggs) and vegetables than did controls. The relative risks of lung cancer across increasing quartiles of meat (i.e., pork) consumption, for example, were 1.00, 0.67, 0.72 and 0.46 (p for trend less than 0.01). The relative risks of lung cancer across increasing quartiles of consumption of dark-green, leafy vegetables were 1.00, 0.62, 0.52 and 0.41 (p for trend less than 0.01). Although specific dietary constituent(s) responsible for the protective effect of vegetable consumption could not be identified, carotenoids other than beta-carotene, or compounds in cruciferous or Allium vegetables, are possibilities.

Animals↗
PubMed1992

Alcohol and cancer.

Although ethanol has generally not been found to induce cancer in experimental animals, the consumption of alcoholic beverages has been linked to increased risks of several cancers in humans. Risks of oral, pharyngeal, laryngeal, esophageal, and liver cancer are elevated among drinkers, typically in proportion to the amount consumed. Evidence associating colorectal and breast cancer with alcohol drinking is suggestive but awaits confirmation. All types of alcoholic beverages seem to be implicated, pointing to an etiological role for ethanol or its metabolites. The mechanisms, however, by which alcohol induces cancer in humans are not clear. This review summarizes epidemiological studies of alcohol and cancer, focusing primarily on characteristics of the association that may provide clues to causal pathways.

Alcohol Drinking↗
PubMed1992

Cigarette smoking and cancers of the renal pelvis and ureter.

A population-based case-control study of renal pelvis and ureter cancers (502 cases, 496 controls) conducted in three areas of the United States found cigarette smoking to be associated with a 3.1-fold increase in risk, with long-term (greater than 45 years) smokers having a 7.2-fold increased risk. Statistically significant dose-response associations were observed for both cancer sites and in both sexes regardless of the measure used: cigarettes per day, duration of use, or pack years. A significant decreasing trend in risk with increasing years quit smoking was also demonstrated for these cancers. Attributable risk estimates indicate that approximately 7 of 10 cancers of the renal pelvis and ureter among men and almost 4 of 10 among women are caused by smoking. The results of this study, the largest to date, confirm that cigarette smoking is the major cause of cancers of the renal pelvis and ureter, and that cessation of smoking could eliminate a large proportion of these tumors.

Carcinoma, Transitional Cell↗
PubMed1992

Renal cell cancer among architects and allied professionals in Sweden.

The Swedish Cancer-Environment Registry was used to evaluate a recent report of a large excess risk of renal cell cancer among architects in Los Angeles. We identified 131 renal cell cancers among male Swedish architects and allied professionals during a 19-year follow-up period (1961-1979). Compared with the Swedish population, there was no significant excess of renal cell cancer among architects and allied professionals (standardized incidence ratio (SIR) = 1.15; 131 cases). Although it was not possible to estimate the risk for architects alone, the SIR was only 1.06 (16 cases) in a subset of professionals employed in architectural and engineering firms. However, a significant increase in risk (SIR = 1.38) was observed in a related group of workers employed as engineers and construction supervisors in the home construction industry.

Architecture↗
PubMed1992

Bladder cancer and occupation in Shanghai, 1980-1984.

To investigate occupational determinants of bladder cancer in the urban area of Shanghai, occupation and industry information for 1,219 incident bladder cancer cases diagnosed during the period 1980 to 1984 were compared with 1982 census data on employment. Standardized incidence ratios (SIR) for bladder cancer were estimated for occupation and industry classifications. Significant excess risks were observed for plastic products workers (male: SIR = 432; female: SIR = 368); textile bleachers, dyers, and finishers (male: SIR = 169); metal refining and processing workers (male: SIR = 139; female: SIR = 197); petroleum refining workers (male: SIR = 2152); railway engine drivers and firemen (male: SIR = 683); and workers employed in industries of apparel and other textile products manufacturing (female: SIR = 204); paper processing (male: SIR = 146; female: SIR = 226); organic chemical manufacturing (male: SIR = 186); plastic product manufacturing (male: SIR = 218; female: SIR = 272); and metallurgy (male: SIR = 107; female: SIR = 561). This study indicates that many of the industries and occupations that are responsible for increased risk throughout the world are also associated with occupational bladder cancer in Shanghai.

Adult↗
PubMed1992

Oral contraceptives and primary liver cancer among young women.

The association of oral contraceptive use with liver cancer was examined in a study of 76 deaths from primary liver cancer, 22 deaths from cancer of the intrahepatic bile ducts, and 629 controls among women aged 25 to 49 years. The subjects in the study are from the 1986 National Mortality Followback Survey, which included a questionnaire sent or administered to the next-of-kin of almost 20,000 deceased individuals in the United States. Information on a number of lifestyle factors was collected, including questions on oral contraceptive use. Increased risks of primary liver cancer were found for ever-users (odds ratio [OR] = 1.6, 95 percent confidence interval [CI] = 0.9-2.6), and for long-term (greater than or equal to 10 years) users (OR = 2.0, CI = 0.8-4.8) of oral contraceptives. When the analysis was restricted to subjects whose spouse or parent was the respondent, more pronounced risks were seen for ever-users (OR = 2.7, CI = 1.4-5.3) and long-term users (OR = 4.8, CI = 1.7-14.0). No clear excess risk was found for cancer of the intrahepatic bile ducts. This study, the largest to date, adds to the number of investigations demonstrating an increased risk of primary liver cancer with use, particularly long-term use, of oral contraceptives.

Adult↗
PubMed1992

A cohort study of tobacco use, diet, occupation, and lung cancer mortality.

In 1966, a cohort of White males aged 35 or over, who were policy-holders with the Lutheran Brotherhood Insurance Society (United States), completed a mail questionnaire on tobacco use, diet, and demographic characteristics. During the 20 years of follow-up, 219 lung cancer deaths occurred. Besides the strong relationship with cigarette smoking, we observed an effect on lung cancer risk among current users of cigars or pipes who were nonsmokers of cigarettes (relative risk [RR] = 3.5, 95 percent confidence interval [CI] = 1.0-12.6) or who were past/occasional users of cigarettes (RR = 2.7, CI = 1.4-5.3). In addition, elevated risks (from 1.5 to 2.6) of lung cancer were found among craftsmen and laborers, with the highest risks among subjects who worked in the mining or manufacturing industry. No association between current (as of 1966) use of beer or hard liquor and lung cancer was observed, although past users were at elevated risk. An inverse association between lung cancer and intake of fruits was observed, and risks of lung cancer were lower among persons in the highest dietary intake quintiles of vitamins A and C. Except for oranges, however, none of the inverse associations with fruits or dietary nutrients had statistically significant trends. The findings from this cohort study add to the evidence of an adverse effect of cigar/pipe smoking and possibly protective effect of dietary factors on lung cancer risk.

Ascorbic Acid↗
PubMed1992

A comparison of radiographic interpretation of silica exposed workers using the 1963 and the 1986 Chinese roentgenodiagnostic criteria of pneumoconioses.

As part of a larger study relating to silica exposure, silicosis, and lung cancer mortality in Chinese mine and factory workers, 1936 old posterior-anterior chest X-rays were re-interpreted according to the 1986 Chinese Roentgenodiagnostic Criteria of pneumoconioses. Each film was independently read by three individuals from a panel of eleven radiologists, and this reading was compared to the original one. Subsequent to the independent readings, a groups of three readers interpreted the films together, called the consensus readings. Comparisons were made by Chinese stage of pneumoconiosis. For the entire cohort, there was a crude agreement of 57.4% between the old and the new interpretations. Agreement within one step of full agreement was 92.5%. The interpretations done by median reading and by consensus were very similar. In general, there was a tendency for the old readings to be slightly higher compared to the new interpretations. This tendency was most marked in the tin mines, followed in decreasing order by the iron/copper mines, the potteries, and the tungsten mines. The agreement between the old and new interpretations is felt to be satisfactory.

Humans↗
PubMed1992

Oral and pharyngeal cancer and occupation: a case-control study.

We studied the relation between occupation and oral and pharyngeal cancer with a population-based case-control study conducted in four areas of the United States. The study group included 1,114 incident male and female cases and 1,268 frequency-matched controls. After adjustment for age, race, smoking, alcohol, and study location, an analysis of lifetime occupational histories revealed a small number of noteworthy associations. Risk was increased among male carpet installers (23 cases, 4 controls), with an adjusted odds ratio of 7.7 [95% confidence interval (CI) = 2.4-24.9], and tended to rise with longer duration of employment. A decreased risk was found among male and female textile mill workers (odds ratio 0.48, 95% CI = 0.27-0.88). Previously reported increases in oral cancer risks among printing workers, electrical and electronics workers, and workers other than carpet installers who were possibly exposed to formaldehyde were not found in this study. For several employment groups, including male machinists, primary metal industry workers, petroleum industry workers, painters, furniture and fixture industry workers, woodworking machine operators, and workers with inferred exposure to fossil fuel combustion, odds ratios were approximately 2.0 for cancers of pharyngeal sites.

Adolescent↗