The effect of socioeconomic status on the long-term outcome of cancer.

This study reports the 8- to 10-year follow-up of male and female patients between the ages of 25 and 70, admitted to two Ontario Regional Cancer Centres with newly diagnosed cancers of a number of common sites. Information was gathered by interview on education, occupation, and chronic illnesses other than cancer. Stage of disease at diagnosis, exact pathologic diagnosis, date of diagnosis, treatment before and after clinic admission, and status of each patient on the last date for which information was available were obtained from clinic charts. Cox's proportional hazards model was used to examine the relationship between socioeconomic status (SES) and duration of survival, with adjustment for other significant prognostic factors. For breast and prostate, there is weak evidence that high SES is associated with improved survival; for other sites, there is no evidence that SES affected survival.

The Canadian Labour Force Ten Percent Sample Study. Cancer mortality among men, 1965-1979.

The mortality experience of 415,309 men enrolled in the Canadian Labour Force 10% Sample Study has been updated to the end of 1979. The occupation and industry in which these men were employed between 1965 and 1969 were available, and these records were matched to the Canadian National Mortality Data Base by computerized record linkage. A total of 9,739 deaths from cancer between 1965 and 1979 were identified. Analyses were conducted with respect to men employed in 274 occupations and 294 industries with respect to mortality from 33 different types of cancer resulting in 243 associations in which the 90% lower confidence bound for the relative risk compared to the whole cohort had a value of 1.0 or greater. Based on the criteria of strength of association, dose-response, and consistency, 23 associations were identified as being of particular interest. Of these associations, four (waiters, bartenders and breweries with cancer of the buccal cavity and pharynx, and bartenders with lung cancer) seem most likely to be caused by excess smoking and/or alcohol consumption, and could provide a useful guide for intervention strategies focused on those employed in these occupations. A further seven (carpenters and stomach cancer, clerical occupations and colon cancer, truck drivers, plumbers and pipefitters, sheet metal workers, shipbuilding and repair, and asbestos products manufacturers with lung cancer) have support in terms of biological plausibility and/or other studies in the literature and appear to warrant more intensive study. The third group of associations, although demonstrating strength of association, a dose-response effect, and/or consistency, may well have arisen by chance given the many comparisons made in this study.

The adequacy of suicide statistics for use in epidemiology and public health.

In spite of persistent criticisms regarding their validity, official suicide statistics continue to be used in epidemiologic studies that have substantial public health implications. We ask which epidemiologic findings might be affected by underreporting in the suicide rate. We estimate the extent of potential underreporting by comparing Canadian suicide rates with and without deaths of undetermined origin (UDs) added. Our results tend to confirm findings from other jurisdictions, specifically that underreporting is probably higher among females and cases of poisoning and drowning. The highest underreporting in the 1950-82 period was in 1977-1978. Overall, the average potential underreporting was found to be 17.5% for females and 12% for males. Still, underreporting is not sufficiently large that reasonable reformulations of the suicide rate substantially alter findings, suggesting that most epidemiologic conclusions based on official rates are essentially correct.

The effect of psychosocial factors on lung cancer mortality at one year.

In this study newly diagnosed male and female lung cancer patients admitted to two Ontario Cancer Foundation treatment clinics were interviewed. Information was obtained on demographic variables, presence of other chronic illness and the following psychosocial attributes: locus of control, social support and personality traits. From the clinic charts, information on stage of disease and pathological diagnosis was obtained. After controlling for the effects of stage and pathological diagnosis, the following psychological variables were found to increase the odds of death from lung cancer among males and females combined at one year after diagnosis: a high need for one aspect of social support, a reserved personality and the extremes of the personality trait soberness vs enthusiasm.

The effect of socioeconomic factors on the early prognosis of cancer.

Previous studies have suggested that cancer patients of low socioeconomic status (SES) have poorer short and long-term survival than cancer patients of higher SES. In this study male and female patients between the ages of 25 and 70, admitted to two Ontario Cancer Treatment and Research Foundation Clinics with newly diagnosed cancers of a number of common sites, were interviewed to obtain information on education and occupation, and chronic illnesses other than cancer. Information on stage of disease at diagnosis, exact pathologic diagnosis, date of diagnosis, and treatment before and after admission to the clinic was obtained from clinic charts. Using multiple logistic regression analysis to control for the effect of stage and other variables, there was no convincing evidence that cancer patients of low SES measured by either education or occupation had a less favourable outcome at one year after diagnosis from cancers of all sites combined or lung cancer specifically. The data suggested that any single measure of SES affects males and females differently.

Relationship of smoking to lifestyle factors in women.

The purposes of this research were to examine the relationship of female smoking and lifestyle factors and to assess the applicability of an index of "emancipation" to smoking status in women who live in the Province of Ontario. The index of "emancipation," developed by Eide, was based on distinguishing women who are not following traditional roles as housewives from those who are. While reports in the literature confirm that occupational status, marital status and educational achievement are related to female smoking, little is known about the relationship of smoking to other lifestyle factors (e.g., sexual activity, use of cosmetic agents). Some of these relationships were examined through the secondary analysis of two data sets--one from a population survey design to assess relationships between socio-economic status, sexual behavior, and the occurrence of antibodies to herpes simplex virus type 2, and the other from a case-control study designed to test the hypothesis that oxidative hair dyes were carcinogenic. Five hundred and sixty-six women participated in the former study and 1,155 in the latter. Analyses revealed that smokers are more active sexually than "never" and "ex-smokers" for all groups of women. In addition, a curvilinear relationship with "emancipation" was found in two of the three groups of women. A higher level of smoking was found in women who were in the middle ranges of "emancipation," a finding very similar to that of Eide (1984, 1985). The possibility that increased levels of stress and/or personality characteristics underlie these relationships is discussed.

Sexual and socioeconomic factors affecting the risk of past infections with herpes simplex virus type 2.

Between November 1978 and May 1980, a cross-sectional survey of 566 females and 391 males, aged 35 to 50 years, living in metropolitan Toronto, was conducted to examine the influence of socioeconomic status and sexual behavior on the occurrence of antibodies to herpes simplex virus type 2. Antibodies to the virus were detected in 17.5% of females and 12.8% of males. Lower socioeconomic status was associated with an increased risk of herpes simplex virus type 2 seropositivity for females but not for males. An increased risk of seropositivity was associated in both sexes with young age at first intercourse, multiple sexual partners, and renting rather than owning their residence. The risk associated with each of these attributes remained when the effects of the other attributes including socioeconomic status and age at interview were controlled. The greatest risk was associated with renting. If the renting effect is real, it suggests that there is some determinant of risk not measured by this study, which is more important than socioeconomic status or sexual behavior.

A comparison of estrogen use by women with endometrial cancer, gynecologic disorders, and other illnesses.

Exogenous estrogen use was determined by interview in 206 endometrial cancer patients, 191 women with nonmalignant gynecologic disorders, and 199 women with other illnesses. Separate comparisons of these patients with gynecologic and other illness control subjects provided estimates of the risk of endometrial cancer among estrogen users, adjusted for the effects of confounding variables, of 1.5 (95% confidence limits 0.9 and 2.7) and 4.8 (2.7 and 8.4), respectively. In both comparisons, risk increased with increasing duration of use; regardless of duration of use, risks were higher among users of estrogen within 12 months of diagnosis than among past users. The effects of bias, including surveillance bias, on the results were considered and it was concluded that the true risk was not less than the case/gynecologic control estimate and was likely to approach the case/other control estimate.

Case-control study of hair dye use by patients with breast cancer and endometrial cancer.

A case-control study was undertaken of use of permanent and semipermanent hair dyes by women with cancers of several sites, including breast and endometrium. In London, Ontario, 50 cases of of breast cancer and in Toronto 35 cases of breast cancer and 36 cases of endometrial cancer were identified in cancer treatment centers. In London, controls were selected from hospitalized women with diseases other than cancer; in Toronto, controls were selected from women living in the same neighborhood as the patients with cancer. The results did not suggest an increased risk of either breast or endometrial cancer in users of permanent or permanent and semipermanent dyes combined. Although the numbers of cases and controls were small, the consistency of the results for both sites, in both study centers, and the absence of any clear positive relationship between various measures of intensity of use and risk of cancer provided evidence that a large increase in risk was not missed.

Cancer mortality in oil refinery workers.

The cancer mortality experience from 1964 to 1973 of employees of the Imperial Oil Limited was examined in a cohort study. Employees in jobs which exposed them on a daily basis to crude petroleum or its products, compared with nonexposed employees, were found to have more than three times the risk of esophageal and stomach cancer and about twice the risk of lung cancer. In the exposed group, increasing risks of both cancers occurred with increasing duration of employment. In the absence of more complete information on the similarity of the exposed and nonexposed employees, these results cannot be ascribed with certainty to a carcinogenic effect of petroleum. However, there was no other clear explanation for the results, and further study is required. When refinery workers were compared with nonrefinery workers without consideration of exposure to petroleum in either group, the refinery workers were found to have twice the risk of cancer of the intestines (including rectum) and other digestive organs. No relationship with duration of employment was evident. Although the increased intestinal cancer mortality in the refinery workers was not consistent, bias was not an obvious explanation for the observed relationship. Therefore, the presence on a refinery site of a carcinogen other than petroleum has not been ruled out, and further study is urged.