Tobacco smoking, cancer and social class

Consumption of tobacco products, both by smoking and by other means, has long been causally connected with cancers of the lung, larynx, mouth and pharynx, oesophagus, bladder, and many other sites. Tobacco is the main specific contributor to total mortality in many developed countries and has become a major contributor in the developing countries as well. In most industrialized countries, prevalence of cigarette smoking is currently higher in low than in high social classes, although in some industrialized countries smoking was more frequent in high social classes during the first half of this century. The latter pattern of tobacco consumption is more likely to apply to developing countries. To formulate and carry out effective tobacco control activities it is essential to assess the relative incidence of tobacco-related cancers in different social strata and the prevalence of tobacco use across strata. Despite many years of data gathering the information base is far from complete, especially in developing countries where tobacco use is increasing rapidly, and where aggressive marketing by the transnational tobacco industry is occurring. A critical question is the extent to which tobacco usage can 'explain' the observed social class differences in cancer risk. Class differences in lung cancer are likely to be mostly related to the unequal distribution of tobacco smoking between social classes, and in some fairly simple situations this has been satisfactorily demonstrated. Nevertheless, there are many unresolved issues, especially with regard to the role of collateral exposures, such as hazardous occupations, poor diet, and limited access to health care. The question of whether tobacco use 'explains' socioeconomic differences in one or more of the cancers that it causes has rarely been directly addressed in epidemiological studies.     

Organochlorine exposure and risk of breast cancer

BACKGROUND: Some organochlorine compounds may have weak oestrogenic effects and are, therefore, suspected of increasing the risk of breast cancer. We assessed prospectively the risk of breast cancer in relation to serum concentrations of several organochlorine compounds. METHODS: In 1976, serum samples from 7712 women were obtained from participants in the Copenhagen City Heart Study as part of physical examinations and interviews about lifestyle factors. During 17 years of follow-up, 268 women developed invasive breast cancer. Each woman with breast cancer was matched with two breast-cancer-free women from the remaining cohort. We analysed in 1996-97 the serum samples from 240 women with breast cancer and 477 controls. FINDINGS: Dieldrin was associated with a significantly increased dose-related risk of breast cancer (adjusted odds ratio 2.05 [95% CI 1.17-3.57], p for trend 0.01). Beta-hexachlorocyclohexane increased risk slightly but not significantly (p for trend 0.24). There was no overall association between risk of breast cancer and p,p'-dichlorodiphenyltrichloroethane or metabolites or for polychlorinated biphenyls. Exclusion of women with breast cancer diagnosed within 5 years of blood sampling strengthened the result for dieldrin, but did not affect the other results. INTERPRETATION: These findings support the hypothesis that exposure to xeno-oestrogens may increase the risk of breast cancer.     

Helicobacter pylori infection: relation with cardiovascular risk factors, ischaemic heart disease, and social class

OBJECTIVE: To determine whether Helicobacter pylori infection is associated with the development of ischaemic heart disease and whether such infection can explain the social class inequality in ischaemic heart disease. DESIGN: Cardiovascular risk factor levels, prevalence of ischaemic heart disease (Rose questionnaire angina, and/or a history of myocardial infarction), and serum antibodies to H pylori (enzyme linked immunosorbent assay) were assessed in a cross sectional population based survey. SETTING: Belfast and surrounding districts, Northern Ireland. PARTICIPANTS: 1182 men and 1198 women aged 25-64 years randomly selected from the Central Services Agency's general practitioner lists. MAIN OUTCOME MEASURES: The relation of H pylori infection with cardiovascular risk factors and ischaemic heart disease. The association of social class with ischaemic heart disease. RESULTS: Systolic and diastolic blood pressure, plasma viscosity, and total cholesterol were not associated with H pylori infection. A weak negative association existed between H pylori infection and fibrinogen (mean (SE) difference in fibrinogen between infected and uninfected individuals -0.09 (0.04) g/l, P = 0.02) and between infection in women and high density lipoprotein (HDL) cholesterol (mean (SE) difference in HDL cholesterol between infected and uninfected individuals -0.06 (0.02) mmol/l, P = 0.006). A potentially important association was demonstrated between H pylori infection and ischaemic heart disease but this did not reach statistical significance (odds ratio (95% confidence interval (CI) 1.51 (0.93 to 2.45), P = 0.1). Social class was associated with ischaemic heart disease independently of cardiovascular risk factors and H pylori infection (odds ratio, manual v non-manual (95% CI) 1.82 (1.14 to 2.91), P = 0.01). CONCLUSION: H pylori may be independently associated with the development of ischaemic heart disease but if this is so the mechanism by which this effect is exerted is not through increased concentration of plasma fibrinogen. H pylori infection does not explain the social class inequality in ischaemic heart disease which exists independently of known cardiovascular risk factors.     

Environmental risk, biological risk, and developmental outcome.

The impact of 2 environmental and 2 biological risk measures was studied in 175 preterm children. Levels of family risk, which included family composition, support, and interaction variables, and social class, as well as increases or decreases in family risk over the 1st yr of life, were examined with intraventricular hemorrhage (IVH) and other neonatal medical complications as predictors of cognitive and motor outcomes in the 2nd yr of life. Family risk, early medical risk, and the family risk?×?IVH interaction emerged as significant predictors of later development. Family risk had less impact on Ss at highest medical risk. Different regression equations for each outcome underscored the specificity of environmental effects on developmental outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivation, race, social class, and IQ.

Administered the Performance subscales of the WISC to 208 male and 208 female junior and senior high school students (aged 12-16 yrs) to test the prediction that if performance responded to the manipulation of the testee's motivation state, the size of interracial differences in mean IQ would be more flexible than was suggested by A. R. Jensen's (1969) review of the literature. The variables of test atmosphere (evaluative or gamelike), tester expectation (high or low), race of tester (Black or White), and race of S (Black or White) were manipulated. The pattern of mean IQ scores as well as self-ratings of mood indicated that test performance was optimal at moderate levels of motivational arousal. A replication of the experiment employing 208 male Ss increased cell sizes to the point that socioeconomic status could be treated as an independent variable. Results suggested that interracial differences in mean IQ might be erased depending upon the social psychological characteristics of the test setting and the socioeconomic background of the testee. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposure to occupational carcinogens and social class differences in cancer occurrence

It has been estimated that occupational exposures are responsible for about 4% of all human cancers in industrialized countries. These cancers are concentrated among manual workers and in the lower social classes, thus contributing to the social class gradient in cancer incidence and mortality. On the basis of the 1971 cancer mortality data from England and Wales, it was estimated that occupational cancer is responsible for about a third of the total cancer difference between high (I, II and III-NM) and low (III-M, IV and V) social classes, and for about half of the difference for lung and bladder cancer. However, direct evidence on the extent of the contribution of occupational exposure to carcinogens to social class differences is lacking, and several problems, such as the possible interaction between carcinogens and the effect of extraoccupational confounding factors, add further elements of uncertainty.     

Race, social class, religion, and nationality as determinants of social distance.

"In a study of social distance of college students with respect to various social objects, a factorial design with two levels of value of race, social class, religion, and nationality was employed and analyses of variance were computed on social distance scores. For white Ss race and social class were found to be more important determinants of social distance than religion or nationality… . The data are interpreted in terms of a theory of prejudice that employs conformity, cognitive dissonance, and insecurity as its main constructs." (31 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Possible explanations for social class differences in cancer patient survival

Social class differences in cancer patient survival have been reported for most cancer types and for a number of countries. The etiology of these differences has been studied less thoroughly and less systematically than social class differences in cancer occurrence. Stage of disease at diagnosis appears to be the most important factor contributing to the social class differences in cancer patient survival. This has been observed most clearly for gastrointestinal and gynaecological cancers. Social class differences in survival are generally wider for patients diagnosed with cancer at local stages than for those diagnosed with cancer at advanced stages. The reasons why cancers are more frequently diagnosed at a local stage in high than in low social classes in not properly understood at the moment. Of other potential contributing factors, the role of treatment and psychosocial factors has scarcely been studied. Biological indicators of tumour aggressiveness have failed to explain the social class differences.     

Achievement striving, social class, and test anxiety.

It was hypothesized that compared to working-class Ss, middle-class Ss would show little improvement in test performance under financial incentive. Tests used were a simple motor test and an intelligence test. Ss were high school juniors and seniors. Results with both tests support the hypothesis that middle-class test performance is more highly generalized and less subject to improvement through increased striving for material reward. "The main difference between the two groups seems to be that while working-class striving and performance tend to rise uniformly in response to reward stimuli, in the middle-class reward-induced increases in striving may either raise the level of performance or touch off anxiety responses that lower it." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social class, sense of control, and social explanation.

Lower social class is associated with diminished resources and perceived subordinate rank. On the basis of this analysis, the authors predicted that social class would be closely associated with a reduced sense of personal control and that this association would explain why lower class individuals favor contextual over dispositional explanations of social events. Across 4 studies, lower social class individuals, as measured by subjective socioeconomic status (SES), endorsed contextual explanations of economic trends, broad social outcomes, and emotion. Across studies, the sense of control mediated the relation between subjective SES and contextual explanations, and this association was independent of objective SES, ethnicity, political ideology, and self-serving biases. Finally, experimentally inducing a higher sense of control attenuated the tendency for lower subjective SES individuals to make more contextual explanations (Study 4). Implications for future research on social class as well as theoretical distinctions between objective SES and subjective SES are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Means-ends thinking, adjustment, and social class among elementary-school-aged children.

Presented 6 stories to 74 normal and 34 emotionally disturbed middle- and lower-class 10-12 yr. olds to test Ss' cognitive capacity in solving simulated real-life problems. This capacity was measured by means-ends thinking, defined as an ability to construct a story plot that reflects planning, awareness of potential obstacles, and recognition of time necessary to reach a stated goal. Irrespective of social class and intellectual functioning, disturbed youngsters in special schools expressed both fewer elements of means-ends thinking and stories more limited to pragmatic, impulsive, and physically aggressive means than did normal Ss in regular schools. Implications are that training in this area early in a child's life could supplement a preventive mental health program. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationship between values, social class, and duration of psychotherapy.

Investigated the relationship between values, social class, and duration of psychotherapy of 249 patients and 104 therapists at a moderate-cost outpatient clinic in New York City. Values were measured by the Strong Vocational Interest Blank, Ways to Live scale, Study of Values, and the Optimal Personality Integration Scale. Lower-class patients tended to be more authoritarian-submissive than upper-class patients. The significant linear relationship indicated that the lower the social class and the higher (more authoritarian-submissive) the patient's score relative to his therapist, the longer the duration of treatment. It is postulated that authoritarian-submissive patients might tend to remain in therapy precisely because of this quality. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Occupational exposure to paint, lacquer and solvents, and cancer risk in the area of the upper aero-digestive tract

So far, only few studies exist that have investigated the influence of occupational exposure to paint and lacquer on the risk of cancer in the upper aerodigestive tract. Based on data from the Heidelberg case control study which enrolled 369 patients with carcinomas of the upper aerodigestive tract and 1476 randomized control subjects, the relative risk of head and neck cancer in patients exposed to paint, lacquer and varnish was analyzed. The relative risk (RR) of squamous cell cancer (after adjustment for possible alcohol and tobacco effects) was significantly increased for the larynx (RR = 2.3) and the oral cavity (RR = 3.6). However, this risk was not increased for the pharynx. Our findings and a critical analysis of the literature provide evidence that chronic exposure to paint, varnish and lacquer is a definite risk factor for cancer of the upper aerodigestive tract. Further studies are required to confirm these findings, and to identify more precisely toxic substances encountered in the workplace.     

Self-concept differences in relation to identification, religion, and social class.

"This study focused on the relationships between… three socialization variables of parental identification, religious affiliation, and social class to two aspects of the self-concept, dominance and love… . No significant differences in self-concept scores as a function of parental identification were observed… . Catholic subjects have significantly higher love scores than do Jewish subjects, and the former have significantly higher love than dominance scores… . Upper class subjects have significantly higher dominance scores than lower class subjects, and upper class subjects are significantly higher on dominance than on love." From Psyc Abstracts 36:01:3GC94B. (PsycINFO Database Record (c) 2010 APA, all rights reserved)